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Sample records for age-specific reproductive success

  1. Experimental evidence of environmental effects on age-specific reproductive success: the importance of resource quality.

    PubMed Central

    Pärt, T.

    2001-01-01

    Age-specific access to high-quality resources (e.g. territory or nest site) might be an important determinant for improved reproductive performance with increasing age. I experimentally investigated the effects of territory quality versus other age-related improvements in breeding competence (e.g. foraging skills, breeding experience and local knowledge) on age-specific reproductive success. Territory quality (i.e. territory field layer height) was manipulated in year 2 of northern wheatears (Oenanthe oenanthe) that were breeding in the same territory in two consecutive years. Changing territory quality by changing field layer height had a strong effect on within-individual change in the reproductive success of wheatears. This effect was mainly due to a corresponding change in nest predation risk. When territory quality was kept constant (i.e. no between-year change in territory field layer height), within-individual reproductive success did not change between subsequent years. Thus, age-related improvements in foraging skills, breeding experience and local familiarity had no significant effect on within-individual changes in reproductive success. Increased reproductive success with increased age in northern wheatears is therefore mainly explained by an improved access to high-quality territories with increasing age. I conclude that age-dependent access to high-quality breeding resources might be a widespread phenomenon in nature. PMID:11674875

  2. Decomposing variation in male reproductive success: age-specific variances and covariances through extra-pair and within-pair reproduction.

    PubMed

    Lebigre, Christophe; Arcese, Peter; Reid, Jane M

    2013-07-01

    Age-specific variances and covariances in reproductive success shape the total variance in lifetime reproductive success (LRS), age-specific opportunities for selection, and population demographic variance and effective size. Age-specific (co)variances in reproductive success achieved through different reproductive routes must therefore be quantified to predict population, phenotypic and evolutionary dynamics in age-structured populations. While numerous studies have quantified age-specific variation in mean reproductive success, age-specific variances and covariances in reproductive success, and the contributions of different reproductive routes to these (co)variances, have not been comprehensively quantified in natural populations. We applied 'additive' and 'independent' methods of variance decomposition to complete data describing apparent (social) and realised (genetic) age-specific reproductive success across 11 cohorts of socially monogamous but genetically polygynandrous song sparrows (Melospiza melodia). We thereby quantified age-specific (co)variances in male within-pair and extra-pair reproductive success (WPRS and EPRS) and the contributions of these (co)variances to the total variances in age-specific reproductive success and LRS. 'Additive' decomposition showed that within-age and among-age (co)variances in WPRS across males aged 2-4 years contributed most to the total variance in LRS. Age-specific (co)variances in EPRS contributed relatively little. However, extra-pair reproduction altered age-specific variances in reproductive success relative to the social mating system, and hence altered the relative contributions of age-specific reproductive success to the total variance in LRS. 'Independent' decomposition showed that the (co)variances in age-specific WPRS, EPRS and total reproductive success, and the resulting opportunities for selection, varied substantially across males that survived to each age. Furthermore, extra-pair reproduction increased

  3. Experimental evidence that age-specific reproductive success is independent of environmental effects

    PubMed Central

    Daunt, F.; Wanless, S.; Harris, M. P.; Monaghan, P.

    1999-01-01

    An age-specific improvement in reproductive performance has been reported in many iteroparous breeders. However, whether this is a consequence of intrinsic differences in competence amongst age classes or extrinsic differences in the environment they experience is unclear since the timing of breeding within a season generally also differs with age. To disentangle these effects, we experimentally manipulated the timing of breeding in shags, Phalacrocorax aristotelis. Old and young individuals thus reared their chicks at the same time both early and late in the breeding season. When breeding in the same environmental conditions, old pairs performed consistently better than young pairs. These data clearly demonstrate that the age-related differences in reproductive performance are not a result of environmental effects, but rather a consequence of intrinsic differences in brood rearing capacity.

  4. Age-specific survival and reproductive probabilities: evidence for senescence in male fallow deer (Dama dama).

    PubMed Central

    McElligott, Alan G; Altwegg, Res; Hayden, Thomas J

    2002-01-01

    Survival and reproduction are key features in the evolution of life-history strategies. In this study, we use capture-mark-resighting and multi-state models to examine survival senescence and reproductive senescence in six successive cohorts of fallow bucks that were studied for 16 years. We found that the overall age-specific survival probabilities of males were highly variable and the best-fitting model revealed that fallow bucks have four life-history stages: yearling, pre-reproductive, prime-age and senescent. Pre-reproductive males (2 and 3 years old) had the highest survival. Survival declined sharply after the age of 9 years, indicating that senescence had begun. When we considered reproducing and non-reproducing males separately, there was no evidence of senescence in the former, and steadily decreasing survival after the onset of social maturity in the latter. Reproduction probability also declined in older males, and thus we provide very strong evidence of senescence. Reproducers had a greater chance of reproducing again in the following year than non-reproducers. Furthermore, there were differences in the survival probabilities, with reproducers consistently surviving better than non-reproducers. In our study population, reproducers allocate more to the effort to reproduce than non-reproducers. Therefore our results indicate the generally higher phenotypic quality of reproducing males. These results, along with earlier studies on the same population, could indicate positive relationships between fitness correlates. PMID:12061956

  5. Senescence and age-specific trade-offs between reproduction and survival in female Asian elephants.

    PubMed

    Robinson, Matthew R; Mar, Khyne U; Lummaa, Virpi

    2012-03-01

    Although studies on laboratory species and natural populations of vertebrates have shown reproduction to impair later performance, little is known of the age-specific associations between reproduction and survival, and how such findings apply to the ageing of large, long-lived species. Herein we develop a framework to examine population-level patterns of reproduction and survival across lifespan in long-lived organisms, and decompose those changes into individual-level effects, and the effects of age-specific trade-offs between fitness components. We apply this to an extensive longitudinal dataset on female semi-captive Asian timber elephants (Elephas maximus) and report the first evidence of age-specific fitness declines that are driven by age-specific associations between fitness components in a long-lived mammal. Associations between reproduction and survival are positive in early life, but negative in later life with up to 71% of later-life survival declines associated with investing in the production of offspring within this population of this critically endangered species.

  6. Age-specific reproduction in female sea otters (Enhydra lutris) from south-central Alaska: analysis of reproductive tracts

    USGS Publications Warehouse

    Bodkin, James L.; Mulcahy, Daniel M.; Lensink, Calvin J.

    1993-01-01

    We estimated age at sexual maturity and age-specific reproductive rates by examining carcasses and reproductive tracts from 177 female sea otters (Enhydra lutris). Carcasses were recovered from south-central Alaska, Primarily from western Prince William Sound, as a result of the T/V Exxon Valdez oil spill in 1989. We found 65% of our sample to be sexually mature. Sexual maturity was first attained at age 2. The proportion of sexually mature animals increased from 30% at age 2 to 100% at age 5. Annual reproductive rates increased from 22% at age 2 to 78% at age 5 and remained relatively stable (75-88%) through to age 15. the sex ratio (female:male) of 49 fetal sea otters was 18:37 and differed significantly from parity. Females younger than 8 tended to produce more female fetuses, while older mothers did not. Our estimates of the reproductive characteristics of female sea otters obtained by examination of reproductive tracts were similiar to those reported in the literature based on in situ observations of marked individuals.

  7. The forms and fitness cost of senescence: age-specific recapture, survival, reproduction, and reproductive value in a wild bird population.

    PubMed

    Bouwhuis, Sandra; Choquet, Rémi; Sheldon, Ben C; Verhulst, Simon

    2012-01-01

    Longitudinal studies of senescence accumulate rapidly from natural populations. However, it is largely unknown whether different fitness components senesce in parallel, how reproductive and survival senescence contribute to declines in reproductive value, and how large the fitness cost of senescence is (the difference between the observed reproductive value and the hypothetical reproductive value, if senescence would not occur). We analyzed age-specific survival in great tits Parus major and combined our results with analyses of reproductive senescence to address these issues. Recapture probability of breeding females declined with age, suggesting age-specific increases in skipped or failed breeding and highlighting an important bias that studies of senescence in wild populations should incorporate. Survival probability also declined with age and in parallel with recruit production. Reproductive value decreased 87% between age 1 and age 9 but at a fitness cost of only 4%; the proportion of the contribution of reproductive senescence versus survival senescence to this cost was 0.7. For 11 other species, we estimated fitness costs of senescence of 6%-63% (average: birds, 9%; mammals, 42%), with relative contributions of reproductive senescence of 0.0-0.7 (average: birds, 0.4; mammals, 0.3). We suggest that understanding when and why reproductive and survival senescence differ will help in the identification of proximate mechanisms underlying variation in rates of senescence and its evolution.

  8. Age-specific cost of first reproduction in female southern elephant seals.

    PubMed

    Desprez, Marine; Harcourt, Robert; Hindell, Mark A; Cubaynes, Sarah; Gimenez, Olivier; McMahon, Clive R

    2014-05-01

    When to commence breeding is a crucial life-history decision that may be the most important determinant of an individual's lifetime reproductive output and can have major consequences on population dynamics. The age at which individuals first reproduce is an important factor influencing the intensity of potential costs (e.g. reduced survival) involved in the first breeding event. However, quantifying age-related variation in the cost of first reproduction in wild animals remains challenging because of the difficulty in reliably recording the first breeding event. Here, using a multi-event capture-recapture model that accounts for both imperfect detection and uncertainty in the breeding status on an 18-year dataset involving 6637 individuals, we estimated age and state-specific survival of female elephant seals (Mirounga leonina) in the declining Macquarie Island population. We detected a clear cost of first reproduction on survival. This cost was higher for both younger first-time breeders and older first-time breeders compared with females recruiting at age four, the overall mean age at first reproduction. Neither earlier primiparity nor delaying primiparity appear to confer any evolutionary advantage, rather the optimal strategy seems to be to start breeding at a single age, 4 years.

  9. Age-specific cost of first reproduction in female southern elephant seals

    PubMed Central

    Desprez, Marine; Harcourt, Robert; Hindell, Mark A.; Cubaynes, Sarah; Gimenez, Olivier; McMahon, Clive R.

    2014-01-01

    When to commence breeding is a crucial life-history decision that may be the most important determinant of an individual's lifetime reproductive output and can have major consequences on population dynamics. The age at which individuals first reproduce is an important factor influencing the intensity of potential costs (e.g. reduced survival) involved in the first breeding event. However, quantifying age-related variation in the cost of first reproduction in wild animals remains challenging because of the difficulty in reliably recording the first breeding event. Here, using a multi-event capture–recapture model that accounts for both imperfect detection and uncertainty in the breeding status on an 18-year dataset involving 6637 individuals, we estimated age and state-specific survival of female elephant seals (Mirounga leonina) in the declining Macquarie Island population. We detected a clear cost of first reproduction on survival. This cost was higher for both younger first-time breeders and older first-time breeders compared with females recruiting at age four, the overall mean age at first reproduction. Neither earlier primiparity nor delaying primiparity appear to confer any evolutionary advantage, rather the optimal strategy seems to be to start breeding at a single age, 4 years. PMID:24872464

  10. Age-specific reproduction in female sea otters (`enhydra lutris`) from southcentral Alaska: Analysis of reproductive tracts. Marine mammal study 6-4. Exxon Valdez oil spill state/federal natural resource damage assessment final report

    SciTech Connect

    Bodkin, J.L.; Mulcahy, D.M.; Lensink, C.J.

    1996-06-01

    We estimated age of sexual maturity and age-specific reproductive rates by examining carcasses and reproductive tracts from 177 female sea otters (Enhydra lutris). Carcasses were recovered from southcentral Alaska, primarily western Prince William Sound, following the T/V Exxon Valdez oil spill in 1989. Our estimates of the reproductive characteristics of female sea otters obtained by examination of reproductive tracts were similar to those in the literature based on in situ observations of marked individuals.

  11. Heterosis in age-specific selected populations of a seed beetle: sex differences in longevity and reproductive behavior.

    PubMed

    Stojković, Biljana; Đorđević, Mirko; Janković, Jelena; Savković, Uroš; Tucić, Nikola

    2015-04-01

    We tested mutation accumulation hypothesis for the evolution of senescence using short-lived and long-lived populations of the seed-feeding beetle, Acanthoscelides obtectus (Say), obtained by selection on early- and late-life for many generations. The expected consequence of the mutation accumulation hypothesis is that in short-lived populations, where the force of natural selection is the strongest early in life, the late-life fitness traits should decline due to genetic drift which increases the frequency of mutations with deleterious effects in later adult stages. Since it is unlikely that identical deleterious mutations will increase in several independent populations, hybrid vigor for late-life fitness is expected in offspring obtained in crosses among populations selected for early-life fitness traits. We tested longevity of both sexes, female fecundity and male reproductive behavior for hybrid vigor by comparing hybrid and nonhybrid short-lived populations. Hybrid vigor was confirmed for male virility, mating speed and copulation duration, and longevity of both sexes at late ages. In contrast to males, the results on female fecundity in short-lived populations did not support mutation accumulation as a genetic mechanism for the evolution of this trait. Contrary to the prediction of this hypothesis, male mating ability indices and female fecundity in long-lived populations exhibited hybrid vigor at all assayed age classes. We demonstrate that nonhybrid long-lived populations diverged randomly regarding female and male reproductive fitness, indicating that sexually antagonistic selection, when accompanied with genetic drift for female fecundity and male virility, might be responsible for overriding natural selection in the independently evolving long-lived populations.

  12. Female access and diet affect insemination success, senescence, and the cost of reproduction in male Mexican fruit flies Anastrepha ludens.

    PubMed

    Harwood, James F; Chen, Kehui; Liedo, Pablo; Müller, Hans-Georg; Wang, Jane-Ling; Morice, Amy E; Carey, James R

    2015-03-01

    Hypotheses exploring the influence of dietary conditions on the life history trade-off between survival and reproductive success are extensively tested in female insects, but are rarely explored in males. Here, the impact of dietary quality and female access on age-specific reproduction and survival of male Mexican fruit flies, Anastrepha ludens Loew (Diptera: Tephritidae), are examined. There is a clear cost of female access for males with access to dietary protein, measurable as a decrease in life expectancy, which is further influenced by the age when females are introduced. A protein deficient diet reduces the lifespan benefit of virginity and masks the detrimental effect of female access on male life expectancy. Dietary protein is not necessary for reproductive success, but access to protein at eclosion improves the lifetime reproductive success of males compared to when it is delayed. Overall, reproductive success diminishes as the male flies age, regardless of the dietary conditions, providing evidence for reproductive senescence in males. Delaying the males' access to a protein source fails to influence the negative effect of age on reproductive ability. Because age specific reproductive rates decline with age, regardless of diet, male fitness does not benefit from lifespan extension. Therefore, males can be expected to allocate available resources towards reproductive effort in favour of extended lifespan, regardless of mate and protein availability.

  13. Female access and diet affect insemination success, senescence, and the cost of reproduction in male Mexican fruit flies Anastrepha ludens

    PubMed Central

    HARWOOD, JAMES F.; CHEN, KEHUI; LIEDO, PABLO; MÜLLER, HANS-GEORG; WANG, JANE-LING; MORICE, AMY E.; CAREY, JAMES R.

    2014-01-01

    Hypotheses exploring the influence of dietary conditions on the life history trade-off between survival and reproductive success are extensively tested in female insects, but are rarely explored in males. Here, the impact of dietary quality and female access on age-specific reproduction and survival of male Mexican fruit flies, Anastrepha ludens Loew (Diptera: Tephritidae), are examined. There is a clear cost of female access for males with access to dietary protein, measurable as a decrease in life expectancy, which is further influenced by the age when females are introduced. A protein deficient diet reduces the lifespan benefit of virginity and masks the detrimental effect of female access on male life expectancy. Dietary protein is not necessary for reproductive success, but access to protein at eclosion improves the lifetime reproductive success of males compared to when it is delayed. Overall, reproductive success diminishes as the male flies age, regardless of the dietary conditions, providing evidence for reproductive senescence in males. Delaying the males’ access to a protein source fails to influence the negative effect of age on reproductive ability. Because age specific reproductive rates decline with age, regardless of diet, male fitness does not benefit from lifespan extension. Therefore, males can be expected to allocate available resources towards reproductive effort in favour of extended lifespan, regardless of mate and protein availability. PMID:25709143

  14. Queen succession through asexual reproduction in termites.

    PubMed

    Matsuura, Kenji; Vargo, Edward L; Kawatsu, Kazutaka; Labadie, Paul E; Nakano, Hiroko; Yashiro, Toshihisa; Tsuji, Kazuki

    2009-03-27

    The evolution and maintenance of sexual reproduction may involve important tradeoffs because asexual reproduction can double an individual's contribution to the gene pool but reduces diversity. Moreover, in social insects the maintenance of genetic diversity among workers may be important for colony growth and survival. We identified a previously unknown termite breeding system in which both parthenogenesis and sexual reproduction are conditionally used. Queens produce their replacements asexually but use normal sexual reproduction to produce other colony members. These findings show how eusociality can lead to extraordinary reproductive systems and provide important insights into the advantages and disadvantages of sex.

  15. Factors affecting the reproductive success of dominant male meerkats.

    PubMed

    Spong, Göran F; Hodge, Sarah J; Young, Andrew J; Clutton-Brock, Tim H

    2008-05-01

    Identifying traits that affect the reproductive success of individuals is fundamental for our understanding of evolutionary processes. In cooperative breeders, a dominant male typically restricts mating access to the dominant female for extended periods, resulting in pronounced variation in reproductive success among males. This may result in strong selection for traits that increase the likelihood of dominance acquisition, dominance retention and reproductive rates while dominant. However, despite considerable research on reproductive skew, few studies have explored the factors that influence these three processes among males in cooperative species. Here we use genetic, behavioural and demographic data to investigate the factors affecting reproductive success in dominant male meerkats (Suricata suricatta). Our data show that dominant males sire the majority of all offspring surviving to 1 year. A male's likelihood of becoming dominant is strongly influenced by age, but not by weight. Tenure length and reproductive rate, both important components of dominant male reproductive success, are largely affected by group size and composition, rather than individual traits. Dominant males in large groups have longer tenures, but after this effect is controlled, male tenure length also correlates negatively to the number of adult females in the group. Male reproductive rate also declines as the number of intra- and extra-group competitors increases. As the time spent in the dominant position and reproductive rate while dominant explain > 80% of the total variance in reproductive success, group composition thus has major implications for male reproductive success.

  16. Lifetime reproductive success of female mountain gorillas.

    PubMed

    Robbins, Andrew M; Stoinski, Tara; Fawcett, Katie; Robbins, Martha M

    2011-12-01

    Studies of lifetime reproductive success (LRS) are important for understanding population dynamics and life history strategies, yet relatively little information is available for long-lived species. This study provides a preliminary assessment of LRS among female mountain gorillas in the Virunga volcanoes region. Adult females produced an average of 3.6 ± 2.1 surviving offspring during their lifetime, which indicates a growing population that contrasts with most other great apes. The standardized variance in LRS (variance/mean(2) = 0.34) was lower than many other mammals and birds. When we excluded the most apparent source of environmental variability (poaching), the average LRS increased to 4.3 ± 1.8 and the standardized variance dropped in half. Adult lifespan was a greater source of variance in LRS than fertility or offspring survival. Females with higher LRS had significantly longer adult lifespans and higher dominance ranks. Results for LRS were similar to another standard fitness measurement, the individually estimated finite rate of increase (λ(ind) ), but λ(ind) showed diminishing benefits for greater longevity.

  17. Superior reproductive success on human blood without sugar is not limited to highly anthropophilic mosquito species.

    PubMed

    Braks, M A H; Juliano, S A; Lounibos, L P

    2006-03-01

    Anthropophilic mosquitoes such as Aedes aegypti L. (Diptera: Culicidae) have been shown to have superior reproductive success on human blood when sugar is not available. Life-table experiments were conducted with Aedes albopictus Skuse and Ae. aegypti to compare the effects of sugar availability on age-specific survivorship, lifetime and daily fecundity, and blood-feeding frequency when offered human blood daily. There were no significant interactions between the effects of sugar availability and mosquito species for these four variables, indicating similar effects of sugar availability for both species. Lifetime fecundity was not significantly affected by sugar availability, but sugar-deprived females had significantly reduced age-specific survivorship than did sugar-fed females. In absence of sugar, females took bloodmeals twice as often, resulting in a higher daily fecundity. The results indicate that superior reproductive success on human blood without sugar does not seem to be limited to highly anthropophilic mosquito species, such as Ae. aegypti. We conclude that evolution of a highly anthropophilic feeding strategy is not an inevitable result of the ability to thrive on human blood alone.

  18. Neonatal manipulation of oxytocin influences female reproductive behavior and success.

    PubMed

    Cushing, Bruce S; Levine, Karyn; Cushing, Nancy L

    2005-01-01

    During early neonatal development, oxytocin (OT) may influence the expression of adult behavior and physiology. Here we test the prediction that early postnatal exposure to OT or an oxytocin antagonist (OTA) can affect the subsequent expression of sexual receptivity and reproductive success of females. To test this hypothesis, female prairie voles (Microtus ochrogaster) received one of four treatments within 24 h of birth. Three groups received an intraperitoneal injection of OT, OTA, or isotonic saline. A fourth group was handled, but not injected. Around 75 days of age, females were paired with sexually experienced males for 72 h and sexual activity was recorded. Treatment had no effect on the probability of mating. Injection, regardless of treatment, reduced latency to mate compared with handled controls. OT and OTA treatment decreased mating bout frequency compared to saline and handled controls, while OTA treatment increased reproductive success, probability of successfully producing a litter. The results suggest that neonatally OT, both endogenous and exogenous, can affect the expression of adult female reproductive activity and that blocking the effects of endogenous OT during neonatal development can affect female reproductive success. Finally, the results suggest that a number of aspects of reproduction are regulated by OT during the postnatal period, but that the mechanism of action may differ depending upon the reproductive activity.

  19. Developmental stress increases reproductive success in male zebra finches

    PubMed Central

    Crino, Ondi L.; Prather, Colin T.; Driscoll, Stephanie C.; Good, Jeffrey M.; Breuner, Creagh W.

    2014-01-01

    There is increasing evidence that exposure to stress during development can have sustained effects on animal phenotype and performance across life-history stages. For example, developmental stress has been shown to decrease the quality of sexually selected traits (e.g. bird song), and therefore is thought to decrease reproductive success. However, animals exposed to developmental stress may compensate for poor quality sexually selected traits by pursuing alternative reproductive tactics. Here, we examine the effects of developmental stress on adult male reproductive investment and success in the zebra finch (Taeniopygia guttata). We tested the hypothesis that males exposed to developmental stress sire fewer offspring through extra-pair copulations (EPCs), but invest more in parental care. To test this hypothesis, we fed nestlings corticosterone (CORT; the dominant avian stress hormone) during the nestling period and measured their adult reproductive success using common garden breeding experiments. We found that nestlings reared by CORT-fed fathers received more parental care compared with nestlings reared by control fathers. Consequently, males fed CORT during development reared nestlings in better condition compared with control males. Contrary to the prediction that developmental stress decreases male reproductive success, we found that CORT-fed males also sired more offspring and were less likely to rear non-genetic offspring compared with control males, and thus had greater overall reproductive success. These data are the first to demonstrate that developmental stress can have a positive effect on fitness via changes in reproductive success and provide support for an adaptive role of developmental stress in shaping animal phenotype. PMID:25297860

  20. Reproductive success and failure: the role of winter body mass in reproductive allocation in Norwegian moose.

    PubMed

    Milner, Jos M; van Beest, Floris M; Solberg, Erling J; Storaas, Torstein

    2013-08-01

    A life history strategy that favours somatic growth over reproduction is well known for long-lived iteroparous species, especially in unpredictable environments. Risk-sensitive female reproductive allocation can be achieved by a reduced reproductive effort at conception, or the subsequent adjustment of investment during gestation or lactation in response to unexpected environmental conditions or resource availability. We investigated the relative importance of reduced investment at conception compared with later in the reproductive cycle (i.e. prenatal, perinatal or neonatal mortality) in explaining reproductive failure in two high-density moose (Alces alces) populations in southern Norway. We followed 65 multiparous, global positioning system (GPS)-collared females throughout the reproductive cycle and focused on the role of maternal nutrition during gestation in determining reproductive success using a quasi-experimental approach to manipulate winter forage availability. Pregnancy rates in early winter were normal (≥0.8) in all years while spring calving rates ranged from 0.4 to 0.83, with prenatal mortality accounting for most of the difference. Further losses over summer reduced autumn recruitment rates to 0.23-0.69, despite negligible predation. Over-winter mass loss explained variation in both spring calving and autumn recruitment success better than absolute body mass in early or late winter. Although pregnancy was related to body mass in early winter, overall reproductive success was unrelated to pre-winter body condition. We therefore concluded that reproductive success was limited by winter nutritional conditions. However, we could not determine whether the observed reproductive allocation adjustment was a bet-hedging strategy to maximise reproduction without compromising survival or whether females were simply unable to invest more resources in their offspring.

  1. Sigma virus and male reproductive success in Drosophila melanogaster

    PubMed Central

    Pattanaik, Swetapadma; Johnson, Laura; Matos, Luis F.; Brusini, Jérémie; Wayne, Marta L.

    2016-01-01

    The risk of disease transmission can affect female mating rate, and thus sexual conflict. Furthermore, the interests of a sexually transmitted organism may align or diverge with those of either sex, potentially making the disease agent a third participant in the sexual arms race. In Drosophila melanogaster, where sexual conflict over female mating rate is well established, we investigated how a common, non-lethal virus (sigma virus) might affect this conflict. We gave uninfected females the opportunity to copulate twice in no-choice trials: either with two uninfected males, or with one male infected with sigma virus followed by an uninfected male. We assessed whether females respond behaviorally to male infection, determined whether male infection affects either female or male reproductive success, and measured offspring infection rates. Male infection status did not influence time to copulation, or time to re-mating. However, male infection did affect male reproductive success: first males sired a significantly greater proportion of offspring, as well as more total offspring, when they were infected with sigma virus. Thus viral infection may provide males an advantage in sperm competition, or, possibly, females may preferentially use infected sperm. We found no clear costs of infection in terms of offspring survival. Viral reproductive success (the number of infected offspring) was strongly correlated with male reproductive success. Further studies are needed to demonstrate whether virus-induced changes in reproductive success affect male and female lifetime fitness, and whether virus-induced changes are under male, female, or viral control. PMID:27616808

  2. Alternative reproductive tactics and reproductive success in male Carollia perspicillata (Seba's short-tailed bat).

    PubMed

    Fasel, N; Saladin, V; Richner, H

    2016-11-01

    The use of alternative reproductive tactics (ARTs) is widespread in animals. Males of some species may change tactics depending on age, body condition and social environment. Many bat species are polygynous where a fraction of males only have access to fertile females. For polygynous bats, knowledge of the reproductive success of males using different ARTs is scarce, and it remains unclear how age of males is related to switching decisions between social statuses. We studied a large captive population of Carollia perspicillata, where males are either harem holders, bachelors or peripheral males. Using a multistate procedure, we modelled the age-related switches in reproductive tactics and in survival probability. From the model, we calculated the reproductive success and the frequencies of males displaying different reproductive tactics. As in mammals, the switch between social statuses is often related to age, we predicted that the transition probability of bachelor and peripheral males to harem status would increase with age. We show, however, that social status transition towards a harem holding position was not related to age. Reproductive success changed with age and social status. Harem males had a significantly higher reproductive success than bachelor males except between a short period from 3.8 to 4.4 years of age where success was similar, and a significantly higher reproductive success than peripheral males between 2.6 and 4.4 years of age. Harem males showed a clear decrease in the probability of maintaining social status with age, which suggests that senescence reduces resource holding potential.

  3. Pollinator limitation on reproductive success in Iris tuberosa

    PubMed Central

    Pellegrino, Giuseppe

    2015-01-01

    Variation in plant and floral size can have conflicting effects on pollination and fruit production in flowering plants. This research examines the contributions of plant height, flower size and pollinator visitation to reproductive success in four populations of Iris tuberosa. The plants were pollinated exclusively by hymenopteran species, primarily during sunny days. Pollination supplementation increased the proportion of flowers that matured into fruit, with 95 % fruit set for hand-pollinated compared with 74.15 % for naturally pollinated flowers. The pollinator visitation rate and the proportion of fruit produced were not significantly different between tall and short plants or between small and large flowers. Furthermore, the increase in plant size and floral display did not increase the frequency of pollinator visitations and so did not increase the fruit set. Thus, despite the widespread effects of flowering plant size on pollinator attraction and plant reproduction in other species, these effects are lacking in I. tuberosa. This study quantifies the role of pollinators in the reproductive success of I. tuberosa. Pollinators visited tall/short plants and large/small flowers in equal proportion, suggesting that plant and floral display size do not affect pollinator attraction and reproductive success in I. tuberosa. These results suggest that sexual reproduction of I. tuberosa is fairly limited by pollinators and not by resource limitation. PMID:25527476

  4. Rock sparrow song reflects male age and reproductive success.

    PubMed

    Nemeth, Erwin; Kempenaers, Bart; Matessi, Giuliano; Brumm, Henrik

    2012-01-01

    The evolution of mating signals is closely linked to sexual selection. Acoustic ornaments are often used as secondary sexual traits that signal the quality of the signaller. Here we show that song performance reflects age and reproductive success in the rock sparrow (Petronia petronia). In an Alpine population in south-east France, we recorded the songs of males and assessed their genetic breeding success by microsatellite analysis. In addition to temporal and spectral song features, we also analysed for the first time whether the sound pressure level of bird song reflects reproductive success. Males with higher breeding success sang at a lower rate and with a higher maximum frequency. We found also that older males gained more extra-pair young and had a higher overall breeding success, although they also differed almost significantly by having a higher loss of paternity in their own nests. Older males could be distinguished from yearlings by singing at lower rate and higher amplitudes. Our findings suggest that song rate may be used as a signal of age and together with song pitch as a signal of reproductive success in this species. Alternatively, younger and less successful males might try to compensate their inferior status by increased song rates and lower pitch. Independent of age and quality, high-amplitude songs correlated with paternity loss in the own nest, suggesting that in this species song amplitude is not an indicator of male quality but high-intensity songs may be rather a response to unfaithful social mates.

  5. Migratory carryover effects and endocrinological correlates of reproductive decisions and reproductive success in female albatrosses.

    PubMed

    Crossin, Glenn T; Phillips, Richard A; Trathan, Phil N; Fox, Derren S; Dawson, Alistair; Wynne-Edwards, Katherine E; Williams, Tony D

    2012-04-01

    Physiological mechanisms mediating carryover effects, wherein events or activities occurring in one season, habitat, or life-history stage affect important processes in subsequent life-history stages, are largely unknown. The mechanism most commonly invoked to explain carryover effects from migration centres on the acquisition and utilization of resources (e.g. body mass, or individual 'condition'). However, other mechanisms are plausible, e.g. trade-offs reflecting conflict or incompatibility between physiological regulatory systems required for different activities or life-history stages (migration vs. reproduction). Here we show that in female black-browed albatrosses (Thalassarche melanophris) the decision to reproduce or to defer reproduction, made prior to their arrival at breeding colonies after long-distance migration, is associated with condition-related (body mass, hematocrit, hemoglobin concentrations) and hormonal (progesterone, testosterone, estrogen-dependent yolk precursors) traits. In contrast, reproductive success showed little association with condition but showed significant associations with the steroidogenic processes underlying follicle development. Specifically, success was determined by reproductive readiness via differences in steroid hormones and hormone-dependent traits. Successful albatrosses were characterized by high progesterone and high estradiol-dependent yolk precursor levels, whereas failed albatrosses had high testosterone and low yolk precursor levels. Results are discussed with reference to migratory carryover effects and how these can differentially affect the physiologies influencing reproductive decisions and reproductive success.

  6. Impact of Supplementary Feeding on Reproductive Success of White Storks

    PubMed Central

    Hilgartner, Roland; Stahl, Daniel; Zinner, Dietmar

    2014-01-01

    European white stork (Ciconia ciconia) populations have been object to several conservation measures such as reintroduction programs, habitat improvement or supplementary feeding in the last decades. Although recent white stork censuses revealed an upward trend of most of the western populations, evaluations of the relative importance of certain conservation measures are still scarce or even lacking. In our study we analyzed the effect of supplementary feeding on the reproductive success of white storks in conjunction with other factors such as weather or nest site characteristics. We present data of 569 breeding events at 80 different nest sites located in variable distances to an artificial feeding site at Affenberg Salem (south-western Germany) collected from 1990–2012. A multilevel Poisson regression revealed that in our study population (1) reproductive success was negatively affected by monthly precipitation in April, May and June, (2) pairs breeding on power poles had a lower reproductive success than pairs breeding on platforms or trees and (3) reproductive success was significantly higher in pairs breeding in close distance to the feeding site. The number of fledglings per nest decreased by 8% per kilometer distance to the feeding site. Our data suggest that supplementary feeding increases fledgling populations which may be a tool to attenuate population losses caused by factors such as habitat deterioration or unfavorable conditions in wintering habitats. PMID:25119566

  7. Frontiers in Reproduction (FIR): An Assessment of Success.

    PubMed

    Ascoli, Mario; Mebane, Dorianne; Fazleabas, Asgerally T

    2016-07-01

    The Frontiers in Reproduction (FIR) course has been held annually since 1998 at the Marine Biological Laboratories in Woods Hole, MA. The primary purpose of the course is to train young reproductive biologists in cutting-edge techniques that would strengthen their career opportunities. An initial evaluation of the FIR course was conducted by surveying the participants who took the course between 1998 and 2002. The findings of this survey were published in Biology of Reproduction in 2006, which highlighted the overall positive impact the course had on the training and upward career trajectory of the participants during the first 5 yr. The current study was designed to access the continued impact of FIR at the 10-yr mark by evaluating the participants who took the course between 1998 and 2008 using two different survey mechanisms. Based on these evaluations and feedback from the participants, it was evident that 1) FIR continues to have a significant positive impact on the careers of the participants, 2) the majority of the participants continue to be involved in research or administration related to the reproductive sciences, 3) nearly 90% of the attendees have been successful in obtaining funding for their research, and 4) most alumni have published at least five manuscripts in higher impact journals since they took the course. Therefore, it is evident that FIR participants are highly successful and continue to significantly impact the advances in the reproductive sciences worldwide.

  8. Why do good hunters have higher reproductive success?

    PubMed

    Smith, Eric Alden

    2004-12-01

    Anecdotal evidence from many hunter-gatherer societies suggests that successful hunters experience higher prestige and greater reproductive success. Detailed quantitative data on these patterns are now available for five widely dispersed cases (Ache, Hadza, !Kung, Lamalera, and Meriam) and indicate that better hunters exhibit higher age-corrected reproductive success than other men in their social group. Leading explanations to account for this pattern are: (1) direct provisioning of hunters' wives and offspring, (2) dyadic reciprocity, (3) indirect reciprocity, (4) costly signaling, and (5) phenotypic correlation. I examine the qualitative and quantitative evidence bearing on these explanations and conclude that although none can be definitively rejected, extensive and apparently unconditional sharing of large game somewhat weakens the first three explanations. The costly signaling explanation has support in some cases, although the exact nature of the benefits gained from mating or allying with or deferring to better hunters needs further study.

  9. Redefining reproductive success in songbirds: Moving beyond the nest success paradigm

    USGS Publications Warehouse

    Streby, Henry M.; Refsnider, Jeanine M.; Andersen, David E.

    2014-01-01

    One of the most commonly estimated parameters in studies of songbird ecology is reproductive success, as a measure of either individual fitness or population productivity. Traditionally, the “success” in reproductive success refers to whether, or how many, nestlings leave nests. Here, we advocate that “reproductive success” in songbirds be redefined as full-season productivity, orthe number of young raised to independence from adult care in a breeding season. A growing body of evidence demonstrates interdependence between nest success and fledgling survival, and emphasizes that data from either life stage alone can produce misleading measures of individual fitness and population productivity. Nest success, therefore, is an insufficient measure of reproductive success, and songbird ecology needs to progress beyond this long-standing paradigm. Full-season productivity, an evolutionarily rational measure of reproductive success, provides the framework for appropriately addressing unresolved questions about the adaptive significance of many breeding behaviors and within which effective breeding-grounds conservation and management can be designed.

  10. Female gonadal hormones and reproductive behaviors as key determinants of successful reproductive output of breeding whooping cranes (Grus americana)

    USGS Publications Warehouse

    Brown, Megan E; Converse, Sarah J.; Chandler, Jane N.; Shafer, Charles; Brown, Janine L; Keefer, Carol L; Songsasen, Nucharin

    2016-01-01

    Reproductive success of endangered whooping cranes (Grus americana) maintained ex situ is poor. As part of an effort to identify potential causes of poor reproductive success in a captive colony, we used non-invasive endocrine monitoring to assess gonadal and adrenal steroids of bird pairs with various reproductive outcomes and evaluated the relationships of hormones and behaviors to reproductive performance. Overall, reproductively successful (i.e., egg laying) females had significantly higher mean estrogen levels but lower mean progestogen concentrations than did unsuccessful females. Other hormones, including glucocorticoids and androgens, were not significantly different between successful and unsuccessful individuals. Observations of specific behaviors such as unison calling, marching, and the number of copulation attempts, along with overall time spent performing reproductive behaviors, were significantly higher in successful pairs. Our findings indicate that overall reproductive performance of whooping crane pairs is linked to female gonadal hormone excretion and reproductive behaviors, but not to altered adrenal hormone production.

  11. Female gonadal hormones and reproductive behaviors as key determinants of successful reproductive output of breeding whooping cranes (Grus americana).

    PubMed

    Brown, Megan E; Converse, Sarah J; Chandler, Jane N; Shafer, Charles; Brown, Janine L; Keefer, Carol L; Songsasen, Nucharin

    2016-05-01

    Reproductive success of endangered whooping cranes (Grus americana) maintained ex situ is poor. As part of an effort to identify potential causes of poor reproductive success in a captive colony, we used non-invasive endocrine monitoring to assess gonadal and adrenal steroids of bird pairs with various reproductive outcomes and evaluated the relationships of hormones and behaviors to reproductive performance. Overall, reproductively successful (i.e., egg laying) females had significantly higher mean estrogen levels but lower mean progestogen concentrations than did unsuccessful females. Other hormones, including glucocorticoids and androgens, were not significantly different between successful and unsuccessful individuals. Observations of specific behaviors such as unison calling, marching, and the number of copulation attempts, along with overall time spent performing reproductive behaviors, were significantly higher in successful pairs. Our findings indicate that overall reproductive performance of whooping crane pairs is linked to female gonadal hormone excretion and reproductive behaviors, but not to altered adrenal hormone production.

  12. Factors influencing brown trout reproductive success in Ozark tailwater rivers

    USGS Publications Warehouse

    Pender, D.R.; Kwak, T.J.

    2002-01-01

    The reproductive success of brown trout Salmo trutta in White River, Arkansas, tailwater reaches is highly variable, resulting in the need for supplemental stocking. A better understanding of the physical and biotic factors affecting reproduction and survival would enhance the contribution of wild fish. We compared fecundity, reproductive chronology, physical habitat, water quality, trout density, food availability, diet, predation, and competitive interactions among four tailwater reaches to identify factors influencing brown trout reproductive success. The fecundity and condition factor of prespawning brown trout were significantly lower at Beaver Tailwater, a reach known for reproductive failure, than at other sites, among which no differences were found. Brown trout spawning was observed from 11 October to 23 November 1996, and juvenile emergence began on 28 February 1997. Significant among-site differences were detected for spawning and juvenile microhabitat variables, but the variables fell within or near suitable or optimal ranges reported in the literature for this species. Age-0 brown trout density differed significantly among sites, but growth and condition did not. Predation by Ozark sculpin Cottus hypselurus on trout eggs or age-0 trout of any species was not observed among the 418 stomachs examined. Ozark sculpin density and diet overlap with age-0 brown trout were highest and invertebrate food availability and water fertility were lowest at Beaver Tailwater relative to the other reaches. Our findings indicate that differences in trophic conditions occur among tailwater reaches, and a lower system productive capacity was identified at Beaver Tailwater. We suggest that management efforts include refining the multispecies trout stocking regime to improve production efficiency, enhancing flow regulation, and increasing habitat complexity to increase invertebrate and fish productivity. Such efforts may lead to improved natural reproduction and the

  13. Assessing relative abundance and reproductive success of shrubsteppe raptors

    USGS Publications Warehouse

    Lehman, Robert N.; Carpenter, L.B.; Steenhof, Karen; Kochert, Michael N.

    1998-01-01

    From 1991-1994, we quantified relative abundance and reproductive success of the Ferruginous Hawk (Buteo regalis), Northern Harrier (Circus cyaneus), Burrowing Owl (Speotytoc unicularia), and Short-eared Owl (Asio flammeus) on the shrubsteppe plateaus (benchlands) in and near the Snake River Birds of Prey National Conservation Area in southwestern Idaho. To assess relative abundance, we searched randomly selected plots using four sampling methods: point counts, line transects, and quadrats of two sizes. On a persampling-effort basis, transects were slightly more effective than point counts and quadrats for locating raptor nests (3.4 pairs detected/100 h of effort vs. 2.2-3.1 pairs). Random sampling using quadrats failed to detect a Short-eared Owl population increase from 1993 to 1994. To evaluate nesting success, we tried to determine reproductive outcome for all nesting attempts located during random, historical, and incidental nest searches. We compared nesting success estimates based on all nesting attempts, on attempts found during incubation, and the Mayfield model. Most pairs used to evaluate success were pairs found incidentally. Visits to historical nesting areas yielded the highest number of pairs per sampling effort (14.6/100 h), but reoccupancy rates for most species decreased through time. Estimates based on all attempts had the highest sample sizes but probably overestimated success for all species except the Ferruginous Hawk. Estimates of success based on nesting attempts found during incubation had the lowest sample sizes. All three methods yielded biased nesting snccess estimates for the Northern Harrier and Short-eared Owl. The estimate based on pairs found during incubation probably provided the least biased estimate for the Burrowing Owl. Assessments of nesting success were hindered by difficulties in confirming egg laying and nesting success for all species except the Ferruginous hawk.

  14. Linking genotoxic responses and reproductive success in ecotoxicology

    SciTech Connect

    Anderson, S.L.; Wild, G.C.

    1994-12-01

    The potential of genotoxicity biomarkers as predictors of detrimental environmental effects, such as altered reproductive success of wild organisms, must be rigorously determined. Recent research to evaluate relationships between genotoxic responses and indicators of reproductive success in model animals is described from an ecotoxicological perspective. Genotoxicity can be correlated with reproductive effects such as gamete loss due to cell death; embryonic mortality; and heritable mutations in a range of model animals including polychaete worms, nematodes, sea urchins, amphibians, and fish. In preliminary studies, the polychaete worm, Neanthes arenaceodentata, and the nematode, Caenorhabditis elegans, have also shown the potential for cumulative DNA damage in gametes. If DNA repair capacity is limited in gametes, then selected life history traits such as long and synchronous periods of gametogenesis may confer vulnerability to genotoxic substances in chronic exposures. Recommendations for future research include strategic development of animal models that can be used to elucidate multiple mechanisms of effect (multiend point) at varying levels of biological organization (multilevel). 27 refs., 2 tabs.

  15. Do "helpers at the nest" increase their parents' reproductive success?

    PubMed

    Crognier, E; Baali, A; Hilali, M K

    2001-01-01

    "Helpers at the nest," usually offspring of a preceding litter who contribute by feeding the young to increase the reproductive success of a breeding pair, are known in many species of birds and mammals. Although similar behaviors were described by ethnological observations in several human societies, there is a lack of data on their existence and role. This study of 794 reproductive life histories of post-menopausal Berber women of Southern Morocco aims to provide such information. Results show that the presence of "probable helpers" in the household is related to higher fertility scores and is associated with improved survival of offspring to sexual maturity. In contrast to sparse observations from other human societies, there is no indication that child caretaking would be specific to eldest daughters. Although the association between offspring survival and helping patterns seems highly probable, there is no confirmation that child caretaking per se is the relevant variable. Contrary to nonhuman helpers at the nest, workloads of children range from housekeeping to light agricultural tasks, and are not focused on assisting younger siblings. The improvement of reproductive success is probably the result of multiple interactions, among which the network of kinship would play a role at both the levels of economy and reciprocal assistance.

  16. Determinants of reproductive success in dominant female meerkats.

    PubMed

    Hodge, Sarah J; Manica, A; Flower, T P; Clutton-Brock, T H

    2008-01-01

    1. In cooperative societies with high reproductive skew, selection on females is likely to operate principally through variation in the probability of acquiring dominant status and variation in reproductive success while dominant. Despite this, few studies of cooperative societies have investigated the factors that influence which females become dominant, and/or their reproductive output while in the dominant position. 2. Here we use long-term data from a wild meerkats population to describe variation in the breeding success of dominant female meerkats Suricata suricatta and investigate its causes. 3. Female meerkats compete intensely for breeding positions, and the probability of acquiring the breeding role depends upon a female's age in relation to competitors and her weight, both at the time of dominance acquisition and early in life. 4. Once dominant, individual differences in breeding success depend principally on the duration of dominance tenure. Females remain for longer in the dominant position if they are heavier than their competitors at the start of dominance, and if the number of adult female competitors at the start is low. 5. Female breeding success is also affected by variation in fecundity and pup survival, both of which increase with group size. After controlling for these effects, female body weight has a positive influence on breeding rate and litter size, while the number of adult female competitors reduces litter survival. 6. These findings suggest that selection for body weight and competitive ability will be high in female meerkats, which may moderate their investment in cooperative activities. We suggest that similar consequences of competition may occur among females in other cooperative societies where the benefits of attaining dominance status are high.

  17. Evaluation of a reproductive index to estimate grasshopper sparrow and eastern meadowlark reproductive success

    USGS Publications Warehouse

    Althoff, D.P.; Gipson, P.S.; Pontius, J.S.; Japuntich, R.D.

    2009-01-01

    We compared an index of reproductive success based on breeding behavior to actual nest fates of grasshopper sparrows (Ammodramus savannarum) and eastern meadowlarks (Sturnella magna) on 12 plots (4-ha). Concordance of results between the two methods was 58% for grasshopper sparrows and 42% for eastern meadowlarks on a plot-by-plot basis. The indirect method yielded higher estimates of reproductive activity than nest monitoring for the balance of the plots,. There was little evidence that brown-headed cowbird (Molothrus ater) parasitism influenced the estimates of reproductive success using the indirect method. We concluded that nests and about-to-fledge nestlings were missed during searches on some plots. It may be appropriate to use an indirect method to more efficiently survey territories and/or plots for species with hard-to-find nests or when monitoring large areas. Use of a reproductive index may be appropriate and more time-efficient than nest searching and monitoring for comparing management effects such as burning, grazing, haying, military training, and other localized disturbances that are likely to affect reproductive success of grasshopper sparrows and eastern meadowlarks. However, nest monitoring may be necessary for more precise estimates of productivity necessary for long-term monitoring. Nest monitoring results are also likely to allow for direct comparisons to results from other studies because the index method requires intimate knowledge of the species being evaluated - a factor that could lead to reduced precision because the experience level of technicians relying only on behavioral cues from study-to-study is likely to vary considerably.

  18. Reproductive endocrinology and weight change in relation to reproductive success in the magellanic penguin (Spheniscus magellanicus).

    PubMed

    Fowler, G S; Wingfield, J C; Boersma, P D; Sosa, R A

    1994-06-01

    The Magellanic penguin is a colonial monogamous species that lays only a single clutch of two eggs per year. However, failed breeders remain at the colony and engage in nest building, fights, and copulations without relaying. The seasonal changes in reproductive hormones and body weight through the nesting cycle were studied, with respect to the reproductive success or failure of individuals. Body weight changed dramatically in both sexes through the season, in response to fasting during incubation, and high body weight in males at the onset of incubation was a strong predictor of eventual reproductive success. Circulating steroid hormones had a biphasic seasonal pattern, with elevated levels during the sexual phase of breeding (prior to egg laying), declining to low, stable levels during the parental phase after eggs were laid. Luteinizing hormone levels were elevated in females, but not in males, prior to egg laying. Both sexes responded to reproductive failure by increasing the secretion of testosterone, and females also increased the secretion of estradiol, a response that would be expected of a species that can renest following failure. However, renesting is extremely rare, and this hormonal response to failure may instead serve to promote maintenance of pair bonds and also territory ownership across years.

  19. Habitat fragmentation and reproductive success: a structural equation modelling approach.

    PubMed

    Le Tortorec, Eric; Helle, Samuli; Käyhkö, Niina; Suorsa, Petri; Huhta, Esa; Hakkarainen, Harri

    2013-09-01

    1. There is great interest on the effects of habitat fragmentation, whereby habitat is lost and the spatial configuration of remaining habitat patches is altered, on individual breeding performance. However, we still lack consensus of how this important process affects reproductive success, and whether its effects are mainly due to reduced fecundity or nestling survival. 2. The main reason for this may be the way that habitat fragmentation has been previously modelled. Studies have treated habitat loss and altered spatial configuration as two independent processes instead of as one hierarchical and interdependent process, and therefore have not been able to consider the relative direct and indirect effects of habitat loss and altered spatial configuration. 3. We investigated how habitat (i.e. old forest) fragmentation, caused by intense forest harvesting at the territory and landscape scales, is associated with the number of fledged offspring of an area-sensitive passerine, the Eurasian treecreeper (Certhia familiaris). We used structural equation modelling (SEM) to examine the complex hierarchical associations between habitat loss and altered spatial configuration on the number of fledged offspring, by controlling for individual condition and weather conditions during incubation. 4. Against generally held expectations, treecreeper reproductive success did not show a significant association with habitat fragmentation measured at the territory scale. Instead, our analyses suggested that an increasing amount of habitat at the landscape scale caused a significant increase in nest predation rates, leading to reduced reproductive success. This effect operated directly on nest predation rates, instead of acting indirectly through altered spatial configuration. 5. Because habitat amount and configuration are inherently strongly collinear, particularly when multiple scales are considered, our study demonstrates the usefulness of a SEM approach for hierarchical partitioning

  20. Sexual selection leads to a tenfold difference in reproductive success of alternative reproductive tactics in male Atlantic salmon.

    PubMed

    Tentelier, Cédric; Lepais, Olivier; Larranaga, Nicolas; Manicki, Aurélie; Lange, Frédéric; Rives, Jacques

    2016-06-01

    The precocious maturation of some male Atlantic salmon (Salmo salar L.) has become a textbook example of alternative mating tactics, but the only estimates of reproductive success available so far are either the collective contribution of precocious males to reproduction in the wild or individual reproductive success in oversimplified experimental conditions. Using genetic parentage analysis on anadromous and precocious potential spawners and their offspring, we quantified components of individual reproductive success of both tactics in a natural population. On average, precocious males produced 2.24 (variance 67.62) offspring, against 27.17 (3080) for anadromous males. For both tactics, most of the variance in reproductive success was due to mating success, with 83% of precocious males having no mate, against 50% for anadromous males. Body size increased reproductive success of anadromous males and tended to decrease precocious males' reproductive success. Although these results do not solve the coexistence of alternative reproductive tactics (ARTs) in Atlantic salmon, their inclusion in comprehensive models of lifetime reproductive success should shed light on the evolution of precocious maturation in Atlantic salmon and its effect on the selection of phenotypic traits.

  1. Sexual selection leads to a tenfold difference in reproductive success of alternative reproductive tactics in male Atlantic salmon

    NASA Astrophysics Data System (ADS)

    Tentelier, Cédric; Lepais, Olivier; Larranaga, Nicolas; Manicki, Aurélie; Lange, Frédéric; Rives, Jacques

    2016-06-01

    The precocious maturation of some male Atlantic salmon ( Salmo salar L.) has become a textbook example of alternative mating tactics, but the only estimates of reproductive success available so far are either the collective contribution of precocious males to reproduction in the wild or individual reproductive success in oversimplified experimental conditions. Using genetic parentage analysis on anadromous and precocious potential spawners and their offspring, we quantified components of individual reproductive success of both tactics in a natural population. On average, precocious males produced 2.24 (variance 67.62) offspring, against 27.17 (3080) for anadromous males. For both tactics, most of the variance in reproductive success was due to mating success, with 83 % of precocious males having no mate, against 50 % for anadromous males. Body size increased reproductive success of anadromous males and tended to decrease precocious males' reproductive success. Although these results do not solve the coexistence of alternative reproductive tactics (ARTs) in Atlantic salmon, their inclusion in comprehensive models of lifetime reproductive success should shed light on the evolution of precocious maturation in Atlantic salmon and its effect on the selection of phenotypic traits.

  2. Warfare and reproductive success in a tribal population.

    PubMed

    Glowacki, Luke; Wrangham, Richard

    2015-01-13

    Intergroup conflict is a persistent feature of many human societies yet little is known about why individuals participate when doing so imposes a mortality risk. To evaluate whether participation in warfare is associated with reproductive benefits, we present data on participation in small-scale livestock raids among the Nyangatom, a group of nomadic pastoralists in East Africa. Nyangatom marriages require the exchange of a significant amount of bridewealth in the form of livestock. Raids are usually intended to capture livestock, which raises the question of whether and how these livestock are converted into reproductive opportunities. Over the short term, raiders do not have a greater number of wives or children than nonraiders. However, elders who were identified as prolific raiders in their youth have more wives and children than other elders. Raiders were not more likely to come from families with fewer older maternal sisters or a greater number of older maternal brothers. Our results suggest that in this cultural context raiding provides opportunities for increased reproductive success over the lifetime.

  3. Male reproductive tactics and reproductive success of the group-living feral cat (Felis catus).

    PubMed

    Yamane, A

    1998-06-01

    Male reproductive tactics and reproductive success of the feral cat (Felis catus) were investigated in a group-living cat population on a small island. Two main reproductive tactics depending on body weight were clearly documented. Heavier (dominant) males used the tactics of courting not only the females of their own group, but also the females of a group other than their own. On the other hand, lighter males mainly utilized the tactics of courting only females of their own group. However, the former tactics were expected to be unsuccessful from the observation that extra-group copulations were rare because of their decreased courtship rank during extra-group visits. Results for the paternity of kittens obtained by the analysis of polymorphic microsatellite DNA revealed that more than half of the kittens of grouping females were fathered by extra-group males, suggesting that the tactics were more successful than expected. This discrepancy between the observed copulation and the actual paternity also suggesting the probability that some female choice may be operating upon the mating system of this group-living cat population.

  4. Correlates of reproductive success in a Caribbean village.

    PubMed

    Flinn, M V

    1986-06-01

    The concept of individual reproductive success was investigated in a rural Trinidadian village by analyzing genealogical, economic and demographic data. The author conducted field research in the village of Grand Anse, on the northern coast of Trinidad, with 342 inhabitants, collecting accurate genealogies, information on economic assets and occupations, residence, horticultural productivity, flow of material resources between individuals, and past and current mating and marriage relationships. Individuals with more land had more offspring, especially so for males. Males with land had more offspring by more mates than less prosperous males. Although this may have occurred because females desired males who were well dressed, gave them presents, and appeared to be able to support children, in fact, the village elders exerted considerable control over mating relationships. Young males with a father resident in the village had more children. Fathers helped their sons get jobs, controlled land, conferred social standing. The findings were surprisingly congruent with current evolutionary models of mating systems developed from the study of nonhuman organisms: specifically the hypothesis that organisms evolve to amass resources in ways that maximize the reproduction of their genetic materials.

  5. Limits to reproductive success of Sarracenia purpurea (Sarraceniaceae).

    PubMed

    Ne'eman, Gidi; Ne'eman, Rina; Ellison, Aaron M

    2006-11-01

    Plant biologists have an enduring interest in assessing components of plant fitness and determining limits to seed set. Consequently, the relative contributions of resource and pollinator availability have been documented for a large number of plant species. We experimentally examined the roles of resource and pollen availability on seed set by the northern pitcher plant Sarracenia purpurea. We were able to distinguish the relative contributions of carbon (photosynthate) and mineral nutrients (nitrogen) to reproductive success. We also determined potential pollinators of this species. The bees Bombus affinis and Augochlorella aurata and the fly Fletcherimyia fletcheri were the only floral visitors to S. purpurea that collected pollen. Supplemental pollination increased seed set by <10%, a much lower percentage than would be expected, given data from noncarnivorous, animal-pollinated taxa. Seed set was reduced by 14% in plants that could not capture prey and by another 23% in plants whose pitcher-shaped leaves were also prevented from photosynthesizing. We conclude that resources are more important than pollen availability in determining seed set by this pitcher plant and that reproductive output may be another "cost" of the carnivorous habit.

  6. Reproductive success of belted kingfishers on the upper Hudson River.

    PubMed

    Bridge, Eli S; Kelly, Jeffrey F

    2013-08-01

    Belted kingfishers (Megaceryle alcyon) are predators in many North American aquatic ecosystems; as such, they are prone to bioaccumulation of certain environmental contaminants. In 2002 and 2004, kingfisher eggs collected near the upper Hudson River in New York had elevated concentrations of polychlorinated biphenyls (PCBs), and the kingfisher population in this area was reported to be at risk because of PCB exposure. From 2007 to 2009, the authors monitored 69 kingfisher nests on the Hudson River to track both nest success and survival of individual nestlings. The study site consisted of 2 adjacent sections of the Hudson River, 1 upstream and 1 downstream of a historic PCB source. The authors compared models of nest success that differentially incorporated the following 4 variables that they deemed most likely to affect reproductive output: 1) river section (upstream vs downstream of PCB source), 2) year, 3) hatch date, and 4) abandonment by 1 parent. After ranking models according to Akaike's information criterion for small sample sizes, it was clear that parental abandonment was the most important of the factors examined. River section was not an important parameter, and overall nesting success was slightly higher in the PCB-contaminated section than in the upstream area. These findings support the conclusion that kingfisher productivity is not adversely impacted by PCB contamination in the upper Hudson River.

  7. Incorporating Results of Avian Toxicity Tests into a Model of Annual Reproductive Success

    EPA Science Inventory

    This manuscript presents a modeling approach for translating results from laboratory avian reproduction tests into an estimate of pesticide-caused change in the annual reproductive success of birds, also known as fecundity rate.

  8. Prey selectivity affects reproductive success of a corallivorous reef fish.

    PubMed

    Brooker, Rohan M; Jones, Geoffrey P; Munday, Philip L

    2013-06-01

    Most animals consume a narrower range of food resources than is potentially available in the environment, but the underlying basis for these preferences is often poorly understood. Foraging theory predicts that prey selection should represent a trade-off between prey preferences based on nutritional value and prey availability. That is, species should consume preferred prey when available, but select less preferred prey when preferred prey is rare. We employed both field observation and laboratory experiments to examine the relationship between prey selection and preferences in the obligate coral-feeding filefish, Oxymonacanthus longirostris. To determine the drivers of prey selection, we experimentally established prey preferences in choice arenas and tested the consequences of prey preferences for key fitness-related parameters. Field studies showed that individuals fed almost exclusively on live corals from the genus Acropora. While diet was dominated by the most abundant species, Acropora nobilis, fish appeared to preferentially select rarer acroporids, such as A. millepora and A. hyacinthus. Prey choice experiments confirmed strong preferences for these corals, suggesting that field consumption is constrained by availability. In a longer-term feeding experiment, reproductive pairs fed on non-preferred corals exhibited dramatic reductions to body weight, and in hepatic and gonad condition, compared with those fed preferred corals. The majority of pairs fed preferred corals spawned frequently, while no spawning was observed for any pairs fed a non-preferred species of coral. These experiments suggest that fish distinguish between available corals based on their intrinsic value as prey, that reproductive success is dependent on the presence of particular coral species, and that differential loss of preferred corals could have serious consequences for the population success of these dietary specialists.

  9. Variance in the reproductive success of dominant male mountain gorillas.

    PubMed

    Robbins, Andrew M; Gray, Maryke; Uwingeli, Prosper; Mburanumwe, Innocent; Kagoda, Edwin; Robbins, Martha M

    2014-10-01

    Using 30 years of demographic data from 15 groups, this study estimates how harem size, female fertility, and offspring survival may contribute to variance in the siring rates of dominant male mountain gorillas throughout the Virunga Volcano Region. As predicted for polygynous species, differences in harem size were the greatest source of variance in the siring rate, whereas differences in female fertility and offspring survival were relatively minor. Harem size was positively correlated with offspring survival, even after removing all known and suspected cases of infanticide, so the correlation does not seem to reflect differences in the ability of males to protect their offspring. Harem size was not significantly correlated with female fertility, which is consistent with the hypothesis that mountain gorillas have minimal feeding competition. Harem size, offspring survival, and siring rates were not significantly correlated with the proportion of dominant tenures that occurred in multimale groups versus one-male groups; even though infanticide is less likely when those tenures end in multimale groups than one-male groups. In contrast with the relatively small contribution of offspring survival to variance in the siring rates of this study, offspring survival is a major source of variance in the male reproductive success of western gorillas, which have greater predation risks and significantly higher rates of infanticide. If differences in offspring protection are less important among male mountain gorillas than western gorillas, then the relative importance of other factors may be greater for mountain gorillas. Thus, our study illustrates how variance in male reproductive success and its components can differ between closely related species.

  10. Breeding experience, alternative reproductive strategies and reproductive success in a captive colony of zebra finches (Taeniopygia guttata).

    PubMed

    Baran, Nicole M; Adkins-Regan, Elizabeth

    2014-01-01

    Birds exhibit a remarkable diversity of different reproductive strategies both between and within species. Species such as the zebra finch (Taeniopygia guttata) may evolve the flexible use of alternative reproductive strategies, as well as benefit from prior breeding experience, which allows them to adaptively respond to unpredictable environments. In birds, the flexible use of alternative reproductive strategies, such as extra-pair mating, has been reported to be associated with fast reproduction, high mortality and environmental variability. However, little is known about the role of previous breeding experience in the adaptive use of alternative reproductive strategies. Here we performed an in-depth study of reproductive outcomes in a population of domesticated zebra finches, testing the impact of prior breeding experience on the use of alternative reproductive strategies and reproductive success. We provide evidence that older females with prior breeding experience are quicker to initiate a clutch with a new partner and have increased success in chick rearing, even in a captive colony of zebra finches with minimal foraging demands. We also find evidence that the breeding experience of other females in the same social group influences reproductive investment by female zebra finches. Furthermore, we demonstrate that the use of alternative reproductive strategies in female zebra finches is associated with previous failed breeding attempts with the same pair partner. The results provide evidence that age and breeding experience play important roles in the flexible use of both facultative and adaptive reproductive strategies in female zebra finches.

  11. Accurate Alternative Measurements for Female Lifetime Reproductive Success in Drosophila melanogaster

    PubMed Central

    Nguyen, Trinh T. X.; Moehring, Amanda J.

    2015-01-01

    Fitness is an individual’s ability to survive and reproduce, and is an important concept in evolutionary biology. However, accurately measuring fitness is often difficult, and appropriate fitness surrogates need to be identified. Lifetime reproductive success, the total progeny an organism can produce in their lifetime, is thought to be a suitable proxy for fitness, but the measure of an organism’s reproductive output across a lifetime can be difficult or impossible to obtain. Here we demonstrate that the short-term measure of reproductive success across five days provides a reasonable prediction of an individual's total lifetime reproductive success in Drosophila melanogaster. However, the lifetime reproductive success of a female that has only mated once is not correlated to the lifetime reproductive success of a female that is allowed to mate multiple times, demonstrating that these measures should not serve as surrogates nor be used to make inferences about one another. PMID:26125633

  12. Steelhead Kelt Reconditioning and Reproductive Success, 2008 Annul Report.

    SciTech Connect

    Hatch, Douglas R.

    2009-04-02

    Iteroparity, the ability to repeat spawn, is a natural life history strategy that is expressed by some species from the family Salmonidae. Current rates of observed steelhead Oncorhynchus mykiss iteroparity rates in the Columbia River Basin are severely depressed due to anthropogenic development which includes operation of the hydropower system and other habitat degradations. Artificial reconditioning, which is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and redevelop mature gonads, is evaluated in this study as method to restore depressed steelhead populations. To test the efficacy of steelhead kelt reconditioning as a management and recovery tool different scenarios were investigated ranging from very low intensity (collect and transport fish) to high intensity (collect and feed fish in captivity until rematuration). Examinations of gamete and progeny viability were performed for first-time spawners and reconditioned kelt steelhead. We have continued to examine reproductive success of reconditioned kelt steelhead in Omak Creek using microsatellite loci to perform parentage analysis on juvenile O. mykiss . The groundwork has also begun on developing a genetic analysis of the Yakima subbasin in order to determine steelhead kelt contribution by utilizing parentage analysis on a larger scale. A research and study plan has been developed cooperatively with the University of Idaho to determine the feasibility of steelhead kelt reconditioning program in the Snake River Basin. Analysis of management scenarios indicated that while no-term and short-term reconditioned kelts continue to perform well outmigrating to the ocean but returns from these groups have been low ranging from 0-12% during 2002-2008. Survival (56%) of fish in the long-term treatment in 2008 was the highest we have observed in this project. Analyzing the three different management scenarios within the Yakima River subbasin

  13. When do we eat? Ingestive behavior, survival, and reproductive success.

    PubMed

    Schneider, Jill E; Wise, Justina D; Benton, Noah A; Brozek, Jeremy M; Keen-Rhinehart, Erin

    2013-09-01

    The neuroendocrinology of ingestive behavior is a topic central to human health, particularly in light of the prevalence of obesity, eating disorders, and diabetes. The study of food intake in laboratory rats and mice has yielded some useful hypotheses, but there are still many gaps in our knowledge. Ingestive behavior is more complex than the consummatory act of eating, and decisions about when and how much to eat usually take place in the context of potential mating partners, competitors, predators, and environmental fluctuations that are not present in the laboratory. We emphasize appetitive behaviors, actions that bring animals in contact with a goal object, precede consummatory behaviors, and provide a window into motivation. Appetitive ingestive behaviors are under the control of neural circuits and neuropeptide systems that control appetitive sex behaviors and differ from those that control consummatory ingestive behaviors. Decreases in the availability of oxidizable metabolic fuels enhance the stimulatory effects of peripheral hormones on appetitive ingestive behavior and the inhibitory effects on appetitive sex behavior, putting a new twist on the notion of leptin, insulin, and ghrelin "resistance." The ratio of hormone concentrations to the availability of oxidizable metabolic fuels may generate a critical signal that schedules conflicting behaviors, e.g., mate searching vs. foraging, food hoarding vs. courtship, and fat accumulation vs. parental care. In species representing every vertebrate taxa and even in some invertebrates, many putative "satiety" or "hunger" hormones function to schedule ingestive behavior in order to optimize reproductive success in environments where energy availability fluctuates.

  14. Factors influencing territorial occupancy and reproductive success in a Eurasian Eagle-owl (Bubo bubo) population.

    PubMed

    León-Ortega, Mario; Jiménez-Franco, María V; Martínez, José E; Calvo, José F

    2017-01-01

    Modelling territorial occupancy and reproductive success is a key issue for better understanding the population dynamics of territorial species. This study aimed to investigate these ecological processes in a Eurasian Eagle-owl (Bubo bubo) population in south-eastern Spain during a seven-year period. A multi-season, multi-state modelling approach was followed to estimate the probabilities of occupancy and reproductive success in relation to previous state, time and habitat covariates, and accounting for imperfect detection. The best estimated models showed past breeding success in the territories to be the most important factor determining a high probability of reoccupation and reproductive success in the following year. In addition, alternative occupancy models suggested the positive influence of crops on the probability of territory occupation. By contrast, the best reproductive model revealed strong interannual variations in the rates of breeding success, which may be related to changes in the abundance of the European Rabbit, the main prey of the Eurasian Eagle-owl. Our models also estimated the probabilities of detecting the presence of owls in a given territory and the probability of detecting evidence of successful reproduction. Estimated detection probabilities were high throughout the breeding season, decreasing in time for unsuccessful breeders but increasing for successful breeders. The probability of detecting reproductive success increased with time, being close to one in the last survey. These results suggest that reproduction failure in the early stages of the breeding season is a determinant factor in the probability of detecting occupancy and reproductive success.

  15. Conditions during adulthood affect cohort-specific reproductive success in an Arctic-nesting goose population

    PubMed Central

    Bearhop, Stuart; Hilton, Geoff M.; Walsh, Alyn; Fox, Anthony David

    2016-01-01

    Variation in fitness between individuals in populations may be attributed to differing environmental conditions experienced among birth (or hatch) years (i.e., between cohorts). In this study, we tested whether cohort fitness could also be explained by environmental conditions experienced in years post-hatch, using 736 lifelong resighting histories of Greenland white-fronted geese (Anser albifrons flavirostris) marked in their first winter. Specifically, we tested whether variation in age at first successful reproduction, the size of the first successful brood and the proportion of successful breeders by cohort was explained by environmental conditions experienced on breeding areas in west Greenland during hatch year, those in adulthood prior to successful reproduction and those in the year of successful reproduction, using North Atlantic Oscillation indices as proxies for environmental conditions during these periods. Fifty-nine (8%) of all marked birds reproduced successfully (i.e., were observed on wintering areas with young) only once in their lifetime and 15 (2%) reproduced successfully twice or thrice. Variation in age at first successful reproduction was explained by the environmental conditions experienced during adulthood in the years prior to successful reproduction. Birds bred earliest (mean age 4) when environmental conditions were ‘good’ prior to the year of successful reproduction. Conversely, birds successfully reproduced at older ages (mean age 7) if they experienced adverse conditions prior to the year of successful reproduction. Hatch year conditions and an interaction between those experienced prior to and during the year of successful reproduction explained less (marginally significant) variation in age at first successful reproduction. Environmental conditions did not explain variation in the size of the first successful brood or the proportion of successful breeders. These findings show that conditions during adulthood prior to the year of

  16. Classical Markov Chains: A Unifying Framework for Understanding Avian Reproductive Success

    EPA Science Inventory

    Traditional methods for monitoring and analysis of avian nesting success have several important shortcomings, including 1) inability to handle multiple classes of nest failure, and 2) inability to provide estimates of annual reproductive success (because birds can, and typically ...

  17. Condition dependence of male and female reproductive success: insights from a simultaneous hermaphrodite.

    PubMed

    Janicke, Tim; Chapuis, Elodie

    2016-02-01

    Sexually selected traits are predicted to show condition dependence by capturing the genetic quality of its bearer. In separate-sexed organisms, this will ultimately translate into condition dependence of reproductive success of the sex that experiences sexual selection, which is typically the male. Such condition dependence of reproductive success is predicted to be higher in males than females under conditions promoting intense sexual selection. For simultaneous hermaphrodites, however, sex allocation theory predicts that individuals in poor condition channel relatively more resources into the male sex function at the expense of the female function. Thus, male reproductive success is expected to be less condition dependent than female reproductive success. We subjected individuals of the simultaneously hermaphroditic snail Physa acuta to two feeding treatments to test for condition dependence of male and female reproductive success under varying levels of male-male competition. Condition dependence was found for female, but not for male, reproductive success, meaning that selection on condition is relatively stronger through the female sex function. This effect was consistent over both male-male competition treatments. Decomposition of male and female reproductive performance revealed that individuals in poor condition copulated more in their male role, indicating an increased male allocation to mate acquisition. These findings suggest that sex-specific condition dependence of reproductive success is at least partially driven by condition-dependent sex allocation. We discuss the implications of condition-dependent sex allocation for the evolution of sexually selected traits in simultaneous hermaphrodites.

  18. Group size and composition influence male and female reproductive success in black howler monkeys (Alouatta pigra).

    PubMed

    Van Belle, Sarie; Estrada, Alejandro

    2008-06-01

    It has been argued that grouping patterns might influence the reproductive performance of individuals. Increasing group size results in greater travel costs and competition over depletable food resources, which could lead to reduced individual reproductive success. However, in groups with an increasing number of males, female reproductive success is predicted to augment because larger male groups might better protect immatures from infanticidal attacks. In contrast, male reproductive success is predicted to decrease with number of males in a group because fertilization cannot be shared between males. In this paper, we test these predictions on the Mesoamerican black howler monkey (Alouatta pigra) with data on group size and composition for 120 groups from eight populations of black howler monkeys existing in eight protected forests in Mexico and Guatemala. Male and female reproductive success were calculated as a deviation of the observed number of infants (or immatures) from the expected number of infants (or immatures), relative to the number of males and females in a group. Results indicate that both male and female reproductive success decreased with group size. Male reproductive success decreased with an increasing number of males in a group and with increasing proportion of males relative to females in a group. Decreased female reproductive success was associated with increasing number of females in a group, and female reproductive success had a tendency to increase with increasing number of males in a group. These results suggest that in black howler monkeys, living in larger groups might negatively affect the reproductive success of each member. Our findings are similar to those reported for a population of a sister species, Alouatta palliata, living in larger groups.

  19. Variance in male lifetime reproductive success and estimation of the degree of polygyny in a primate.

    PubMed

    Dubuc, Constance; Ruiz-Lambides, Angelina; Widdig, Anja

    2014-07-01

    The degree of polygyny is predicted to influence the strength of direct male-male competition, leading to a high variance in male lifetime reproductive success and to reproduction limited to the prime period of adulthood. Here, we explore the variance in male lifetime reproductive success and reproductive time in an anthropoid primate forming multimale-multifemale groups. Males of this species form dominance hierarchies, which are expected to skew reproduction toward few high-ranking males. At the same time, however, females mate with multiple males (polygynandry), which should limit the degree of polygyny. Using 20 years of genetic and demographic data, we calculated lifetime reproductive success for the free-ranging rhesus macaque (Macaca mulatta) population of Cayo Santiago for subjects that died naturally or reached senescence. Our results show that 1) male lifetime reproductive success was significantly skewed (range: 0-47 offspring; males reproducing below average: 62.8%; nonbreeders: 17.4%), 2) variance in male lifetime reproductive success was 5 times larger than in females, and 3) male lifetime reproductive success was more influenced by variation in fecundity (60%) than longevity (25%), suggesting that some direct male-male competition takes place. However, the opportunity for selection (i.e., standardized variance in male lifetime reproductive success) is low compared with that in other large mammal species characterized by a high degree of polygyny. Moreover, male reproductive life extended much beyond the prime period, showing that physical strength was not required to acquire mates. We conclude that rhesus macaques exhibit a moderate degree of polygyny and, therefore, low levels of direct male-male competition for fertile females, despite the fact that males form linear dominance hierarchies.

  20. Effects of flowering phenology and synchrony on the reproductive success of a long-flowering shrub

    PubMed Central

    Rodríguez-Pérez, Javier; Traveset, Anna

    2016-01-01

    Flowering phenology and synchrony with biotic and abiotic resources are crucial traits determining the reproductive success in insect-pollinated plants. In seasonal climates, plants flowering for long periods should assure reproductive success when resources are more predictable. In this work, we evaluated the relationship between flowering phenology and synchrony and reproductive success in Hypericum balearicum, a shrub flowering all year round but mainly during spring and summer. We studied two contrasting localities (differing mostly in rainfall) during 3 years, and at different biological scales spanning from localities to individual flowers and fruits. We first monitored (monthly) flowering phenology and reproductive success (fruit and seed set) of plants, and assessed whether in the locality with higher rainfall plants had longer flowering phenology and synchrony and relatively higher reproductive success within or outside the flowering peak. Secondly, we censused pollinators on H. balearicum individuals and measured reproductive success along the flowering peak of each locality to test for an association between (i) richness and abundance of pollinators and (ii) fruit and seed set, and seed weight. We found that most flowers (∼90 %) and the highest fruit set (∼70 %) were produced during the flowering peak of each locality. Contrary to expectations, plants in the locality with lower rainfall showed more relaxed flowering phenology and synchrony and set more fruits outside the flowering peak. During the flowering peak of each locality, the reproductive success of early-flowering individuals depended on a combination of both pollinator richness and abundance and rainfall; by contrast, reproductive success of late-flowering individuals was most dependent on rainfall. Plant species flowering for long periods in seasonal climates, thus, appear to be ideal organisms to understand how flowering phenology and synchrony match with biotic and abiotic resources, and

  1. Effects of flowering phenology and synchrony on the reproductive success of a long-flowering shrub.

    PubMed

    Rodríguez-Pérez, Javier; Traveset, Anna

    2016-02-02

    Flowering phenology and synchrony with biotic and abiotic resources are crucial traits determining the reproductive success in insect-pollinated plants. In seasonal climates, plants flowering for long periods should assure reproductive success when resources are more predictable. In this work, we evaluated the relationship between flowering phenology and synchrony and reproductive success in Hypericum balearicum, a shrub flowering all year round but mainly during spring and summer. We studied two contrasting localities (differing mostly in rainfall) during 3 years, and at different biological scales spanning from localities to individual flowers and fruits. We first monitored (monthly) flowering phenology and reproductive success (fruit and seed set) of plants, and assessed whether in the locality with higher rainfall plants had longer flowering phenology and synchrony and relatively higher reproductive success within or outside the flowering peak. Secondly, we censused pollinators on H. balearicum individuals and measured reproductive success along the flowering peak of each locality to test for an association between (i) richness and abundance of pollinators and (ii) fruit and seed set, and seed weight. We found that most flowers (∼90 %) and the highest fruit set (∼70 %) were produced during the flowering peak of each locality. Contrary to expectations, plants in the locality with lower rainfall showed more relaxed flowering phenology and synchrony and set more fruits outside the flowering peak. During the flowering peak of each locality, the reproductive success of early-flowering individuals depended on a combination of both pollinator richness and abundance and rainfall; by contrast, reproductive success of late-flowering individuals was most dependent on rainfall. Plant species flowering for long periods in seasonal climates, thus, appear to be ideal organisms to understand how flowering phenology and synchrony match with biotic and abiotic resources, and

  2. Reproductive success is predicted by social dynamics and kinship in managed animal populations

    PubMed Central

    Newman, Saul J.; Eyre, Simon; Kimble, Catherine H.; Arcos-Burgos, Mauricio; Hogg, Carolyn; Easteal, Simon

    2016-01-01

    Kin and group interactions are important determinants of reproductive success in many species. Their optimization could, therefore, potentially improve the productivity and breeding success of managed populations used for agricultural and conservation purposes. Here we demonstrate this potential using a novel approach to measure and predict the effect of kin and group dynamics on reproductive output in a well-known species, the meerkat Suricata suricatta. Variation in social dynamics predicts 30% of the individual variation in reproductive success of this species in managed populations, and accurately forecasts reproductive output at least two years into the future. Optimization of social dynamics in captive meerkat populations doubles their projected reproductive output. These results demonstrate the utility of a quantitative approach to breeding programs informed by social and kinship dynamics. They suggest that this approach has great potential for improvements in the management of social endangered and agricultural species. PMID:27990255

  3. Reproductive success is predicted by social dynamics and kinship in managed animal populations.

    PubMed

    Newman, Saul J; Eyre, Simon; Kimble, Catherine H; Arcos-Burgos, Mauricio; Hogg, Carolyn; Easteal, Simon

    2016-01-01

    Kin and group interactions are important determinants of reproductive success in many species. Their optimization could, therefore, potentially improve the productivity and breeding success of managed populations used for agricultural and conservation purposes. Here we demonstrate this potential using a novel approach to measure and predict the effect of kin and group dynamics on reproductive output in a well-known species, the meerkat Suricata suricatta. Variation in social dynamics predicts 30% of the individual variation in reproductive success of this species in managed populations, and accurately forecasts reproductive output at least two years into the future. Optimization of social dynamics in captive meerkat populations doubles their projected reproductive output. These results demonstrate the utility of a quantitative approach to breeding programs informed by social and kinship dynamics. They suggest that this approach has great potential for improvements in the management of social endangered and agricultural species.

  4. Reproductive success in the Lusitanian toadfish: Influence of calling activity, male quality and experimental design.

    PubMed

    Amorim, M Clara P; Conti, Carlotta; Sousa-Santos, Carla; Novais, Bruno; Gouveia, Maria D; Vicente, Joana R; Modesto, Teresa; Gonçalves, Amparo; Fonseca, Paulo J

    2016-03-01

    Acoustic signals are sexual ornaments with an established role on mate choice in several taxa, but not in fish. Recent studies have suggested that fish vocal activity may signal male quality and influence male's reproductive success but experimental evidence is lacking. Here we made two experiments to test the hypothesis that vocal activity is essential for male breeding success in a highly vocal fish, the Lusitanian toadfish. We first compared the reproduction success between muted and vocal males. In a second experiment we related male reproduction success with acoustic activity and male quality, including biometric, condition and physiological features. As a proxy for reproductive success we tallied both total number and number of sired eggs, which were correlated. Muting experiments showed that successful mating was dependent on vocalizing. In addition, the number of eggs was positively associated with the male's maximum calling rate. In the second experiment male's reproductive success was positively associated with male condition and negatively related with circulating androgen levels and relative gonad mass, but was not associated with vocal activity. Differences in results may be related with nest design which could have influenced mate choice costs and intra-sexual competition. In the muting experiment nests had a small opening that restrained the large nest-holder but allowed smaller fish, such as females, to pass while in the second experiment fish could move freely. These experiments suggest that a combination of factors, including vocal activity, influence reproductive success in this highly vocal species.

  5. Parental provisioning behaviour plays a key role in linking personality with reproductive success.

    PubMed

    Mutzel, A; Dingemanse, N J; Araya-Ajoy, Y G; Kempenaers, B

    2013-08-07

    Repeatable behavioural traits ('personality') have been shown to covary with fitness, but it remains poorly understood how such behaviour-fitness relationships come about. We applied a multivariate approach to reveal the mechanistic pathways by which variation in exploratory and aggressive behaviour is translated into variation in reproductive success in a natural population of blue tits, Cyanistes caeruleus. Using path analysis, we demonstrate a key role for provisioning behaviour in mediating the link between personality and reproductive success (number of fledged offspring). Aggressive males fed their nestlings at lower rates than less aggressive individuals. At the same time, their low parental investment was associated with increased female effort, thereby positively affecting fledgling production. Whereas male exploratory behaviour was unrelated to provisioning behaviour and reproductive success, fast-exploring females fed their offspring at higher rates and initiated breeding earlier, thus increasing reproductive success. Our findings provide strong support for specific mechanistic pathways linking components of behavioural syndromes to reproductive success. Importantly, relationships between behavioural phenotypes and reproductive success were obscured when considering simple bivariate relationships, underlining the importance of adopting multivariate views and statistical tools as path analysis to the study of behavioural evolution.

  6. Floral visual signal increases reproductive success in a sexually deceptive orchid.

    PubMed

    Rakosy, Demetra; Streinzer, Martin; Paulus, Hannes F; Spaethe, Johannes

    2012-12-01

    Sexually deceptive orchids mimic signals emitted by female insects in order to attract mate-searching males. Specific attraction of the targeted pollinator is achieved by sex pheromone mimicry, which constitutes the major attraction channel. In close vicinity of the flower, visual signals may enhance attraction, as was shown recently in the sexually deceptive orchid Ophrys heldreichii. Here, we conducted an in situ manipulation experiment in two populations of O. heldreichii on Crete to investigate whether the presence/absence of the conspicuous pink perianth affects reproductive success in two natural orchid populations. We estimated reproductive success of three treatment groups (with intact, removed and artificial perianth) throughout the flowering period as pollinaria removal (male reproductive success) and massulae deposition (female reproductive success). Reproductive success was significantly increased by the presence of a strong visual signal-the conspicuous perianth-in one study population, however, not in the second, most likely due to the low pollinator abundance in the latter population. This study provides further evidence that the coloured perianth in O. heldreichii is adaptive and thus adds to the olfactory signal to maximise pollinator attraction and reproductive success.

  7. The effect of sediment on survival, growth, reproductive success and bioaccumulation in Neanthes: Summary report

    SciTech Connect

    Gerlinger, T.V.; Fanizzi, M.; Soong, K.; Armstrong, J.; Reish, D.J.

    1995-12-31

    Sediments taken from the vicinity of the County Sanitation Districts of Orange County ocean outfall were tested for survival, growth, reproduction and bioaccumulation of toxicants on the polychaete, Neanthes arenaceodentata. The end points were survival, growth (dry weight), reproductive success (as number of emerged larvae) and bioaccumulation (metals, DDT, PCBs). Ten experiments have been conducted over a 2 year period of which 2 measured reproductive success. The experiments for survival and growth utilized 2--3 week old post-emergence juvenile worms and subjected them to different test sediments including an inert sediment and plain sea water control. Worms were fed during the experiments. Experiments for reproductive success and bioaccumulation consisted of placing 100 juvenile worms each in 10 gallon aquaria together with test sediment for a 35--40 day period. After which, 10--15 pairs were made and each pair was placed in a separate 1 liter beaker together with sediment for the reproductive experiment. The remaining worms in each aquarium were used for chemical analysis. No toxic responses, as measured by survival, growth and reproductive success, were noted at any station during the 2 year study. Growth was generally lower in the inert sediment and sea water controls compared to test sediments indicating that worms were obtaining some nutrients from the sediment. No difference was noted in the number of emerged juveniles in any test container. While worms accumulated metals and organics in their tissue, there was neither a relationship to the station location nor to survival, growth or reproduction.

  8. Effects of forest fragmentation on male and female reproductive success in Cestrum parqui (Solanaceae).

    PubMed

    Aguilar, Ramiro; Galetto, Leonardo

    2004-03-01

    In this paper we evaluate the effects of forest fragmentation on male (pollen removal, pollen load, and pollen tubes) and female reproductive success (fruit- and seed-set) of Cestrum parqui, a self-incompatible, pollination-specialist plant species. We also measure focal individual conspecific density to account for possible density-related effects that could influence the response variables. We calculate an index which incorporates male and female fitness and gives an integrated assessment of overall reproductive success. Forest fragmentation strongly affected the amount of pollen grains on stigmas and number of pollen tubes as well as seed-set, decreasing from continuous forest to small forest fragments, whereas focal individual conspecific density failed to explain any of the variability for the studied variables. Declines in overall reproductive success (i.e. male and female) in small forest fragments are ascribed to decreases in both the quality and quantity of pollination. Self-incompatibility coupled with a specialist pollination system may be particularly important traits determining the negative fragmentation effects observed in C. parqui. Logarithmic regression models described the behaviour of the variables along the fragmentation size gradient, allowing us to detect a threshold below which the effects of fragmentation begin to negatively affect reproductive success in C. parqui. Our results emphasize the importance of evaluating both components of the total plant fitness, as well as including simultaneously several aspects of pollination and reproduction processes when assessing the effects of forest fragmentation on plant reproductive success.

  9. Effects of chronic avian malaria (Plasmodium relictum) infection on reproductive success of Hawaii Amakihi (Hemignathus virens)

    USGS Publications Warehouse

    Kilpatrick, A.M.; Lapointe, D.A.; Atkinson, C.T.; Woodworth, B.L.; Lease, J.K.; Reiter, M.E.; Gross, K.

    2006-01-01

    We studied the effects of chronic avian malaria (Plasmodium relictum) infections on the reproductive success of a native Hawaiian honeycreeper, Hawaii Amakihi (Hemignathus virens). Chronic malaria infections in male and female parents did not significantly reduce reproductive success as measured by clutch size, hatching success, fledging mass, number of nestlings fledged, nesting success (daily survival rate), and minimum fledgling survival. In fact, nesting success of pairs with chronically infected males was significantly higher than those with uninfected males (76% vs. 38%), and offspring that had at least one parent that had survived the acute phase of malaria infection had a significantly greater chance of being resighted the following year (25% vs. 10%). The reproduction and survival of infected birds were sufficient for a per-capita population growth rate >1, which suggests that chronically infected Hawaii Amakihi could support a growing population. ?? The American Ornithologists' Union, 2006.

  10. Triennial Reproduction Symposium: sperm characteristics that limit success of fertilization.

    PubMed

    Flowers, W L

    2013-07-01

    Current industry estimates of reproductive performance for cattle, sheep, and swine operations indicate that males contribute significantly to fertility failures. This appears to be due to the use of subfertile individuals and emphasizes the need for additional research in identifying characteristics of sperm that compromise fertilization. In theory, sperm characteristics, such as motility or the percentage of normal sperm, form a positive relationship with fertility that reaches a certain maximal fertility (i.e., an asymptotic relationship). It is clear that variation exists among males in terms of how fertility responds to increasing sperm dosage or numbers of normal sperm, both in the slope of the curve and the point at which the fertility reaches a maximum. Variations along the linear portion of fertility curves are due to compensable traits that are involved with the ability of sperm to penetrate the zona pellucida. It appears that most fertility curves reach their plateau when 70% of sperm possess a given compensable trait. The level of fertility at which the plateau occurs is determined by noncompensable traits that are associated with binding of sperm to the oolemma, syngamy, and subsequent development of the zygote. Several studies have shown differences in fertility among males that have similar levels of compensable traits but differed in their noncompensable characteristics. Compensable and noncompensable traits can estimate either individual or functional characteristics of sperm. Intuitively, functional traits such as in vitro penetration should provide a better indication of fertilization than individual ones such as motility. However, correlations of both types with fertility are very similar. Reasons for this may be related to how characteristics of sperm cells are influenced by the female reproductive tract after insemination. Sperm capacitation is a functional trait in boars that is quite different in vitro versus in vivo. If this relationship

  11. Acadian flycatcher nest placement: Does placement influence reproductive success?

    USGS Publications Warehouse

    Wilson, R.R.; Cooper, R.J.

    1998-01-01

    We located 511 Acadian Flycatcher (Empidonax virescens) nests in bottomland hardwood forest of eastern Arkansas. Microhabitat characteristics were measured and their relationship with nest success evaluated. Fifty-two percent of all nesting attempts resulted in predation. Attributes of nest placement were similar between successful and unsuccessful nests, although successful nests were placed higher. Similarly, nonparasitized nests were typically higher than parasitized nests. Nests initiated late in the breeding season were placed in larger trees with higher canopy bases resulting in increased vegetation around the nest. Fifteen different tree species were used for nesting. Acadian Flycatchers chose nest trees in a nonrandom fashion, selecting Nuttall oak (Quercus nuttallii) and possumhaw (Ilex decidua) in greater proportions than their availability. However, there was no relationship between tree species used for nesting and nest success. Nest height was positively correlated with concealment at the nest site, supporting the predator-avoidance theory. No other attribute of nest placement differentiated successful nest sites, suggesting that nest predation is likely a function of random events in space and time.

  12. Systematic review of the influence of foraging habitat on red-cockaded woodpecker reproductive success.

    SciTech Connect

    Garabedian, James E.

    2014-04-01

    Relationships between foraging habitat and reproductive success provide compelling evidence of the contribution of specific vegetative features to foraging habitat quality, a potentially limiting factor for many animal populations. For example, foraging habitat quality likely will gain importance in the recovery of the threatened red-cockaded woodpecker Picoides borealis (RCW) in the USA as immediate nesting constraints are mitigated. Several researchers have characterized resource selection by foraging RCWs, but emerging research linking reproductive success (e.g. clutch size, nestling and fledgling production, and group size) and foraging habitat features has yet to be synthesized. Therefore, we reviewed peer-refereed scientific literature and technical resources (e.g. books, symposia proceedings, and technical reports) that examined RCW foraging ecology, foraging habitat, or demography to evaluate evidence for effects of the key foraging habitat features described in the species’ recovery plan on group reproductive success. Fitness-based habitat models suggest foraging habitat with low to intermediate pine Pinus spp. densities, presence of large and old pines, minimal midstory development, and herbaceous groundcover support more productive RCW groups. However, the relationships between some foraging habitat features and RCW reproductive success are not well supported by empirical data. In addition, few regression models account for > 30% of variation in reproductive success, and unstandardized multiple and simple linear regression coefficient estimates typically range from -0.100 to 0.100, suggesting ancillary variables and perhaps indirect mechanisms influence reproductive success. These findings suggest additional research is needed to address uncertainty in relationships between foraging habitat features and RCW reproductive success and in the mechanisms underlying those relationships.

  13. Early growth, dominance acquisition and lifetime reproductive success in male and female cooperative meerkats.

    PubMed

    English, Sinead; Huchard, Elise; Nielsen, Johanna F; Clutton-Brock, Tim H

    2013-11-01

    In polygynous species, variance in reproductive success is higher in males than females. There is consequently stronger selection for competitive traits in males and early growth can have a greater influence on later fitness in males than in females. As yet, little is known about sex differences in the effect of early growth on subsequent breeding success in species where variance in reproductive success is higher in females than males, and competitive traits are under stronger selection in females. Greater variance in reproductive success has been documented in several singular cooperative breeders. Here, we investigated consequences of early growth for later reproductive success in wild meerkats. We found that, despite the absence of dimorphism, females who exhibited faster growth until nutritional independence were more likely to become dominant, whereas early growth did not affect dominance acquisition in males. Among those individuals who attained dominance, there was no further influence of early growth on dominance tenure or lifetime reproductive success in males or females. These findings suggest that early growth effects on competitive abilities and fitness may reflect the intensity of intrasexual competition even in sexually monomorphic species.

  14. Early growth, dominance acquisition and lifetime reproductive success in male and female cooperative meerkats

    PubMed Central

    English, Sinead; Huchard, Elise; Nielsen, Johanna F; Clutton-Brock, Tim H

    2013-01-01

    In polygynous species, variance in reproductive success is higher in males than females. There is consequently stronger selection for competitive traits in males and early growth can have a greater influence on later fitness in males than in females. As yet, little is known about sex differences in the effect of early growth on subsequent breeding success in species where variance in reproductive success is higher in females than males, and competitive traits are under stronger selection in females. Greater variance in reproductive success has been documented in several singular cooperative breeders. Here, we investigated consequences of early growth for later reproductive success in wild meerkats. We found that, despite the absence of dimorphism, females who exhibited faster growth until nutritional independence were more likely to become dominant, whereas early growth did not affect dominance acquisition in males. Among those individuals who attained dominance, there was no further influence of early growth on dominance tenure or lifetime reproductive success in males or females. These findings suggest that early growth effects on competitive abilities and fitness may reflect the intensity of intrasexual competition even in sexually monomorphic species. PMID:24340181

  15. The relationship between sex change and reproductive success in a protandric marine gastropod

    PubMed Central

    Brante, Antonio; Quiñones, Adriana; Silva, Francisco

    2016-01-01

    Protandric species switch sex during their lifetime. According to theory, the time (body size) at which sex change occurs is determined by the reproductive success of individuals affected by social interactions as well as by post-copulatory factors. Experimental evidence is biased to few social systems making the exploration of general patterns difficult. We used the protandric marine gastropod Crepidula coquimbensis that partakes in intrabrood sibling cannibalism to test the following hypotheses: 1. Male-male competition for access to females and sibling cannibalism determine male reproductive success; 2. Males with greater access to females and with higher reproductive success will have reduced growth rates and will delay sex change. Artificial aggregations with different social structures were constructed and male reproductive success was estimated by paternity analysis. The results supported our expectations showing that male competitive ability for access to the female, time spent by males in the copulatory position, and sibling cannibalism affect reproductive success and influence time to sex change, with less successful males hastening sex change. Also, males that spent more time in the copulatory position had reduced growth rates. Comparing these results with those reported for other sequential hermaphrodites provides evidence supporting general patterns of sex change in nature. PMID:27385040

  16. Men’s status and reproductive success in 33 nonindustrial societies: Effects of subsistence, marriage system, and reproductive strategy

    PubMed Central

    von Rueden, Christopher R.; Jaeggi, Adrian V.

    2016-01-01

    Social status motivates much of human behavior. However, status may have been a relatively weak target of selection for much of human evolution if ancestral foragers tended to be more egalitarian. We test the “egalitarianism hypothesis” that status has a significantly smaller effect on reproductive success (RS) in foragers compared with nonforagers. We also test between alternative male reproductive strategies, in particular whether reproductive benefits of status are due to lower offspring mortality (parental investment) or increased fertility (mating effort). We performed a phylogenetic multilevel metaanalysis of 288 statistical associations between measures of male status (physical formidability, hunting ability, material wealth, political influence) and RS (mating success, wife quality, fertility, offspring mortality, and number of surviving offspring) from 46 studies in 33 nonindustrial societies. We found a significant overall effect of status on RS (r = 0.19), though this effect was significantly lower than for nonhuman primates (r = 0.80). There was substantial variation due to marriage system and measure of RS, in particular status associated with offspring mortality only in polygynous societies (r = −0.08), and with wife quality only in monogamous societies (r = 0.15). However, the effects of status on RS did not differ significantly by status measure or subsistence type: foraging, horticulture, pastoralism, and agriculture. These results suggest that traits that facilitate status acquisition were not subject to substantially greater selection with domestication of plants and animals, and are part of reproductive strategies that enhance fertility more than offspring well-being. PMID:27601650

  17. Men's status and reproductive success in 33 nonindustrial societies: Effects of subsistence, marriage system, and reproductive strategy.

    PubMed

    von Rueden, Christopher R; Jaeggi, Adrian V

    2016-09-27

    Social status motivates much of human behavior. However, status may have been a relatively weak target of selection for much of human evolution if ancestral foragers tended to be more egalitarian. We test the "egalitarianism hypothesis" that status has a significantly smaller effect on reproductive success (RS) in foragers compared with nonforagers. We also test between alternative male reproductive strategies, in particular whether reproductive benefits of status are due to lower offspring mortality (parental investment) or increased fertility (mating effort). We performed a phylogenetic multilevel metaanalysis of 288 statistical associations between measures of male status (physical formidability, hunting ability, material wealth, political influence) and RS (mating success, wife quality, fertility, offspring mortality, and number of surviving offspring) from 46 studies in 33 nonindustrial societies. We found a significant overall effect of status on RS (r = 0.19), though this effect was significantly lower than for nonhuman primates (r = 0.80). There was substantial variation due to marriage system and measure of RS, in particular status associated with offspring mortality only in polygynous societies (r = -0.08), and with wife quality only in monogamous societies (r = 0.15). However, the effects of status on RS did not differ significantly by status measure or subsistence type: foraging, horticulture, pastoralism, and agriculture. These results suggest that traits that facilitate status acquisition were not subject to substantially greater selection with domestication of plants and animals, and are part of reproductive strategies that enhance fertility more than offspring well-being.

  18. An association between male homosexuality and reproductive success.

    PubMed

    Dewar, Colin S

    2003-02-01

    The existence of homosexuality in humans poses a problem for evolutionary theory. Exclusive male homosexuality has a catastrophic effect on reproduction and yet inherited factors appear to contribute to it. Previous attempts to resolve this conundrum are inconsistent with aspects of evolutionary theory. Additional limitations are as follows. Until recently, accounts of homosexuality have paid little attention to the probable existence of adaptive bisexuality in ancestral populations, from which further variations in sexual orientation may have evolved. Secondly, previous explanations have concentrated on the ancestral environment of two to three million years ago as the determinant of modern sexuality, when more recent influences are likely to have had considerable impact. I argue in favour of a longitudinal rather than cross-sectional model of the ancestral environment. Thirdly, they have often ignored the possibility of variable phenotypic expression, whereby those individuals with a genetic propensity for homosexuality exhibit different and adaptive qualities on most other occasions. It has been demonstrated in previous studies that homosexual men have superior linguistic skills compared to heterosexual men. This may be the result of an adaptive feminising effect on the male brain and apply to many practising heterosexuals. Other adaptations to the recent ancestral environment may include enhanced empathy, fine motor skills and impulse control. By drawing together these contributing factors an evolutionary basis for homosexuality can be demonstrated.

  19. Baculum morphology predicts reproductive success of male house mice under sexual selection

    PubMed Central

    2013-01-01

    Background Diversity in penile morphology is characterised by extraordinary variation in the size and shape of the baculum (penis bone) found in many mammals. Although functionally enigmatic, diversity in baculum form is hypothesised to result from sexual selection. According to this hypothesis, the baculum should influence the outcome of reproductive competition among males within promiscuous mating systems. However, a test of this key prediction is currently lacking. Results Here we show that baculum size explains significant variation in the reproductive success of male house mice under competitive conditions. After controlling for body size and other reproductive traits, the width (but not length) of the house mouse baculum predicts both the mean number of offspring sired per litter and total number of offspring sired. Conclusions By providing the first evidence linking baculum morphology to male reproductive success, our results support the hypothesis that evolutionary diversity in baculum form is driven by sexual selection. PMID:23800051

  20. Impact of gene polymorphisms of gonadotropins and their receptors on human reproductive success.

    PubMed

    Casarini, Livio; Santi, Daniele; Marino, Marco

    2015-12-01

    Gonadotropins and their receptors' genes carry several single-nucleotide polymorphisms resulting in endocrine genotypes modulating reproductive parameters, diseases, and lifespan leading to important implications for reproductive success and potential relevance during human evolution. Here we illustrate common genotypes of the gonadotropins and gonadotropin receptors' genes and their clinical implications in phenotypes relevant for reproduction such as ovarian cycle length, age of menopause, testosterone levels, polycystic ovary syndrome, and cancer. We then discuss their possible role in human reproduction and adaptation to the environment. Gonadotropins and their receptors' variants are differently distributed among human populations. Some hints suggest that they may be the result of natural selection that occurred in ancient times, increasing the individual chance of successful mating, pregnancy, and effective post-natal parental cares. The gender-related differences in the regulation of the reproductive endocrine systems imply that many of these genotypes may lead to sex-dependent effects, increasing the chance of mating and reproductive success in one sex at the expenses of the other sex. Also, we suggest that sexual conflicts within the FSH and LH-choriogonadotropin receptor genes contributed to maintain genotypes linked to subfertility among humans. Because the distribution of polymorphic markers results in a defined geographical pattern due to human migrations rather than natural selection, these polymorphisms may have had only a weak impact on reproductive success. On the contrary, such genotypes could acquire relevant consequences in the modern, developed societies in which parenthood attempts often occur at a later age, during a short, suboptimal reproductive window, making clinical fertility treatments necessary.

  1. Conspecific reproductive success and breeding habitat selection: Implications for the study of coloniality

    USGS Publications Warehouse

    Danchin, E.; Boulinier, T.; Massot, M.

    1998-01-01

    Habitat selection is a crucial process in the life cycle of animals because it can affect most components of fitness. It has been proposed that some animals cue on the reproductive success of conspecifics to select breeding habitats. We tested this hypothesis with demographic and behavioral data from a 17-yr study of the Black-legged Kittiwake (Rissa tridactyla), a cliff-nesting seabird. As the hypothesis assumes, the Black-legged Kittiwake nesting environment was patchy, and the relative quality of the different patches (i.e., breeding cliffs) varied in time. The average reproductive success of the breeders of a given cliff was predictable from one year to the next, but this predictability faded after several years. The dynamic nature of cliff quality in the long term is partly explained by the autocorrelation of the prevalence of an ectoparasite that influences reproductive success. As predicted by the performance-based conspecific attraction hypothesis, the reproductive success of current breeders on a given cliff was predictive of the reproductive success of new recruits on the cliff in the following year. Breeders tended to recruit to the previous year's most productive cliffs and to emigrate from the least productive ones. Consequently, the dynamics of breeder numbers on the cliffs were explained by local reproductive success on a year-to-year basis. Because, on average, young Black-legged Kittiwakes first breed when 4 yr old, such a relationship probably results from individual choices based on the assessment of previous-year local quality. When breeders changed breeding cliffs between years, they selected cliffs of per capita higher reproductive success. Furthermore, after accounting for the potential effects of age and sex as well as between-year variations, the effect of individual breeding performance on breeding dispersal was strongly influenced by the average reproductive success of other breeders on the same cliff. Individual breeding performance did

  2. The Importance of Pollinator Generalization and Abundance for the Reproductive Success of a Generalist Plant

    PubMed Central

    Maldonado, María Belén; Lomáscolo, Silvia Beatriz; Vázquez, Diego Pedro

    2013-01-01

    Previous studies have examined separately how pollinator generalization and abundance influence plant reproductive success, but none so far has evaluated simultaneously the relative importance of these pollinator attributes. Here we evaluated the extent to which pollinator generalization and abundance influence plant reproductive success per visit and at the population level on a generalist plant, Opuntia sulphurea (Cactaceae). We used field experiments and path analysis to evaluate whether the per-visit effect is determined by the pollinator’s degree of generalization, and whether the population level effect (pollinator impact) is determined by the pollinator’s degree of generalization and abundance. Based on the models we tested, we concluded that the per-visit effect of a pollinator on plant reproduction was not determined by the pollinators’ degree of generalization, while the population-level impact of a pollinator on plant reproduction was mainly determined by the pollinators’ degree of generalization. Thus, generalist pollinators have the greatest species impact on pollination and reproductive success of O. sulphurea. According to our analysis this greatest impact of generalist pollinators may be partly explained by pollinator abundance. However, as abundance does not suffice as an explanation of pollinator impact, we suggest that vagility, need for resource consumption, and energetic efficiency of generalist pollinators may also contribute to determine a pollinator’s impact on plant reproduction. PMID:24116049

  3. The importance of pollinator generalization and abundance for the reproductive success of a generalist plant.

    PubMed

    Maldonado, María Belén; Lomáscolo, Silvia Beatriz; Vázquez, Diego Pedro

    2013-01-01

    Previous studies have examined separately how pollinator generalization and abundance influence plant reproductive success, but none so far has evaluated simultaneously the relative importance of these pollinator attributes. Here we evaluated the extent to which pollinator generalization and abundance influence plant reproductive success per visit and at the population level on a generalist plant, Opuntia sulphurea (Cactaceae). We used field experiments and path analysis to evaluate whether the per-visit effect is determined by the pollinator's degree of generalization, and whether the population level effect (pollinator impact) is determined by the pollinator's degree of generalization and abundance. Based on the models we tested, we concluded that the per-visit effect of a pollinator on plant reproduction was not determined by the pollinators' degree of generalization, while the population-level impact of a pollinator on plant reproduction was mainly determined by the pollinators' degree of generalization. Thus, generalist pollinators have the greatest species impact on pollination and reproductive success of O. sulphurea. According to our analysis this greatest impact of generalist pollinators may be partly explained by pollinator abundance. However, as abundance does not suffice as an explanation of pollinator impact, we suggest that vagility, need for resource consumption, and energetic efficiency of generalist pollinators may also contribute to determine a pollinator's impact on plant reproduction.

  4. Aroclor 1242 and reproductive success of adult mallards (Anas platyrhynchos)

    USGS Publications Warehouse

    Haseltine, S.D.; Prouty, R.M.

    1980-01-01

    Twenty-four pairs of adult mallards were fed a diet containing 0 or 150 ppm of the PCB Aroclor 1242 for 12 weeks during which egg laying was induced. Laying started in both groups an average of 33 days after PCB treatment began. All hens were allowed to lay a 20-egg clutch; 15 eggs from each clutch were artificially incubated. Eleven hens from each group completed the clutch. There was no difference between the two groups in the time taken to lay the clutch, nor was there a difference in fertility, embryo mortality, or hatching success. Eggshell thickness decreased 8.9% with PCB ingestion; eggs from hens fed PCB contained an average of 105 ppm PCB wet wt. No difference in survival or weight gain to 3 weeks of age was observed between young mallards from eggs laid by PCB-treated hens and control hens.

  5. Replete vitamin D stores predict reproductive success following IVF

    PubMed Central

    Ozkan, Sebiha; Jindal, Sangita; Greenseid, Keri; Shu, Jun; Zeitlian, Gohar; Hickmon, Cheryl; Pal, Lubna

    2009-01-01

    Objective Hypothesizing that levels of 25OH-D in body fluids are reflective of vitamin repletion status, we aimed to determine if 25OH-D levels in the follicular fluid (FF) of infertile women undergoing in vitro fertilization (IVF) demonstrate a relationship with IVF cycle parameters and outcome. Design Prospective Cohort study Setting Academic tertiary care center Patients 84 infertile women undergoing IVF Interventions FF from follicles ≥14mm; serum (n=10) and FF levels of 25OH-D Main outcome measures Clinical pregnancy (CP) (defined as evidence of intrauterine gestation sac on ultrasound) following IVF; IVF cycle parameters. Results Serum and FF levels of 25OH-D were highly correlated (r=0.94, p<0.001). In a predominantly Caucasian population (66%), significantly lower FF 25OH-D levels were noted in Black versus non-Black patients (p=0.001). Significant inverse correlations were seen between FF 25OH-D levels and BMI (r−0.25, p=0.035). Significantly higher CP and implantation rates were observed across tertiles of FF25OH-D (p=0.029 and p=0.041 respectively); patients achieving CP following IVF (n=26) exhibited significantly higher FF levels of 25OH-D (p=0.005). Multivariable logistic regression analysis confirmed FF 25OH-D levels as an independent predictor to success of an IVF cycle; adjusting for age, BMI, ethnicity and number of embryos transferred (ET) each ng/ml increase in FF 25OH-D increased the likelihood for achieving CP by 6% (p=0.030). Conclusion Our findings that women with higher vitamin D level in their serum and FF are significantly more likely to achieve CP following IVF-ET are novel. A potential for benefit of vitamin D supplementation on treatment success in infertile patients undergoing IVF is suggested that merits further investigation. PMID:19589516

  6. Beyond lifetime reproductive success: the posthumous reproductive dynamics of male Trinidadian guppies

    PubMed Central

    López-Sepulcre, Andrés; Gordon, Swanne P.; Paterson, Ian G.; Bentzen, Paul; Reznick, David N.

    2013-01-01

    In semelparous populations, dormant germ banks (e.g. seeds) have been proposed as important in maintaining genotypes that are adaptive at different times in fluctuating environments. Such hidden storage of genetic diversity need not be exclusive to dormant banks. Genotype diversity may be preserved in many iteroparous animals through sperm-storage mechanisms in females. This allows males to reproduce posthumously and increase the effective sizes of seemingly female-biased populations. Although long-term sperm storage has been demonstrated in many organisms, the understanding of its importance in the wild is very poor. We here show the prevalence of male posthumous reproduction in wild Trinidadian guppies, through the combination of mark–recapture and pedigree analyses of a multigenerational individual-based dataset. A significant proportion of the reproductive population consisted of dead males, who could conceive up to 10 months after death (the maximum allowed by the length of the dataset), which is more than twice the estimated generation time. Demographic analysis shows that the fecundity of dead males can play an important role in population growth and selection. PMID:23740786

  7. Do Phoretic Mites Influence the Reproductive Success of Ips grandicollis (Coleoptera: Curculionidae)?

    PubMed

    Pfammatter, Jesse A; Raffa, Kenneth F

    2015-12-01

    Ips grandicollis (Eichhoff) can be an important pest of plantation trees in the Great Lakes region. Mites commonly occur in phoretic association with this beetle, but little is known about their effects on beetle population dynamics. We assessed the effects of phoretic mites on the reproductive success of I. grandicollis using complementary correlative and manipulative approaches. First, we allowed beetles to colonize Pinus resinosa (Ait) logs from sites across Wisconsin, reared them in a common environment, and related the species identities and abundances of mites with beetle production from each log. We found a positive relationship between I. grandicollis abundance and the presence of five mite species, Histiostoma spp., Dendrolaelaps quadrisetus (Berlese), Iponemus confusus (Lindquist), Trichouropoda australis Hirschmann, and Tarsonemus spp. While the abundance of individual mite species was positively correlated with beetle abundance, assessments of mite community structure did not explain beetle reproduction. Next, we introduced beetles that either had a natural complement of mites or whose mites were mechanically reduced into logs, and compared reproductive success between these beetles. We found no difference in colonization rates or beetle emergence between mite-present and mite-reduced treatments. Collectively, these results suggest a correlative, rather than causal, link between beetle reproductive success and mite incidence and abundances. These mites and beetles likely benefit from mutually suitable environments rather than exerting strong reciprocal impacts. Although mites may have some effects on I. grandicollis reproductive success, they likely play a minimal role compared to factors such as tree quality, beetle predation, and weather.

  8. A generalist brood parasite modifies use of a host in response to reproductive success

    PubMed Central

    Louder, Matthew I. M.; Schelsky, Wendy M.; Albores, Amber N.; Hoover, Jeffrey P.

    2015-01-01

    Avian obligate brood parasites, which rely solely on hosts to raise their young, should choose the highest quality hosts to maximize reproductive output. Brown-headed cowbirds (Molothrus ater) are extreme host generalists, yet female cowbirds could use information based on past reproductive outcomes to make egg-laying decisions thus minimizing fitness costs associated with parasitizing low-quality hosts. We use a long-term (21 years) nest-box study of a single host, the prothonotary warbler (Protonotaria citrea), to show that local cowbird reproductive success, but not host reproductive success, was positively correlated with the probability of parasitism the following year. Experimental manipulations of cowbird success corroborated that female cowbirds make future decisions about which hosts to use based on information pertaining to past cowbird success, both within and between years. The within-year pattern, in particular, points to local cowbird females selecting hosts based on past reproductive outcomes. This, coupled with high site fidelity of female cowbirds between years, points to information use, rather than cowbird natal returns alone, increasing parasitism rates on highly productive sites between years. PMID:26336180

  9. Male seminal fluid substances affect sperm competition success and female reproductive behavior in a seed beetle.

    PubMed

    Yamane, Takashi; Goenaga, Julieta; Rönn, Johanna Liljestrand; Arnqvist, Göran

    2015-01-01

    Male seminal fluid proteins are known to affect female reproductive behavior and physiology by reducing mating receptivity and by increasing egg production rates. Such substances are also though to increase the competitive fertilization success of males, but the empirical foundation for this tenet is restricted. Here, we examined the effects of injections of size-fractioned protein extracts from male reproductive organs on both male competitive fertilization success (i.e., P2 in double mating experiments) and female reproduction in the seed beetle Callosobruchus maculatus. We found that extracts of male seminal vesicles and ejaculatory ducts increased competitive fertilization success when males mated with females 1 day after the females' initial mating, while extracts from accessory glands and testes increased competitive fertilization success when males mated with females 2 days after the females' initial mating. Moreover, different size fractions of seminal fluid proteins had distinct and partly antagonistic effects on male competitive fertilization success. Collectively, our experiments show that several different seminal fluid proteins, deriving from different parts in the male reproductive tract and of different molecular weight, affect male competitive fertilization success in C. maculatus. Our results highlight the diverse effects of seminal fluid proteins and show that the function of such proteins can be contingent upon female mating status. We also document effects of different size fractions on female mating receptivity and egg laying rates, which can serve as a basis for future efforts to identify the molecular identity of seminal fluid proteins and their function in this model species.

  10. Male Seminal Fluid Substances Affect Sperm Competition Success and Female Reproductive Behavior in a Seed Beetle

    PubMed Central

    Yamane, Takashi; Goenaga, Julieta; Rönn, Johanna Liljestrand; Arnqvist, Göran

    2015-01-01

    Male seminal fluid proteins are known to affect female reproductive behavior and physiology by reducing mating receptivity and by increasing egg production rates. Such substances are also though to increase the competitive fertilization success of males, but the empirical foundation for this tenet is restricted. Here, we examined the effects of injections of size-fractioned protein extracts from male reproductive organs on both male competitive fertilization success (i.e., P2 in double mating experiments) and female reproduction in the seed beetle Callosobruchus maculatus. We found that extracts of male seminal vesicles and ejaculatory ducts increased competitive fertilization success when males mated with females 1 day after the females’ initial mating, while extracts from accessory glands and testes increased competitive fertilization success when males mated with females 2 days after the females’ initial mating. Moreover, different size fractions of seminal fluid proteins had distinct and partly antagonistic effects on male competitive fertilization success. Collectively, our experiments show that several different seminal fluid proteins, deriving from different parts in the male reproductive tract and of different molecular weight, affect male competitive fertilization success in C. maculatus. Our results highlight the diverse effects of seminal fluid proteins and show that the function of such proteins can be contingent upon female mating status. We also document effects of different size fractions on female mating receptivity and egg laying rates, which can serve as a basis for future efforts to identify the molecular identity of seminal fluid proteins and their function in this model species. PMID:25893888

  11. Elevated glucocorticoid concentrations during gestation predict reduced reproductive success in subordinate female banded mongooses.

    PubMed

    Sanderson, J L; Nichols, H J; Marshall, H H; Vitikainen, E I K; Thompson, F J; Walker, S L; Cant, M A; Young, A J

    2015-10-01

    Dominant females in social species have been hypothesized to reduce the reproductive success of their subordinates by inducing elevated circulating glucocorticoid (GC) concentrations. However, this 'stress-related suppression' hypothesis has received little support in cooperatively breeding species, despite evident reproductive skews among females. We tested this hypothesis in the banded mongoose (Mungos mungo), a cooperative mammal in which multiple females conceive and carry to term in each communal breeding attempt. As predicted, lower ranked females had lower reproductive success, even among females that carried to term. While there were no rank-related differences in faecal glucocorticoid (fGC) concentrations prior to gestation or in the first trimester, lower ranked females had significantly higher fGC concentrations than higher ranked females in the second and third trimesters. Finally, females with higher fGC concentrations during the third trimester lost a greater proportion of their gestated young prior to their emergence from the burrow. Together, our results are consistent with a role for rank-related maternal stress in generating reproductive skew among females in this cooperative breeder. While studies of reproductive skew frequently consider the possibility that rank-related stress reduces the conception rates of subordinates, our findings highlight the possibility of detrimental effects on reproductive outcomes even after pregnancies have become established.

  12. Elevated glucocorticoid concentrations during gestation predict reduced reproductive success in subordinate female banded mongooses

    PubMed Central

    Sanderson, J. L.; Nichols, H. J.; Marshall, H. H.; Vitikainen, E. I. K.; Thompson, F. J.; Walker, S. L.; Cant, M. A.; Young, A. J.

    2015-01-01

    Dominant females in social species have been hypothesized to reduce the reproductive success of their subordinates by inducing elevated circulating glucocorticoid (GC) concentrations. However, this ‘stress-related suppression' hypothesis has received little support in cooperatively breeding species, despite evident reproductive skews among females. We tested this hypothesis in the banded mongoose (Mungos mungo), a cooperative mammal in which multiple females conceive and carry to term in each communal breeding attempt. As predicted, lower ranked females had lower reproductive success, even among females that carried to term. While there were no rank-related differences in faecal glucocorticoid (fGC) concentrations prior to gestation or in the first trimester, lower ranked females had significantly higher fGC concentrations than higher ranked females in the second and third trimesters. Finally, females with higher fGC concentrations during the third trimester lost a greater proportion of their gestated young prior to their emergence from the burrow. Together, our results are consistent with a role for rank-related maternal stress in generating reproductive skew among females in this cooperative breeder. While studies of reproductive skew frequently consider the possibility that rank-related stress reduces the conception rates of subordinates, our findings highlight the possibility of detrimental effects on reproductive outcomes even after pregnancies have become established. PMID:26510673

  13. Agonistic reciprocity is associated with reduced male reproductive success within haremic social networks

    PubMed Central

    Solomon-Lane, Tessa K.; Pradhan, Devaleena S.; Willis, Madelyne C.; Grober, Matthew S.

    2015-01-01

    While individual variation in social behaviour is ubiquitous and causes social groups to differ in structure, how these structural differences affect fitness remains largely unknown. We used social network analysis of replicate bluebanded goby (Lythrypnus dalli) harems to identify the reproductive correlates of social network structure. In stable groups, we quantified agonistic behaviour, reproduction and steroid hormones, which can both affect and respond to social/reproductive cues. We identified distinct, optimal social structures associated with different reproductive measures. Male hatching success (HS) was negatively associated with agonistic reciprocity, a network structure that describes whether subordinates ‘reciprocated’ agonism received from dominants. Egg laying was associated with the individual network positions of the male and dominant female. Thus, males face a trade-off between promoting structures that facilitate egg laying versus HS. Whether this reproductive conflict is avoidable remains to be determined. We also identified different social and/or reproductive roles for 11-ketotestosterone, 17β-oestradiol and cortisol, suggesting that specific neuroendocrine mechanisms may underlie connections between network structure and fitness. This is one of the first investigations of the reproductive and neuroendocrine correlates of social behaviour and network structure in replicate, naturalistic social groups and supports network structure as an important target for natural selection. PMID:26156769

  14. Cutting edge assessment of the impact of autoimmunity on female reproductive success.

    PubMed

    Gleicher, Norbert; Weghofer, Andrea; Barad, David H

    2012-05-01

    There, likely, is no more controversial issue in reproductive medicine than the effects of autoimmunity on female reproductive success. Published studies are, therefore, often biased. We performed PubMed, Google Scholar and Medline searches for the years 2000-2010 under various key words and phrases, referring to effects of autoimmunity/autoimmune diseases on pregnancy/pregnancy outcomes/pregnancy rates/reproduction/reproductive outcomes/fertility/infertility/fertility treatments/infertility treatments, and a number of similar terms. Reference lists of selected manuscripts were evaluated for additional, potential references. All selected manuscripts were reviewed by at least one author (N.G.). Opinions were reached based on preferential review of only selected studies, which offered data, primarily developed in pursuit of unrelated scientific questions. Data from various medical fields point, surprisingly effectively, toward significant impacts of autoimmunity on female reproductive success. Autoimmunity not only increases miscarriage risks but also reduces female fecundity and infertility treatment success. A, likely, reason why differences of opinion have persisted is that effects are primarily observed in genetically predisposed women, with specific fragile X mental retardation 1 (FMR1) genotypes. This discovery coincides with recently increasing appreciation of the importance of the long arm of the X chromosome (Xq) in control of functional ovarian reserve (reflective of female fertility) and autoimmunity, with FMR1at Xq27.3, located at cross roads of both. Autoimmune effects on female reproductive success deserve recognition. Further investigations must not ignore patient stratification, based on ovarian FMR1 genotypes. Genetic definition of high-risk patients should lead to development of successful therapeutic interventions.

  15. Carotenoid supplementation enhances reproductive success in captive strawberry poison frogs (Oophaga pumilio).

    PubMed

    Dugas, Matthew B; Yeager, Justin; Richards-Zawacki, Corinne L

    2013-01-01

    Amphibians are currently experiencing the most severe declines in biodiversity of any vertebrate, and their requirements for successful reproduction are poorly understood. Here, we show that supplementing the diet of prey items (fruit flies) with carotenoids has strong positive effects on the reproduction of captive strawberry poison frogs (Oophaga pumilio), substantially increasing the number of metamorphs produced by pairs. This improved reproduction most likely arose via increases in the quality of both the fertilized eggs from which tadpoles develop and trophic eggs that are fed to tadpoles by mothers. Frogs in this colony had previously been diagnosed with a Vitamin A deficiency, and this supplementation may have resolved this issue. These results support growing evidence of the importance of carotenoids in vertebrate reproduction and highlight the nuanced ways in which nutrition constrains captive populations.

  16. Diseases and reproductive success in a wild mammal: example in the alpine chamois.

    PubMed

    Pioz, Maryline; Loison, Anne; Gauthier, Dominique; Gibert, Philippe; Jullien, Jean-Michel; Artois, Marc; Gilot-Fromont, Emmanuelle

    2008-04-01

    Density-dependent and climatic factors affect reproduction and dynamics of wild ungulates. Parasites can also decrease reproductive success through either a direct abortive effect or a negative impact on host growth and body condition. However, few studies have investigated the effect of parasitism on fecundity of ungulates in natural conditions. We studied three bacterial infections caused by Salmonella enterica serovar Abortusovis, Chlamydophila abortus and Coxiella burnetii. These bacteria are leading causes of reproductive failure in sheep, goat and cattle, which raises the question of their influence on population dynamics of wild ungulates. A long-term study of demography and epidemiology of an alpine chamois (Rupicapra rupicapra, L.) population (Les Bauges Reserve, France) and a generalized linear modeling approach were used to analyze the reproductive success of chamois according to population density, weather conditions and the prevalence of antibodies against the three bacteria in females. This approach enabled us to identify the confounding effect of weather and parasitism on fecundity in a natural population. After accounting for density, the prevalence of antibodies against the three bacteria explained 36% of the annual variation in reproductive success, and weather conditions explained an additional 31%. This study was, to our knowledge, the first to compare the decrease in fecundity due to bacterial infections and weather conditions in a population of wild mountain ungulates.

  17. Life as a bachelor: quantifying the success of an alternative reproductive tactic in male blue monkeys

    PubMed Central

    Cords, Marina

    2015-01-01

    In species that live in one-male groups, resident males monopolize access to a group of females and are assumed to have higher reproductive success than bachelors. We tested this assumption using genetic, demographic, and behavioral data from 8 groups of wild blue monkeys observed over 10 years to quantify reproduction by residents and bachelors and compare the success of the two tactics. We used maximum-likelihood methods to assign sires to 104 offspring born in the study groups, 36 of which were sired by extra-group males, i.e., residents of neighboring groups and bachelors. Among these extra-group males, high-ranking males (many of whom were neighboring residents) were more likely to sire offspring than low-ranking males, but the time these visiting males spent in the mother’s group when she conceived (male presence) did not predict their relative success. When bachelors competed for reproduction with other bachelors, neither rank nor male presence during the mother’s conceptive period affected the probability of siring an offspring, suggesting that highly opportunistic mating with conceptive females is important in bachelor reproduction. In a second analysis, we used long-term data to estimate resident and bachelor reproductive success over the long term, and particularly to determine if there are any circumstances in which a typical bachelor may sire as many offspring as a typical resident during one or two periods of residency. Our findings generally support the assumption of a resident reproductive advantage because in most circumstances, a lifelong bachelor would be unable to sire as many offspring as a resident. However, a bachelor who performs at the average rate in the average number of groups for several years may have similar lifetime reproductive success as a male whose reproduction is limited to one short period of residency, especially in a small group. Our findings suggest that one should not assume a resident reproductive advantage for males

  18. Quantifying the effects of pesticide exposure on annual reproductive success of birds.

    PubMed

    Etterson, Matthew A; Bennett, Richard S

    2013-10-01

    The Markov chain nest productivity model (MCnest) was developed for quantifying the effects of specific pesticide-use scenarios on the annual reproductive success of simulated populations of birds. Each nesting attempt is divided into a series of discrete phases (e.g., egg laying, incubation, nestling rearing), and results from avian toxicity tests are used to represent the types of effects possible in the field during each breeding phase. The expected exposure dose each day throughout the breeding season can be compared to the toxicity thresholds assigned to each breeding phase to determine whether the nest attempt is at risk. The primary output of the model is an estimate of the number of successful nest attempts per female per year, which is multiplied by the number of fledglings per successful nest to estimate the number of fledglings per female per breeding season (i.e., annual reproductive success). In this article, we present a series of MCnest simulations to demonstrate the extent to which the magnitude of change in annual reproductive success can be affected by considering life history attributes and the timing of pesticide applications relative to a species' typical breeding phenology. For a given pesticide-use scenario, MCnest can identify which species are at greatest risk. By allowing multiple species to be run under a single scenario, it can also help to identify the life-history traits that contribute to a species' vulnerability to a given pesticide-use scenario. It also can determine which application dates have the greatest impact and demonstrate the extent to which pesticide characteristics (e.g., residue half-life, mode of action) affect productivity. MCnest goes beyond the current qualitative screening-level assessments of risks to avian reproduction to provide an approach for quantifying the reduction in annual reproductive success by integrating species life history and timing of pesticide exposures, despite limitations in existing information

  19. Selecting surrogate endpoints for estimating pesticide effects on avian reproductive success

    EPA Science Inventory

    A Markov chain nest productivity model (MCnest) has been developed for projecting the effects of a specific pesticide-use scenario on the annual reproductive success of avian species of concern. A critical element in MCnest is the use of surrogate endpoints, defined as measured ...

  20. On the reproductive success of early-generation hatchery fish in the wild

    PubMed Central

    Christie, Mark R; Ford, Michael J; Blouin, Michael S

    2014-01-01

    Large numbers of hatchery salmon spawn in wild populations each year. Hatchery fish with multiple generations of hatchery ancestry often have heritably lower reproductive success than wild fish and may reduce the fitness of an entire population. Whether this reduced fitness also occurs for hatchery fish created with local- and predominantly wild-origin parents remains controversial. Here, we review recent studies on the reproductive success of such ‘early-generation’ hatchery fish that spawn in the wild. Combining 51 estimates from six studies on four salmon species, we found that (i) early-generation hatchery fish averaged only half the reproductive success of their wild-origin counterparts when spawning in the wild, (ii) the reduction in reproductive success was more severe for males than for females, and (iii) all species showed reduced fitness due to hatchery rearing. We review commonalities among studies that point to possible mechanisms (e.g., environmental versus genetic effects). Furthermore, we illustrate that sample sizes typical of these studies result in low statistical power to detect fitness differences unless the differences are substantial. This review demonstrates that reduced fitness of early-generation hatchery fish may be a general phenomenon. Future research should focus on determining the causes of those fitness reductions and whether they lead to long-term reductions in the fitness of wild populations. PMID:25469167

  1. Effects of nectar robbing on male and female reproductive success of a pollinator-dependent plant

    PubMed Central

    Rojas-Nossa, Sandra V.; Sánchez, José María; Navarro, Luis

    2016-01-01

    Background and Aims Nectar robbers affect host fitness in different ways and by different magnitudes, both directly and indirectly, and potentially constitute an important part of pollination interactions. The aim of this study was to assess the effect of nectar robbing on several variables that characterize the reproductive success of Lonicera etrusca, a pollinator-dependent plant with long, tubular flowers that produce abundant nectar. Methods Using fluorescent powder dye as a proxy for pollen, the distance of pollen dispersal was compared for robbed and non-robbed flowers. Artificial nectar robbing treatments were applied to test its effects on four additional measures of reproductive success, namely the quantity of pollen exported, fruit set, seed/ovule ratio and seed weight. Key Results Nectar robbing was not found to have any significant negative consequences on female and male components of reproductive success as determined through the five variables that were measured. Conclusions Although L. etrusca exhibits high levels of nectar robbing and nectar robbers are common floral visitors, no evidence was found of detrimental changes in the components of reproductive success. A combination of morphological and ecological mechanisms is proposed to explain how plants may compensate for the energetic loss caused by the nectar robbers. PMID:26482653

  2. Dominance, body size and internal relatedness influence male reproductive success in eastern grey kangaroos (Macropus giganteus).

    PubMed

    Miller, Emily J; Eldridge, Mark D B; Cooper, Desmond W; Herbert, Catherine A

    2010-01-01

    Knowledge of the determinants of reproductive success is essential for understanding the adaptive significance of particular traits. The present study examined whether particular behavioural, morphological, physiological or genetic traits were correlated with male dominance and reproductive success using three semi-free-ranging captive populations (n = 98) of the eastern grey kangaroo (Macropus giganteus). The morphological traits measured included bodyweight, head, forearm, tail, pes and leg length, forearm and bicep circumference, and testis size. Blood samples were collected to determine serum testosterone concentrations. All individuals were typed for 10 microsatellite loci and paternity determined for each pouch young. To determine the influence of relatedness and genetic diversity on male reproductive success, internal relatedness, standardised heterozygosity and mean d(2) were calculated. Dominant males sired a significantly higher proportion of offspring than smaller, lower-ranked males and had higher testosterone concentrations. Males that sired offspring were significantly heavier and had larger body size. Sires were significantly more heterozygous and genetically dissimilar to breeding females than non-sires. Despite the wealth of knowledge on the social organisation of kangaroos, this is the first study to assign parentage and male reproductive success using molecular evidence.

  3. Quantifying the effects of pesticide exposure on annual reproductive success of birds (presentation)

    EPA Science Inventory

    The Markov chain nest productivity model (MCnest) was developed for quantifying the effects of specific pesticide‐use scenarios on the annual reproductive success of simulated populations of birds. Each nesting attempt is divided into a series of discrete phases (e.g., egg ...

  4. Quantifying the effects of pesticide exposure on annual reproductive success of birds

    EPA Science Inventory

    The Markov chain nest productivity model (MCnest) was developed for quantifying the effects of specific pesticide-use scenarios on the annual reproductive success of simulated populations of birds. Each nesting attempt is divided into a series of discrete phases (e.g., egg layin...

  5. Resource availability, breeding site selection, and reproductive success of red-winged blackbirds.

    PubMed

    Turner, Andrew M; McCarty, John P

    1997-12-01

    Red-winged blackbirds are polygynous and show strong breeding site preferences, but it is unclear which environmental factors regulate their reproductive success and are ultimately responsible for shaping their patterns of habitat selection and their mating system. We evaluated the effect of variation in insect emergence rates on the reproductive success of male and female redwings nesting on replicate ponds. The number of male and female redwings that settled on a pond varied two- to three-fold among ponds, but was not related to insect emergence rates. Insect emergence rates had a positive effect on the number of nestlings successfully fledged by females, the number of nestlings fledged from male territories, and on the mass of nestlings at fledging. Typha stem density also varied widely among ponds, and was positively related to male and female settling density and mass of nestlings at fledging, but not to the number of nestlings fledged by females or males. We conclude that alternative breeding sites differ in their ability to support redwing reproduction, and that the availability of emerging odonates is an important environmental factor influencing the reproductive success of both male and female red-winged blackbirds.

  6. The impact of parental investment on lifetime reproductive success in Iceland

    PubMed Central

    Lynch, Emily C.

    2017-01-01

    Background Demonstrating the impact that parents have on the fitness of their children is a crucial step towards understanding how parental investment has affected human evolution. Parents not only transfer genes to their children, they also influence their environments. By analyzing reproductive patterns within and between different categories of close relatives, this study provides insight into the genetic and environmental effects that parents have on the fitness of their offspring. Methods We use data spanning over two centuries from an exceptionally accurate Icelandic genealogy, Íslendingabók, to analyze the relationship between the fertility rates of close relatives. Also, using genetic data, we determine narrow sense heritability estimates (h2) to further explore the genetic impact on lifetime reproductive success. Finally, we construct four simulations to model the expected contribution of genes and resources on reproductive success. Results The relationship between the reproduction of all full sibling pairs was significant and positive across all birth decades (r = 0.19) while the reproductive relationship between parents and offspring was often negative across many decades and undetectable overall (r = 0.00) (Fig. 1 and Table 1). Meanwhile, genetic data among 8,456 pairs of full siblings revealed a narrow sense heritability estimate (h2) of 0.00 for lifetime reproductive success. A resources model (following the rule that resources are transmitted from parents to children, distributed equally among siblings, and are the only factor affecting reproductive success) revealed a similar trend: a negative relationship between parent and offspring reproduction (r =  − 0.35) but a positive relationship among full siblings (r = 0.28). The relationship between parent and offspring lifetime reproductive success (LRS) and full sibling LRS was strongly and positively correlated across time (r = 0.799, p < 0.001). Similarly, the LRS among full

  7. Spatially variable habitat quality contributes to within-population variation in reproductive success.

    PubMed

    Griffen, Blaine D; Norelli, Alexandra P

    2015-04-01

    Variation in habitat quality is common across terrestrial, freshwater, and marine habitats. We investigated how habitat quality influenced the reproductive potential of mud crabs across 30 oyster reefs that were degraded to different extents. We further coupled this field survey with a laboratory experiment designed to mechanistically determine the relationship between resource consumption and reproductive performance. We show a >10-fold difference in average reproductive potential for crabs across reefs of different quality. Calculated consumption rates for crabs in each reef, based on a type II functional response, suggest that differences in reproductive performance may be attributed to resource limitation in poor quality reefs. This conclusion is supported by results of our laboratory experiment where crabs fed a higher quality diet of abundant animal tissue had greater reproductive performance. Our results demonstrate that spatial variation in habitat quality can be a considerable contributor to within-population individual variation in reproductive success (i.e., demographic heterogeneity). This finding has important implications for assessing population extinction risk.

  8. Relationship between reproductive success and male plasma vitellogenin concentrations in cunner, Tautogolabrus adspersus.

    PubMed Central

    Mills, Lesley J; Gutjahr-Gobell, Ruth E; Horowitz, Doranne Borsay; Denslow, Nancy D; Chow, Marjorie C; Zaroogian, Gerald E

    2003-01-01

    The gene for vitellogenin, an egg yolk protein precursor, is usually silent in male fish but can be induced by estrogen exposure. For this reason, vitellogenin production in male fish has become a widely used indicator of exposure to exogenous estrogens or estrogen mimics in the aquatic environment. The utility of this indicator to predict impacts on fish reproductive success is unclear because information on the relationship between male plasma vitellogenin and reproductive end points in male and female fish is limited. In the research reported in this article, we investigated whether the presence of male plasma vitellogenin is a reliable indicator of decreased reproductive success in mature fish. Adult and sexually mature male and female cunner (Tautogolabrus adspersus) were exposed to 17ss-estradiol, ethynylestradiol, or estrone, three steroidal estrogens that elicit the vitellogenic response. Data were gathered and pooled on egg production, egg viability, egg fertility, sperm motility, and male plasma vitellogenin concentrations. All males, including two with plasma vitellogenin levels exceeding 300 mg/mL, produced motile sperm. Neither percent fertile eggs nor percent viable eggs produced by reproductively active fish demonstrated a significant correlation with male plasma vitellogenin concentrations. Male gonadosomatic index and average daily egg production by females showed significant, but weak, negative correlation with male plasma vitellogenin concentrations. Results suggest that male plasma vitellogenin expression is not a reliable indicator of male reproductive dysfunction in adult cunner exposed to estrogens for 2-8 weeks during their reproductive season, at least in relation to capacity to produce motile sperm or fertilize eggs. Male plasma vitellogenin expression may serve as an indicator of reduced female reproductive function caused by estrogen exposure. PMID:12515685

  9. Determinants and Patterns of Reproductive Success in the Greater Horseshoe Bat during a Population Recovery

    PubMed Central

    Ward, Helen L.; Ransome, Roger D.; Jones, Gareth; Rossiter, Stephen J.

    2014-01-01

    An individual's reproductive success will depend on traits that increase access to mates, as well as the number of mates available. In most well-studied mammals, males are the larger sex, and body size often increases success in intra-sexual contests and thus paternity. In comparison, the determinants of male success in species with reversed sexual size dimorphism (RSD) are less well understood. Greater horseshoe bats (Rhinolophus ferrumequinum) exhibit RSD and females appear to exert mate choice when they visit and copulate with males in their underground territories. Here we assessed putative determinants of reproductive success in a colony of greater horseshoe bats during a 19-year period of rapid population growth. We genotyped 1080 bats with up to 40 microsatellite loci and assigned maternity to 99.5% of pups, and paternity to 76.8% of pups. We found that in spite of RSD, paternity success correlated positively with male size, and, consistent with our previous findings, also with age. Female reproductive success, which has not previously been studied in this population, was also age-related and correlated positively with individual heterozygosity, but not with body size. Remarkable male reproductive skew was detected that initially increased steadily with population size, possibly coinciding with the saturation of suitable territories, but then levelled off suggesting an upper limit to a male's number of partners. Our results illustrate that RSD can occur alongside intense male sexual competition, that male breeding success is density-dependent, and that male and female greater horseshoe bats are subject to different selective pressures. PMID:24551052

  10. Pairing and reproductive success in two sympatric species of Hyalella (Crustacea, Amphipoda, Dogielinotidae) from southern Brazil

    NASA Astrophysics Data System (ADS)

    da Silva Castiglioni, Daniela; Bond-Buckup, Georgina

    2008-01-01

    This study aimed at characterizing pairing and reproductive success in relation to male and female sizes of the sympatric freshwater gammarideans Hyalella pleoacuta and H. castroi from southern Brazil. These amphipods exhibit precopulatory mate guarding, in which a male will carry a potential mate beneath its ventral surface, guarding the female for several days until it molts and lays its eggs. The specimens were collected monthly with nets, from November 2003 to July 2004 in two trout aquaculture ponds at Sítio Vale das Trutas locality, São José dos Ausentes County, southern Brazil. The precopulatory pairs and ovigerous females were identified and separated in the field. In the laboratory, they were measured (cephalothorax length in mm), using a micrometer eyepiece in a stereoscopic microscope. Pairing success was estimated from the proportion of mating males and females related to their respective non-pairing individuals by size classes. Reproductive success was estimated from egg production. The mean cephalothorax length of paired males was larger than that of the unpaired males. For females, however, body size not affect pairing success for either species, because mean cephalothorax length of paired females did not differ significantly from unpaired females. Paired and unpaired males of both species of Hyalella were larger than the females. Positive assortative mating by size was observed in both species; i.e., larger males tended to pair with larger females. Male pairing success increased sharply with size. In both species, reproductive success in males increased with body size; however, the females of intermediate size classes showed greater reproductive success. This result supports the hypothesis that loading constraints play a part in structuring size-assortative pairing in these species.

  11. Linking biomarkers to reproductive success of caged fathead minnows in streams with increasing urbanization

    USGS Publications Warehouse

    Crago, J.; Corsi, S.R.; Weber, D.; Bannerman, R.; Klaper, R.

    2011-01-01

    Reproductive and oxidative stress biomarkers have been recommended as tools to assess the health of aquatic organisms. Though validated in the laboratory, there are few studies that tie a change in gene expression to adverse reproductive or population outcomes in the field. This paper looked at 17 streams with varying degrees of urbanization to assess the use of biomarkers associated with reproduction or stress in predicting reproductive success of fathead minnows. In addition, the relationship between biomarkers and water quality measures in streams with varying degrees of urbanization was examined. Liver vitellogenin mRNA was correlated with reproduction within a period of 11. d prior to sampling irrespective of habitat, but its correlation with egg output declined at 12. d and beyond indicating its usefulness as a short-term biomarker but its limits as a biomarker of total reproductive output. Stress biomarkers such as glutathione S-transferase may be better correlated with factors affecting reproduction over a longer term. There was a significant correlation between GST mRNA and a variety of anthropogenic pollutants. There was also an inverse correlation between glutathione S-transferase and the amount of the watershed designated as wetland. Egg production over the 21-d was negatively correlated with the amount of urbanization and positively correlated to wetland habitats. This study supports the development of multiple biomarkers linking oxidative stress and other non-reproductive endpoints to changes in aquatic habitats will be useful for predicting the health of fish populations and identifying the environmental factors that may need mitigation for sustainable population management. ?? 2010 Elsevier Ltd.

  12. The reproductive cycle of the Tasmanian devil (Sarcophilus harrisii) and factors associated with reproductive success in captivity.

    PubMed

    Keeley, T; O'Brien, J K; Fanson, B G; Masters, K; McGreevy, P D

    2012-04-01

    Numbers of wild Tasmanian devils are declining as a result of the fatal, transmissible Devil Facial Tumor Disease. A captive insurance population program has been initiated but current captive breeding rates are sub-optimal and therefore the goal of this project was to increase our understanding of the estrous cycle of the devil and elucidate potential causes of failed male-female pairings. Temporal patterns of fecal progestagen and corticosterone metabolite concentrations were examined for females (n=41) in three categories of reproductive status (successful: viable young, n=20 estrous cycles; unsuccessful: paired with a male but no young confirmed, n=44 estrous cycles; non-mated: no access to a male during estrus, n=8 estrous cycles) but substantial differences were not found. Females were more likely to produce pouch young if pairing with the male extended into late proestrus (P<0.05), thereby decreasing the time between pairing and presumed ovulation. The interval between the end of proestrous elevation in progestagen metabolite concentrations and the beginning of the luteal phase was 7.6±2.3 days in successful females. The length of the luteal phase in successful females was 12.5±1.4 days which was not different from unsuccessful or non-mated females (P>0.05). Unsuccessful females had 1-3 estrous cycles within a single year. Successful females were predominantly wild-caught (17/19, 90%) and most produced young following the first estrous cycle of the season (18/20, 90%). Unsuccessful females were predominantly captive born (20/27, 74%) in this study. It is possible that a proportion of females that do not produce pouch young achieve conception but the timing of reproductive failure continues to be elusive in this species.

  13. Effects of male social status on reproductive success and on behavior in mice (Mus musculus).

    PubMed

    D'Amato, F R

    1988-06-01

    Differences in reproduction as well as in behavior in the presence of females were evaluated according to dominant and subordinate male rank in albino mice, in the temporary absence of each male's antagonist. Dominant males reproduced more successfully than subordinate males. Subordinate males were generally inactive, except for displacement activities, during the first 15 min they were exposed to female partners. These findings suggest that mechanisms other than male-male interference or mating order may be operating or influencing behavior and reproductive results.

  14. The ART of mating: alternative reproductive tactics and mating success in a nest-guarding fish.

    PubMed

    Mascolino, S; Benvenuto, C; Gubili, C; Sacchi, C; Boufana, B; Mariani, S

    2016-12-01

    Behavioural observations in the field of male Mediterranean damselfish Chromis chromis were combined with molecular analyses, using bi-parentally and maternally inherited markers, to investigate reproductive success patterns of alternative reproductive tactics (ARTs) in terms of number of eggs sired and number of females contributing to each nest. Cuckoldry was observed in every nest sampled, with at least two and up to seven sneaker males per nest. The nesting male, however, always significantly fertilized the greater number of eggs (on average 49%) in each clutch, whereas each sneaker fertilized around 7% of the clutch. The average number of females whose eggs were fertilized by nesting males was 6·76 (range 2-13), while each sneaker on average fertilized the eggs of 1·74 (range 1-8) females. Using this sibship reconstruction, some of the factors involved in the regulation of the dynamic equilibrium of reproductive success were investigated between the two ARTs shown by C. chromis males. Results show that the sneakers' reproductive success was positively linked to egg clutch size; the density of individuals in the nesting area negatively affected the size of egg clutches; the rate of defence behaviours performed by nesting males negatively influenced the number of females contributing to each nest.

  15. Experimental reduction of intromittent organ length reduces male reproductive success in a bug

    PubMed Central

    Dougherty, Liam R.; Rahman, Imran A.; Burdfield-Steel, Emily R.; Greenway, E. V. (Ginny); Shuker, David M.

    2015-01-01

    It is now clear in many species that male and female genital evolution has been shaped by sexual selection. However, it has historically been difficult to confirm correlations between morphology and fitness, as genital traits are complex and manipulation tends to impair function significantly. In this study, we investigate the functional morphology of the elongate male intromittent organ (or processus) of the seed bug Lygaeus simulans, in two ways. We first use micro-computed tomography (micro-CT) and flash-freezing to reconstruct in high resolution the interaction between the male intromittent organ and the female internal reproductive anatomy during mating. We successfully trace the path of the male processus inside the female reproductive tract. We then confirm that male processus length influences sperm transfer by experimental ablation and show that males with shortened processi have significantly reduced post-copulatory reproductive success. Importantly, male insemination function is not affected by this manipulation per se. We thus present rare, direct experimental evidence that an internal genital trait functions to increase reproductive success and show that, with appropriate staining, micro-CT is an excellent tool for investigating the functional morphology of insect genitalia during copulation. PMID:25972470

  16. Late snowmelt delays plant development and results in lower reproductive success in the High Arctic.

    PubMed

    Cooper, Elisabeth J; Dullinger, Stefan; Semenchuk, Philipp

    2011-01-01

    In tundra areas where the growing season is short, any delay in the start of summer may have a considerable effect on plant development, growth and reproductive success. Climate models suggest long-term changes in winter precipitation in the Arctic, which may lead to deeper snow cover and a resultant delay in date of snow melt. In this paper, we investigated the role of snow depth and melt out date on the phenological development and reproductive success of vascular plants in Adventdalen, Svalbard (78° 10'N, 16° 06'E). Effects of natural variations in snow accumulation were demonstrated using two vegetation types (snow depth: meadow 21 cm, heath 32 cm), and fences were used to experimentally increase snow depth by over 1m. Phenological delay was greatest directly after snowmelt in the earlier phenological phases, and had the largest effect on the early development of those species which normally green-up early (i.e. Dryas, Papaver, Salix, Saxifraga). Compressed growing seasons and length of the reproductive period led to a reduced reproductive success in some of the study species. There were fewer flowers, fewer plots with dispersing seeds, and lower germination rates. This can have consequences for plant establishment and community composition in the long-term.

  17. Conspecific reproductive success affects age of recruitment in a great cormorant, Phalacrocorax carbo sinensis, colony.

    PubMed

    Frederiksen, M; Bregnballe, T

    2001-07-22

    Few studies have addressed the proximate factors affecting the age at which individuals of long-lived bird species are recruited into the breeding population. We use capture-recapture analysis of resightings of 16 birth cohorts of colour-ringed great cormorants, Phalacrocorax carbo sinensis, in a Danish colony to assess the evidence for two hypotheses: conspecific attraction (earlier recruitment when the colony is large) and conspecific reproductive success (earlier recruitment following years of high breeding success). For both males and females, conspecific reproductive success was the most important covariate explaining the interannual variation in age of recruitment; colony size was also important for females. These covariates explained nearly 60% of the year-to-year variation for both sexes. The age of recruitment increased for cohorts born after 1990, and this increase was correlated with a decline in breeding success in the colony; we interpret this as an indirect and delayed density-dependent effect. Females were recruited earlier than males (mean age of recruitment for cohorts born before 1990: 2.98 years versus 3.53 years); the most plausible reason for this is a skewed sex ratio in favour of males in the adult population. Recruitment of males may thus, to some extent, be constrained by the availability of females. This study provides the first evidence that conspecific reproductive success can affect the age at which individual birds start to breed.

  18. Effects of extreme weather on reproductive success in a temperate-breeding songbird.

    PubMed

    Pipoly, Ivett; Bókony, Veronika; Seress, Gábor; Szabó, Krisztián; Liker, András

    2013-01-01

    The frequency of extreme meteorological events such as heat waves and rainstorms is predicted to increase with climate change. However, there is still little information about how extreme weather influences reproduction in animals. It may not only affect breeding success but might also alter offspring sex ratio if males and females are differentially sensitive to meteorological conditions during development. We investigated the relationship between meteorological conditions and reproductive success over 6 years in a house sparrow population in central Europe. We found that hatching success increased with the number of extremely hot days (daily maximum >31°C) and decreased with the number of extremely cold days (<16°C) during incubation, although the latter effect held only for clutches with relatively short incubation periods. Fledging success was unrelated to weather variables. However, the frequency of extremely hot days had a negative effect on fledglings' body mass and tarsus length, although both of these traits were positively related to average temperature. Additionally, fledglings' body mass increased with the length of period without rainfall before fledging. Male to female ratio among fledglings did not differ from 1:1 and did not vary with weather variables. The magnitude of the effects of extreme meteorological events was usually small, although in some cases comparable to those of ecologically relevant predictors of reproductive success. Our results indicate that meteorological conditions have complex effects on breeding success, as the effects of extreme weather can differ between different aspects of reproduction and also from the effects of overall meteorological conditions.

  19. Problem-solving performance and reproductive success of great tits in urban and forest habitats.

    PubMed

    Preiszner, Bálint; Papp, Sándor; Pipoly, Ivett; Seress, Gábor; Vincze, Ernő; Liker, András; Bókony, Veronika

    2017-01-01

    Success in problem solving, a form of innovativeness, can help animals exploit their environments, and recent research suggests that it may correlate with reproductive success. Innovativeness has been proposed to be especially beneficial in urbanized habitats, as suggested by superior problem-solving performance of urban individuals in some species. If there is stronger selection for innovativeness in cities than in natural habitats, we expect problem-solving performance to have a greater positive effect on fitness in more urbanized habitats. We tested this idea in great tits (Parus major) breeding at two urban sites and two forests by measuring their problem-solving performance in an obstacle-removal task and a food-acquisition task. Urban pairs were significantly faster problem-solvers in both tasks. Solving speed in the obstacle-removal task was positively correlated with hatching success and the number of fledglings, whereas performance in the food-acquisition task did not correlate with reproductive success. These relationships did not differ between urban and forest habitats. Neophobia, sensitivity to human disturbance, and risk taking in the presence of a predator did not explain the relationships of problem-solving performance either with habitat type or with reproductive success. Our results suggest that the benefit of innovativeness in terms of reproductive success is similar in urban and natural habitats, implying that problem-solving skills may be enhanced in urban populations by some other benefits (e.g. increased survival) or reduced costs (e.g. more opportunities to gain practice with challenging tasks).

  20. Pulsed resources affect the timing of first breeding and lifetime reproductive success of tawny owls.

    PubMed

    Millon, A; Petty, S J; Lambin, X

    2010-03-01

    1. According to life-history theory, environmental variability and costs of reproduction account for the prevalence of delayed reproduction in many taxa. Empirical estimates of the fitness consequences of different ages at first breeding in a variable environment are few however such that the contributions of environmental and individual variability remains poorly known. 2. Our objectives were to elucidate processes that underpin variation in delayed reproduction and to assess lifetime consequences of the age of first breeding in a site-faithful predator, the tawny owl Strix aluco L. subjected to fluctuating selection linked to cyclical variation in vole density (typically 3-year cycles with low, increasing and decreasing vole densities in successive years). 3. A multistate capture-recapture model revealed that owl cohorts had strikingly different juvenile survival prospects, with estimates ranging from 0.08 to 0.33 respectively for birds born in Decrease and Increase phases of the vole cycle. This resulted in a highly skewed population structure with >75% of local recruits being reared during Increase years. In contrast, adult survival remained constant throughout a vole cycle. The probability of commencing reproduction was lower at age 1 than at older ages, and especially so for females. From age 2 onwards, pre-breeders had high probabilities of entering the breeding population. 4. Variation in lifetime reproductive success was driven by the phase of the vole cycle in which female owls started their breeding career (26-47% of variance explained, whether based on the number of local recruits or fledglings), more than by age at first breeding or by conditions experienced at birth. Females who postponed reproduction to breed for the first time at age 3 during an Increase phase, produced more recruits, even when accounting for birds that may have died before reproduction. No such effects were detected for males. 5. Sex-specific costs of early reproduction may have

  1. Effects of fire on golden eagle territory occupancy and reproductive success

    USGS Publications Warehouse

    Kochert, Michael N.; Steenhof, Karen; Marzluff, J.M.; Carpenter, L.B.

    1999-01-01

    We examined effects of fire on golden eagle (Aquila chrysaetos) territory occupancy and reproductive success in southwestern Idaho because wildfires since 1980 have resulted in large-scale losses of shrub habitat in the Snake River Plain. Success (percentage of pairs that raised young) at burned territories declined after major fires (P = 0.004). Pairs in burned areas that could expand into adjacent vacant territories were as successful as pairs in unburned territories and more successful than pairs in burned territories that could not expand. Success at extensively burned territories was lowest 4-6 years after burning but increased 4-5 years later. The incidence and extent of fires did not help predict territories that would have low occupancy and success rates in postburn years. The presence of a vacant neighboring territory and the amount of agriculture and proportion of shrubs within 3 km of the nesting centroid best predicted probability of territory occupancy. Nesting success during preburn years best predicted the probability of a territory being successful in postburn years. Burned territories with high success rates during preburn years continued to have high success rates during postburn years, and those with low success in preburn years continued to be less successful after burning. In areas where much shrub habitat has been lost to fire, management for golden eagles should include active fire suppression and rehabilitation of burned areas.

  2. Stress and success: individual differences in the glucocorticoid stress response predict behavior and reproductive success under high predation risk.

    PubMed

    Vitousek, Maren N; Jenkins, Brittany R; Safran, Rebecca J

    2014-11-01

    A fundamental element of how vertebrates respond to stressors is by rapidly elevating circulating glucocorticoid hormones. Individual variation in the magnitude of the glucocorticoid stress response has been linked with reproductive success and survival. But while the adaptive value of this response is believed to stem in part from changes in the expression of hormone-mediated behaviors, it is not clear how the behavior of stronger and weaker glucocorticoid responders differs during reproduction, or during exposure to ecologically relevant stressors. Here we report that in a population of barn swallows (Hirundo rustica erythrogaster) experiencing high rates of nest predation, circulating levels of corticosterone (the primary avian glucocorticoid) during exposure to a standardized stressor predict aspects of subsequent behavior and fitness. Individuals that mounted a stronger corticosterone stress response during the early reproductive period did not differ in clutch size, but fledged fewer offspring. Parents with higher stress-induced corticosterone during the early reproductive period later provisioned their nestlings at lower rates. Additionally, in the presence of a model predator stress-induced corticosterone was positively associated with the latency to return to the nest, but only among birds that were observed to return. Model comparisons revealed that stress-induced hormones were better predictors of the behavioral and fitness effects of exposure to transient, ecologically relevant stressors than baseline corticosterone. These findings are consistent with functional links between individual variation in the hormonal and behavioral response to stressors. If such links occur, then selection on the heritable components of the corticosterone stress response could promote adaptation to novel environments or predation regimes.

  3. Differential reproductive success favours strong host preference in a highly specialized brood parasite

    PubMed Central

    De Mársico, María C; Reboreda, Juan C

    2008-01-01

    Obligate avian brood parasites show dramatic variation in the degree to which they are host specialists or host generalists. The screaming cowbird Molothrus rufoaxillaris is one of the most specialized brood parasites, using a single host, the bay-winged cowbird (Agelaioides badius) over most of its range. Coevolutionary theory predicts increasing host specificity the longer the parasite interacts with a particular avian community, as hosts evolve defences that the parasite cannot counteract. According to this view, host specificity can be maintained if screaming cowbirds avoid parasitizing potentially suitable hosts that have developed effective defences against parasitic females or eggs. Specialization may also be favoured, even in the absence of host defences, if the parasite's reproductive success in alternative hosts is lower than that in the main host. We experimentally tested these hypotheses using as alternative hosts two suitable but unparasitized species: house wrens (Troglodytes aedon) and chalk-browed mockingbirds (Mimus saturninus). We assessed host defences against parasitic females and eggs, and reproductive success of the parasite in current and alternative hosts. Alternative hosts did not discriminate against screaming cowbird females or eggs. Egg survival and hatching success were similarly high in current and alternative hosts, but the survival of parasitic chicks was significantly lower in alternative hosts. Our results indicate that screaming cowbirds have the potential to colonize novel hosts, but higher reproductive success in the current host may favour host fidelity. PMID:18647716

  4. Voluntary exercise at the expense of reproductive success in Djungarian hamsters ( Phodopus sungorus)

    NASA Astrophysics Data System (ADS)

    Petri, Ines; Scherbarth, Frank; Steinlechner, Stephan

    2010-09-01

    Energy demands of gestation and lactation represent a severe challenge for small mammals. Therefore, additional energetic burdens may compromise successful breeding. In small rodents, food restriction, cold exposure (also in combination) and wheel running to obtain food have been shown to diminish reproductive outcome. Although exhibited responses such as lower incidence of pregnancy, extended lactation periods and maternal infanticide were species dependent, their common function is to adjust energetic costs to the metabolic state reflecting the trade-off between maternal investment and self-maintenance. In the present study, we sought to examine whether voluntary exercise affects reproduction in Djungarian hamsters ( Phodopus sungorus), which are known for their high motivation to run in a wheel. Voluntary exercise resulted in two different effects on reproduction; in addition to increased infanticide and cannibalism, which was evident across all experiments, the results of one experiment provided evidence that free access to a running wheel may prevent successful pregnancy. It seems likely that the impact of voluntary wheel running on reproduction was associated with a reduction of internal energy resources evoked by extensive exercise. Since the hamsters were neither food-restricted nor forced to run in the present study, an energetic deficit as reason for infanticide in exercising dams would emphasise the particularly high motivation to run in a wheel.

  5. Parasitism, immune response and reproductive success in the house martin Delichonurbica.

    PubMed

    de Lope, F; Møller, A P; de la Cruz, C

    1998-04-01

    Parasites often exert strong selection pressures on their hosts that have evolved anti-parasite defences to counter the negative effects of parasites. We studied the relationship between intensity of parasitism, one aspect of host immune response, and host reproductive success, using the house martin bug Oeciacushirundinis and its house martin Delichonurbica host as a model system. Experimental manipulation of parasite load of nests during laying of the first clutch altered the intensity of parasitism. Parasites reduced the reproductive success of their hosts measured in terms of body condition and survival of nestlings. Host immune response, measured as the concentration of gammaglobulins and total plasma proteins, was positively associated with parasite reproduction, estimated as the number of juvenile parasites, but was only weakly related to the intensity of adult parasites. The concentration of gammaglobulins was negatively related to nestling body mass, implying a trade-off between immune function and body condition. Parasite reproduction thus exerts a cost on hosts by increasing the immune response.

  6. Effects of dietary uranium on reproductive endpoints--fecundity, survival, reproductive success--of the fish Danio rerio.

    PubMed

    Simon, Olivier; Mottin, Elmina; Geffroy, Benjamin; Hinton, Thomas

    2011-01-01

    Exposure to metal-contaminated water has been shown to result in a number of reproductive abnormalities in adult and larvae fish, such as failure of oocyte maturation and teratogenic effects. Recently, dietary uptake of metals by fish has been recognized as a critical route of exposure, however, the mechanisms of metal uptake and toxicity are poorly understood and in need of further investigation. The objectives of the present study are to quantify uranium (U dietary transfers from spiked artificial diets) in Danio rerio tissues and embryos, as well as establish its effect on reproduction and embryonic development. Uranium's environmental prominence is currently increasing because of new mining and milling activities. Uranium concentrations range from 0.02 µg/L in natural waters to 2 mg/L. The focus of this study was to examine the trophic transfer and effects of U following exposure modalities (dose, exposure duration 1 to 20 d). Two different isotopes were used to distinguish between chemical and radioactivity toxicity of U. Results showed that U trophic transfer was low (0.52%). Uranium tissue distributions showed that accumulation occurred in digestive organs (liver, digestive tract) following dietary exposure. High levels of U were measured in the gonads (female in particular, >20% of relative burden). High U accumulation levels in eggs indicated maternal transfer of the contaminant. Moreover, U trophic exposure led to a reduction in reproduction success as a function of U accumulated levels. High U exposure conditions strongly reduced the total number of eggs (50%) and their viability at 10 d (reduction of the clutch number, low quality of eggs).

  7. Body Condition Indices Predict Reproductive Success but Not Survival in a Sedentary, Tropical Bird

    PubMed Central

    Milenkaya, Olga; Catlin, Daniel H.; Legge, Sarah; Walters, Jeffrey R.

    2015-01-01

    Body condition may predict individual fitness because those in better condition have more resources to allocate towards improving their fitness. However, the hypothesis that condition indices are meaningful proxies for fitness has been questioned. Here, we ask if intraspecific variation in condition indices predicts annual reproductive success and survival. We monitored a population of Neochmia phaeton (crimson finch), a sedentary, tropical passerine, for reproductive success and survival over four breeding seasons, and sampled them for commonly used condition indices: mass adjusted for body size, muscle and fat scores, packed cell volume, hemoglobin concentration, total plasma protein, and heterophil to lymphocyte ratio. Our study population is well suited for this research because individuals forage in common areas and do not hold territories such that variation in condition between individuals is not confounded by differences in habitat quality. Furthermore, we controlled for factors that are known to impact condition indices in our study population (e.g., breeding stage) such that we assessed individual condition relative to others in the same context. Condition indices that reflect energy reserves predicted both the probability of an individual fledging young and the number of young produced that survived to independence, but only during some years. Those that were relatively heavy for their body size produced about three times more independent young compared to light individuals. That energy reserves are a meaningful predictor of reproductive success in a sedentary passerine supports the idea that energy reserves are at least sometimes predictors of fitness. However, hematological indices failed to predict reproductive success and none of the indices predicted survival. Therefore, some but not all condition indices may be informative, but because we found that most indices did not predict any component of fitness, we question the ubiquitous interpretation of

  8. Combining site occupancy, breeding population sizes and reproductive success to calculate time-averaged reproductive output of different habitat types: an application to Tricolored Blackbirds.

    PubMed

    Holyoak, Marcel; Meese, Robert J; Graves, Emily E

    2014-01-01

    In metapopulations in which habitat patches vary in quality and occupancy it can be complicated to calculate the net time-averaged contribution to reproduction of particular populations. Surprisingly, few indices have been proposed for this purpose. We combined occupancy, abundance, frequency of occurrence, and reproductive success to determine the net value of different sites through time and applied this method to a bird of conservation concern. The Tricolored Blackbird (Agelaius tricolor) has experienced large population declines, is the most colonial songbird in North America, is largely confined to California, and breeds itinerantly in multiple habitat types. It has had chronically low reproductive success in recent years. Although young produced per nest have previously been compared across habitats, no study has simultaneously considered site occupancy and reproductive success. Combining occupancy, abundance, frequency of occurrence, reproductive success and nest failure rate we found that that large colonies in grain fields fail frequently because of nest destruction due to harvest prior to fledging. Consequently, net time-averaged reproductive output is low compared to colonies in non-native Himalayan blackberry or thistles, and native stinging nettles. Cattail marshes have intermediate reproductive output, but their reproductive output might be improved by active management. Harvest of grain-field colonies necessitates either promoting delay of harvest or creating alternative, more secure nesting habitats. Stinging nettle and marsh colonies offer the main potential sources for restoration or native habitat creation. From 2005-2011 breeding site occupancy declined 3x faster than new breeding colonies were formed, indicating a rapid decline in occupancy. Total abundance showed a similar decline. Causes of variation in the value for reproduction of nesting substrates and factors behind continuing population declines merit urgent investigation. The method we

  9. Influence of inflorescence size on sexual expression and female reproductive success in a monoecious species.

    PubMed

    Torices, R; Méndez, M

    2011-01-01

    Sex allocation theory forecasts that larger plant size may modify the balance in fitness gain in both genders, leading to uneven optimal male and female allocation. This reasoning can be applied to flowers and inflorescences, because the increase in flower or inflorescence size can differentially benefit different gender functions, and thus favour preferential allocation to specific floral structures. We investigated how inflorescence size influenced sexual expression and female reproductive success in the monoecious Tussilago farfara, by measuring patterns of biomass, and N and P allocation. Inflorescences of T. farfara showed broad variation in sex expression and, according to expectations, allocation to different sexual structures showed an allometric pattern. Unexpectedly, two studied populations had a contrasting pattern of sex allocation with an increase in inflorescence size. In a shaded site, larger inflorescences were female-biased and had disproportionately more allocation to attraction structures; while in an open site, larger inflorescences were male-biased. Female reproductive success was higher in larger, showier inflorescences. Surprisingly, male flowers positively influenced female reproductive success. These allometric patterns were not easily interpretable as a result of pollen limitation when naïvely assuming an unequivocal relationship between structure and function for the inflorescence structures. In this and other Asteraceae, where inflorescences are the pollination unit, both male and female flowers can play a role in pollinator attraction.

  10. Effects of Seasonal Weather on Breeding Phenology and Reproductive Success of Alpine Ptarmigan in Colorado

    PubMed Central

    Wann, Gregory T.; Aldridge, Cameron L.; Braun, Clait E.

    2016-01-01

    Animal populations occurring at high elevations are often assumed to be in peril of extinctions or local extirpations due to elevational-dispersal limitations and thermoregulatory constraints as habitats change and warm. However, long-term monitoring of high-elevation populations is uncommon relative to those occurring at lower elevations, and evidence supporting this assumption is limited. We analyzed 45 years of reproductive data for two Colorado populations of white-tailed ptarmigan (Lagopus leucura), an alpine-endemic species with restricted distribution in western North America. Seasonal temperatures measured by the number of growing degree days warmed significantly at our study sites for pre-nesting, nesting, and brood-rearing seasonal periods (mean advance of 8 growing degree days per decade), and both populations advanced their reproductive phenology over the study period based on median hatch dates (median advance of 3.7 and 1.9 days per decade for the northern and southern sites, respectively). Reproductive performance measured by the number of chicks per hen declined significantly at one study site but not the other, and differences between sites may have been due to habitat degradation at one study area. Annual variability in chicks per hen was large at both sites but only weakly related to seasonal weather. An index of precipitation and temperature during the brood-rearing period was the best predictor for reproductive success with warm and dry conditions relating positively to number of chicks per hen. Our results provide evidence for two alpine ptarmigan populations that are remarkably invariant to fluctuations in seasonal weather with respect to reproductive success as measured by number of chicks per hen in the breeding population. These results are surprising given the general perception of alpine animal populations as being highly sensitive to warming temperatures. PMID:27420478

  11. Physical and neuro-behavioural determinants of reproductive onset and success

    PubMed Central

    Rose, Lynda M.; Loh, Po-Ru; Scott, Robert A.; Helgason, Agnar; Kong, Augustine; Masson, Gisli; Magnusson, Olafur Th.; Gudbjartsson, Daniel; Thorsteinsdottir, Unnur; Buring, Julie E.; Ridker, Paul M.; Sulem, Patrick

    2016-01-01

    The ages of puberty, first sexual intercourse and first birth signify the onset of reproductive ability, behaviour and success, respectively. These sequenced events have behavioural, physiological and health significance, and may also influence overall reproductive fitness. In a genome-wide association study of 125,667 white men and women aged 40-69 in the UK Biobank Study, we identify 38 sequence variants with association P-values <5×10-8 with age at first sexual intercourse. Findings were taken forward in up to 241,910 men and women from deCODE Iceland and 20,187 from Women’s Genome Health Study. Several of these loci also exhibit strong associations with behavioural traits (rs4856591 in CADM2 and risk taking propensity: P=4.3×10-10; rs73195303 in MSRA and irritable temperament: P=5.8×10-11) and other reproductive traits (rs67229052 in ESR1 and both age at first birth: P=1.2x10-13 and number of children: P=4.8×10-12; rs2188151 in SEMA3F and age at first birth: P=8.76×10-15). In Mendelian randomisation analyses, we demonstrate likely causal influences of earlier puberty timing on earlier first sexual intercourse, earlier first birth and fewer years of education. In turn, likely causal consequences of earlier first sexual intercourse include reproductive, educational, psychiatric and cardiometabolic outcomes. These findings point to the existence of developmental and neuro-behavioural regulators of reproductive activity and success. PMID:27089180

  12. Retrospective investigation of captive red wolf reproductive success in relation to age and inbreeding.

    PubMed

    Lockyear, K M; Waddell, W T; Goodrowe, K L; MacDonald, S E

    2009-05-01

    The critically endangered red wolf (Canis rufus) has been subject to a strictly managed captive breeding program for three decades. A retrospective demographic analysis of the captive population was performed based on data from the red wolf studbook. Data analyses revealed a decrease in the effective population size relative to the total population size, and changes in age structure and inbreeding coefficients over time. To varying degrees, the probability of successful breeding and litter sizes declined in association with increasing dam age and sire inbreeding coefficients. Neonate survival also declined with increasing dam age. Recent changes in strategies regarding breed-pair recommendations have resulted in moderate increases in reproductive success.

  13. Age-Specific Morbidity among Navy Pilots

    DTIC Science & Technology

    1983-10-01

    categories. Younger pilots have the highest rates for disorders of tooth development and eruption and accidental ...rates among aviation officers for accidental injuries were attributed prim.arily to athletic or sports activities. Comparisons of hospitalizations...important age-specific health problems (i.e., accidental injuries among young pilots and cardiovascular conditions among older pilots). In order for

  14. Male dominance rank, mating and reproductive success in captive bonobos (Pan paniscus).

    PubMed

    Marvan, R; Stevens, J M G; Roeder, A D; Mazura, I; Bruford, M W; de Ruiter, J R

    2006-01-01

    In the recent past, application of DNA genotyping techniques has enabled researchers to more accurately test relationships between dominance rank (DR), mating success (MS) and reproductive success (RS). Paternity studies often reveal that reproductive outcome does not always correlate with male DR and/or MS and thus open room for discussion and interpretation of alternative reproductive tactics of both sexes. In this study, we analysed male DR, MS and RS in a group of bonobos at Twycross Zoo (UK). Genetic relationships were determined using 8 tetrameric microsatellite loci. Despite clear and asymmetric dominance relationships, analysed using normalised David's scores based on a dyadic index of dominance among the group's 3 mature males, we found that the most dominant male did not sire the most offspring. In fact, both infants conceived during the observation period were found to be sired by the lower-ranking males. Although the alpha male had almost exclusive mating access to one of the females during the time she was showing a maximal anogenital swelling, her infant was sired by the lowest-ranking male who mostly mated with her when outside the maximal swelling period. This result suggests that either sperm competition operates and/or ovulation is decoupled from the phase of maximal anogenital swelling which could allow greater female choice.

  15. Host adaptations reduce the reproductive success of Varroa destructor in two distinct European honey bee populations.

    PubMed

    Locke, Barbara; Conte, Yves Le; Crauser, Didier; Fries, Ingemar

    2012-06-01

    Honey bee societies (Apis mellifera), the ectoparasitic mite Varroa destructor, and honey bee viruses that are vectored by the mite, form a complex system of host-parasite interactions. Coevolution by natural selection in this system has been hindered for European honey bee hosts since apicultural practices remove the mite and consequently the selective pressures required for such a process. An increasing mite population means increasing transmission opportunities for viruses that can quickly develop into severe infections, killing a bee colony. Remarkably, a few subpopulations in Europe have survived mite infestation for extended periods of over 10 years without management by beekeepers and offer the possibility to study their natural host-parasite coevolution. Our study shows that two of these "natural" honey bee populations, in Avignon, France and Gotland, Sweden, have in fact evolved resistant traits that reduce the fitness of the mite (measured as the reproductive success), thereby reducing the parasitic load within the colony to evade the development of overt viral infections. Mite reproductive success was reduced by about 30% in both populations. Detailed examinations of mite reproductive parameters suggest these geographically and genetically distinct populations favor different mechanisms of resistance, even though they have experienced similar selection pressures of mite infestation. Compared to unrelated control colonies in the same location, mites in the Avignon population had high levels of infertility while in Gotland there was a higher proportions of mites that delayed initiation of egg-laying. Possible explanations for the observed rapid coevolution are discussed.

  16. Ivermectin alters reproductive success, body condition and sexual trait expression in dung beetles.

    PubMed

    González-Tokman, Daniel; Martínez M, Imelda; Villalobos-Ávalos, Yesenia; Munguía-Steyer, Roberto; Ortiz-Zayas, María Del Rosario; Cruz-Rosales, Magdalena; Lumaret, Jean-Pierre

    2017-07-01

    Ivermectin is a very common parasiticide used in livestock. It is excreted in the dung and has negative effects on survival and reproduction of dung-degrading organisms, including dung beetles. Here we exposed the dung beetle Euoniticellus intermedius to different concentrations of ivermectin in the food and evaluated reproductive success and the expression of traits associated with survival and reproduction under laboratory conditions. It is the first time the effects of ivermectin were evaluated on offspring physiological condition and the expression of a secondary sexual trait. We also registered the number of emerged beetles, sex ratio and body size of emerged adult beetles. Besides reducing the number of emerged beetles and body size, as found in the same and other insects, ivermectin at high doses reduced muscle mass while at intermediate doses it increased lipid mass. Ivermectin changed offspring sex ratio and at high doses increased the size of male horn, which is an important trait defining the male mating success. Our results highlight the importance of regulating parasiticide usage in livestock in order to maintain ecosystem services provided by dung beetles and confirm that contaminants impose new environmental conditions that not only impact on wild animal survival, but also on evolutionary processes such as sexual selection.

  17. Early reproductive success of the hard clam (Mercenaria mercenaria) from Five Sites in Long Island Sound

    SciTech Connect

    Stiles, S.; Choromanski, J.; Nelson, D.; Miller, J.; Greig, R.; Sennefelder, G. )

    1991-09-01

    Early reproductive success of hard clams (Mercenaria mercenaria) in Long Island Sound was measured to determine whether pollution may have adverse effects on fragile recruitment to fisheries. Clams were collected at five sites in 1987 when ready to spawn naturally, along with water from within 39 cm of the bottom. Levels of polychlorinated biphenyls (PCBs), copper, and cadmium were measured in the mature gonad and were found to be generally low. Clams were spawned and the gametes were collected and cultured both in their respective site waters and in reference laboratory seawater. In both site and reference seawater, embryos of clams from the most highly industrialized area (Bridgeport) with higher contaminant levels exhibited more irregularity in chromosome numbers and greater larval abnormality, possible indicators of long-term sublethal effects. Fertilization and early meiotic success at 1 to 1 1/2 h were significantly lower for clams from Norwalk than for those from Greenwich. At 48 h, mortality was lowest for Greenwich larvae and highest for Norwalk larvae in their respective site waters, but the mortality for these two sites was significantly lower than for other sites in reference water. This suggests sporadically poor environmental quality. Milford larvae also had significant mortality. Population-level significance of pollution effects on clam reproduction will depend on how contaminated the environment is over the entire reproductive season of the clams in Long Island Sound, and over how large a portion of the spawning grounds.

  18. A Successful Crayfish Invader Is Capable of Facultative Parthenogenesis: A Novel Reproductive Mode in Decapod Crustaceans

    PubMed Central

    Buřič, Miloš; Hulák, Martin; Kouba, Antonín

    2011-01-01

    Biological invasions are impacting biota worldwide, and explaining why some taxa tend to become invasive is of major scientific interest. North American crayfish species, particularly of the family Cambaridae, are prominent invaders in freshwaters, defying the “tens rule” which states that only a minority of species introduced to new regions become established, and only a minority of those become invasive and pests. So far, success of cambarid invaders has largely been attributed to rapid maturation, high reproductive output, aggressiveness, and tolerance to pollution. We provide experimental evidence that females of one cambarid species particularly widespread in Europe, the spiny-cheek crayfish Orconectes limosus, are capable of facultative parthenogenesis. Such reproductive mode has never before been recognized in decapods, the most diverse crustacean order. As shown by analysis of seven microsatellite loci, crayfish females kept physically separated from males produced genetically homogeneous offspring identical with maternal individuals; this suggests they reproduced by apomixis, unlike those females which mated with males and had a diverse offspring. Further research is needed to clarify what environmental conditions are necessary for a switch to parthenogenesis in O. limosus, and what role it plays in natural crayfish populations. However, if such reproductive plasticity is present in other cambarid crayfish species, it may contribute to the overwhelming invasive success of this group. PMID:21655282

  19. Effect of Testosterone Administration and Spiking on Reproductive Success of Broiler Breeder Flocks.

    PubMed

    Ordas, B; Vahedi, S; Seidavi, A; Rahati, M; Laudadio, V; Tufarelli, V

    2015-10-01

    Age negatively affects reproductive success of broiler breeder flocks. One of the main hormones involved in the change of fertility with the age is testosterone (TT). The introduction of young males at later production stages of broiler flocks is known as spiking and is expected to reduce the fertility decline with age. The aim of this study was to determine the effect of injection of different levels of TT and the effect of spiking on reproductive fitness of broiler breeder flocks. Two experiments were conducted on Ross 308 breeder flocks for 10 weeks (41-50 weeks of age). The experiment 1 included a control and three treatments corresponding to three doses of TT (0.1, 0.2 and 0.3 cc), while the experiment 2 included a control and one treatment corresponding to spiking. The lower dose of TT (0.1 cc) and the spiking clearly slowed down the decline in hatchability. Therefore, either the external administration of TT to the males when the natural concentration of TT starts to decline or spiking the breeder flock with young roosters could contribute to improve reproductive success in later stages of the production cycle in broiler breeder flocks.

  20. Host adaptations reduce the reproductive success of Varroa destructor in two distinct European honey bee populations

    PubMed Central

    Locke, Barbara; Conte, Yves Le; Crauser, Didier; Fries, Ingemar

    2012-01-01

    Honey bee societies (Apis mellifera), the ectoparasitic mite Varroa destructor, and honey bee viruses that are vectored by the mite, form a complex system of host–parasite interactions. Coevolution by natural selection in this system has been hindered for European honey bee hosts since apicultural practices remove the mite and consequently the selective pressures required for such a process. An increasing mite population means increasing transmission opportunities for viruses that can quickly develop into severe infections, killing a bee colony. Remarkably, a few subpopulations in Europe have survived mite infestation for extended periods of over 10 years without management by beekeepers and offer the possibility to study their natural host–parasite coevolution. Our study shows that two of these “natural” honey bee populations, in Avignon, France and Gotland, Sweden, have in fact evolved resistant traits that reduce the fitness of the mite (measured as the reproductive success), thereby reducing the parasitic load within the colony to evade the development of overt viral infections. Mite reproductive success was reduced by about 30% in both populations. Detailed examinations of mite reproductive parameters suggest these geographically and genetically distinct populations favor different mechanisms of resistance, even though they have experienced similar selection pressures of mite infestation. Compared to unrelated control colonies in the same location, mites in the Avignon population had high levels of infertility while in Gotland there was a higher proportions of mites that delayed initiation of egg-laying. Possible explanations for the observed rapid coevolution are discussed. PMID:22833790

  1. A successful crayfish invader is capable of facultative parthenogenesis: a novel reproductive mode in decapod crustaceans.

    PubMed

    Buřič, Miloš; Hulák, Martin; Kouba, Antonín; Petrusek, Adam; Kozák, Pavel

    2011-01-01

    Biological invasions are impacting biota worldwide, and explaining why some taxa tend to become invasive is of major scientific interest. North American crayfish species, particularly of the family Cambaridae, are prominent invaders in freshwaters, defying the "tens rule" which states that only a minority of species introduced to new regions become established, and only a minority of those become invasive and pests. So far, success of cambarid invaders has largely been attributed to rapid maturation, high reproductive output, aggressiveness, and tolerance to pollution. We provide experimental evidence that females of one cambarid species particularly widespread in Europe, the spiny-cheek crayfish Orconectes limosus, are capable of facultative parthenogenesis. Such reproductive mode has never before been recognized in decapods, the most diverse crustacean order. As shown by analysis of seven microsatellite loci, crayfish females kept physically separated from males produced genetically homogeneous offspring identical with maternal individuals; this suggests they reproduced by apomixis, unlike those females which mated with males and had a diverse offspring. Further research is needed to clarify what environmental conditions are necessary for a switch to parthenogenesis in O. limosus, and what role it plays in natural crayfish populations. However, if such reproductive plasticity is present in other cambarid crayfish species, it may contribute to the overwhelming invasive success of this group.

  2. Red-cockaded Woodpecker Picoides borealis Microhabitat Characteristics and Reproductive Success in a Loblolly-Shortleaf Pine Forest

    USGS Publications Warehouse

    Wood, Douglas R.; Burger, L. Wesley; Vilella, Francisco

    2014-01-01

    We investigated the relationship between red-cockaded woodpecker (Picoides borealis) reproductive success and microhabitat characteristics in a southeastern loblolly (Pinus taeda) and shortleaf (P. echinata) pine forest. From 1997 to 1999, we recorded reproductive success parameters of 41 red-cockaded woodpecker groups at the Bienville National Forest, Mississippi. Microhabitat characteristics were measured for each group during the nesting season. Logistic regression identified understory vegetation height and small nesting season home range size as predictors of red-cockaded woodpecker nest attempts. Linear regression models identified several variables as predictors of red-cockaded woodpecker reproductive success including group density, reduced hardwood component, small nesting season home range size, and shorter foraging distances. Red-cockaded woodpecker reproductive success was correlated with habitat and behavioral characteristics that emphasize high quality habitat. By providing high quality foraging habitat during the nesting season, red-cockaded woodpeckers can successfully reproduce within small home ranges.

  3. Does catch and release affect the mating system and individual reproductive success of wild Atlantic salmon (Salmo salar L.)?

    PubMed

    Richard, Antoine; Dionne, Mélanie; Wang, Jinliang; Bernatchez, Louis

    2013-01-01

    In this study, we documented the breeding system of a wild population of Atlantic salmon (Salmo salar L.) by genetically sampling every returning adult and assessed the determinants of individual fitness. We then quantified the impacts of catch and release (C&R) on mating and reproductive success. Both sexes showed high variance in individual reproductive success, and the estimated standardized variance was higher for males (2.86) than for females (0.73). We found a weak positive relationship between body size and fitness and observed that fitness was positively correlated with the number of mates, especially in males. Mature male parr sired 44% of the analysed offspring. The impact of C&R on the number of offspring was size dependent, as the reproductive success of larger fish was more impaired than smaller ones. Also, there was an interactive negative effect of water temperature and air exposure time on reproductive success of C&R salmon. This study improves our understanding of the complex reproductive biology of the Atlantic salmon and is the first to investigate the impact of C&R on reproductive success. Our study expands the management toolbox of appropriate C&R practices that promote conservation of salmon populations and limit negative impacts on mating and reproductive success.

  4. Effects of southern flying squirrels Glaucomys volans on red-cockaded woodpecker Picoides borealis reproductive success

    USGS Publications Warehouse

    Laves, K.S.; Loeb, S.C.

    1999-01-01

    Anecdotal data gathered from many populations suggest that southern flying squirrel (SFS, Glaucomys volans) use of the endangered red-cockaded woodpecker's (RCW, Picoides borealis) nest and roost cavities may negatively affect RCW populations. We conducted a controlled experiment to determine the effects of SFSs on RCW reproductive success. During the 1994 and 1995 breeding seasons, SFSs were removed from 30 RCW clusters and 32 clusters served as controls. SFSs were the most frequently encountered occupants of RCW cavities and used 20-33% of RCW cavities in control and treatment clusters over both years. Treatment groups produced significantly more successful nests (??? 1 fledgling) than control groups in 1994. In 1995 however, there was no difference in the number of successful nests. In both years, RCW groups nesting in treatment clusters produced significantly more fledglings than groups in control clusters in each of four experimental areas, averaging approximately 0.7 additional fledglings per nesting group. Loss of entire clutches or broods, possibly as a result of predation or abandonment, was a major factor limiting reproduction in control groups in 1994. In contrast, differences in partial brood loss appeared to be the cause of differential fledging success in 1995 Usurpation of RCW roost cavities by SFSs may have placed greater energetic demands on RCWs for cavity defence or thermoregulation, thus reducing energy available for reproduction. Our results show that SFS use of RCW cavities during the breeding season has a significant impact on RCWs and that management of RCW populations should include activities that either minimize SFS populations in RCW clusters or limit access of SFSs to RCW cavities.

  5. Successful Pregnancy Following Assisted Reproduction in Woman With Systemic Lupus Erythematosus and Hypertension: A Case Report.

    PubMed

    de Macedo, José Fernando; de Macedo, Gustavo Capinzaiki; Campos, Luciana Aparecida; Baltatu, Ovidiu Constantin

    2015-09-01

    Patients with systemic lupus erythematosus have a poor prognosis of pregnancy, since it is associated with significant maternal and fetal morbidity, including spontaneous miscarriage, pre-eclampsia, intrauterine growth restriction, fetal death and pre-term delivery. We report a case with successful pregnancy in a patient with systemic lupus erythematosus and hypertension. A 39-year-old nulliparous woman presented with systemic lupus erythematosus with antinuclear and antiphospholipid antibodies, hypertension and recurrent pregnancy loss presented for assisted reproduction. The patient responded well to enoxaparin and prednisone during both assisted reproduction and prenatal treatment. This case report indicates that prescription of immunosuppressant and blood thinners can be safely recommended throughout the whole prenatal period in patients with systemic lupus erythematosus. Enoxaparin and prednisone may be prescribed concurrently during pregnancy.

  6. Life histories, blood revenge, and reproductive success among the Waorani of Ecuador

    PubMed Central

    Beckerman, Stephen; Erickson, Pamela I.; Yost, James; Regalado, Jhanira; Jaramillo, Lilia; Sparks, Corey; Iromenga, Moises; Long, Kathryn

    2009-01-01

    The Waorani may have the highest rate of homicide of any society known to anthropology. We interviewed 121 Waorani elders of both sexes to obtain genealogical information and recollections of raids in which they and their relatives participated. We also obtained complete raiding histories of 95 warriors. An analysis of the raiding histories, marital trajectories, and reproductive histories of these men reveals that more aggressive warriors have lower indices of reproductive success than their milder brethren. This result contrasts the findings of Chagnon [Chagnon N (1988) Science 239:985–992] for the Yanomamo. We suggest that the spacing of revenge raids may be involved in the explanation of why the consequences of aggressiveness differ between these 2 warlike lowland South American peoples. PMID:19433797

  7. Reproductive success and nest attentiveness of mallard ducks Anas platyrhynchos fed aroclor 1254

    USGS Publications Warehouse

    Custer, T.W.; Heinz, G.H.

    1980-01-01

    A dietary dosage of 25 ppm Aroclor 1254 fed to 9 mo. old mallards Anas platyrhynchos for at least 1 mo. before egg-laying had no detrimental effect on reproductive success or nest attentiveness when hens were allowed to incubate their own eggs. The treatment caused no effect on number of hens laying, date of 1st egg laid or clutch size. Fertility of eggs was greater among Aroclor-treated birds (87.7%) than among controls (73.2%). Aroclor may have stimulated males to come into reproductive condition sooner than controls. Hatching of fertile eggs and survival of ducklings to 3 wk of age were similar in treated and control groups. The number of times off the nest per day and total time off the nest per day were the same for control and Aroclor-treated hens in days 14-17 of incubation.

  8. Reproductive success and nest attentiveness of mallard ducks fed Aroclor 1254

    USGS Publications Warehouse

    Custer, T.W.; Heinz, G.H.

    1980-01-01

    A dietary dosage of 25 ppm Aroclor 1254 fed to nine-month-old mallards Anas platyrhynchos for at least a month before egg-laying had no detrimental effect on reproductive success or nest attentiveness when hens were allowed to incubate their own eggs. The treatment caused no effect on number of hens laying, date of first egg laid or clutch size. Fertility of eggs was greater among Aroclor-treated birds (87?7%) than among controls (73?2%). Aroclor may have stimulated males to come into reproductive condition sooner than controls. Hatching of fertile eggs and survival of ducklings to 3 weeks of age were similar in treated and control groups. The number of times off the nest per day and total time off the nest per day were the same for control and Aroclor-treated hens in days 14?17 of incubation.

  9. Mojave desert tortoise (Gopherus agassizii) thermal ecology and reproductive success along a rainfall cline.

    PubMed

    Sieg, Annette E; Gambone, Megan M; Wallace, Bryan P; Clusella-Trullas, Susana; Spotila, James R; Avery, Harold W

    2015-05-01

    Desert resource environments (e.g. microclimates, food) are tied to limited, highly localized rainfall regimes which generate microgeographic variation in the life histories of inhabitants. Typically, enhanced growth rates, reproduction and survivorship are observed in response to increased resource availability in a variety of desert plants and short-lived animals. We examined the thermal ecology and reproduction of US federally threatened Mojave desert tortoises (Gopherus agassizii), long-lived and large-bodied ectotherms, at opposite ends of a 250-m elevation-related rainfall cline within Ivanpah Valley in the eastern Mojave Desert, California, USA. Biophysical operative environments in both the upper-elevation, "Cima," and the lower-elevation, "Pumphouse," plots corresponded with daily and seasonal patterns of incident solar radiation. Cima received 22% more rainfall and contained greater perennial vegetative cover, which conferred 5°C-cooler daytime shaded temperatures. In a monitored average rainfall year, Cima tortoises had longer potential activity periods by up to several hours and greater ephemeral forage. Enhanced resource availability in Cima was associated with larger-bodied females producing larger eggs, while still producing the same number of eggs as Pumphouse females. However, reproductive success was lower in Cima because 90% of eggs were depredated versus 11% in Pumphouse, indicating that predatory interactions produced counter-gradient variation in reproductive success across the rainfall cline. Land-use impacts on deserts (e.g. solar energy generation) are increasing rapidly, and conservation strategies designed to protect and recover threatened desert inhabitants, such as desert tortoises, should incorporate these strong ecosystem-level responses to regional resource variation in assessments of habitat for prospective development and mitigation efforts.

  10. The effect of female quality on male ejaculatory expenditure and reproductive success in a praying mantid.

    PubMed

    Jayaweera, Anuradhi; Barry, Katherine L

    2015-01-01

    Strategic ejaculation is a behavioural strategy shown by many animals as a response to sperm competition and/or as a potential mechanism of cryptic male choice. Males invest more mating resources when the risk of sperm competition increases or they invest more in high quality females to maximize their reproductive output. We tested this hypothesis in the false garden mantid Pseudomantis albofimbriata, where females are capable of multiply mating and body condition is an indicator of potential reproductive fitness. We predicted male mantids would ejaculate strategically by allocating more sperm to high quality females. To determine if and how males alter their ejaculate in response to mate quality, we manipulated female food quantity so that females were either in good condition with many eggs (i.e. high quality) or poor condition with few eggs (i.e. low quality). Half of the females from each treatment were used in mating trials in which transferred sperm was counted before fertilisation occurred and the other half of females were used in mating trials where fertilisation occurred and ootheca mass and total eggs in the ootheca were recorded. Opposed to our predictions, the total number of sperm and the proportion of viable sperm transferred did not vary significantly between female treatments. Male reproductive success was entirely dependent on female quality/fecundity, rather than on the number of sperm transferred. These results suggest that female quality is not a major factor influencing postcopulatory male mating strategies in P. albofimbriata, and that sperm number has little effect on male reproductive success in a single mating scenario.

  11. The Effect of Female Quality on Male Ejaculatory Expenditure and Reproductive Success in a Praying Mantid

    PubMed Central

    Jayaweera, Anuradhi; Barry, Katherine L.

    2015-01-01

    Strategic ejaculation is a behavioural strategy shown by many animals as a response to sperm competition and/or as a potential mechanism of cryptic male choice. Males invest more mating resources when the risk of sperm competition increases or they invest more in high quality females to maximize their reproductive output. We tested this hypothesis in the false garden mantid Pseudomantis albofimbriata, where females are capable of multiply mating and body condition is an indicator of potential reproductive fitness. We predicted male mantids would ejaculate strategically by allocating more sperm to high quality females. To determine if and how males alter their ejaculate in response to mate quality, we manipulated female food quantity so that females were either in good condition with many eggs (i.e. high quality) or poor condition with few eggs (i.e. low quality). Half of the females from each treatment were used in mating trials in which transferred sperm was counted before fertilisation occurred and the other half of females were used in mating trials where fertilisation occurred and ootheca mass and total eggs in the ootheca were recorded. Opposed to our predictions, the total number of sperm and the proportion of viable sperm transferred did not vary significantly between female treatments. Male reproductive success was entirely dependent on female quality/fecundity, rather than on the number of sperm transferred. These results suggest that female quality is not a major factor influencing postcopulatory male mating strategies in P. albofimbriata, and that sperm number has little effect on male reproductive success in a single mating scenario. PMID:25970459

  12. Determinants of reproductive success across sequential episodes of sexual selection in a firefly.

    PubMed

    South, A; Lewis, S M

    2012-08-22

    Because females often mate with multiple males, it is critical to expand our view of sexual selection to encompass pre-, peri- and post-copulatory episodes to understand how selection drives trait evolution. In Photinus fireflies, females preferentially respond to males based on their bioluminescent courtship signals, but previous work has shown that male paternity success is negatively correlated with flash attractiveness. Here, we experimentally manipulated both the attractiveness of the courtship signal visible to female Photinus greeni fireflies before mating and male nuptial gift size to determine how these traits might each influence mate acceptance and paternity share. We also measured pericopulatory behaviours to examine their influence on male reproductive success. Firefly males with larger spermatophores experienced dual benefits in terms of both higher mate acceptance and increased paternity share. We found no effect of courtship signal attractiveness or pericopulatory behaviour on male reproductive success. Taken together with previous results, this suggests a possible trade-off for males between producing an attractive courtship signal and investing in nuptial gifts. By integrating multiple episodes of sexual selection, this study extends our understanding of sexual selection in Photinus fireflies and provides insight into the evolution of male traits in other polyandrous species.

  13. Determinants of reproductive success across sequential episodes of sexual selection in a firefly

    PubMed Central

    South, A.; Lewis, S. M.

    2012-01-01

    Because females often mate with multiple males, it is critical to expand our view of sexual selection to encompass pre-, peri- and post-copulatory episodes to understand how selection drives trait evolution. In Photinus fireflies, females preferentially respond to males based on their bioluminescent courtship signals, but previous work has shown that male paternity success is negatively correlated with flash attractiveness. Here, we experimentally manipulated both the attractiveness of the courtship signal visible to female Photinus greeni fireflies before mating and male nuptial gift size to determine how these traits might each influence mate acceptance and paternity share. We also measured pericopulatory behaviours to examine their influence on male reproductive success. Firefly males with larger spermatophores experienced dual benefits in terms of both higher mate acceptance and increased paternity share. We found no effect of courtship signal attractiveness or pericopulatory behaviour on male reproductive success. Taken together with previous results, this suggests a possible trade-off for males between producing an attractive courtship signal and investing in nuptial gifts. By integrating multiple episodes of sexual selection, this study extends our understanding of sexual selection in Photinus fireflies and provides insight into the evolution of male traits in other polyandrous species. PMID:22535779

  14. Canada Geese at the Hanford Site – Trends in Reproductive Success, Migration Patterns, and Contaminant Concentrations

    SciTech Connect

    Simmons, Mary Ann; Poston, Ted M.; Tiller, Brett L.; Stegen, Amanda; Hand, Kristine D.; Brandenberger, Jill M.

    2010-05-25

    Pacific Northwest National Laboratory (PNNL) has conducted several studies for the U.S. Department of Energy (DOE) to evaluate the status and condition of Canada geese on the Hanford Reach of the Columbia River. This report summarizes results of studies of Canada geese (Branta canadensis moffitti) at the Hanford Site dating back to the 1950s. Results include information on the nesting (reproductive) success of Canada geese using the Hanford Reach, review of the local and regional migration of this species using data from bird banding studies, and summary data describing monitoring and investigations of the accumulation of Hanford-derived and environmental contaminants by resident goose populations.

  15. It takes two to tango: reproductive skew and social correlates of male mating success in a lek-breeding bird

    PubMed Central

    Ryder, Thomas B.; Parker, Patricia G.; Blake, John G.; Loiselle, Bette A.

    2009-01-01

    Variance in reproductive success among individuals is a defining characteristic of many social vertebrates. Yet, our understanding of which male attributes contribute to reproductive success is still fragmentary in most cases. Male–male reproductive coalitions, where males jointly display to attract females, are of particular interest to evolutionary biologists because one male appears to forego reproduction to assist the social partner. By examining the relationship between social behaviour and reproductive success, we can elucidate the proximate function of coalitions in the context of mate choice. Here, we use data from a 4-year study of wire-tailed manakins (Pipra filicauda) to provide molecular estimates of reproductive skew and to test the hypothesis that male–male social interactions, in the context of coordinated displays, positively influence a male's reproductive success. More specifically, we quantify male–male social interactions using network metrics and predict that greater connectivity will result in higher relative reproductive success. Our data show that four out of six leks studied had significant reproductive skew, with success apportioned to very few individuals in each lek. Metrics of male social affiliations derived from our network analysis, especially male connectivity, measured as the number of males with whom the focal male has extended interactions, were strong predictors of the number of offspring sired. Thus, network connectivity is associated with male fitness in wire-tailed manakins. This pattern may be the result of shared cues used by both sexes to assess male quality, or the result of strict female choice for coordinated display behaviour. PMID:19324732

  16. Yes we can! Successful examples of disallowing 'conscientious objection' in reproductive health care.

    PubMed

    Fiala, Christian; Gemzell Danielsson, Kristina; Heikinheimo, Oskari; Guðmundsson, Jens A; Arthur, Joyce

    2016-06-01

    Reproductive health care is the only field in medicine where health care professionals (HCPs) are allowed to limit a patient's access to a legal medical treatment - usually abortion or contraception - by citing their 'freedom of conscience.' However, the authors' position is that 'conscientious objection' ('CO') in reproductive health care should be called dishonourable disobedience because it violates medical ethics and the right to lawful health care, and should therefore be disallowed. Three countries - Sweden, Finland, and Iceland - do not generally permit HCPs in the public health care system to refuse to perform a legal medical service for reasons of 'CO' when the service is part of their professional duties. The purpose of investigating the laws and experiences of these countries was to show that disallowing 'CO' is workable and beneficial. It facilitates good access to reproductive health services because it reduces barriers and delays. Other benefits include the prioritisation of evidence-based medicine, rational arguments, and democratic laws over faith-based refusals. Most notably, disallowing 'CO' protects women's basic human rights, avoiding both discrimination and harms to health. Finally, holding HCPs accountable for their professional obligations to patients does not result in negative impacts. Almost all HCPs and medical students in Sweden, Finland, and Iceland who object to abortion or contraception are able to find work in another field of medicine. The key to successfully disallowing 'CO' is a country's strong prior acceptance of women's civil rights, including their right to health care.

  17. Landscape composition, patch size, and distance to edges: Interactions affecting duck reproductive success

    USGS Publications Warehouse

    Horn, David Joseph; Phillips, Michael L.; Koford, Rolf R.; Clark, William R.; Sovada, Marsha A.; Greenwood, Raymond J.

    2005-01-01

    Prairies and other North American grasslands, although highly fragmented, provide breeding habitat for a diverse array of species, including species of tremendous economic and ecological importance. Conservation and management of these species requires some understanding of how reproductive success is affected by edge effects, patch size, and characteristics of the landscape. We examined how differences in the percentage of grassland in the landscape influenced the relationships between the success of nests of upland-nesting ducks and (1) field size and (2) distance to nearest field and wetland edges. We collected data on study areas composed of 15–20% grassland and areas composed of 45–55% grassland in central North Dakota, USA during the 1996 and 1997 nesting seasons. Daily survival rates (DSRs) of duck nests were greater in study areas with 45–55% grassland than with 15–20% grassland. Within study areas, we detected a curvilinear relationship between DSR and field size: DSRs were highest in small and large fields and lowest in moderately sized fields. In study areas with 15–20% grassland, there was no relationship between probability of hatching and distance to nearest field edge, whereas in study areas with 45–55% grassland, there was a positive relationship between these two variables. Results of this study support the conclusion that both landscape composition and configuration affect reproductive success of ground-nesting birds. We are prompted to question conservation strategies that favor clustering moderately sized patches of nesting habitat within agricultural landscapes because our results show that such patches would have low nest success, most likely caused by predation. Understanding the pattern of nest success, and the predator–prey mechanisms that produce the pattern, will enable design of patch configurations that are most conducive to meeting conservation goals.

  18. Ranunculus glacialis L.: successful reproduction at the altitudinal limits of higher plant life.

    PubMed

    Wagner, Johanna; Steinacher, Gerlinde; Ladinig, Ursula

    2010-07-01

    Biodiversity decreases with increasing altitude, mainly because of the increasingly adverse climate. In the European Alps, only a few plant species occur above 4,000 m a.s.l., among these is Ranunculus glacialis L. Current studies have shown that R. glacialis has a highly conservative growth strategy and low developmental plasticity in response to different dates of snowmelt. Therefore, it was of particular interest to observe whether this strategy is maintained at higher altitudes and to reveal the reproductive limits. We examined the effect of the date of snowmelt on reproductive development and reproductive success in R. glacialis over several years at two subnival sites (2,650 and 2,880 m a.s.l.) and at a nival site (3,440 m a.s.l.) in the Austrian Alps. At the subnival sites, reproductive performance was relatively stable (prefloration period, i.e. snowmelt to onset of anthesis, 2-3 weeks; postfloration period, i.e. onset of anthesis until fruit maturity, 4-5 weeks). Depending on the date of flowering, the mean seed/ovule (S/O) ratio was 0.5-0.8. The temporal safety margin between seed maturation and the onset of winter conditions was at least 1 month. The situation was quite different in the nival zone: the prefloration period usually lasted 1 month, anthesis up to 2 weeks, and seed development 6-7 weeks; when seeds matured in time, the S/O ratio was 0.4-0.6. Overall, R. glacialis shows a high developmental plasticity. At higher altitudes, R. glacialis can double the time taken for seed development but runs a high risk of seeds not maturing in time.

  19. Effects of protein supplementation during heifer development on reproductive characteristics and success in beef heifers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 2-yr study was conducted to determine the effects of feeding different protein supplements during heifer development on reproductive traits and performance. Our hypothesis was that protein supplementation would enhance reproductive performance in heifers with below average reproductive characteris...

  20. Effects of pollination limitation and seed predation on female reproductive success of a deceptive orchid.

    PubMed

    Walsh, Ryan P; Arnold, Paige M; Michaels, Helen J

    2014-06-09

    For many species of conservation significance, multiple factors limit reproduction. This research examines the contributions of plant height, number of flowers, number of stems, pollen limitation and seed predation to female reproductive success in the deceit-pollinated orchid, Cypripedium candidum. The deceptive pollination strategy employed by many orchids often results in high levels of pollen limitation. While increased floral display size may attract pollinators, C. candidum's multiple, synchronously flowering stems could promote selfing and also increase attack by weevil seed predators. To understand the joint impacts of mutualists and antagonists, we examined pollen limitation, seed predation and the effects of pollen source over two flowering seasons (2009 and 2011) in Ohio. In 2009, 36 pairs of plants size-matched by flower number, receiving either supplemental hand or open pollination, were scored for fruit maturation, mass of seeds and seed predation. Pollen supplementation increased proportion of flowers maturing into fruit, with 87 % fruit set when hand pollinated compared with 46 % for naturally pollinated flowers. Inflorescence height had a strong effect, as taller inflorescences had higher initial fruit set, while shorter stems had higher predation. Seed predation was seen in 73 % of all fruits. A parallel 2011 experiment that included a self-pollination treatment and excluded seed predators found initial and final fruit set were higher in the self and outcross pollination treatments than in the open-pollinated treatment. However, seed mass was higher in both open pollinated and outcross pollination treatments compared with hand self-pollinated. We found greater female reproductive success for taller flowering stems that simultaneously benefited from increased pollination and reduced seed predation. These studies suggest that this species is under strong reinforcing selection to increase allocation to flowering stem height. Our results may help

  1. Reproductive success of bromadiolone-resistant rats in absence of anticoagulant pressure.

    PubMed

    Heiberg, Ann-Charlotte; Leirs, Herwig; Siegismund, Hans R

    2006-09-01

    Resistance to anticoagulant rodenticides in brown rats (Rattus norvegicus Berk.) is associated with pleiotropic effects, notably with an increased dietary vitamin K requirement. Owing to this disadvantage, resistance is believed to be selected against if anticoagulant selection is absent. In small experimental populations of wild brown rats, an investigation was carried out to establish whether tolerance to anticoagulant exposure changed over a period of 2 years. In the same populations, DNA microsatellite markers were used to infer parentage, and this made it possible to estimate reproductive success of sensitive and resistant rats and estimate effective population size, Ne. Even though there was evidence for a selection against resistant rats with high vitamin K requirement, anticoagulant tolerance was not seen to be significantly influenced in the absence of bromadiolone selection. As the population size under investigation was small, random genetic drift may have played a role in this. In the presence of bromadiolone selection, however, the tolerance was significantly increased, suggesting that continuous selection will increase the proportion of highly resistant rats in the population. It was found that, for both males and females, surprisingly few individuals contributed to the next generation with numerous offspring, and most breeders contributed with none or a single offspring. The expected higher reproductive success and consequent increase in proportional numbers of sensitive rats in the absence of anticoagulant selection could not be observed. Among the resistant rats, moderately resistant females were found to be better breeders than highly resistant breeders, but for resistant males the reverse was true. This could be explained by the fact that the increased vitamin K requirement results in sex differential selection; in highly resistant males the selection presumably takes place at the immature stage, whereas in females the vitamin K requirement

  2. Effects of pollination limitation and seed predation on female reproductive success of a deceptive orchid

    PubMed Central

    Walsh, Ryan P.; Arnold, Paige M.; Michaels, Helen J.

    2014-01-01

    For many species of conservation significance, multiple factors limit reproduction. This research examines the contributions of plant height, number of flowers, number of stems, pollen limitation and seed predation to female reproductive success in the deceit-pollinated orchid, Cypripedium candidum. The deceptive pollination strategy employed by many orchids often results in high levels of pollen limitation. While increased floral display size may attract pollinators, C. candidum's multiple, synchronously flowering stems could promote selfing and also increase attack by weevil seed predators. To understand the joint impacts of mutualists and antagonists, we examined pollen limitation, seed predation and the effects of pollen source over two flowering seasons (2009 and 2011) in Ohio. In 2009, 36 pairs of plants size-matched by flower number, receiving either supplemental hand or open pollination, were scored for fruit maturation, mass of seeds and seed predation. Pollen supplementation increased proportion of flowers maturing into fruit, with 87 % fruit set when hand pollinated compared with 46 % for naturally pollinated flowers. Inflorescence height had a strong effect, as taller inflorescences had higher initial fruit set, while shorter stems had higher predation. Seed predation was seen in 73 % of all fruits. A parallel 2011 experiment that included a self-pollination treatment and excluded seed predators found initial and final fruit set were higher in the self and outcross pollination treatments than in the open-pollinated treatment. However, seed mass was higher in both open pollinated and outcross pollination treatments compared with hand self-pollinated. We found greater female reproductive success for taller flowering stems that simultaneously benefited from increased pollination and reduced seed predation. These studies suggest that this species is under strong reinforcing selection to increase allocation to flowering stem height. Our results may help

  3. Age-specific breeding in Emperor Geese

    USGS Publications Warehouse

    Schmutz, J.A.

    2000-01-01

    I studied the frequency with which Emperor Geese (Chen canagica) of known age were observed breeding on the Yukon-Kuskokwim Delta, Alaska. No one- or two-year old geese were observed on nests. Three-year old geese bred at a lower rate than four-year old geese. These data suggest that patterns of age-specific breeding in Emperor Geese are similar to other sympatrically nesting, large bodied geese [Greater White-fronted Geese (Anser albifrons)] but delayed relative to smaller bodied geese [Cackling Canada Geese (Branta canadensis minima) and Pacific Black Brant (B. bernicla nigricans)].

  4. Age-Specific Correlates of Child Growth.

    PubMed

    Rieger, Matthias; Trommlerová, Sofia Karina

    2016-02-01

    Growth faltering describes a widespread phenomenon that height- and weight-for-age of children in developing countries collapse rapidly in the first two years of life. We study age-specific correlates of child nutrition using Demographic and Health Surveys from 56 developing countries to shed light on the potential drivers of growth faltering. Applying nonparametric techniques and exploiting within-mother variation, we find that maternal and household factors predict best the observed shifts and bends in child nutrition age curves. The documented interaction between age and maternal characteristics further underlines the need not only to provide nutritional support during the first years of life but also to improve maternal conditions.

  5. Reproductive success of barn swallows nesting near a selenium-contaminated lake in east Texas, USA

    USGS Publications Warehouse

    King, K.A.; Custer, T.W.; Weaver, D.A.

    1994-01-01

    Reproductive success and contaminant levels in 1986 and 1987 were compared between Barn Swallows nesting at selenium-contaminated Martin Lake, Texas, USA, and swallows nesting at a reference site. Nests were initiated about the same time or earlier at Martin Lake than at the reference site and clutch size was similar between the two locations. Nest success was significantly higher a Martin Lake than at the reference site and no embryo or chick deformities were documented. Selenium concentrations in 14 of 20 eggs from Martin Lake were above background ( gt 3 ppm, dry weight); two of 20 eggs contained gt 5 ppm, a concentration associated with a 20% embryo mortality/deformity rate in some bird species. Selenium concentrations in the kidneys of adult swallows were higher at Martin Lake (mean = 14 ppm dry weight) than at the reference site (5.8 ppm). DDE, the only detected organochlorine compound, was in two of 10 eggs from Martin Lake; these concentrations were below those associated with chronic poisoning and reproductive problems. The maximum mercury concentration in livers of adult Barn Swallows (0.83 ppm, dry weight) was within the range for background levels ( lt 5 ppm).

  6. Reproductive success of barn swallows nesting near a selenium-contaminated lake in east Texas, USA

    USGS Publications Warehouse

    King, K.A.; Custer, T.W.; Weaver, D.A.

    1994-01-01

    Reproductive success and contaminant levels in 1986 and 1987 were compared between Barn Swallows nesting at selenium-contaminated Martin Lake, Texas, USA, and swallows nesting at a reference site. Nests were initiated about the same time or earlier at Martin Lake than at the reference site and clutch size was similar between the two locations. Nest success was significantly higher at Martin Lake than at the reference site and no embryo or chick deformities were documented. Selenium concentrations in 14 of 20 eggs from Martin Lake were above background (> 3 ppm, dry weight); two of 20 eggs contained > 5 ppm, a concentration associated with a 20% embryo mortality/deformity rate in some bird species. Selenium concentrations in the kidneys of adult swallows were higher at Martin Lake (mean = 14 ppm dry weight) than at the reference site (5.8 ppm). DDE, the only detected organochlorine compound, was in two of 10 eggs from Martin Lake; these concentrations were below those associated with chronic poisoning and reproductive problems. The maximum mercury concentration in livers of adult Barn Swallows (0.83 ppm, dry weight) was within the range for background levels (< 5 ppm).

  7. The relationship between reproductive success and demographic structure in remnant populations of Primula veris

    NASA Astrophysics Data System (ADS)

    Brys, Rein; Jacquemyn, Hans; Endels, Patrick; Hermy, Martin; De Blust, Geert

    2003-12-01

    Plants often suffer reductions in fecundity due to fragmentation, degradation and destruction of populations and their sites. Whether this decrease in seed production has population-level consequences is generally unknown. Here, we aimed to determine the current status of remnant populations in the perennial herb Primula veris in Belgium. Furthermore, we investigated the effects of reduced population size and morph bias on reproductive success and explored if changes in demographic structure could be associated with population fecundity. We studied 69 populations that differed in population size from three to nearly 1500 flowering plants. Three different population types could be distinguished: (a) "dynamic" populations, characterized by high densities of 1 year old juveniles, (b) "normal" populations with adult age-stages prevailing, but still a considerable number of juveniles, and (c) "regressive" populations, in which only flowering adults dominate and rejuvenation hardly occurs. The three population types differed with respect to population size and morph frequency. Dynamic populations were significantly larger and showed a weaker morph bias compared to the intermediate normal and the small regressive populations. Reproductive success, studied the previous year in 26 populations, decreased significantly with decreasing population size and was significantly associated with the demographic structure of the populations. Coefficients of variation for the proportion of flowers setting fruit, the number of seeds per fruit and the total number of seeds per plant decreased significantly with increasing population size. Hence, the observed variability in seed set may be one of the causal factors affecting the observed types of population demographic structure.

  8. Mismatched partners that achieve postpairing behavioral similarity improve their reproductive success

    PubMed Central

    Laubu, Chloé; Dechaume-Moncharmont, François-Xavier; Motreuil, Sébastien; Schweitzer, Cécile

    2016-01-01

    Behavioral similarity between partners is likely to promote within-pair compatibility and to result in better reproductive success. Therefore, individuals are expected to choose a partner that is alike in behavioral type. However, mate searching is very costly and does not guarantee finding a matching partner. If mismatched individuals pair, they may benefit from increasing their similarity after pairing. We show in a monogamous fish species—the convict cichlid—that the behavioral similarity between mismatched partners can increase after pairing. This increase resulted from asymmetrical adjustment because only the reactive individual became more alike its proactive partner, whereas the latter did not change its behavior. The mismatched pairs that increased their similarity not only improved their reproductive success but also raised it up to the level of matched pairs. While most studies assume that assortative mating results from mate choice, our study suggests that postpairing adjustment could be an alternative explanation for the high behavioral similarity between partners observed in the field. It also explains why interindividual behavioral differences can be maintained within a given population. PMID:26973869

  9. Effects of individual and population parameters on reproductive success in three sexually deceptive orchid species.

    PubMed

    Vandewoestijne, S; Róis, A S; Caperta, A; Baguette, M; Tyteca, D

    2009-05-01

    Reproductive success (RS) in orchids in general, and in non-rewarding species specifically, is extremely low. RS is pollinator and pollination limited in food deceptive orchids, but this has rarely been studied in sexually deceptive orchid species. Here, we tested the effects of several individual (plant height, inflorescence size, nearest neighbour distance and flower position) and population (patch geometry, population density and size) parameters on RS in three sexually deceptive Ophrys (Orchidaceae) species. Inter-specific differences were observed in RS of flowers situated in the upper versus the lower part of the inflorescence, likely due to species-specific pollinator behaviour. For all three species examined, RS increased with increasing plant height, inflorescence size and nearest neighbour distance. RS generally increased with decreasing population density and increasing patch elongation. Given these results, we postulate that pollinator availability, rather than pollinator learning, is the most limiting factor in successful reproduction for sexually deceptive orchids. Our results also suggest that olfactory 'display' (i.e. versus optical display), in terms of inflorescence size (and co-varying plant height), plays a key role in individual RS of sexually deceptive orchids. In this regard, several hypotheses are suggested and discussed.

  10. Genotypic variation influences reproductive success and thermal stress tolerance in the reef building coral, Acropora palmata

    NASA Astrophysics Data System (ADS)

    Baums, I. B.; Devlin-Durante, M. K.; Polato, N. R.; Xu, D.; Giri, S.; Altman, N. S.; Ruiz, D.; Parkinson, J. E.; Boulay, J. N.

    2013-09-01

    The branching coral Acropora palmata is a foundation species of Caribbean reefs that has been decimated in recent decades by anthropogenic and natural stressors. Declines in population density and genotypic diversity likely reduce successful sexual reproduction in this self-incompatible hermaphrodite and might impede recovery. We investigated variation among genotypes in larval development under thermally stressful conditions. Six two-parent crosses and three four-parent batches were reared under three temperatures and sampled over time. Fertilization rates differed widely with two-parent crosses having lower fertilization rates (5-56 %, mean 22 % ± 22 SD) than batches (from 31 to 87 %, mean 59 % ± 28 SD). Parentage analysis of larvae in batch cultures showed differences in gamete compatibility among parents, coinciding with significant variation in both sperm morphology and egg size. While all larval batches developed more rapidly at increased water temperatures, rate of progression through developmental stages varied among batches, as did swimming speed. Together, these results indicate that loss of genotypic diversity exacerbates already severe limitations in sexual reproductive success of A. palmata. Nevertheless, surviving parental genotypes produce larvae that do vary in their phenotypic response to thermal stress, with implications for adaptation, larval dispersal and population connectivity in the face of warming sea surface temperatures.

  11. Tropical winter habitat limits reproductive success on the temperate breeding grounds in a migratory bird.

    PubMed Central

    Norris, D. Ryan; Marra, Peter P.; Kyser, T. Kurt; Sherry, Thomas W.; Ratcliffe, Laurene M.

    2004-01-01

    Identifying the factors that control population dynamics in migratory animals has been constrained by our inability to track individuals throughout the annual cycle. Using stable carbon isotopes, we show that the reproductive success of a long-distance migratory bird is influenced by the quality of habitat located thousands of kilometres away on tropical wintering grounds. For male American redstarts (Setophaga ruticilla), winter habitat quality influenced arrival date on the breeding grounds, which in turn affected key variables associated with reproduction, including the number of young fledged. Based on a winter-habitat model, females occupying high-quality winter habitat were predicted to produce more than two additional young and to fledge offspring up to a month earlier compared with females wintering in poor-quality habitat. Differences of this magnitude are highly important considering redstarts are single brooded, lay clutches of only three to five eggs and spend only two-and-a-half months on the breeding grounds. Results from this study indicate the importance of understanding how periods of the annual cycle interact for migratory animals. Continued loss of tropical wintering habitat could have negative effects on migratory populations in the following breeding season, minimizing density-dependent effects on the breeding grounds and leading to further population declines. If conservation efforts are to be successful, strategies must incorporate measures to protect all the habitats used during the entire annual cycle of migratory animals. PMID:15002772

  12. Nectar Robbing Positively Influences the Reproductive Success of Tecomella undulata (Bignoniaceae)

    PubMed Central

    Singh, Vineet Kumar; Barman, Chandan; Tandon, Rajesh

    2014-01-01

    The net consequence of nectar robbing on reproductive success of plants is usually negative and the positive effect is rarely produced. We evaluated the influence of nectar robbing on the behaviour of pollinators and the reproductive success of Tecomella undulata (Bignoniaceae) in a natural population. Experimental pollinations showed that the trees were strictly self-incompatible. The three types of floral colour morphs of the tree viz. red, orange and yellow, lacked compatibility barriers. The pollinators (Pycnonotus cafer and Pycnonotus leucotis) and the robber (Nectarinia asiatica) showed equal preference for all the morphs, as they visited each morph with nearly equal frequency and flower-handling time. The sunbirds caused up to 60% nectar robbing, mostly (99%) by piercing through the corolla tube. Although nectar is replenished at regular intervals, insufficient amount of nectar compelled the pollinators to visit additional trees in bloom. Data of manual nectar robbing from the entire tree showed that the pollinators covered lower number of flowers per tree (5 flowers/tree) and more trees per bout (7 trees/bout) than the unrobbed ones (19 flowers/tree and 2 trees bout). The robbed trees set a significantly greater amount of fruits than the unrobbed trees. However, the number of seeds in a fruit did not differ significantly. The study shows that plant-pollinator-robber interaction may benefit the self-incompatible plant species under conditions that increases the visits of pollinators among the compatible conspecifics in a population. PMID:25036554

  13. Effective gene dispersal and female reproductive success in Mediterranean maritime pine (Pinus pinaster Aiton).

    PubMed

    González-Martínez, Santiago C; Burczyk, Jaroslaw; Nathan, Ran; Nanos, Nikos; Gil, Luis; Alía, Ricardo

    2006-12-01

    Understanding population-scale processes that affect allele frequency changes across generations is a long-standing interest in genetic, ecological and evolutionary research. In particular, individual differences in female reproductive success and the spatial scale of gene flow considerably affect evolutionary change and patterns of local selection. In this study, a recently developed maximum-likelihood (ML) method based on established offspring, the Seedling Neighbourhood Model, was applied and exponentially shaped dispersal kernels were fitted to both genetic and ecological data in a widespread Mediterranean pine, Pinus pinaster Aiton. The distribution of female reproductive success in P. pinaster was very skewed (about 10% of trees mothered 50% of offspring) and significant positive female selection gradients for diameter (gamma = 0.7293) and cone crop (gamma = 0.4524) were found. The selective advantage of offspring mothered by bigger trees could be due to better-quality seeds. These seeds may show more resilience to severe summer droughts and microsite variation related to water and nutrient availability. Both approaches, ecological and of parentage, consistently showed a long-distance dispersal component in saplings that was not found in dispersal kernels based on seed shadows, highlighting the importance of Janzen-Connell effects and microenvironmental variation for survival at early stages of establishment in this Mediterranean key forest tree.

  14. The red-cockaded woodpecker on the Savannah River Site: Aspects of reproductive success.

    SciTech Connect

    Johnston, Peter A; Imm, Donald, W.; Jarvis, William L

    2004-12-31

    Red-cockaded woodpecker; Road to Recovery. Proceedings of the 4th Red-cockaded woodpecker Symposium. Ralph Costa and Susan J. Daniels, eds. Savannah, Georgia. January, 2003. Chapter 5. Status and Trends of Populations. Pp 224-229. Abstract: The red-cockaded woodpecker (Picoides borealis) population on the Savannah River Site has been closely monitored and studied over the last 17 years. In 1985, the USDA Forest Service Southern Research Station was given responsibility to study and manage this population in an effort to prevent its extirpation. In December 1985, there were only 4 individuals on the site: 1 pair and 2 solitary males. The population had increased to a total of 175 individuals in 42 active clusters in 2002. Although this represents a very successful recovery effort, there has been substantial annual variation in nesting survival from banding to fledging. Data were analyzed to more completely understand the factors affecting reproduction. No significant effects of age of the breeding male and female, years paired, number of helpers, habitat quality, number of nestings, and time of nest initiation were found when comparing reproductive success in 117 nesting attempts from 1999 to 2002. However, the number of neighboring groups had a direct effect on mortality rates, possibly demonstrating the importance of cluster spacing.

  15. Native pollen thieves reduce the reproductive success of a hermaphroditic plant, Aloe maculata.

    PubMed

    Hargreaves, Anna L; Harder, Lawrence D; Johnson, Steven D

    2010-06-01

    Pollen is unique among floral rewards in functioning as both a carrier of gametes and an attractant and nutritious resource for floral visitors. Animals that collect pollen without pollinating (pollen thieves) could reduce siring success of thieved plants and cause pollen limitation of seed set at the population level; however, such impacts on plant reproduction have not been demonstrated experimentally. To test these effects we added hives of native honey bees (Apis mellifera scutellata) to populations of a primarily bird-pollinated plant, Aloe maculata, in eastern South Africa. In field and aviary trials, bee addition increased pollen removal from anthers but decreased pollen deposition on stigmas, and so reduced both male and female pollination components. Further, total seed production decreased with hive addition in the aviary experiment and in three of four field populations, indicating that population-level pollen theft can also compromise reproductive success. In the field, naturally occurring allodapine bees also seemed to act as pollen thieves, outweighing the effect of honey bee hive addition at one of the four aloe populations. Our results highlight the importance of social bees as pollen thieves, even of plants that have evolved in their presence, and the role of dichogamy in promoting pollen theft. Given the commonness of both social bees and dichogamy, pollen theft is likely a much more common influence on floral ecology and evolution than suggested by the sparse literature.

  16. Factors affecting reproductive success in three entomophilous orchid species in Hungary.

    PubMed

    Vojtkó, Anna E; Sonkoly, Judit; Lukács, Balázs András; Molnár V, Attila

    2015-06-01

    The reproductive success of orchids is traditionally estimated by determining the fruit-set of individuals. Here, we investigated both the fruit and the seed production of three orchid species and the factors that may affect individual fruit-set, like pollination strategy, individual traits or the annual amount of precipitation. The species [Dactylorhiza sambucina (L.) Soó, Dactylorhiza majalis (Rchb.) P. F. Hunt & Summerhayes and Platanthera bifolia (L.) L. C. M. Richard] were studied in three consecutive years (2010-2012) in the Bükk Mountains, Hungary. All three species were proved to be non-autogamous by a bagging experiment. Data analyses showed significant differences between seed numbers but not between fruit-sets of species. There was no statistical difference in individual reproductive success between wet and dry years, however, the effect of the annual amount of precipitation is significant on the population level. Comparison of published fruit-set data revealed accordance with our results in P. bifolia, but not in D. sambucina and D. majalis. We assume that the surprisingly high fruit-set values of the two Dactylorhiza species may be due to the fact that the pollination crisis reported from Western European countries is not an actual problem in the Bükk Mountains, Hungary.

  17. Off-road vehicles affect nesting behaviour and reproductive success of American Oystercatchers Haematopus palliatus

    USGS Publications Warehouse

    Borneman, Tracy E.; Rose, Eli T.; Simons, Theodore R.

    2016-01-01

    As human populations and associated development increase, interactions between humans and wildlife are occurring with greater frequency. The effects of these interactions, particularly on species whose populations are declining, are of great interest to ecologists, conservationists, land managers and natural resource policy-makers. The American Oystercatcher Haematopus palliatus, a species of conservation concern in the USA, nests on coastal beaches subject to various forms of anthropogenic disturbance, including aircraft overflights, off-road vehicles and pedestrians. This study assessed the effects of these human disturbances on the incubation behaviour and reproductive success of nesting American Oystercatchers at Cape Lookout National Seashore, on the Atlantic coast of the USA. We expanded on-going monitoring of Oystercatchers at Cape Lookout National Seashore by supplementing periodic visual observations with continuous 24-h video and audio recording at nests. Aircraft overflights were not associated with changes in Oystercatcher incubation behaviour, and we found no evidence that aircraft overflights influenced Oystercatcher reproductive success. However, Oystercatchers were on their nests significantly less often during off-road vehicle and pedestrian events than they were during control periods before the events, and an increase in the number of off-road vehicles passing a nest during incubation was consistently associated with significant reductions in daily nest survival (6% decrease in daily nest survival for a one-vehicle increase in the average number of vehicles passing a nest each day; odds ratio = 0.94; 95% confidence interval (CI) 0.90, 0.98) and hatching success (12% decrease in hatching success for a one-vehicle increase in the average number of vehicles passing a nest each day; odds ratio = 0.88; 95% CI 0.76, 0.97). Management of vehicles and pedestrians in areas of Oystercatcher breeding is important for the conservation of American

  18. Are hotshots always hot? A longitudinal study of hormones, behavior, and reproductive success in male marine iguanas.

    PubMed

    Vitousek, Maren N; Rubenstein, Dustin R; Nelson, Karin N; Wikelski, Martin

    2008-07-01

    Polygynous lek-mating systems are characterized by high reproductive skew, with a small number of males gaining a disproportionate share of copulations. In lekking species, where female choice drives male mating success and patterns of reproductive skew, female preferences for 'good genes' should lead to preferred males having high reproductive success in all years. Here we investigate whether these 'hotshot' males have steroid hormone patterns that are consistent over time (between two mating seasons), and whether hormone levels consistently predict display behavior. We test these questions in the Galápagos marine iguana (Amblyrhynchus cristatus), a lekking vertebrate with high male reproductive skew. We found that male mating success and testosterone levels were not consistent across years. The most successful males showed an inverse relationship in copulation success between years. Similarly, territorial males that had high testosterone in one year had low levels in the next. Across years, testosterone was strongly associated with head-bob display, suggesting that this steroid plays a key role in mate attraction. These results suggest that female marine iguanas are not choosing the same 'hotshot' males in every year, but instead base their reproductive decisions on male behavioral traits that are hormonally mediated and variable across years. By using testosterone to regulate their costly display behaviors male marine iguanas appear to have a mechanism that allows them to adjust their reproductive effort depending on extrinsic and/or intrinsic factors.

  19. Sex-biased inbreeding effects on reproductive success and home range size of the critically endangered black rhinoceros.

    PubMed

    Cain, Bradley; Wandera, Antony B; Shawcross, Susan G; Edwin Harris, W; Stevens-Wood, Barry; Kemp, Stephen J; Okita-Ouma, Benson; Watts, Phillip C

    2014-04-01

    A central premise of conservation biology is that small populations suffer reduced viability through loss of genetic diversity and inbreeding. However, there is little evidence that variation in inbreeding impacts individual reproductive success within remnant populations of threatened taxa, largely due to problems associated with obtaining comprehensive pedigree information to estimate inbreeding. In the critically endangered black rhinoceros, a species that experienced severe demographic reductions, we used model selection to identify factors associated with variation in reproductive success (number of offspring). Factors examined as predictors of reproductive success were age, home range size, number of nearby mates, reserve location, and multilocus heterozygosity (a proxy for inbreeding). Multilocus heterozygosity predicted male reproductive success (p< 0.001, explained deviance >58%) and correlated with male home range size (p < 0.01, r(2) > 44%). Such effects were not apparent in females, where reproductive success was determined by age (p < 0.01, explained deviance 34%) as females raise calves alone and choose between, rather than compete for, mates. This first report of a 3-way association between an individual male's heterozygosity, reproductive output, and territory size in a large vertebrate is consistent with an asymmetry in the level of intrasexual competition and highlights the relevance of sex-biased inbreeding for the management of many conservation-priority species. Our results contrast with the idea that wild populations of threatened taxa may possess some inherent difference from most nonthreatened populations that necessitates the use of detailed pedigrees to study inbreeding effects. Despite substantial variance in male reproductive success, the increased fitness of more heterozygous males limits the loss of heterozygosity. Understanding how individual differences in genetic diversity mediate the outcome of intrasexual competition will be

  20. Winter habitat quality but not long-distance dispersal influences apparent reproductive success in a migratory bird.

    PubMed

    Rushing, Clark S; Marra, Peter P; Dudash, Michele R

    2016-05-01

    Long-distance breeding and natal dispersal play central roles in many ecological and evolutionary processes, including gene flow, population dynamics, range expansion, and individual responses to fluctuating biotic and abiotic conditions. However, the relative contribution of long-distance dispersal to these processes depends on the ability of dispersing individuals to successfully reproduce in their new environment. Unfortunately, due to the difficulties associated with tracking dispersal in the field, relatively little is known about its reproductive consequences. Furthermore, because reproductive success is influenced by a variety of processes, disentangling the influence of each of these processes is critical to understanding the direct consequences of dispersal. In this study, we used stable hydrogen and carbon isotopes to estimate long-distance dispersal and winter territory quality in a migratory bird, the American Redstart (Setophaga ruticilla). We then applied Aster life-history models to quantify the strength of influence of these factors on apparent reproductive success. We found no evidence that male or female reproductive success was lower for long-distance dispersers relative to non-dispersing individuals. In contrast, carry-over effects from the winter season did influence male, but not female, reproductive success. Use of Aster models further revealed that for adult males, winter territory quality influenced the number of offspring produced whereas for yearling males, high-quality winter territories were associated with higher mating and nesting success. These results suggest that although long-distance natal and breeding dispersal carry no immediate reproductive cost for American Redstarts, reproductive success in this species may ultimately be limited by the quality of winter habitat.

  1. Parasites of the shore crab Carcinus maenas (L.): implications for reproductive potential and invasion success.

    PubMed

    Zetlmeisl, C; Hermann, J; Petney, T; Glenner, H; Griffiths, C; Taraschewski, H

    2011-03-01

    The European shore crab, Carcinus maenas, is one of the most successful marine invasive species. Its success has been in part attributed to the loss of parasites, rekindling an interest in host-parasite interactions and impacts on host fitness in this crab. In the present study, we investigated C. maenas populations from Europe, South Africa and Australia for parasites, and assessed their impact on the fitness of male crabs. For the shore crab, testes weight along with success in mating competition is traded off against other life-history traits. We therefore used this parameter as an indicator both for reproductive fitness and a possible resource trade-off in response to parasite infestation. In the native range, crabs infested with Sacculina carcini showed significantly lower testes weight than uninfected crabs. However, helminth parasites did not generally cause reduced testes weights. Crab populations from South Africa and Australia were either parasitized at very low prevalences, or were completely parasite free. However, no population level effect of this parasite release was reflected in testes weight. These findings do not support a severe fitness impact of helminth parasites on C. maenas, which questions the role of parasites on its population dynamics, both in the native area and for invasive success.

  2. Effects of chronic irradiation on the reproductive success of the polychaete worm, Neanthes arenaceodentata.

    PubMed

    Harrison, F L; Anderson, S L

    1994-12-01

    Effects of lifetime exposure to chronic irradiation on reproductive success were assessed for laboratory populations of Neanthes arenaceodentata. Exposure was initiated upon the spawning of the parental (P1) female and was terminated upon spawning of the first filial (F1) generation female; broods from the F1 pairs were sacrificed before hatching occurred. Groups of worms in the experiments received either no radiation (controls) or 0.19, 2.1 or 17 mGy h-1. The total dose received was either background or approximately 0.55, 6.5 or 54 Gy, respectively. The mean number of embryos in the broods from the F1 females exposed to 17 mGy h-1 was statistically significantly different from the mean number of embryos from control females; however, the mean number of embryos in the broods from the F1 females exposed to 0.19 and 2.1 mGy h-1 was not significantly different from the mean number from control females. For all the radiation-exposed groups, there was a statistically significant reduction in the number and percentage of live embryos in the broods from the F1 pairs as well as a statistically significant increase in the numbers and percentages of abnormal embryos. Results on embryo abnormalities and mortalities indicate that dominant- and recessive-lethal mutations were most likely induced in the germ cells and that these mutations had an adverse effect on reproductive success by affecting the survival of early-life stages. Except for pairs exposed to 17 mGy h-1, there was no evidence of gamete killing or reduced fertilization success, because the number of developing embryos in the broods did not decrease with increased dose. Data for the estimated hatch number and actual hatch number indicated that doses as low as 0.19 mGy h-1 can reduce significantly the number of larvae that hatch when lifetime doses are given.

  3. The influence of female age on male mating preference and reproductive success in cabbage beetle, Colaphellus bowringi.

    PubMed

    Liu, Xing-Ping; He, Hai-Min; Xue, Fang-Sen

    2014-08-01

    The influence of female age on male mating preference and reproductive success has been studied using a promiscuous cabbage beetle, Colaphellus bowringi Baly (Coleoptera: Chrysomelidae). In a simultaneous choice test, middle-aged females had significantly greater mating success than young and old females. In single pair trials, when paired with middle-aged virgin males, middle-aged females mated faster, copulated longer, and had greater fecundity and fertility than young or old females, while the longevity of males was not significantly affected by female age. This study on C. bowringi suggests that middle-aged females are more receptive to mating, which can result in the highest male reproductive success.

  4. Effects of contaminants on reproductive success of aquatic birds nesting at Edwards Air Force Base, California

    USGS Publications Warehouse

    Hothem, R.L.; Crayon, J.J.; Law, M.A.

    2006-01-01

    Contamination by organochlorine pesticides (OCs), polychlorinated biphenyls, metals, and trace elements at Edwards Air Force Base (EAFB), located in the Mojave Desert, could adversely affect nesting aquatic birds, especially at the sewage lagoons that comprise Piute Ponds. Estimates of avian reproduction, in conjunction with analyses of eggs and avian foods for contaminant residues, may indicate the potential for negative effects on avian populations. From 1996 to 1999, we conducted studies at the Piute Ponds area of EAFB to evaluate the impacts of contaminants on nesting birds. Avian reproduction was evaluated in 1999. Eggs were collected for chemical analyses in 1996 and 1999, and African clawed frogs (Xenopus laevis), a likely food source, were collected for chemical analyses in 1998. Avian species occupying the higher trophic levels-black-crowned night-heron (Nycticorax nycticorax), white-faced ibis (Plegadis chihi), and American avocet (Recurvirostra americana)-generally bioaccumulated higher concentrations of contaminants in their eggs. Reproductive success and egg hatchability of night-herons and white-faced ibises in the Piute Ponds were similar to results observed at other western colonies. Deformities were observed in only one embryo in this study, but concentrations of contaminants evaluated in this ibis embryo were considered insufficient to have caused the deformities. Because clawed frogs, a primary prey item for night-herons at Piute Ponds, had no detectable levels of any OCs, it is likely that OCs found in night-heron eggs were acquired from the wintering grounds rather than from EAFB. The presence of isomers of dichlorodiphenyltrichloroethane (DDT) in ibis eggs indicated recent exposure, but invertebrates used for food by ibises were not sampled at Piute Ponds, and conclusions about the source of OCs in ibis eggs could not be made. Concentrations of contaminants in random and failed eggs of individual species were not different, and we concluded

  5. Facultative Apomixis in Garcinia atroviridis (Clusiaceae) and Effects of Different Pollination Regimes on Reproductive Success.

    PubMed

    Pangsuban, Sasithorn; Bamroongrugsa, Noparat; Kanchanapoom, Kamnoon; Nualsri, Charassri

    2009-12-01

    Various aspects of the reproductive success of Garcinia atroviridis Griff. were studied. Controlled pollination experiments were carried out in an orchard located in Songkhla province, southern Thailand, from February to July 2003. Floral longevity, stigma receptivity, and pollen viability were examined before carrying out the experiments. Three pollination treatments were compared: open pollination, manual pollination with bags, and bags without pollination (apogamy). Although there was no significant difference in the initial fruit set, bagged and manual pollination produced a significantly greater fruit drop rate than apogamy or natural pollination at one week after the flowers had been pollinated. On the other hand, the apogamy treatment had a greater fruit drop rate than natural and manual pollination treatments before fruit maturation. In addition, unpollinated bagged flowers bore fewer and smaller fruit than naturally and manually cross-pollinated flowers. Although the fruits from unpollinated flowers were capable of asexual seed formation, they produced fewer seeds and had poorer seed quality (defined as average fresh weight and germination rate) than those from the other treatments. The occurrence of asexual and sexual reproduction was also studied using Random Amplification of Polymorphic DNA (RAPD) analysis and by comparing the patterns of bands produced from DNA extracted from the offspring of the naturally cross-pollinated fruits. On average, 58% of the offspring had a genetic constitution identical to that of the maternal parent (ranging from 36% to 87%), indicating that some offspring were produced without prior fertilisation. However, the remainder showed polymorphism, demonstrating the occurrence of sexual reproduction. These findings indicate that facultative apomixis occurred in the study population. However, a residual sexuality was important for fruit production, fruit size, normal seed set and seed quality.

  6. Effects of contaminants on reproductive success of aquatic birds nesting at Edwards Air Force Base, California.

    PubMed

    Hothem, R L; Crayon, J J; Law, M A

    2006-11-01

    Contamination by organochlorine pesticides (OCs), polychlorinated biphenyls, metals, and trace elements at Edwards Air Force Base (EAFB), located in the Mojave Desert, could adversely affect nesting aquatic birds, especially at the sewage lagoons that comprise Piute Ponds. Estimates of avian reproduction, in conjunction with analyses of eggs and avian foods for contaminant residues, may indicate the potential for negative effects on avian populations. From 1996 to 1999, we conducted studies at the Piute Ponds area of EAFB to evaluate the impacts of contaminants on nesting birds. Avian reproduction was evaluated in 1999. Eggs were collected for chemical analyses in 1996 and 1999, and African clawed frogs (Xenopus laevis), a likely food source, were collected for chemical analyses in 1998. Avian species occupying the higher trophic levels--black-crowned night-heron (Nycticorax nycticorax), white-faced ibis (Plegadis chihi), and American avocet (Recurvirostra americana)--generally bioaccumulated higher concentrations of contaminants in their eggs. Reproductive success and egg hatchability of night-herons and white-faced ibises in the Piute Ponds were similar to results observed at other western colonies. Deformities were observed in only one embryo in this study, but concentrations of contaminants evaluated in this ibis embryo were considered insufficient to have caused the deformities. Because clawed frogs, a primary prey item for night-herons at Piute Ponds, had no detectable levels of any OCs, it is likely that OCs found in night-heron eggs were acquired from the wintering grounds rather than from EAFB. The presence of isomers of dichlorodiphenyltrichloroethane (DDT) in ibis eggs indicated recent exposure, but invertebrates used for food by ibises were not sampled at Piute Ponds, and conclusions about the source of OCs in ibis eggs could not be made. Concentrations of contaminants in random and failed eggs of individual species were not different, and we concluded

  7. Delayed breeding affects lifetime reproductive success differently in male and female green woodhoopoes.

    PubMed

    Hawn, Amanda T; Radford, Andrew N; du Plessis, Morné A

    2007-05-15

    In cooperatively breeding species, many individuals only start breeding long after reaching physiological maturity [1], and this delay is expected to reduce lifetime reproductive success (LRS) [1-3]. Although many studies have investigated how nonbreeding helpers might mitigate the assumed cost of delayed breeding (reviewed in [3]), few have directly quantified the cost itself [4, 5] (but see [6, 7]). Moreover, although life-history tradeoffs frequently influence the sexes in profoundly different ways [8, 9], it has been generally assumed that males and females are similarly affected by a delayed start to breeding [7]. Here, we use 24 years of data to investigate the sex-specific cost of delayed breeding in the cooperatively breeding green woodhoopoe (Phoeniculus purpureus) and show that age at first breeding is related to LRS differently in males and females. As is traditionally expected, males that started to breed earlier in life had greater LRS than those that started later. However, females showed the opposite pattern: Those individuals that started to breed later in life actually had greater LRS than those that started earlier. In both sexes, the association between age at first breeding and LRS was driven by differences in breeding-career length, rather than per-season productivity. We hypothesize that the high mortality rate of young female breeders, and thus their short breeding careers, is related to a reduced ability to deal with the high physiological costs of reproduction in this species. These results demonstrate the importance of considering sex-specific reproductive costs when estimating the payoffs of life-history decisions and bring into question the long-held assumption that delayed breeding is necessarily costly.

  8. Scale Dependence of Female Ungulate Reproductive Success in Relation to Nutritional Condition, Resource Selection and Multi-Predator Avoidance

    PubMed Central

    Duquette, Jared F.; Belant, Jerrold L.; Svoboda, Nathan J.; Beyer, Dean E.; Lederle, Patrick E.

    2015-01-01

    Female ungulate reproductive success is dependent on the survival of their young, and affected by maternal resource selection, predator avoidance, and nutritional condition. However, potential hierarchical effects of these factors on reproductive success are largely unknown, especially in multi-predator landscapes. We expanded on previous research of neonatal white-tailed deer (Odocoileus virginianus) daily survival within home ranges to assess if resource use, integrated risk of 4 mammalian predators, maternal nutrition, winter severity, hiding cover, or interactions among these variables best explained landscape scale variation in daily or seasonal survival during the post-partum period. We hypothesized that reproductive success would be limited greater by predation risk at coarser spatiotemporal scales, but habitat use at finer scales. An additive model of daily non-ideal resource use and maternal nutrition explained the most (69%) variation in survival; though 65% of this variation was related to maternal nutrition. Strong support of maternal nutrition across spatiotemporal scales did not fully support our hypothesis, but suggested reproductive success was related to dam behaviors directed at increasing nutritional condition. These behaviors were especially important following severe winters, when dams produced smaller fawns with less probability of survival. To increase nutritional condition and decrease wolf (Canis lupus) predation risk, dams appeared to place fawns in isolated deciduous forest patches near roads. However, this resource selection represented non-ideal resources for fawns, which had greater predation risk that led to additive mortalities beyond those related to resources alone. Although the reproductive strategy of dams resulted in greater predation of fawns from alternative predators, it likely improved the life-long reproductive success of dams, as many were late-aged (>10 years old) and could have produced multiple litters of fawns. Our

  9. Scale Dependence of Female Ungulate Reproductive Success in Relation to Nutritional Condition, Resource Selection and Multi-Predator Avoidance.

    PubMed

    Duquette, Jared F; Belant, Jerrold L; Svoboda, Nathan J; Beyer, Dean E; Lederle, Patrick E

    2015-01-01

    Female ungulate reproductive success is dependent on the survival of their young, and affected by maternal resource selection, predator avoidance, and nutritional condition. However, potential hierarchical effects of these factors on reproductive success are largely unknown, especially in multi-predator landscapes. We expanded on previous research of neonatal white-tailed deer (Odocoileus virginianus) daily survival within home ranges to assess if resource use, integrated risk of 4 mammalian predators, maternal nutrition, winter severity, hiding cover, or interactions among these variables best explained landscape scale variation in daily or seasonal survival during the post-partum period. We hypothesized that reproductive success would be limited greater by predation risk at coarser spatiotemporal scales, but habitat use at finer scales. An additive model of daily non-ideal resource use and maternal nutrition explained the most (69%) variation in survival; though 65% of this variation was related to maternal nutrition. Strong support of maternal nutrition across spatiotemporal scales did not fully support our hypothesis, but suggested reproductive success was related to dam behaviors directed at increasing nutritional condition. These behaviors were especially important following severe winters, when dams produced smaller fawns with less probability of survival. To increase nutritional condition and decrease wolf (Canis lupus) predation risk, dams appeared to place fawns in isolated deciduous forest patches near roads. However, this resource selection represented non-ideal resources for fawns, which had greater predation risk that led to additive mortalities beyond those related to resources alone. Although the reproductive strategy of dams resulted in greater predation of fawns from alternative predators, it likely improved the life-long reproductive success of dams, as many were late-aged (>10 years old) and could have produced multiple litters of fawns. Our

  10. Evaluating endocrine endpoints relative to reproductive success in Japanese quail exposed to estrogenic chemicals [poster

    USGS Publications Warehouse

    Henry, P.F.P.; Russek-Cohen, E.; Casey, C.S.; Abdelnabi, M.A.; Ottinger, M.A.

    2000-01-01

    The standard US EPA guidelines for avian reproductive testing may not be sufficiently sensitive to detect effects of sublethal and chronic exposure to endocrine disrupting toxins. There is a need to evaluate endocrine endpoints as potential markers for contaminant effects, and to determine their effectiveness and sensitivity when applied to wildlife. To this end, a three generational test was conducted using the Japanese quail (Coturnix japonica) and a proven estrogenic PCB. Birds were exposed during embryonic development via maternal deposition and/or direct egg injection at day 4. Standard measures of reproductive success and productivity used in toxicological studies, as well as multiple measures of physiological and behavioral responses used in endocrine studies were collected. Long term effects on growth and apparent development were similar between treated and control offspring. Fertility of treated eggs decreased from 75%+ 4.4 (x + se) for P1, to 59% + 12.5 for F1 and 54% + 14.2 for F2. All paired control birds mated to produce viable eggs, whereas 27 % of the F1 and 41 % of the F2 treated pairs failed to produce at least 1 viable egg. Although some decreases in productivity can be related to direct toxic exposure, the response from one generation to the next was not linear with treatment, indicating a potential effect from behavioral or other endocrine alterations.

  11. Lifetime reproductive success is maximized with optimal major histocompatibility complex diversity

    PubMed Central

    Kalbe, Martin; Eizaguirre, Christophe; Dankert, Ilka; Reusch, Thorsten B.H.; Sommerfeld, Ralf D.; Wegner, K. Mathias; Milinski, Manfred

    2008-01-01

    Individual diversity at the major histocompatibility complex (MHC) is predicted to be optimal at intermediate rather than at maximal levels. We showed previously in sticklebacks that an intermediate MHC diversity is predominant in natural populations and provides maximal resistance in experimental multiple parasite infections in the laboratory. However, what counts ultimately is the lifetime reproductive success (LRS). Here, we measured LRS of six laboratory-bred sib-groups—to minimize the influence of non-MHC genes—three-spined sticklebacks (Gasterosteus aculeatus) during their entire breeding period, each in a seminatural enclosure in the lake of their parents, where they were exposed to the natural spectrum of parasites. We collected developing clutches at regular intervals and determined parenthood for a representative number of eggs (2279 in total) per clutch with 18 microsatellites. Both males and females with an intermediate MHC class IIB variant number had the highest LRS. The mechanistic link of MHC diversity and LRS differed between the sexes: in females, we found evidence for a trade-off between number of eggs and immunocompentence, whereas in males this correlation was concealed by different timing strategies of reproduction. PMID:19033141

  12. Lifetime Number of Mates Interacts with Female Age to Determine Reproductive Success in Female Guppies

    PubMed Central

    Evans, Jonathan P.

    2012-01-01

    In many species, mating with multiple males confers benefits to females, but these benefits may be offset by the direct and indirect costs associated with elevated mating frequency. Although mating frequency (number of mating events) is often positively associated with the degree of multiple mating (actual number of males mated), most studies have experimentally separated these effects when exploring their implications for female fitness. In this paper I describe an alternative approach using the guppy Poecilia reticulata, a livebearing freshwater fish in which females benefit directly and indirectly from mating with multiple males via consensual matings but incur direct and indirect costs of mating as a consequence of male sexual harassment. In the present study, females were experimentally assigned different numbers of mates throughout their lives in order to explore how elevated mating frequency and multiple mating combine to influence lifetime reproductive success (LRS) and survival (i.e. direct components of female fitness). Under this mating design, survival and LRS were not significantly affected by mating treatment, but there was a significant interaction between brood size and reproductive cycle (a correlate of female age) because females assigned to the high mating treatment produced significantly fewer offspring later in life compared to their low-mating counterparts. This negative effect of mating treatment later in life may be important in these relatively long-lived fishes, and this effect may be further exacerbated by the known cross-generational fitness costs of sexual harassment in guppies. PMID:23071816

  13. Canalization of body size matters for lifetime reproductive success of male predatory mites (Acari: Phytoseiidae)

    PubMed Central

    Walzer, Andreas; Schausberger, Peter

    2014-01-01

    The adaptive canalization hypothesis predicts that highly fitness-relevant traits are canalized via past selection, resulting in low phenotypic plasticity and high robustness to environmental stress. Accordingly, we hypothesized that the level of phenotypic plasticity of male body size of the predatory mites Phytoseiulus persimilis (low plasticity) and Neoseiulus californicus (high plasticity) reflects the effects of body size variation on fitness, especially male lifetime reproductive success (LRS). We first generated small and standard-sized males of P. persimilis and N. californicus by rearing them to adulthood under limited and ample prey supply, respectively. Then, adult small and standard-sized males were provided with surplus virgin females throughout life to assess their mating and reproductive traits. Small male body size did not affect male longevity or the number of fertilized females but reduced male LRS of P. persimilis but not N. californicus. Proximately, the lower LRS of small than standard-sized P. persimilis males correlated with shorter mating durations, probably decreasing the amount of transferred sperm. Ultimately, we suggest that male body size is more strongly canalized in P. persimilis than N. californicus because deviation from standard body size has larger detrimental fitness effects in P. persimilis than N. californicus. © 2014 The Authors. Biological Journal of the Linnean Society published by John Wiley & Sons Ltd on behalf of The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 889–899. PMID:25132689

  14. Vacuoles in sperm head are not associated with head morphology, DNA damage and reproductive success.

    PubMed

    Fortunato, Adriana; Boni, Raffaele; Leo, Rita; Nacchia, Giuseppina; Liguori, Francesca; Casale, Sofia; Bonassisa, Paolo; Tosti, Elisabetta

    2016-02-01

    In this retrospective study of 873 men enrolled for assisted reproduction techniques, relationships between sperm quality parameters, motile sperm organelle morphology examination (MSOME), DNA damage and live birth rate were evaluated. The presence of vacuoles in the sperm heads was detected by MSOME. Either chromatin decondensation or DNA fragmentation was used to study DNA damage. Results show that age significantly affected some of the examined parameters. In particular, sperm concentration was positively correlated (R = 0.088; P = 0.01) and chromatin decondensation was negatively correlated (R = -0.102; P = 0.003) with age. Furthermore, live birth rate was significantly lower in men aged 40 years or older (P < 0.02) compared with the younger age groups. The presence of sperm head vacuoles was not associated with head morphology, main sperm quality parameters, DNA fragmentation and live birth rate. Considering sperm heads in relation to the shape (normal/abnormal) and vacuoles (presence/absence), no significant variations in the occurrence of vacuoles in either normal or abnormal heads were found. These data suggest that vacuoles are physiological features that do not alter sperm functionality, and it seems that MSOME is not necessary for increasing the success of assisted reproduction techniques.

  15. The generalist Inga subnuda subsp. luschnathiana (Fabaceae): negative effect of floral visitors on reproductive success?

    PubMed

    Avila, R; Pinheiro, M; Sazima, M

    2015-05-01

    Inga species are characterised by generalist or mixed pollination system. However, this feature does not enhance reproductive rates in species with very low fruit set under natural conditions. Some ecological and genetic factors are associated with this feature, and to test the effect of massive visits on pollination success in Inga subnuda subsp. luschnathiana, we studied the efficacy of polyads deposited on stigmas of flowers isolated from visitors and polyads exposed to visitors. The proportion of polyads fixed in stigmas decreased after exposure to visitors (24 h) in comparison to stigmas isolated from visitors (hummingbirds, bees, wasps, hawkmoths and bats), and fruit set was very low. Furthermore, nectar production, sugar composition and other floral biology traits were evaluated. Increased nectar production, sugar availability and sucrose dominance during the night indicates adaptation to nocturnal visitors and supports their role as main pollinators; although the brush-flower morphology, time of anthesis, nectar dynamics and chemical composition also allow daytime visitors. Thus the species is an important resource for a diverse group of floral visitors. We conclude that excess visits (diurnal and nocturnal) are responsible for the decrease in fixed polyads in stigmas of I. subnuda subsp. luschnathiana flowers, thus contributing, with others factors, to its low fruit set. Therefore, the generalist pollination system does not result in reproductive advantages because the low fruit set in natural conditions could be the result of a negative effect of visitors/pollinators.

  16. Male reproductive success and its behavioural correlates in a polygynous mammal, the Galápagos sea lion (Zalophus wollebaeki).

    PubMed

    Pörschmann, Ulrich; Trillmich, Fritz; Mueller, Birte; Wolf, Jochen B W

    2010-06-01

    Sexual selection theory predicts competitive males and choosy females. Nevertheless, since molecular marker-based studies, paternity outside the expected mating patterns has increasingly been described. Even in highly polygynous systems, where paternity is expected to be strongly skewed towards large, dominant males, alternative mating tactics have been suggested. We examined reproductive success in the polygynous Galápagos sea lion (Zalophus wollebaeki). Semiaquatic territoriality allows females to move freely and may lower the degree of polygyny otherwise suggested by both territorial behaviour and strong sexual dimorphism. We assigned paternities with 22 microsatellites and analysed how male reproductive success was related to size, dominance status, intra-sexual agonistic behaviour, proximity to females, and attendance in the colony. Male behaviour was consistent across two seasons for all parameters under consideration. Attendance was by far the most important determinant of paternal success. Skew in reproductive success towards large, dominant males was weak and dominance status played no role. This appears to be caused by an extremely long reproductive season lasting five or more months, making it difficult for any male to monopolize receptive females. Females seem to choose displaying males that were present in the colony for a long time rather than dominance per se. Sexual dimorphism in Galápagos sea lions may thus be more influenced by selection for fasting than fighting ability. Our data provide further evidence for alternative mating tactics, as several males gained relatively high reproductive success despite short attendance and hardly any involvement in agonistic interactions.

  17. Reproductive success and heavy metal contamination in Rhode Island common terns

    USGS Publications Warehouse

    Custer, T.W.; Franson, J.C.; Moore, John F.; Myers, J.E.

    1986-01-01

    Common tern cIutch size, reproductive success and growth of young recorded from an abandoned barge on the Providence River, an area of heavy metal contamination, were equal to, or greater than, .from less contaminated areas. Concentrations of copper and zinc were higher in livers of nestling terns from the Providence River than from other, less contaminated, areas. However, concentrations of magnesium, manganese, and iron and the frequency of nickel were equal, or lower, at Providence than other, less contaminated, locations. Among-colony trends in residues of copper, zinc and nickel in prey samples were similar to trends .found in nestling livers. Uric acid concentrations in nestling blood were twice as high in the Providence River than another colony and may have resulted from moderate levels of chromium in the diet.

  18. Flower color preferences of insects and livestock: effects on Gentiana lutea reproductive success

    PubMed Central

    Losada, María; Veiga, Tania; Guitián, Javier; Guitián, José; Guitián, Pablo

    2016-01-01

    Angiosperms diversification was primarily driven by pollinator agents, but non-pollinator agents also promoted floral evolution. Gentiana lutea shows pollinator driven flower color variation in NW Spain. We test whether insect herbivores and livestock, which frequently feed in G.lutea, play a role in G. lutea flower color variation, by answering the following questions: (i) Do insect herbivores and grazing livestock show flower color preferences when feeding on G. lutea? (ii) Do mutualists (pollinators) and antagonists (seed predators, insect herbivores and livestock) jointly affect G. lutea reproductive success? Insect herbivores fed more often on yellow flowering individuals but they did not affect seed production, whereas livestock affected seed production but did not show clear color preferences. Our data indicate that flower color variation of G. lutea is not affected by insect herbivores or grazing livestock. PMID:27014509

  19. Exposure to monocrotophos pesticide during sexual development causes the feminization/demasculinization of the reproductive traits and a reduction in the reproductive success of male guppies (Poecilia reticulata)

    SciTech Connect

    Tian, Hua; Li, Yun; Wang, Wei; Wu, Peng; Ru, Shaoguo

    2012-09-01

    Monocrotophos is a highly toxic organophosphorus pesticide that has been confirmed to be an endocrine‐disrupting chemical. To evaluate the influence of this pollutant on the reproductive system of male fish, we studied the sex steroid levels, reproductive traits, sex ratio, and reproductive success in male guppies (Poecilia reticulata) exposed to 40% monocrotophos pesticide at the nominal concentrations of 0.01, 0.10, and 1.00 mg/L for 90 days from birth to adulthood in a semi‐static exposure system. Radioimmunoassay and western blot analyses demonstrated that the long‐term exposure to monocrotophos pesticide during the sexual development of male guppies caused a significant increase in 17β‐estradiol levels and consequently induced vitellogenin synthesis, suggesting the feminization of the males. Monocrotophos pesticide also caused a significant decrease in testosterone levels, which consequently inhibited testis growth and reduced the sperm count and the area and intensity of their sexually attractive orange spots, which collectively indicated the significant demasculinization of the male sexual characteristics. Furthermore, these changes in the sexual characteristics at the cellular and organ levels translated into ecologically important effects on the reproductive success at the individual level, as measured by a decrease in offspring production and survival rate. The present study provides the first evidence that monocrotophos pesticide can cause severe reproductive abnormalities in fish due to its endocrine‐disrupting action. -- Highlights: ► Monocrotophos pesticide caused an increase in 17β‐estradiol levels of male guppies. ► Monocrotophos pesticide induced vitellogenin synthesis of male guppies. ► Monocrotophos pesticide caused a decrease in testosterone levels of male guppies. ► Monocrotophos pesticide caused demasculinization of male sexual characteristics. ► Monocrotophos pesticide caused a reduction in reproductive success of male

  20. Behavior and reproductive success of rock sandpipers breeding on the Yukon-Kuskokwim river delta, Alaska

    USGS Publications Warehouse

    Johnson, M.; Conklin, J.R.; Johnson, B.L.; McCaffery, B.J.; Haig, S.M.; Walters, J.R.

    2009-01-01

    We studied Rock Sandpiper (Calidris ptilocnemis) breeding behavior and monitored reproductive success from 1998 to 2005 on the Yukon-Kuskokwim River Delta, Alaska, USA. We banded 24 adults and monitored 45 nests. Annual return rate of adults ranged between 67 and 100%. Six pairs of Rock Sandpipers bred at our study site for ???2 years, and among these we did not observe mate change (i.e., when both members of a pair returned and each mated with a new individual). Nests were typically initiated by mid-May and 53% of females laid second clutches if first clutches were lost through mid-June. Males regularly incubated clutches during the morning (0800-1259 hrs AKDT) and afternoon (1300-1759 hrs) and rarely during the evening (1800-2300 hrs), whereas female incubation was relatively consistent throughout the day. Apparent nest success (percent of known nests successfully hatching > 1 chick) among first and second nests was 19 and 44%, respectively (n = 45). A minimum of 44% of hatching nests fledged at least one young. Males cared for young but half of females deserted mate and brood 1-7 days post-hatch. This first description of North American Rock Sandpiper breeding behavior from a color-marked population complements previous work on this species on the Chukotsky Peninsula, Russia.

  1. Effects of an alien ant invasion on abundance, behavior, and reproductive success of endemic island birds.

    PubMed

    Davis, Naomi E; O'Dowd, Dennis J; Green, Peter T; Nally, Ralph Mac

    2008-10-01

    Biological invaders can reconfigure ecological networks in communities, which changes community structure, composition, and ecosystem function. We investigated whether impacts caused by the introduced yellow crazy ant (Anoplolepis gracilipes), a pantropical invader rapidly expanding its range, extend to higher-order consumers by comparing counts, behaviors, and nesting success of endemic forest birds in ant-invaded and uninvaded rainforest on Christmas Island (Indian Ocean). Point counts and direct behavioral observations showed that ant invasion altered abundances and behaviors of the bird species we examined: the Island Thrush (Turdus poliocephalus erythropleurus), Emerald Dove (Chalcophaps indica natalis), and Christmas Island White-eye (Zosterops natalis). The thrush, which frequents the forest floor, altered its foraging and reproductive behaviors in ant-invaded forest, where nest-site location changed, and nest success and juvenile counts were lower. Counts of the dove, which forages exclusively on the forest floor, were 9-14 times lower in ant-invaded forest. In contrast, counts and foraging success of the white-eye, a generalist feeder in the understory and canopy, were higher in ant-invaded forest, where mutualism between the ant and honeydew-secreting scale insects increased the abundance of scale-insect prey. These complex outcomes involved the interplay of direct interference by ants and altered resource availability and habitat structure caused indirectly by ant invasion. Ecological meltdown, rapidly unleashed by ant invasion, extended to these endemic forest birds and may affect key ecosystem processes, including seed dispersal.

  2. Southern Right Whale (Eubalaena australis) Reproductive Success is Influenced by Krill (Euphausia superba) Density and Climate

    PubMed Central

    Seyboth, Elisa; Groch, Karina R.; Dalla Rosa, Luciano; Reid, Keith; Flores, Paulo A. C.; Secchi, Eduardo R.

    2016-01-01

    The reproductive success of southern right whale (Eubalaena australis) depends on body condition and, therefore, on foraging success. This, in turn, might be affected by climatically driven change in the abundance of the species main prey, krill (Euphausia superba), on the feeding grounds. Annual data on southern right whale number of calves were obtained from aerial surveys carried out between 1997 and 2013 in southern Brazil, where the species concentrate during their breeding season. The number of calves recorded each year varied from 7 to 43 ( = 21.11 ± 11.88). Using cross-correlation analysis we examined the response of the species to climate anomalies and krill densities. Significant correlations were found with krill densities (r = 0.69, p = 0.002, lag 0 years), Oceanic Niño Index (r = −0.65, p = 0.03, lag 6 years), Antarctic Oscillation (r = 0.76, p = 0.01, lag 7 years) and Antarctic sea ice area (r = −0.68, p = 0.002, lag 0 years). Our results suggest that global climate indices influence southern right whale breeding success in southern Brazil by determining variation in food (krill) availability for the species. Therefore, increased frequency of years with reduced krill abundance, due to global warming, is likely to reduce the current rate of recovery of southern right whales from historical overexploitation. PMID:27306583

  3. Organochlorine contaminants and reproductive success of double-crested cormorants from Green Bay, Wisconsin, USA

    USGS Publications Warehouse

    Custer, T.W.; Custer, Christine M.; Hines, R.K.; Gutreuter, S.; Stromborg, K.L.; Allen, P.D.; Melancon, M.J.

    1999-01-01

    In 1994 and 1995, nesting success of double-crested cormorants (Phalacrocorax auritus) was measured at Cat Island, in southern Green Bay, Lake Michigan, Wisconsin, USA. Sample eggs at pipping and unhatched eggs were collected and analyzed for organochlorines (including total polychlorinated biphenyls [PCBs] and DDE), hepatic microsomal ethoxyresorufin-O-dealkylase (EROD) activity in embryos, and eggshell thickness. Of 1,570 eggs laid, 32% did not hatch and 0.4% had deformed embryos. Of 632 chicks monitored from hatching to 12 d of age, 9% were missing or found dead; no deformities were observed. The PCB concentrations in sample eggs from clutches with deformed embryos (mean = 10.2 μg/g wet weight) and dead embryos (11.4 μg/g) were not significantly higher than concentrations in sample eggs from nests where all eggs hatched (12.1 μg/g). A logistic regression of hatching success versus DDE, dieldrin, and PCB concentrations in sibling eggs identified DDE and not dieldrin or PCBs as a significant risk factor. A logistic regression of hatching success versus DDE and eggshell thickness implicated DDE and not eggshell thickness as a significant risk factor. Even though the insecticide DDT was banned in the early 1970s, we suggest that DDE concentrations in double-crested cormorant eggs in Green Bay are still having an effect on reproduction in this species.

  4. Effects of pulp and paper mill effluents on reproductive success of largemouth bass.

    PubMed

    Sepúlveda, Maria S; Quinn, Brian P; Denslow, Nancy D; Holm, Stewart E; Gross, Timothy S

    2003-01-01

    This study evaluated the effects of bleached and unbleached kraft mill effluent on reproductive success of largemouth bass (Micropterus salmoides). Bass were exposed to effluent concentrations (0, 10, 20, 40, or 80%) for 28 and 56 d. Parameters measured included hepatosomatic index (HSI) and gonadosomatic index (GSI) and plasma concentrations of 17beta-estradiol (E2), 11-ketotestosterone (11-KT), and vitellogenin (VTG). At the end of the 56-d period, bass were moved to hatchery ponds to evaluate spawning success. Spawning mats with eggs either were brought indoors for evaluation of fecundities, hatchabilities, and egg and fry size (measured at age 3 d), or were left in ponds and fry number and size recorded (average age of 14 d). Effluent exposure was verified by measuring resin acids (isopimaric, abietic. and dehydroabietic acids) in bile. Compared to controls, exposed bass had greater concentrations of resin acids in bile. In general, exposed females had lower concentrations of E2 and VTG (> or = 20% effluent), whereas males had lower concentrations of 11-KT (> or = 20% effluent) and increased E2 (> or = 20% effluent). The HSI values increased in females (> or = 10% effluent), and GSI values decreased in both sexes (> or = 40% effluent). Fecundity, egg size, and hatchability did not differ across treatments, but an increase in the frequency of fry abnormalities and a decrease in fry weights was observed at effluent exposures of 40% and higher. However, results from the pond study, revealed a significant reduction in fry growth and survival (> or = 10%). This decline may have been caused by an increased frequency of deformities, in conjunction with alterations of growth. These changes could have resulted from alterations in egg quality because of failure of parental reproductive systems, from acute embryo toxicity after translocation of contaminants from the mother to the developing embryo, or from both.

  5. Sociosexual behaviors and reproductive success of rats (Rattus norvegicus) in a seminatural environment.

    PubMed

    Chu, Xi; Guarraci, Fay A; Ågmo, Anders

    2015-11-01

    A promiscuous pattern of copulation has been reported in both wild and domestic rats, and multiple paternity is common. In the present study we determined whether male sociosexual behaviors were associated with reproductive success or not. Groups of rats (3 males and 4 cycling females) were housed in a seminatural environment for a period of 8 days. Sociosexual interactions were observed whenever one or several females were in behavioral estrus. Paternity of the offspring sired was determined by analyses of single nucleotide polymorphisms. Fertility was quantified either as the total number of offspring, or the mean proportion of offspring from all females, sired by the male. Although the total numbers of male social and sexual behaviors during the 8 day period were unrelated to reproductive success, male fertility was correlated with the number of intromissions and ejaculations. In addition intromission and ejaculation ratios (the proportion of mounts ending in intromission and the proportion of the total number of ejaculations received by a female that was contributed by a particular male, respectively) were also correlated with male fertility. Fewer mounts as well as fewer male pursuits of the female were demonstrated by males siring entire litters than by males siring multipaternity litters. Ejaculation order was unrelated to fertility. Male or female preferences (based on various sociosexual interactions) were not strongly related to fertility. Female preference only showed a limited effect. Specifically, preferred males (males who were sniffed most) sired fewer pups. Male dominance status did not affect female preferences, copulatory behavior or fertility. It appears that only behaviors directly related to sperm transfer are important for fertility. Social behaviors in both males and females play a very limited or no role in determining rats' fertility.

  6. Double decomposition: decomposing the variance in subcomponents of male extra-pair reproductive success.

    PubMed

    Losdat, Sylvain; Arcese, Peter; Reid, Jane M

    2015-09-01

    1. Extra-pair reproductive success (EPRS) is a key component of male fitness in socially monogamous systems and could cause selection on female extra-pair reproduction if extra-pair offspring (EPO) inherit high value for EPRS from their successful extra-pair fathers. However, EPRS is itself a composite trait that can be fully decomposed into subcomponents of variation, each of which can be further decomposed into genetic and environmental variances. However, such decompositions have not been implemented in wild populations, impeding evolutionary inference. 2. We first show that EPRS can be decomposed into the product of three life-history subcomponents: the number of broods available to a focal male to sire EPO, the male's probability of siring an EPO in an available brood and the number of offspring in available broods. This decomposition of EPRS facilitates estimation from field data because all subcomponents can be quantified from paternity data without need to quantify extra-pair matings. Our decomposition also highlights that the number of available broods, and hence population structure and demography, might contribute substantially to variance in male EPRS and fitness. 3. We then used 20 years of complete genetic paternity and pedigree data from wild song sparrows (Melospiza melodia) to partition variance in each of the three subcomponents of EPRS, and thereby estimate their additive genetic variance and heritability conditioned on effects of male coefficient of inbreeding, age and social status. 4. All three subcomponents of EPRS showed some degree of within-male repeatability, reflecting combined permanent environmental and genetic effects. Number of available broods and offspring per brood showed low additive genetic variances. The estimated additive genetic variance in extra-pair siring probability was larger, although the 95% credible interval still converged towards zero. Siring probability also showed inbreeding depression and increased with male age

  7. Impact of group size on female reproductive success of free-ranging Rhinopithecus roxellana in the Qinling Mountains, China.

    PubMed

    Zhao, Dapeng; Li, Baoguo; Watanabe, Kunio

    2011-01-01

    Group size influences female reproductive success through scramble/contest feeding competition, predation pressures and infanticide risks in primates. The Sichuan snub-nosed monkey (Rhinopithecus roxellana) is an endangered folivorous colobine species living in a multilevel society. From 2002 to 2008, we studied a free-ranging band of R. roxellana in the Qinling Mountains of China to examine the effect of group size on female reproductive success. During our observation period, the number of monkeys in the study band fluctuated from 61 to 108, and the number of one-male/multi-female groups within it varied from 7 to 10. A significant negative linear relationship was found between group size and birth rate, but group size was not significantly correlated with infant survival rate or interbirth interval. These results suggest that group size influences female reproductive success via within-group scramble competition in this folivorous species.

  8. Reproductive investment, synchrony and recruitment success in marine broadcast spawners: Effects of mating system and habitat (exposed shore versus estuary).

    PubMed

    Monteiro, Carla A; Serrão, Ester A; Pearson, Gareth A

    2015-12-01

    The timing and synchrony of gamete release in broadcast spawners have important implications for fertilization success, recruitment and to explain differences in reproductive success under distinct reproductive modes in sympatry. Our objective was to compare the reproductive timing and investment for sister species with contrasting mating systems; Fucus guiryi (selfing hermaphroditic) and Fucus vesiculosus (dioecious) in habitats with different wave exposures (exposed shore and estuary). Over two months, daily gamete release, recruitment and population structure were recorded. Our results show spawning synchrony between species and habitats, but release events in hermaphrodites occupied broader temporal windows in estuarine than exposed shore habitats. On the exposed shore both species increased the synchrony of release and amount of eggs. In the estuary, hermaphrodites relied on broader temporal spawning windows and a larger canopy, and the dioecious species had higher recruitment success, important factors determining persistence.

  9. Increase in male reproductive success and female reproductive investment in invasive populations of the harlequin ladybird Harmonia axyridis.

    PubMed

    Laugier, Guillaume J M; Le Moguédec, Gilles; Tayeh, Ashraf; Loiseau, Anne; Osawa, Naoya; Estoup, Arnaud; Facon, Benoît

    2013-01-01

    Reproductive strategy affects population dynamics and genetic parameters that can, in turn, affect evolutionary processes during the course of biological invasion. Life-history traits associated with reproductive strategy are therefore potentially good candidates for rapid evolutionary shifts during invasions. In a series of mating trials, we examined mixed groups of four males from invasive and native populations of the harlequin ladybird Harmonia axyridis mating freely during 48 hours with one female of either type. We recorded the identity of the first male to copulate and after the 48 h-period, we examined female fecundity and share of paternity, using molecular markers. We found that invasive populations have a different profile of male and female reproductive output. Males from invasive populations are more likely to mate first and gain a higher proportion of offspring with both invasive and native females. Females from invasive populations reproduce sooner, lay more eggs, and have offspring sired by a larger number of fathers than females from native populations. We found no evidence of direct inbreeding avoidance behaviour in both invasive and native females. This study highlights the importance of investigating evolutionary changes in reproductive strategy and associated traits during biological invasions.

  10. The effects of glutathione depletion on reproductive success in oysters, Crassostrea virginica.

    PubMed

    Ringwood, A H; Conners, D E

    2000-01-01

    Glutathione (GSH) is a ubiquitous tripeptide that functions as a very important modulator of cellular homeostasis, including detoxification of metals and oxyradicals. Therefore, depletion of GSH may predispose organisms to pollutant stress. Reproductively active oysters (Crassostrea virginica) were exposed to buthionine sulfoximine in the laboratory to deplete gonadal GSH. The effects of metal exposures (Cd and Cu) on fertilization and developmental assays were evaluated using gametes from control and GSH-depleted adults. Fertilization success was not affected by GSH status, i.e. the fertilization rates of gametes derived from GSH-depleted adults were the same or slightly higher. However, GSH depletion did increase the susceptibility of developing embryos to metal toxicity, i.e. adverse effects on embryonic development were observed at lower metal concentrations with gametes derived from GSH-depleted adults. These effects may be related to diminished removal of free radicals or increased availability of metals. Whereas sperm penetration of embryonic membranes and fertilization success may be facilitated by free radicals, the persistence of free radicals during subsequent developmental periods may adversely affect differentiation and normal development. GSH probably also plays an important role in scavenging toxic metals and reducing metal interactions with essential developmental processes. These results suggest that parental depletion of GSH may increase the susceptibility of embryos to metal toxicity.

  11. Individual quality, early-life conditions, and reproductive success in contrasted populations of large herbivores.

    PubMed

    Hamel, Sandra; Gaillard, Jean-Michel; Festa-Bianchet, Marco; Côté, Steeve D

    2009-07-01

    Variations among individuals in phenotypic quality and fitness often confound analyses of life-history strategies assessed at the population level. We used detailed long-term data from three populations of large herbivores with generation times ranging from four to nine years to quantify heterogeneity in individual quality among females, and to assess its influence on mean annual reproductive success over the lifetime (MRS). We also determined how environmental conditions in early life shaped individual quality and tested A. Lomnicki's hypothesis that variance in individual quality should increase when environmental conditions deteriorate. Using multivariate analyses (PCA), we identified one (in sheep and deer) or two (in goats) covariations among life-history traits (longevity, success in the last breeding opportunity, adult mass, and social rank) as indexes of individual quality that positively influenced MRS of females. Individual quality was reduced by unfavorable weather, low resource availability, and high population density in the year of birth. Early-life conditions accounted for 35-55% of variation in individual quality. In roe deer, we found greater variance in individual quality for cohorts born under unfavorable conditions as opposed to favorable ones, but the opposite was found in bighorn sheep and mountain goats. Our results demonstrate that heterogeneity in female quality can originate from environmental conditions in early life and can markedly influence the fitness of females in species located at different positions along the slow-fast continuum of life-history strategies.

  12. Reproductive success of kittiwakes and murres in sequential stages of the nesting period: Relationships with diet and oceanography

    NASA Astrophysics Data System (ADS)

    Renner, Heather M.; Drummond, Brie A.; Benson, Anna-Marie; Paredes, Rosana

    2014-11-01

    Reproductive success is one of the most easily-measured and widely studied demographic parameters of colonial nesting seabirds. Nevertheless, factors affecting the sequential stages (egg laying, incubation, chick-rearing) of reproductive success are less understood. We investigated the separate sequential stages of reproductive success in piscivorous black-legged kittiwakes (Rissa tridactyla) and thick-billed murres (Uria lomvia) using a 36-year dataset (1975-2010) on the major Pribilof Islands (St. Paul and St. George), which have recently had contrasting population trajectories. Our objectives were to evaluate how the proportion of successful nests varied among stages, and to quantify factors influencing the probability of nest success at each stage in each island. We modeled the probability of nest success at each stage using General Linear Mixed Models incorporating broad-scale and local climate variables, and diet as covariates as well as other measures of reproduction such as timing of breeding and reproductive output in the previous year and previous stage. For both species we found: (1) Success in previous stages of the breeding cycle and success in the prior year better explained overall success than any environmental variables. Phenology was also an important predictor of laying success for kittiwakes. (2) Fledging success was lower when chick diets contained oceanic fish found farther from the colonies and small invertebrates, rather than coastal fish species. (3) Differences in reproductive variables at St. Paul and St. George islands did not correspond to population trends between the two islands. Our results highlight the potential importance of adult condition and annual survival to kittiwake and murre productivity and ultimately, populations. Adult condition carrying over from the previous year ultimately seems to drive annual breeding success in a cascade effect. Furthermore, condition and survival appear to be important contributors to population

  13. Reproductive success in relation to dominance rank in the absence of prime-age males in Barbary macaques.

    PubMed

    Modolo, Lara; Martin, Robert D

    2008-01-01

    In some primate species dominance rank of males is correlated with reproductive success, whereas in other species this relationship is inconsistent. Barbary macaques (Macaca sylvanus) live in a promiscuous mating system in which males are ranked in a dominance hierarchy that influences their access to females. High-ranking males usually monopolize fertile females during their estrous period and show increased mating activities. Subadult males generally rank below adult males. For Barbary macaque females in the Gibraltar colony, there was no correlation between dominance status and reproductive success. Paternity data for 31 offspring collected over four consecutive breeding seasons were used to test whether male social rank was associated with reproductive success and whether reproductive success was mainly confined to a small number of males. Genetic variation was assessed using 14 microsatellite markers for a dataset of 127 individuals sampled in all five social groups of the Gibraltar colony. Paternity analysis was conducted for offspring in one social group only, where all in-group males were sampled. Eighty-three percent of the offspring could be assigned to an in-group candidate father; none of the extra-group males appeared to have sired an infant. Male dominance rank was not found to contribute to the observed variation in male reproductive output. Fifty-nine percent of the offspring was sired by two low-ranking males, whereas the two top-ranking males sired one-fifth. A highly significant correlation was found for male age and dominance rank. Reproductive success of subadult males might be explained by the gap in the age distribution of male group members. These missing prime males are usually regarded as serious competitors for older males. Subadult males may have gained easier access to females in their absence. In addition, the presence of inbreeding avoidance mechanisms, which might also have overpowered possible rank effects, cannot be excluded.

  14. Mercury Reduces Avian Reproductive Success and Imposes Selection: An Experimental Study with Adult- or Lifetime-Exposure in Zebra Finch

    PubMed Central

    Varian-Ramos, Claire W.; Swaddle, John P.; Cristol, Daniel A.

    2014-01-01

    Mercury is a global pollutant that biomagnifies in food webs, placing wildlife at risk of reduced reproductive fitness and survival. Songbirds are the most diverse branch of the avian evolutionary tree; many are suffering persistent and serious population declines and we know that songbirds are frequently exposed to mercury pollution. Our objective was to determine the effects of environmentally relevant doses of mercury on reproductive success of songbirds exposed throughout their lives or only as adults. The two modes of exposure simulated philopatric species versus dispersive species, and are particularly relevant because of the heightened mercury-sensitivity of developing nervous systems. We performed a dosing study with dietary methylmercury in a model songbird species, the zebra finch (Taeniopygia guttata), at doses from 0.3 – 2.4 parts per million. Birds were exposed to mercury either as adults only or throughout their lives. All doses of mercury reduced reproductive success, with the lowest dose reducing the number of independent offspring produced in one year by 16% and the highest dose, representing approximately half the lethal dose for this species, causing a 50% reduction. While mercury did not affect clutch size or survivorship, it had the most consistent effect on the proportion of chicks that fledged from the nest, regardless of mode of exposure. Among birds exposed as adults, mercury caused a steep increase in the latency to re-nest after loss of a clutch. Birds exposed for their entire lifetimes, which were necessarily the offspring of dosed parents, had up to 50% lower reproductive success than adult-exposed birds at low doses of methylmercury, but increased reproductive success at high doses, suggesting selection for mercury tolerance at the highest level of exposure. Our results indicate that mercury levels in prey items at contaminated sites pose a significant threat to populations of songbirds through reduced reproductive success. PMID

  15. Senescence rates and late adulthood reproductive success are strongly influenced by personality in a long-lived seabird.

    PubMed

    Patrick, Samantha C; Weimerskirch, Henri

    2015-01-22

    Studies are increasingly demonstrating that individuals differ in their rate of ageing, and this is postulated to emerge from a trade-off between current and future reproduction. Recent theory predicts a correlation between individual personality and life-history strategy, and from this comes the prediction that personality may predict the intensity of senescence. Here we show that boldness correlates with reproductive success and foraging behaviour in wandering albatrosses, with strong sex-specific differences. Shy males show a strong decline in reproductive performance with age, and bold females have lower reproductive success in later adulthood. In both sexes, bolder birds have longer foraging trips and gain more mass per trip as they get older. However, the benefit of this behaviour appears to differ between the sexes, such that it is only matched by high reproductive success in males. Together our results suggest that personality linked foraging adaptations with age are strongly sex-specific in their fitness benefits and that the impact of boldness on senescence is linked to ecological parameters.

  16. The effects of a remediated fly ash spill and weather conditions on reproductive success and offspring development in tree swallows.

    PubMed

    Beck, Michelle L; Hopkins, William A; Jackson, Brian P; Hawley, Dana M

    2015-03-01

    Animals are exposed to natural and anthropogenic stressors during reproduction that may individually or interactively influence reproductive success and offspring development. We examined the effects of weather conditions, exposure to element contamination from a recently remediated fly ash spill, and the interaction between these factors on reproductive success and growth of tree swallows (Tachycineta bicolor) across nine colonies. Females breeding in colonies impacted by the spill transferred greater concentrations of mercury (Hg), selenium (Se), strontium, and thallium to their eggs than females in reference colonies. Parental provisioning of emerging aquatic insects resulted in greater blood Se concentrations in nestlings in impacted colonies compared to reference colonies, and these concentrations remained stable across 2 years. Egg and blood element concentrations were unrelated to reproductive success or nestling condition. Greater rainfall and higher ambient temperatures during incubation were later associated with longer wing lengths in nestlings, particularly in 2011. Higher ambient temperatures and greater Se exposure posthatch were associated with longer wing lengths in 2011 while in 2012, blood Se concentrations were positively related to wing length irrespective of temperature. We found that unseasonably cold weather was associated with reduced hatching and fledging success among all colonies, but there was no interactive effect between element exposure and inclement weather. Given that blood Se concentrations in some nestlings exceeded the lower threshold of concern, and concentrations of Se in blood and Hg in eggs are not yet declining, future studies should continue to monitor exposure and effects on insectivorous wildlife in the area.

  17. Estimating reproductive success of Aethina tumida (Coleoptera: Nitidulidae) in honey bee colonies by trapping emigrating larvae.

    PubMed

    Arbogast, Richard T; Torto, Baldwyn; Willms, Steve; Fombong, Ayuka T; Duehl, Adrian; Teal, Peter E A

    2012-02-01

    The small hive beetle (Aethina tumida Murray) is a scavenger and facultative predator in honey bee colonies, where it feeds on pollen, honey, and bee brood. Although a minor problem in its native Africa, it is an invasive pest of honey bees in the United States and Australia. Adult beetles enter bee hives to oviposit and feed. Larval development occurs within the hive, but mature larvae leave the hive to pupate in soil. The numbers leaving, which can be estimated by trapping, measure the reproductive success of adult beetles in the hive over any given period of time. We describe a trap designed to intercept mature larvae as they reach the end of the bottom board on their way to the ground. Trap efficiency was estimated by releasing groups of 100 larvae into empty brood boxes and counting the numbers trapped. Some larvae escaped, but mean efficiency ranged from 87.2 to 94.2%. We envision the trap as a research tool for study of beetle population dynamics, and we used it to track numbers of larvae leaving active hives for pupation in the soil. The traps detected large increases and then decreases in numbers of larvae leaving colonies that weakened and died. They also detected small numbers of larvae leaving strong European and African colonies, even when no larvae were observed in the hives.

  18. Effects of mercury exposure on the reproductive success of tree swallows (Tachycineta bicolor).

    PubMed

    Brasso, Rebecka L; Cristol, Daniel A

    2008-02-01

    An experimental tree swallow population was established in the headwaters of the Shenandoah River, Virginia, USA to assess the accumulation and effects of mercury contamination on birds that eat emergent aquatic insects. One tributary, the South River, was contaminated with mercury before 1950. Reproductive success of swallows nesting within 50 m of this river was compared to that of three uncontaminated reference tributaries in 2005 and 2006. Female swallows on the contaminated stretch of river had significantly elevated blood and feather total mercury (blood: 3.56 +/- 2.41 ppm ww vs. 0.17 +/- 0.15 ppm reference; feather: 13.55 +/- 6.94 ppm vs. 2.34 +/- 0.87 ppm reference), possibly the highest ever reported for an insectivorous songbird. Insects collected by the swallows to be fed to nestlings averaged 0.97 +/- 1.11 ppm dw total mercury, significantly higher than on reference sites. Swallows in the contaminated area produced fewer fledglings than those in reference areas. The effect of mercury contamination on productivity was detectable only for young females in the contaminated area that were breeding for the first time in 2006, a segment of the population that may already have been stressed by inexperience. Tree swallows served as practical and effective biomonitors for mercury levels and effects and have great potential as proxy biomonitors for more logistically challenging birds such as loons or eagles.

  19. Syllable Type Consistency is Related to Age, Social Status, and Reproductive Success in the Tropical Mockingbird.

    PubMed

    Botero, Carlos A; Rossman, Rachel J; Caro, Lina M; Stenzler, Laura M; Lovette, Irby J; De Kort, Selvino R; Vehrencamp, Sandra L

    2009-03-01

    Many animals repeat standardized displays multiple times while attracting a mate or deterring a rival. In such contexts it is possible that the ability to perform each display or signal type in a consistent fashion is under direct selection. Studies on sexual selection on song learning in birds have focused on differences in repertoire size with less attention to the potential importance of being able to perform each song/syllable type with high consistency. We present evidence that tropical mockingbirds decrease the variation between renditions of each syllable type as they grow older (i.e., become more consistent) and that more consistent males in this species tend to have higher dominance status and reproductive success. These findings stress the importance of consistency in the performance of sexual displays and suggest that this parameter may be very relevant even in species that are selected for high vocal diversity (i.e., large repertoires). In addition to signalling dominance status and age, we hypothesize that syllable type consistency may also be an indicator of the integrity of brain function in birds analogous to the tests used for neuropsychological assessment in humans.

  20. Thyroid function and reproductive success in rodents exposed to perchlorate via food and water.

    PubMed

    Smith, Philip N; Severt, Scott A; Jackson, J W Andrew; Anderson, Todd A

    2006-04-01

    The purpose of the present study was to determine if exposure to perchlorate via food items would have effects on mammals similar to those caused by exposure through drinking water at approximately equivalent doses. Prairie voles (Microtus ochrogaster) and deer mice (Peromyscus maniculatus) were used to assess the potential toxicity of perchlorate-contaminated food items. Voles and mice were divided randomly into three treatment groups--perchlorate-contaminated food (PCF), perchlorate-contaminated water (PCW), and control groups--such that each treatment group contained equal numbers of males and females. Rodents in PCF treatment groups were fed chow formulated with soybean plant matter that had been grown with perchlorate-contaminated irrigation water. Individuals in the control and PCF groups were provided distilled/deionized drinking water, whereas the PCW group received drinking water containing sodium perchlorate. Only slight differences among treatment groups were observed in a variety of endpoints, including reproductive success, tissue perchlorate concentrations, thyroid hormone concentrations, and thyroid histology. However, trends observed in the present study suggest that perchlorate exposure via water may result in slightly greater effects than exposure to perchlorate via food. These data and recent reports of perchlorate in a wide variety of food items indicate that exposure via food intake is an important consideration when examining cumulative risk among humans, livestock, and wildlife.

  1. Mhc-linked survival and lifetime reproductive success in a wild population of great tits.

    PubMed

    Sepil, Irem; Lachish, Shelly; Sheldon, Ben C

    2013-01-01

    Major histocompatibility complex (Mhc) genes are frequently used as a model for adaptive genetic diversity. Although associations between Mhc and disease resistance are frequently documented, little is known about the fitness consequences of Mhc variation in wild populations. Further, most work to date has involved testing associations between Mhc genotypes and fitness components. However, the functional diversity of the Mhc, and hence the mechanism by which selection on Mhc acts, depends on how genotypes map to the functional properties of Mhc molecules. Here, we test three hypotheses that relate Mhc diversity to fitness: (i) the maximal diversity hypothesis, (ii) the optimal diversity hypothesis and (iii) effect of specific Mhc types. We combine mark-recapture methods with analysis of long-term breeding data to investigate the effects of Mhc class I functional diversity (Mhc supertypes) on individual fitness in a wild great tit (Parus major) population. We found that the presence of three different Mhc supertypes was associated with three different components of individual fitness: survival, annual recruitment and lifetime reproductive success (LRS). Great tits possessing Mhc supertype 3 experienced higher survival rates than those that did not, whereas individuals with Mhc supertype 6 experienced higher LRS and were more likely to recruit offspring each year. Conversely, great tits that possessed Mhc supertype 5 had reduced LRS. We found no evidence for a selective advantage of Mhc diversity, in terms of either maximal or optimal supertype diversity. Our results support the suggestion that specific Mhc types are an important determinant of individual fitness.

  2. Chronic stress in free-living European starlings reduces corticosterone concentrations and reproductive success.

    PubMed

    Cyr, Nicole E; Michael Romero, L

    2007-03-01

    Chronic increases in stress hormones such as glucocorticoids are maladaptive, yet studies demonstrating a causal relationship among chronic stress, increases in glucocorticoid concentrations, and subsequent fitness costs in free-living animals are lacking. We experimentally induced chronic psychological stress in female European starlings (Sturnus vulgaris) by subjecting half of the females at our study site to a chronic stress protocol consisting of 4, 30 min stressors (loud radio, predator calls, a novel object, or predator decoys including a snake, rat, and owl) administered in random order daily for 8 days after clutch completion. Experimental females were captured at the end of the chronic stress protocol (9 days after the onset of the chronic stress protocol), and unstressed control females were captured at the same stage of the nesting cycle. Chronically stressed females had lower baseline corticosterone (CORT, the avian glucocorticoid) concentrations and lower reproductive success than unstressed females. Furthermore, surviving nestlings in experimentally stressed broods showed sensitization of the CORT response to acute stress, which is a physiological change that could persist to adulthood. Attenuation of baseline CORT concentrations in adult females is contrary to the general assumption that elevated CORT concentrations indicate stress, suggesting that more research is necessary before CORT concentrations can be used to accurately assess chronic stress in field studies.

  3. Maternally transferred dioxin-like compounds can affect the reproductive success of European eel.

    PubMed

    Foekema, Edwin M; Kotterman, Michiel; de Vries, Pepijn; Murk, Albertinka J

    2016-01-01

    Reported concentrations of dioxin-like compounds accumulated in the European eel (Anguilla anguilla) were used to perform a risk assessment for eel larval survival, taking into account a modeled amplification of tissue concentrations with a factor of 1.33 during spawning migration. The calculated concentrations of dioxin-like compounds finally deposited in the eggs were compared with the internal effect concentrations for survival of early life stages of the European eel; these concentrations, by lack of experimental data, were estimated from a sensitivity distribution based on literature data by assuming that eel larvae are among the 10% most sensitive teleost fish species. Given concentrations of dioxin-like contaminants and assuming a relatively high sensitivity, it can be expected that larvae from eggs produced by eel from highly contaminated locations in Europe will experience increased mortality as a result of maternally transferred dioxin-like contaminants. As historical persistent organic pollutant concentrations in eel tissue were higher, this impact must have been stronger in the past. Potential effects of other compounds or effects on the migration, condition, and fertility of the parental animals were not taken into account. It is important to further study the overall impact of contaminants on the reproductive success of the European eel as this may have been underestimated until now.

  4. Male heterozygosity predicts territory size, song structure and reproductive success in a cooperatively breeding bird.

    PubMed

    Seddon, Nathalie; Amos, William; Mulder, Raoul A; Tobias, Joseph A

    2004-09-07

    Recent studies of non-social animals have shown that sexually selected traits signal at least one measure of genetic quality: heterozygosity. To determine whether similar cues reveal group quality in more complex social systems, we examined the relationship between territory size, song structure and heterozygosity in the subdesert mesite (Monias benschi), a group-living bird endemic to Madagascar. Using nine polymorphic microsatellite loci, we found that heterozygosity predicted both the size of territories and the structure of songs used to defend them: more heterozygous groups had larger territories, and more heterozygous males used longer, lower-pitched trills in their songs. Heterozygosity was linked to territory size and song structure in males, but not in females, implying that these traits are sexually selected by female choice and/or male-male competition. To our knowledge, this study provides the first direct evidence in any animal that territory size is related to genetic diversity. We also found a positive association between seasonal reproductive success and heterozygosity, suggesting that this heritable characteristic is a reliable indicator of group quality and fitness. Given that heterozygosity predicts song structure in males, and can therefore be determined by listening to acoustic cues, we identify a mechanism by which social animals may assess rival groups, prospective partners and group mates, information of potential importance in guiding decisions related to conflict, breeding and dispersal.

  5. Male heterozygosity predicts territory size, song structure and reproductive success in a cooperatively breeding bird.

    PubMed Central

    Seddon, Nathalie; Amos, William; Mulder, Raoul A.; Tobias, Joseph A.

    2004-01-01

    Recent studies of non-social animals have shown that sexually selected traits signal at least one measure of genetic quality: heterozygosity. To determine whether similar cues reveal group quality in more complex social systems, we examined the relationship between territory size, song structure and heterozygosity in the subdesert mesite (Monias benschi), a group-living bird endemic to Madagascar. Using nine polymorphic microsatellite loci, we found that heterozygosity predicted both the size of territories and the structure of songs used to defend them: more heterozygous groups had larger territories, and more heterozygous males used longer, lower-pitched trills in their songs. Heterozygosity was linked to territory size and song structure in males, but not in females, implying that these traits are sexually selected by female choice and/or male-male competition. To our knowledge, this study provides the first direct evidence in any animal that territory size is related to genetic diversity. We also found a positive association between seasonal reproductive success and heterozygosity, suggesting that this heritable characteristic is a reliable indicator of group quality and fitness. Given that heterozygosity predicts song structure in males, and can therefore be determined by listening to acoustic cues, we identify a mechanism by which social animals may assess rival groups, prospective partners and group mates, information of potential importance in guiding decisions related to conflict, breeding and dispersal. PMID:15315898

  6. Floral scents affect reproductive success in fly-pollinated Alocasia odora (Araceae).

    PubMed

    Miyake, Takashi; Yafuso, Masako

    2003-03-01

    We evaluated the role of floral scents in the reproductive success of Alocasia odora C. Koch (Araceae). Alocasia odora is pollinated by its specific pollinators, Colocasiomyia alocasiae (Okada) and C. xenalocasiae (Okada) (Diptera: Drosophilidae). These flies use the spadix of A. odora as breeding sites. The appendix, which is at an upper part of the spadix and is the most attractive region, attracted these pollinators by emitting volatiles, although the male zone of the inflorescence was also attractive. The number of flies attracted was positively correlated with appendix size. During the pistillate phase of the protogynous spadix, attracted flies aggregated in the lower part (female zone) to mate, lay eggs, and perhaps obtain nutrients. The flies moved to the upper part (male zone) of the spadix by the tightening of the constriction separating the upper and lower parts, and then the staminate phase started. This movement of the flies on the spadix promotes outcrossing of A. odora. Removal of the appendix or the whole upper part of the spadix resulted in much reduced fruit set, suggesting that the absence of the scent-producing region leads to insufficient pollination because of reduced pollinator attraction.

  7. Environmental variability drives shifts in the foraging behaviour and reproductive success of an inshore seabird.

    PubMed

    Kowalczyk, Nicole D; Reina, Richard D; Preston, Tiana J; Chiaradia, André

    2015-08-01

    Marine animals forage in areas that aggregate prey to maximize their energy intake. However, these foraging 'hot spots' experience environmental variability, which can substantially alter prey availability. To survive and reproduce animals need to modify their foraging in response to these prey shifts. By monitoring their inter-annual foraging behaviours, we can understand which environmental variables affect their foraging efficiency, and can assess how they respond to environmental variability. Here, we monitored the foraging behaviour and isotopic niche of little penguins (Eudyptula minor), over 3 years (2008, 2011, and 2012) of climatic and prey variability within Port Phillip Bay, Australia. During drought (2008), penguins foraged in close proximity to the Yarra River outlet on a predominantly anchovy-based diet. In periods of heavy rainfall, when water depth in the largest tributary into the bay (Yarra River) was high, the total distance travelled, maximum distance travelled, distance to core-range, and size of core- and home-ranges of penguins increased significantly. This larger foraging range was associated with broad dietary diversity and high reproductive success. These results suggest the increased foraging range and dietary diversity of penguins were a means to maximize resource acquisition rather than a strategy to overcome local depletions in prey. Our results demonstrate the significance of the Yarra River in structuring predator-prey interactions in this enclosed bay, as well as the flexible foraging strategies of penguins in response to environmental variability. This plasticity is central to the survival of this small-ranging, resident seabird species.

  8. The effects of experimental lake acidification on the reproductive success of tree swallows

    SciTech Connect

    St. Louis, V.L.

    1992-01-01

    The effects of lake acidification on reproductive success of tree swallows (Tachycineta bicolor) breeding near experimentally acidified and unmanipulated reference lakes at the Experimental Lake Area (ELA) were studied. Tree swallows are aerial insectivores that commonly breed near water and forage on emergent insects. Predictions suggest that avian food abundance and quality may be altered due to acidification. Breeding swallows foraged on chironomids emerging at their nest-site lakes before searching for food elsewhere. Among the calcium-rich items consumed by the swallows, fish bones were most numerous, followed by crayfish exoskeleton, clam shell, and bird eggshell. We found significantly fewer calcium-rich items in the stomachs of nestlings from acid lakes than in those from reference lakes. Chironomid species were significantly more abundant in acid lakes, while the Chironominae were less numerous. Biomass of emerging chironomids either increased significantly following acidification, or was not different from that of reference lakes. Concentrations of Al, Ca, Mn, and Zn were on average higher in chironomids from a number of the acid lakes than in chironomids from reference lakes. Calcium concentrations in chironomids from the most acid lake were significantly lower, suggesting that Ca may be difficult to sequester at low pH levels. Hepatic concentrations of metallothioneins in tree swallow nestlings were negatively correlated with pH of the nest-site lake. Additive concentrations of Cu and Zn in the liver were correlated with liver MT concentrations, but Cd was not. Near acidified lakes, eggs were smaller in certain dimensions, hatching success was lower, certain nestling body characters were smaller, nestling wing length was shorter, and growth functions were different than near unmanipulated reference lakes. Clearly even non-aquatic organisms are affected by acidification of freshwater ecosystems.

  9. Recent progress in plant reproduction research: the story of the male gametophyte through to successful fertilization.

    PubMed

    Suzuki, Go

    2009-11-01

    Sexual reproduction is an important biological event not only for evolution but also for breeding in plants. It is a well known fact that Charles Darwin (1809-1882) was interested in the reproduction system of plants as part of his concept of 'species' and 'evolution.' His keen observation and speculation is timeless even in the current post-genome era. In the Darwin anniversary year of 2009, I have summarized recent molecular genetic studies of plant reproduction, focusing especially on male gametophyte development, pollination and fertilization. We are just beginning to understand the molecular mechanisms of the elaborate reproduction system in flowering plants, which have been a mystery for >100 years.

  10. Influence of Nest Box Color and Release Sites on Osmia lignaria (Hymenoptera: Megachilidae) Reproductive Success in a Commercial Almond Orchard.

    PubMed

    Artz, Derek R; Allan, Matthew J; Wardell, Gordon I; Pitts-Singer, Theresa L

    2014-12-01

    Intensively managed, commercial orchards offer resources for managed solitary bees within agricultural landscapes and provide a means to study bee dispersal patterns, spatial movement, nest establishment, and reproduction. In 2012, we studied the impact of 1) the color of nest boxes covaried with four nest box density treatments and 2) the number of bee release sites covaried with two nest box density treatments on the reproductive success of Osmia lignaria Say in a California almond orchard pollinated by a mixture of O. lignaria and Apis mellifera L. Nest box color influenced the number of nests, total cells, and cells with male and female brood. More nests and cells were produced in light blue nest boxes than in orange or yellow nest boxes. The covariate nest box density also had a significant effect on brood production. The number of release sites did not affect O. lignaria nesting and reproduction, but the number of cavities in nest boxes influenced reproduction. Overall, the color of nest boxes and their distribution, but not the number of release sites, can greatly affect O. lignaria nest establishment and reproductive success in a commercial almond orchard. The ability to locate nesting sites in a homogenous, large orchard landscape may also be facilitated by the higher frequency of nest boxes with low numbers of cavities, and by the ability to detect certain nest box colors that best contrast with the blooming trees.

  11. Effects of short-term grazing exclusion on plant phenology and reproductive succession in a Tibetan alpine meadow

    PubMed Central

    Zhu, Juntao; Zhang, Yangjian; Liu, Yaojie

    2016-01-01

    Grazing exclusion (GE) has been widely considered as an effective avenue for restoring degraded grasslands throughout the world. GE, via modifying abiotic and biotic environments, inevitably affects phenological development. A five-year manipulative experiment was conducted in a Tibetan alpine meadow to examine the effects of GE on phenological processes and reproductive success. The study indicated that GE strongly affected phenological development of alpine plant species. Specifically, the low-growing, shallow-rooted species (LSS), such as Kobresia pygmaea, are more sensitive to GE-caused changes on upper-soil moisture and light. GE advanced each phonological process of K. pygmaea, except in the case of the treatment of fencing for 5 years (F5), which postponed the reproductive stage and lowered the reproductive success of K. pygmaea. Increased soil moisture triggered by GE, especially in the upper soil, may stimulate growth of LSS. However, the thick litter layer under the F5 treatment can influence the photoperiod of LSS, resulting in suppression of its reproductive development. These findings indicate that plant traits associated with resource acquisition, such as rooting depth and plant height, mediate plant phenology and reproductive responses to grazing exclusion treatments. PMID:27301554

  12. Effects of short-term grazing exclusion on plant phenology and reproductive succession in a Tibetan alpine meadow.

    PubMed

    Zhu, Juntao; Zhang, Yangjian; Liu, Yaojie

    2016-06-15

    Grazing exclusion (GE) has been widely considered as an effective avenue for restoring degraded grasslands throughout the world. GE, via modifying abiotic and biotic environments, inevitably affects phenological development. A five-year manipulative experiment was conducted in a Tibetan alpine meadow to examine the effects of GE on phenological processes and reproductive success. The study indicated that GE strongly affected phenological development of alpine plant species. Specifically, the low-growing, shallow-rooted species (LSS), such as Kobresia pygmaea, are more sensitive to GE-caused changes on upper-soil moisture and light. GE advanced each phonological process of K. pygmaea, except in the case of the treatment of fencing for 5 years (F5), which postponed the reproductive stage and lowered the reproductive success of K. pygmaea. Increased soil moisture triggered by GE, especially in the upper soil, may stimulate growth of LSS. However, the thick litter layer under the F5 treatment can influence the photoperiod of LSS, resulting in suppression of its reproductive development. These findings indicate that plant traits associated with resource acquisition, such as rooting depth and plant height, mediate plant phenology and reproductive responses to grazing exclusion treatments.

  13. Patterns of male reproductive success in a highly promiscuous whale species: the endangered North Atlantic right whale.

    PubMed

    Frasier, T R; Hamilton, P K; Brown, M W; Conger, L A; Knowlton, A R; Marx, M K; Slay, C K; Kraus, S D; White, B N

    2007-12-01

    Parentage analyses of baleen whales are rare, and although mating systems have been hypothesized for some species, little data on realized male reproductive success are available and the patterns of male reproductive success have remained elusive for most species. Here we combine over 20 years of photo-identification data with high-resolution genetic data for the majority of individual North Atlantic right whales to assess paternity in this endangered species. There was significant skew in male reproductive success compared to what would be expected if mating was random (P < 0.001). The difference was due to an excess of males assigned zero paternities, a deficiency of males assigned one paternity, and an excess of males assigned as fathers for multiple calves. The variance in male reproductive success was high relative to other aquatically mating marine mammals, but was low relative to mammals where the mating system is based on resource- and/or mate-defence polygyny. These results are consistent with previous data suggesting that the right whale mating system represents one of the most intense examples of sperm competition in mammals, but that sperm competition on its own does not allow for the same degree of polygyny as systems where males can control access to resources and/or mates. The age distribution of assigned fathers was significantly biased towards older males (P < 0.05), with males not obtaining their first paternity until approximately 15 years of age, which is almost twice the average age of first fertilization in females (8 years), suggesting that mate competition is preventing younger males from reproducing. The uneven distribution of paternities results in a lower effective population size in this species that already has one of the lowest reported levels of genetic diversity, which may further inhibit reproductive success through mate incompatibility of genetically similar individuals.

  14. Methoprene and protein supplements accelerate reproductive development and improve mating success of male tephritid flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have been studying the physiological mechanisms responsible for coordination of reproductive maturity and sex pheromone communication in males of tephritid flies in order to develop methods for acceleration of reproductive maturity among sterilized males. Our studies revealed that the juvenile ho...

  15. An evaluation of the effects of persistent environmental contaminants on the reproductive success of Great Blue Herons (Ardea herodias) in Indiana.

    PubMed

    Baker, S D; Sepúlveda, M S

    2009-04-01

    Contaminants in Great Blue Herons (Ardea herodias) from Indiana were quantified to determine if levels were high enough to impair reproduction. During 2005 and 2006, 35 eggs were collected from 6 colonies and analyzed for contaminants. Between 30 and 101 nests were monitored in 7 colonies weekly over a 3-month period to determine reproductive and fledging success. Average levels (+/-SD) of polychlorinated biphenyls, polycyclic aromatic hydrocarbons, and organochlorine pesticides in egg yolks were 3,101 (+/-4,737), 7.20 (+/-2.96), and 2,869 (+/-2,291) ppb, respectively. Reproductive success (average number of chicks fledged per active nest) and fledging success (number of chicks fledged per successful nest) averaged 1.52 and 1.92 chicks, respectively. Contaminant levels measured in eggs from this region are comparable to those observed not having affects on reproductive success elsewhere; therefore, factors other than environmental contamination may be affecting reproductive success of Great Blue Herons in study colonies.

  16. Maternal transfer of contaminants and reduced reproductive success of southern toads ( Bufo [Anaxyrus] terrestris ) exposed to coal combustion waste.

    PubMed

    Metts, Brian S; Buhlmann, Kurt A; Tuberville, Tracey D; Scott, David E; Hopkins, William A

    2013-03-19

    Bioaccumulation of contaminants and subsequent maternal transfer to offspring are important factors that affect the reproductive success of wildlife. However, maternal transfer of contaminants has rarely been investigated in amphibians. We examined maternal transfer of trace elements in southern toads ( Bufo[Anaxyrus] terrestris) residing in two locations: (1) an active coal combustion waste (CCW) disposal basin and adjacent 40-ha floodplain contaminated with CCW over 35 years ago and (2) an uncontaminated reference site. Our study is among the few to document tissue concentration-dependent maternal transfer of contaminants and associated adverse effects in amphibians. We found that females collected from the CCW-contaminated area had elevated concentrations of Ni, Se, and Sr; these females also transferred elevated levels of Cu, Pb, Se, and Sr to their eggs compared to females from the reference site. Overall reproductive success, estimated as a function of clutch size and offspring viability, was reduced by 27% in clutches collected from parents from the contaminated site compared to the reference site. Offspring viability negatively correlated with female and/or egg concentrations of Se and Ni. Reproductive success negatively correlated with Se and Cu concentrations in females, and Se concentrations in eggs. Our study highlights how exposure to CCW can negatively affect amphibian reproduction.

  17. Male traits, mating tactics and reproductive success in the buff-breasted sandpiper, Tryngites subruficollis.

    PubMed

    Lanctot; Weatherhead; Kempenaers; Scribner

    1998-08-01

    Buff-breasted sandpipers use a variety of mating tactics to acquire mates, including remaining at a single lek for most of the breeding season, attending multiple leks during the season, displaying solitarily or displaying both on leks and solitarily. We found that differences in body size, body condition, fluctuating asymmetry scores, wing coloration, territory location and behaviour (attraction, solicitation and agonistic) did not explain the observed variation in mating tactics used by males. Which males abandoned versus returned to leks was also not related to morphology or behaviour, and there was no tendency for males to join leks that were larger or smaller than the lek they abandoned. These results suggest that male desertion of leks was not dependent on a male's characteristics nor on the size of the lek he was presently attending. Males did join leks with larger males than their previous lek, perhaps to mate with females attracted to these larger 'hotshot' males. Males at both leks and solitary sites successfully mated. Lek tenure did not affect mating success, although lekking males appeared to mate more frequently than solitary males. Courtship disruption and to a lesser extent, female mimicry, were effective at preventing females from mating at leks, and may offer a partial explanation for female mating off leks. Our analysis that combined all males together within a year (regardless of mating tactic) indicated that males that attended leks for longer periods of time and that had fewer wing spots were significantly more likely to mate. Given some evidence that wing spotting declines with age, and that females inspect male underwings during courtship, the latter result suggests that female choice may play some role in determining male success. We suggest that male buff-breasted sandpipers may use alternative mating tactics more readily than males in other 'classic' lek-breeding species because: (1) unpredictable breeding conditions in this species' high

  18. Male traits, mating tactics and reproductive success in the buff-breasted sandpiper, Tryngites subruficollis

    USGS Publications Warehouse

    Lanctot, Richard B.; Weatherhead, Patrick J.; Kempenaers, Bart; Scribner, Kim T.

    1998-01-01

    Buff-breasted sandpipers use a variety of mating tactics to acquire mates, including remaining at a single lek for most of the breeding season, attending multiple leks during the season, displaying solitarily or displaying both on leks and solitarily. We found that differences in body size, body condition, fluctuating asymmetry scores, wing coloration, territory location and behaviour (attraction, solicitation and agonistic) did not explain the observed variation in mating tactics used by males. Which males abandoned versus returned to leks was also not related to morphology or behaviour, and there was no tendency for males to join leks that were larger or smaller than the lek they abandoned. These results suggest that male desertion of leks was not dependent on a male's characteristics nor on the size of the lek he was presently attending. Males did join leks with larger males than their previous lek, perhaps to mate with females attracted to these larger 'hotshot' males. Males at both leks and solitary sites successfully mated. Lek tenure did not affect mating success, although lekking males appeared to mate more frequently than solitary males. Courtship disruption and to a lesser extent, female mimicry, were effective at preventing females from mating at leks, and may offer a partial explanation for female mating off leks. Our analysis that combined all males together within a year (regardless of mating tactic) indicated that males that attended leks for longer periods of time and that had fewer wing spots were significantly more likely to mate. Given some evidence that wing spotting declines with age, and that females inspect male underwings during courtship, the latter result suggests that female choice may play some role in determining male success. We suggest that male buff-breasted sandpipers may use alternative mating tactics more readily than males in other 'classic' lek-breeding species because: (1) unpredictable breeding conditions in this species' high

  19. Characterizing the interaction between the bogus yucca moth and yuccas: do bogus yucca moths impact yucca reproductive success?

    PubMed

    Althoff, David M; Segraves, Kari A; Sparks, Jed P

    2004-07-01

    Yucca moths are most well known for their obligate pollination mutualism with yuccas, where pollinator moths provide yuccas with pollen and, in exchange, the moth larvae feed on a subset of the developing yucca seeds. The pollinators, however, comprise only two of the three genera of yucca moths. Members of the third genus, Prodoxus, are the "bogus yucca moths" and are sister to the pollinator moths. Adult Prodoxus lack the specialized mouthparts used for pollination and the larvae feed on plant tissues other than seeds. Prodoxus larvae feed within the same plants as pollinator larvae and have the potential to influence yucca reproductive success directly by drawing resources away from flowers and fruit, or indirectly by modifying the costs of the mutualism with pollinators. We examined the interaction between the scape-feeding bogus yucca moth, Prodoxus decipiens, and one of its yucca hosts, Yucca filamentosa, by comparing female reproductive success of plants with and without moth larvae. We determined reproductive success by measuring a set of common reproductive traits such as flowering characteristics, seed set, and seed germination. In addition, we also quantified the percent total nitrogen in the seeds to determine whether the presence of larvae could potentially reduce seed quality. Flowering characteristics, seed set, and seed germination were not significantly different between plants with and without bogus yucca moth larvae. In contrast, the percent total nitrogen content of seeds was significantly lower in plants with P. decipiens larvae, and nitrogen content was negatively correlated with the number of larvae feeding within the inflorescence scape. Surveys of percent total nitrogen at three time periods during the flowering and fruiting of Y. filamentosa also showed that larval feeding decreased the amount of nitrogen in fruit tissue. Taken together, the results suggest that although P. decipiens influences nitrogen distribution in Y. filamentosa, this

  20. Chromosomal aberrations, reproductive success, life span, and mortality in irradiated Neanthes arenaceodentata (polychaeta)

    SciTech Connect

    Anderson, S.L.; Harrison, F.L.; Chan, G.; Moore, D.H. II

    1987-10-01

    The polychaete worm Neanthes arenaceodentata ws used in experiments to determine possible relationships between short-term genotoxicity tests and reproductive and lethal consequences of exposure to ionizing radiation. Groups of juvenile N. arenaceodentata received one of four different radiation doses (2, 4, 8, and 16 Gy) to determine dose-effect estimates for chromosomal aberration induction, and groups of both adult and juveniles received one of seven different radiation doses (1, 4, 8.4, 46, 102, 500, and 1000 Gy) to determine dose-effect estimates for reproduction, mortality, and life span. Effects on reproduction and genetic material were observed at the lowest doses and in the same range; detrimental reproductive effects were observed at 1 to 4 Gy, and the frequency of chromosomal aberrations were significantly increased at 2 Gy. Only high doses resulted in acute mortality (>500 Gy) and decreased life span (>100 Gy). Dose-effect estimates for chromosomal aberration induction were dependant on radiation dose and on the stage of the cell cycle at the time of irradiation. Dose-effect estimates for reproduction were dependant on dose and the potential for repopulation of gonadal tissue. Such knowledge is required because factors, such as cell-cycle effects, may modify dose-effect estimates. It is concluded that short-term genotoxicity tests can be predictive of detrimental reproductive effects in those model systems for which basic cell kinetics and reproductive parameters are well known. 4 refs., 11 figs., 13 tabs.

  1. Spatio-temporal variation in European starling reproductive success at multiple small spatial scales.

    PubMed

    Brickhill, Daisy; Evans, Peter Gh; Reid, Jane M

    2015-08-01

    Understanding population dynamics requires spatio-temporal variation in demography to be measured across appropriate spatial and temporal scales. However, the most appropriate spatial scale(s) may not be obvious, few datasets cover sufficient time periods, and key demographic rates are often incompletely measured. Consequently, it is often assumed that demography will be spatially homogeneous within populations that lack obvious subdivision. Here, we quantify small-scale spatial and temporal variation in a key demographic rate, reproductive success (RS), within an apparently contiguous population of European starlings. We used hierarchical cluster analysis to define spatial clusters of nest sites at multiple small spatial scales and long-term data to test the hypothesis that small-scale spatio-temporal variation in RS occurred. RS was measured as the number of chicks alive ca. 12 days posthatch either per first brood or per nest site per breeding season (thereby incorporating multiple breeding attempts). First brood RS varied substantially among spatial clusters and years. Furthermore, the pattern of spatial variation was stable across years; some nest clusters consistently produced more chicks than others. Total seasonal RS also varied substantially among spatial clusters and years. However, the magnitude of variation was much larger and the pattern of spatial variation was no longer temporally consistent. Furthermore, the estimated magnitude of spatial variation in RS was greater at smaller spatial scales. We thereby demonstrate substantial spatial, temporal, and spatio-temporal variation in RS occurring at very small spatial scales. We show that the estimated magnitude of this variation depended on spatial scale and that spatio-temporal variation would not have been detected if season-long RS had not been measured. Such small-scale spatio-temporal variation should be incorporated into empirical and theoretical treatments of population dynamics.

  2. Invasion of an exotic forb impacts reproductive success and site fidelity of a migratory songbird.

    PubMed

    Ortega, Yvette Katina; McKelvey, Kevin Scot; Six, Diana Lee

    2006-08-01

    Although exotic plant invasions threaten natural systems worldwide, we know little about the specific ecological impacts of invaders, including the magnitude of effects and underlying mechanisms. Exotic plants are likely to impact higher trophic levels when they overrun native plant communities, affecting habitat quality for breeding songbirds by altering food availability and/or nest predation levels. We studied chipping sparrows (Spizella passerina) breeding in savannas that were either dominated by native vegetation or invaded by spotted knapweed (Centaurea maculosa), an exotic forb that substantially reduces diversity and abundance of native herbaceous plant species. Chipping sparrows primarily nest in trees but forage on the ground, consuming seeds and arthropods. We found that predation rates did not differ between nests at knapweed and native sites. However, initiation of first nests was delayed at knapweed versus native sites, an effect frequently associated with low food availability. Our seasonal fecundity model indicated that breeding delays could translate to diminished fecundity, including dramatic declines in the incidence of double brooding. Site fidelity of breeding adults was also substantially reduced in knapweed compared to native habitats, as measured by return rates and shifts in territory locations between years. Declines in reproductive success and site fidelity were greater for yearling versus older birds, and knapweed invasion appeared to exacerbate differences between age classes. In addition, grasshoppers, which represent an important prey resource, were substantially reduced in knapweed versus native habitats. Our results strongly suggest that knapweed invasion can impact chipping sparrow populations by reducing food availability. Food chain effects may be an important mechanism by which strong plant invaders impact songbirds and other consumers.

  3. The effects of chronic radiation on reproductive success of the polychaete worm Neanthes arenaceodentata

    SciTech Connect

    Harrison, F.L.; Anderson, S.L.

    1988-12-01

    The effects of lifetime exposure to chronic irradiation on reproductive success were assessed for laboratory populations of the polychaete worm Neanthes arenaceodentata. Lifetime exposure was initiated upon the spawning of the P1 female and was terminated upon spawning of the F1 female. Groups of experimental worms received either no radiation (controls) or 0.19, 2.1, or 17 mGy/h. The total dose received by the worms was either background or approximately 0.55, 6.5, or 54 Gy, respectively. The broods from the F1 mated pairs were sacrificed before hatching occurred, and information was obtained on brood size, on the number of normal and abnormal embryos, and on the number of embryos that were living, dying, and dead. The mean number of embryos in the broods from the F1 females exposed to lifetime radiation of 0.19 and 2.1 mGy/h was not significantly different from the mean number of embryos from control females; however, the mean number of embryos was different from those F1 females exposed to 17 mGy/h. There was a significant reduction in the number of live embryos in the broods from the F1 mated pairs that were exposed to the lowest dose rate given, 0.19 mGy/h, as well as those exposed to 2.1 and 17 mGy/h. Also, increased percentages of abnormal embryos were determined in the broods of all the radiation-exposed groups. 39 refs., 10 figs., 15 tabs.

  4. Contaminant exposure and reproductive success of Ospreys (Pandion haliaetus) nesting in Chesapeake Bay regions of concern

    USGS Publications Warehouse

    Rattner, B.A.; McGowan, P.C.; Golden, N.H.; Hatfield, J.S.; Toschik, P.C.; Lukei, R.F.; Hale, R.C.; Schmitz-Afonso, I.; Rice, C.P.

    2004-01-01

    The Chesapeake Bay osprey population has more than doubled in size since restrictions were placed on the production and use of DDT and other toxic organochlorine contaminants in the 1970s. Ospreys are now nesting in the most highly polluted portions of the Bay. In 2000 and 2001, contaminant exposure and reproduction were monitored in ospreys nesting in regions of concern, including Baltimore Harbor and the Patapsco River, the Anacostia and middle Potomac rivers, and the Elizabeth River, and a presumed reference site consisting of the South, West, and Rhode rivers. A 'sample egg' from each study nest was collected for contaminant analysis, and the fate of eggs remaining in each nest (n = 14-16/site) was monitored at 7- to 10-day intervals from egg incubation through fledging of young. Ospreys fledged young in regions of concern (observed success: 0.88 -1.53 fledglings/active nest), although productivity was marginal for sustaining local populations in Baltimore Harbor and the Patapsco River and in the Anacostia and middle Potomac rivers. Concentrations of p,p'DDE and many other organochlorine pesticides or metabolites, total PCBs, some arylhydrocarbon receptor-active PCB congeners and polybrominated diphenyl ether congeners, and perfluorooctanesulfonate were often greater in sample eggs from regions of concern compared to the reference site. Nonetheless, logistic regression analyses did not provide evidence linking marginal productivity to p,p' -DDE, total PCBs, or arylhydrocarbon receptor-active PCB congener exposure in regions of concern. In view of the moderate concentrations of total PCBs in eggs from the reference site, concerns related to new and emerging toxicants, and the absence of ecotoxicological data for terrestrial vertebrates in many Bay tributaries, a more thorough spatial evaluation of contaminant exposure in ospreys throughout the Chesapeake may be warranted.

  5. Potential Influences of Climate and Nest Structure on Spotted Owl Reproductive Success: A Biophysical Approach

    PubMed Central

    Rockweit, Jeremy T.; Franklin, Alan B.; Bakken, George S.; Gutiérrez, R. J.

    2012-01-01

    Many bird species do not make their own nests; therefore, selection of existing sites that provide adequate microclimates is critical. This is particularly true for owls in north temperate climates that often nest early in the year when inclement weather is common. Spotted owls use three main types of nest structures, each of which are structurally distinct and may provide varying levels of protection to the eggs or young. We tested the hypothesis that spotted owl nest configuration influences nest microclimate using both experimental and observational data. We used a wind tunnel to estimate the convective heat transfer coefficient (hc) of eggs in 25 potential nest configurations that mimicked 2 nest types (top-cavity and platform nests), at 3 different wind speeds. We then used the estimates of hc in a biophysical heat transfer model to estimate how long it would take unattended eggs to cool from incubation temperature (∼36°C) to physiological zero temperature (PZT; ∼26°C) under natural environmental conditions. Our results indicated that the structural configuration of nests influences the cooling time of the eggs inside those nests, and hence, influences the nest microclimate. Estimates of time to PZT ranged from 10.6 minutes to 33.3 minutes. Nest configurations that were most similar to platform nests always had the fastest egg cooling times, suggesting that platform nests were the least protective of those nests we tested. Our field data coupled with our experimental results suggested that nest choice is important for the reproductive success of owls during years of inclement weather or in regions characterized by inclement weather during the nesting season. PMID:22859993

  6. Lead concentrations and reproductive success in European starlings Sturnus vulgaris nesting within highway roadside verges

    USGS Publications Warehouse

    Grue, C.E.; Hoffman, D.J.; Beyer, W.N.; Franson, L.P.

    1986-01-01

    In 1981, the authors studied lead concentrations and reproductive success in free-living European starlings Sturnus vulgaris nesting within the verges of two Maryland highways with different traffic volumes, Route 197(average daily traffic volume[ADT] = 10,800 vehicles) and the Baltimore-Washington Parkway (ADT=52,500 vehicles) and a nearby control area. Concentrations (mg kg-1 dry weight) of lead in the ingesta (84-94 mg kg-1), carcasses (4.0-9.6 mg kg-1)and feathers (6.8-52 mg kg-1) of Parkway nestlings and adults were 3 to 13 times those found in starlings from the control area, whereas lead concentrations in the ingesta and tissues of starlings from the verge of Route 197 were similar to those of controls. Activity of delta-aminolevulinic acid dehydratase (ALAD) in red blood cells (RBCs) of adult and nestling starlings from the Parkway was depressed from 43 to 60% compared to controls. RBC ALAD activity in adults from nests along Route 197 was similar to that of adult starlings from the control area, but that of their young was depressed 17%. Haemoglobin concentrations (-16%) and haematocrits (-10%) in Parkway nestlings were depressed compared with those of nestlings from the other two study areas, whereas those of adults were not affected. Clutch size, number of young hatched and the number of young in nests 1 to 3 days before fledging were similar among sites, as were body weights of adults and prefledging weights of their young. However, brain weights of Parkway nestlings were lower (P < 0.05) than those of nestlings from the other study areas. Results suggests that lead within verges of major highways probably does not pose a serious hazard to adult ground-foraging songbirds. However, the effects of lead-induced reductions in haemoglobin concentration, haematocrit, RBC ALAD activity and brain weight on the postfledging survival of their young are not known.

  7. Potential influences of climate and nest structure on spotted owl reproductive success: a biophysical approach.

    PubMed

    Rockweit, Jeremy T; Franklin, Alan B; Bakken, George S; Gutiérrez, R J

    2012-01-01

    Many bird species do not make their own nests; therefore, selection of existing sites that provide adequate microclimates is critical. This is particularly true for owls in north temperate climates that often nest early in the year when inclement weather is common. Spotted owls use three main types of nest structures, each of which are structurally distinct and may provide varying levels of protection to the eggs or young. We tested the hypothesis that spotted owl nest configuration influences nest microclimate using both experimental and observational data. We used a wind tunnel to estimate the convective heat transfer coefficient (h(c)) of eggs in 25 potential nest configurations that mimicked 2 nest types (top-cavity and platform nests), at 3 different wind speeds. We then used the estimates of h(c) in a biophysical heat transfer model to estimate how long it would take unattended eggs to cool from incubation temperature (~36 °C) to physiological zero temperature (PZT; ~26 °C) under natural environmental conditions. Our results indicated that the structural configuration of nests influences the cooling time of the eggs inside those nests, and hence, influences the nest microclimate. Estimates of time to PZT ranged from 10.6 minutes to 33.3 minutes. Nest configurations that were most similar to platform nests always had the fastest egg cooling times, suggesting that platform nests were the least protective of those nests we tested. Our field data coupled with our experimental results suggested that nest choice is important for the reproductive success of owls during years of inclement weather or in regions characterized by inclement weather during the nesting season.

  8. Contaminant exposure and reproductive success of ospreys (Pandion haliaetus) nesting in Chesapeake Bay regions of concern.

    PubMed

    Rattner, B A; McGowan, P C; Golden, N H; Hatfield, J S; Toschik, P C; Lukei, R F; Hale, R C; Schmitz-Afonso, I; Rice, C P

    2004-07-01

    The Chesapeake Bay osprey population has more than doubled in size since restrictions were placed on the production and use of DDT and other toxic organochlorine contaminants in the 1970s. Ospreys are now nesting in the most highly polluted portions of the Bay. In 2000 and 2001, contaminant exposure and reproduction were monitored in ospreys nesting in regions of concern, including Baltimore Harbor and the Patapsco River, the Anacostia and middle Potomac rivers, and the Elizabeth River, and a presumed reference site consisting of the South, West, and Rhode rivers. A "sample egg" from each study nest was collected for contaminant analysis, and the fate of eggs remaining in each nest (n = 14-16/site) was monitored at 7- to 10-day intervals from egg incubation through fledging of young. Ospreys fledged young in regions of concern (observed success: 0.88-1.53 fledglings/active nest), although productivity was marginal for sustaining local populations in Baltimore Harbor and the Patapsco River and in the Anacostia and middle Potomac rivers. Concentrations of p,p'-DDE and many other organochlorine pesticides or metabolites, total PCBs, some arylhydrocarbon receptor-active PCB congeners and polybrominated diphenyl ether congeners, and perfluorooctanesulfonate were often greater in sample eggs from regions of concern compared to the reference site. Nonetheless, logistic regression analyses did not provide evidence linking marginal productivity to p,p'-DDE, total PCBs, or arylhydrocarbon receptor-active PCB congener exposure in regions of concern. In view of the moderate concentrations of total PCBs in eggs from the reference site, concerns related to new and emerging toxicants, and the absence of ecotoxicological data for terrestrial vertebrates in many Bay tributaries, a more thorough spatial evaluation of contaminant exposure in ospreys throughout the Chesapeake may be warranted.

  9. Spatio-temporal variation in European starling reproductive success at multiple small spatial scales

    PubMed Central

    Brickhill, Daisy; Evans, Peter GH; Reid, Jane M

    2015-01-01

    Understanding population dynamics requires spatio-temporal variation in demography to be measured across appropriate spatial and temporal scales. However, the most appropriate spatial scale(s) may not be obvious, few datasets cover sufficient time periods, and key demographic rates are often incompletely measured. Consequently, it is often assumed that demography will be spatially homogeneous within populations that lack obvious subdivision. Here, we quantify small-scale spatial and temporal variation in a key demographic rate, reproductive success (RS), within an apparently contiguous population of European starlings. We used hierarchical cluster analysis to define spatial clusters of nest sites at multiple small spatial scales and long-term data to test the hypothesis that small-scale spatio-temporal variation in RS occurred. RS was measured as the number of chicks alive ca. 12 days posthatch either per first brood or per nest site per breeding season (thereby incorporating multiple breeding attempts). First brood RS varied substantially among spatial clusters and years. Furthermore, the pattern of spatial variation was stable across years; some nest clusters consistently produced more chicks than others. Total seasonal RS also varied substantially among spatial clusters and years. However, the magnitude of variation was much larger and the pattern of spatial variation was no longer temporally consistent. Furthermore, the estimated magnitude of spatial variation in RS was greater at smaller spatial scales. We thereby demonstrate substantial spatial, temporal, and spatio-temporal variation in RS occurring at very small spatial scales. We show that the estimated magnitude of this variation depended on spatial scale and that spatio-temporal variation would not have been detected if season-long RS had not been measured. Such small-scale spatio-temporal variation should be incorporated into empirical and theoretical treatments of population dynamics. PMID:26380670

  10. Effects of forest fragmentation on phenological patterns and reproductive success of the tropical dry forest tree Ceiba aesculifolia.

    PubMed

    Herrerías-Diego, Yvonne; Quesada, Mauricio; Stoner, Kathryn E; Lobo, Jorge A

    2006-08-01

    Spatial isolation caused by forest fragmentation and temporal isolation caused by asynchronous flowering of plants have been proposed as important factors that affect the reproduction ofplant populations. In a 4-year study, we determined the effects of forest fragmentation and spatial isolation on flowering phenology and reproductive success of the tropical tree Ceiba aesculifolia ([Kunth] Britton & Rose). We conducted our study in the dry forest of Mexico and compared populations in two habitat conditions based on density and environmental conditions: (1) disturbed habitat (four populations of < or =3 reproductive individuals/ha surrounded by agriculturalfields or pastures) and (2) undisturbed habitat (three populations of groups of >6 reproductive individuals/ha surrounded by undisturbed mature forest). We compared the following variables within these populations over 4 years: flowering overlap, proportion of individuals with flowers and fruit, total flower production, total fruit production, fruit set, seed production, and seed abortion. Little overlap in flowering occurred among the populations in the two habitat conditions. The flowering period of trees in the disturbed habitat initiated between 15 to 20 days before the flowering period of trees in the undisturbed habitat during 3 years. Flowering of trees in the undisturbed habitat peaked at the end of the flowering period of the trees in the disturbed habitat. The proportion of trees that flowered was greater in the undisturbed habitat. Nevertheless, total flower production was greater in the disturbed habitat and these differences were maintained across 3 years. The proportion of individuals that produced fruit did not differ across habitat conditions but did differ across years. Total fruit production was greater in the disturbed habitat, but fruit set and seed production were the same across years and between habitat conditions. Seed abortion varied over years between habitats. We concluded that forest

  11. The potential impacts of migratory difficulty, including warmer waters and altered flow conditions, on the reproductive success of salmonid fishes.

    PubMed

    Fenkes, Miriam; Shiels, Holly A; Fitzpatrick, John L; Nudds, Robert L

    2016-03-01

    Climate change and urbanisation of watercourses affect water temperatures and current flow velocities in river systems on a global scale. This represents a particularly critical issue for migratory fish species with complex life histories that use rivers to reproduce. Salmonids are migratory keystone species that provide substantial economical value to ecosystems and human societies. Consequently, a comprehensive understanding of the effects of environmental stressors on their reproductive success is critical in order to ensure their continued abundance during future climatic change. Salmonids are capital breeders, relying entirely on endogenous energy stores to fuel return migration to their natal spawning sites and reproduction upon arrival. Metabolic rates and cost of transport en-route increase with temperature and at extreme temperatures, swimming is increasingly fuelled anaerobically, resulting in an oxygen debt and reduced capacity to recover from exhaustive exercise. Thermally challenged salmonids also produce less viable gametes, which themselves are affected by water temperature after release. Passage through hydrological barriers and temperature changes both affect energy expenditure. As a result, important energetic tradeoffs emerge between extra energy used during migration and that available for other facets of the reproductive cycle, such as reproductive competition and gamete production. However, studies identifying these tradeoffs are extremely sparse. This review focuses on the specific locomotor responses of salmonids to thermal and hydrological challenges, identifying gaps in our knowledge and highlighting the potential implications for key aspects of their reproduction.

  12. The potential impacts of migratory difficulty, including warmer waters and altered flow conditions, on the reproductive success of salmonid fishes

    PubMed Central

    Fenkes, Miriam; Shiels, Holly A.; Fitzpatrick, John L.; Nudds, Robert L.

    2016-01-01

    Climate change and urbanisation of watercourses affect water temperatures and current flow velocities in river systems on a global scale. This represents a particularly critical issue for migratory fish species with complex life histories that use rivers to reproduce. Salmonids are migratory keystone species that provide substantial economical value to ecosystems and human societies. Consequently, a comprehensive understanding of the effects of environmental stressors on their reproductive success is critical in order to ensure their continued abundance during future climatic change. Salmonids are capital breeders, relying entirely on endogenous energy stores to fuel return migration to their natal spawning sites and reproduction upon arrival. Metabolic rates and cost of transport en-route increase with temperature and at extreme temperatures, swimming is increasingly fuelled anaerobically, resulting in an oxygen debt and reduced capacity to recover from exhaustive exercise. Thermally challenged salmonids also produce less viable gametes, which themselves are affected by water temperature after release. Passage through hydrological barriers and temperature changes both affect energy expenditure. As a result, important energetic tradeoffs emerge between extra energy used during migration and that available for other facets of the reproductive cycle, such as reproductive competition and gamete production. However, studies identifying these tradeoffs are extremely sparse. This review focuses on the specific locomotor responses of salmonids to thermal and hydrological challenges, identifying gaps in our knowledge and highlighting the potential implications for key aspects of their reproduction. PMID:26603555

  13. Compatibility drives female preference and reproductive success in the monogamous California mouse (Peromyscus californicus) more strongly than male testosterone measures.

    PubMed

    Gleason, Erin D; Holschbach, Mary A; Marler, Catherine A

    2012-01-01

    Female assessment of male attractiveness and how preferred qualities impact reproductive success is central to the study of mate choice. Male attractiveness may depend on traits beneficial to the reproductive success (RS) of any female, termed 'universal quality', and/or on behavioral and biological interactions between potential mates that reflect 'compatibility'. The steroid hormone testosterone (T) often underlies male attractiveness in rodents and is associated with enhanced paternal care in the monogamous and biparental California mouse (Peromyscus californicus). We hypothesized that (1) T-characteristics are universally attractive to female California mice and that (2) if reproductive success is higher for females mated with preferred males, then females mated with males preferred by other females will also have higher reproductive success. Alternatively, we speculated that pair compatibility, based on emergent pair qualities, is important for a species with coordinated offspring care. We assessed individual T-characteristics in three ways: (1) T-response to GnRH challenges (2) baseline T-level and (3) T-response to a female. Testosterone-response did not predict female preference, but females spent more time investigating males with higher baseline T (accounting for only 9.6% of the variation in investigation time). None of the T-measures was associated with RS. Females paired with males they preferred produced litters more quickly and had higher RS than females paired with their non-preferred males. Naïve females who did not undergo preference tests had equivalent RS regardless of whether their mate was preferred or non-preferred by another female. These data suggest that higher male T elicits investigation, but female preference in the California mouse is more strongly linked with compatibility because individual preference was a better predictor of RS than any T measure.

  14. Reproductive success is driven by local site fidelity despite stronger specialisation by individuals for large-scale habitat preference.

    PubMed

    Patrick, Samantha Clare; Weimerskirch, Henri

    2017-01-24

    There is widespread evidence that within populations, specialists and generalists can coexist and this is particularly prevalent in marine ecosystems, where foraging specialisations are evident. While individuals may limit niche overlap by consistently foraging in specific areas, site fidelity may also emerge as an artefact of habitat choice, but both drivers and fitness consequences of site fidelity are poorly understood. Here, we examine an individual metric of site and habitat fidelity, using tracking data collected over 11 years for black-browed albatrosses (Thalassarche melanophris). Fidelity was calculated as the similarity between pairs of foraging zones, quantifying measures for within and between years. Foraging areas were identified using area-restricted search, defined as periods during which birds decrease speed and increase turning. Our results demonstrate that birds were considerably more specialised in the habitat in which they forage than the exact location they use within years, and there was a similar pattern between years. However, despite this, it was site fidelity that explained reproductive success. Within a single year, females which were more faithful to a specific location had higher reproductive success than non-specialists, and between years there was a tendency for both sexes. Our results suggest that black-browed albatrosses are highly faithful in their foraging habitat but it is rather site fidelity that is more clearly associated with reproductive success.

  15. Organochlorine contaminant exposure and reproductive success of Black-Crowned Night Herons (Nycticorax nycticorax) nesting in Baltimore Harbor, Maryland

    USGS Publications Warehouse

    Rattner, B.A.; McGowan, P.C.; Hatfield, J.S.; Hong, C.-S.; Chu, S.G.

    2001-01-01

    The declining size of the Baltimore Harbor black-crowned night heron (Nycticorax nycticorax) colony has been hypothesized to be linked to PCB exposure. In 1998, a 'sample egg' was collected from 65 black-crowned night heron nests (each containing > three eggs) for contaminant analysis, and the remaining eggs in these 65 nests, plus four two-egg nests, were monitored for hatching and fledging success. Eggs were also collected from 12 nests at Holland Island, a reference site in southern Chesapeake Bay. Samples were analyzed for 26 organochlorine pesticides and metabolites, and 145 PCB congeners. Pesticide and metabolite concentrations, including p,p'-DDE, were well below thresholds associated with adverse reproductive effects at both sites. Average concentration of total PCBs, 12 Ah receptor-active PCB congeners, and toxic equivalents in eggs from Baltimore Harbor were greater (up to 35- fold) than that observed in Holland Island samples. Overall nest success at the Baltimore Harbor heronry was estimated by the Mayfield method to be 0.74, and the mean number of young fledged/hen was 2.05, which is within published productivity estimates for maintaining a stable black-crowned night heron population. Using logistic regression, no significant relationships were found between organochlorine contaminant concentrations in sample eggs and hatching, fledging, or overall reproductive success. Processes other than poor reproduction (e.g., low post- fledging survival, emigration, habitat degradation) may be responsible for the declining size of the Baltimore Harbor colony.

  16. Organochlorine contaminant exposure and reproductive success of black-crowned night-herons (Nycticorax nycticorax) nesting in Baltimore harbor, Maryland.

    PubMed

    Rattner, B A; McGowan, P C; Hatfield, J S; Hong, C S; Chu, S G

    2001-07-01

    The declining size of the Baltimore Harbor black-crowned night-heron (Nycticorax nycticorax) colony has been hypothesized to be linked to polychlorinated biphenyl (PCB) exposure. In 1998, a "sample egg" was collected from 65 black-crowned night-heron nests (each containing > or = three eggs) for contaminant analysis, and the remaining eggs in these 65 nests, plus four two-egg nests, were monitored for hatching and fledging success. Eggs were also collected from 12 nests at Holland Island, a reference site in southern Chesapeake Bay. Samples were analyzed for 26 organochlorine pesticides and metabolities and 145 PCB congeners. Pesticide and metabolite concentrations, including p,p'-DDE, were well below thresholds associated with adverse reproductive effects at both sites. Average concentration of total PCBs, 12 Ah receptor-active PCB congeners, and toxic equivalents in eggs from Baltimore Harbor were greater (up to 35-fold) than that observed in Holland Island samples. Overall nest success at the Baltimore Harbor heronry was estimated by the Mayfield method to be 0.74, and the mean number of young fledged/hen was 2.05, which is within published productivity estimates for maintaining a stable black-crowned night-heron population. Using logistic regression, no significant relationships were found between organochlorine contaminant concentrations in sample eggs and hatching, fledging, or overall reproductive success. Processes other than poor reproduction (e.g., low postfledging survival, emigration, habitat degradation) may be responsible for the declining size of the Baltimore Harbor colony.

  17. Personality traits of pair members predict pair compatibility and reproductive success in a socially monogamous parrot breeding in captivity.

    PubMed

    Fox, Rebecca A; Millam, James R

    2014-01-01

    While pair behavioral compatibility seems to be a determinant of reproductive success in at least some species of monogamous birds, the specific factors underlying among-pair variation in behavioral compatibility remain poorly understood. However, recent research on the relationship between personality traits and reproductive success in several species of socially monogamous birds suggests that the fit between mates' personality traits might play a role in determining behavioral compatibility. To test this hypothesis, we used ten pairs formed by free choice from a captive population of cockatiels (Nymphicus hollandicus) to investigate whether personality ratings could be used to predict pair compatibility and reproductive success in pairs breeding for the first time. We found that pairs that ultimately hatched eggs paired disassortatively for agreeableness (an aggregate measure of social style which measures birds' tendency to be aggressive vs. gentle, submissive, and tolerant of others' behavior), and, as predicted, showed lower intrapair aggression and better coordination during incubation. Conversely, unsuccessful pairs paired assortatively for agreeableness, showed higher levels of intrapair aggression, and showed poorer coordination during incubation. Our results suggest that personality measurements may provide a useful adjunct to other information currently used in selecting mates for birds breeding in captivity.

  18. Behavioral and environmental determinants of reproductive success in traditional Moroccan Berber groups.

    PubMed

    Crognier, E

    1996-06-01

    The reproductive histories of women aged 45-70 years from a homogeneous Berber population of South Morocco were sampled from three contrasting environments: a small town (n = 75), villages in the lowlands (n = 217), and villages in the highlands (n = 128). The main reproductive variables oppose the relatively better conditions of fertile life in the lowlands to the more hostile ones in the highlands. Path analysis confirms this difference through reproductive behaviors and suggests the existence of mechanisms for controlling family size in town and in the rural lowlands, but not in the highlands. The estimates of survival function show significant differences among the three groups, the conditions for survival in the highlands being clearly less favorable. Rank tests of the association of survival data with several covariates indicate the association of survival data with vaccinations and with conditions of delivery. In spite of the lower rate of offspring survival, the highlander group would demonstrate a higher overall number of children reaching reproductive maturity, thanks to an extended reproductive span.

  19. Does Temperature-Mediated Reproductive Success Drive the Direction of Species Displacement in Two Invasive Species of Leafminer Fly?

    PubMed Central

    Wang, Haihong; Reitz, Stuart R.; Xiang, Juncheng; Smagghe, Guy; Lei, Zhongren

    2014-01-01

    Liriomyza sativae and L. trifolii (Diptera: Agromyzidae) are two highly invasive species of leafmining flies, which have become established as pests of horticultural crops throughout the world. In certain regions where both species have been introduced, L. sativae has displaced L. trifolii, whereas the opposite has occurred in other regions. These opposing outcomes suggest that neither species is an inherently superior competitor. The regions where these displacements have been observed (southern China, Japan and western USA) are climatically different. We determined whether temperature differentially affects the reproductive success of these species and therefore if climatic differences could affect the outcome of interspecific interactions where these species are sympatric. The results of life table parameters indicate that both species can develop successfully at all tested temperatures (20, 25, 31, 33°C). L. sativae had consistently higher fecundities at all temperatures, but L. trifolii developed to reproductive age faster. Age-stage specific survival rates were higher for L. sativae at low temperatures, but these were higher for L. trifolii at higher temperatures. We then compared the net reproductive rates (R0) for both species in pure and mixed cultures maintained at the same four constant temperatures. Both species had significantly lower net reproductive rates in mixed species cultures compared with their respective pure species cultures, indicating that both species are subject to intense interspecific competition. Net reproductive rates were significantly greater for L. sativae than for L. trifolii in mixed species groups at the lower temperatures, whereas the opposite occurred at the higher temperature. Therefore, interactions between the species are temperature dependent and small differences could shift the competitive balance between the species. These temperature mediated effects may contribute to the current ongoing displacement of L. sativae by

  20. Effects of shallow natural gas well structures and associated roads on grassland songbird reproductive success in Alberta, Canada

    PubMed Central

    Koper, Nicola

    2017-01-01

    Grassland songbird populations across North America have experienced dramatic population declines due to habitat loss and degradation. In Canada, energy development continues to fragment and disturb prairie habitat, but effects of oil and gas development on reproductive success of songbirds in North American mixed-grass prairies remains largely unknown. From 2010–2012, in southeastern Alberta, Canada, we monitored 257 nests of two ground-nesting grassland songbird species, Savannah sparrow (Passerculus sandwichensis) and chestnut-collared longspur (Calcarius ornatus). Nest locations varied with proximity to and density of conventional shallow gas well structures and associated roads in forty-two 258-ha mixed-grass prairie sites. We estimated the probabilities of nest success and clutch size relative to gas well structures and roads. There was little effect of distance to or density of gas well structure on nest success; however, Savannah sparrow experienced lower nest success near roads. Clutch sizes were lower near gas well structures and cattle water sources. Minimizing habitat disturbance surrounding gas well structures, and reducing abundance of roads and trails, would help minimize impacts on reproductive success for some grassland songbirds. PMID:28355241

  1. Effects of shallow natural gas well structures and associated roads on grassland songbird reproductive success in Alberta, Canada.

    PubMed

    Yoo, Jenny; Koper, Nicola

    2017-01-01

    Grassland songbird populations across North America have experienced dramatic population declines due to habitat loss and degradation. In Canada, energy development continues to fragment and disturb prairie habitat, but effects of oil and gas development on reproductive success of songbirds in North American mixed-grass prairies remains largely unknown. From 2010-2012, in southeastern Alberta, Canada, we monitored 257 nests of two ground-nesting grassland songbird species, Savannah sparrow (Passerculus sandwichensis) and chestnut-collared longspur (Calcarius ornatus). Nest locations varied with proximity to and density of conventional shallow gas well structures and associated roads in forty-two 258-ha mixed-grass prairie sites. We estimated the probabilities of nest success and clutch size relative to gas well structures and roads. There was little effect of distance to or density of gas well structure on nest success; however, Savannah sparrow experienced lower nest success near roads. Clutch sizes were lower near gas well structures and cattle water sources. Minimizing habitat disturbance surrounding gas well structures, and reducing abundance of roads and trails, would help minimize impacts on reproductive success for some grassland songbirds.

  2. The Application of Age-Specific Rates to Divorce

    ERIC Educational Resources Information Center

    England, J. Lynn; Kunz, Phillip R.

    1975-01-01

    Age-Specific divorce rates and weighted divorce rates are evaluated in comparison with several traditional rates. The analysis reversals of the ranking of some states in comparison with rankings based on other divorce rates, and the age-specific rates for young married couples is lower than expected. (Author)

  3. Pollen flow and effects of population structure on selfing rates and female and male reproductive success in fragmented Magnolia stellata populations

    PubMed Central

    2013-01-01

    Background Fragmentation of plant populations may affect mating patterns and female and male reproductive success. To improve understanding of fragmentation effects on plant reproduction, we investigated the pollen flow patterns in six adjacent local populations of Magnolia stellata, an insect-pollinated, threatened tree species in Japan, and assessed effects of maternal plant (genet) size, local genet density, population size and neighboring population size on female reproductive success (seed production rates), and effects of mating distance, paternal genet size, population size and separation of populations on male reproductive success. Results The seed production rate, i.e. the proportion of ovules that successfully turned into seeds, varied between 1.0 and 6.5%, and increased with increasing population size and neighboring population size, and with decreasing maternal genet size and local genet density. The selfing rate varied between 3.6 and 28.9%, and increased with increasing maternal genet size and with declining local genet density. Male reproductive success increased with increasing paternal genet size, and decreased with increasing mating distance and separation of population. Pollen flow between the populations was low (6.1%) and highly leptocurtic. Conclusions Our results indicate that habitat fragmentation, separation and reduced size of populations, affected mating patterns and reproductive success of M. stellata. Local competition for pollinators and plant display size were likely to alter the reproductive success. PMID:23517612

  4. Reproductive success of the Black-crowned Night Heron at Alcatraz Island, San Francisco Bay, California, 1990-2002

    USGS Publications Warehouse

    Hothem, Roger L.; Hatch, Daphne

    2004-01-01

    Nesting chronology, habitat use, subcolony use, and hatchability were documented for the Black-crowned Night Heron (Nycticorax nycticorax) nesting at Alcatraz Island, San Francisco Bay, California during 1990-2002. Reproductive success was estimated using the Mayfield method and compared among years. Totals of monitored nests per year ranged from 68 in 2001 to 341 in 1996, with a trend of declining numbers since 1996. An increase in numbers of the Western Gull (Larus occidentalis), the Black-crowned Night Heron’s primary competitor, occurred during the same period. Overall reproductive success of the Black-crowned Night Heron at Alcatraz Island was below the 13-year average of 56.4% since 1996. During the study, the average number of chicks fledged per nest each year ranged from 0.46 to 1.27, which is less than the two chicks per nest suggested as a requirement for a sustained population. Embryos in five of 187 failed Black-crowned Night Heron eggs were deformed. In 1990 and 1991, eggs were analyzed for a wide range of contaminants, but none appeared to be sufficiently elevated to have caused the observed deformities. Based on these relatively low levels of contaminants, a high hatchability rate (94.5%), and relatively low levels of embryotoxicity, contaminants did not appear to significantly affect Black-crowned Night Heron reproduction at Alcatraz Island. However, predation by the Common Raven (Corvus corax) and Western Gull, interspecific competition with the Western Gull, habitat deterioration, and possible human disturbance are likely factors contributing to the decline in Black-crowned Night Heron reproductive success on Alcatraz Island in recent years.

  5. Morph-specific differences in reproductive success in the distylous Primula veris in a context of habitat fragmentation

    NASA Astrophysics Data System (ADS)

    Van Rossum, Fabienne; De Sousa, Sara Campos; Triest, Ludwig

    2006-11-01

    Heterostylous self-incompatible plant species are particularly sensitive to habitat fragmentation and to disruption of pollination processes because of the need of intermorph cross-pollination for producing seeds. Heterostyly is characterized by sexual polymorphism through the occurrence of two (distyly) or three (tristyly) morph types that differ in floral traits (style length and anther position). We examined whether the long-styled (pin) and short-styled (thrum) morph types show differences in reproductive components and responses to habitat fragmentation in the distylous, self-incompatible perennial herb Primula veris. We documented reproductive components for pin and thrum individuals and their relationships with population size, plant density and morph ratio (pin frequency), in nine populations from Flanders (northern Belgium) located in fragmented habitats of the intensively used agricultural landscape. Seed abortion increased in small populations as a result of inbreeding depression. Fruit set increased with plant density. Seed set was positively related to pin proportion. Seed set was higher for pin than thrum in small populations, but lower in large populations. Two hypotheses can be considered to explain these morph-specific differences: a pollen transfer asymmetry, and a reproductive advantage for the partially self-compatible pin morph. Morph types appear to respond differently to habitat fragmentation constraints. A floral morph type showing partial self-compatibility may be favored in populations under pollination failure, because it can increase reproductive success and mating opportunities through intramorph crosses.

  6. Conflict and cooperation over sex: the consequences of social and genetic polyandry for reproductive success in dunnocks.

    PubMed

    Santos, Eduardo S A; Santos, Luana L S; Lagisz, Malgorzata; Nakagawa, Shinichi

    2015-11-01

    Conflict and cooperation within and between the sexes are among the driving forces that lead to the evolution of mating systems. Among mating strategies, female genetic polyandry and male reproductive cooperation pose challenging evolutionary questions regarding the maintenance of systems where one sex suffers from reduced fitness. Here, we investigate the consequences of social and genetic polyandry for reproductive success of females and males in a population of the dunnock, Prunella modularis. We show that female multiple mating ameliorates the negative effects of inbreeding. We, however, found little evidence that females engage in extra-group (pair) mating with less related or more heterozygous males. Breeding in socially polyandrous groups reduced the amount of paternity lost to extra-group males, such that, on average, cobreeding and monogamous males fledged a similar number of young. Importantly, c. 30% of cobreeding male dyads were related, suggesting they could gain indirect fitness benefits. Taken together, cobreeding males achieve equivalent reproductive success to monogamous counterparts under most circumstances. Our study has revealed unexpected complexities in the variable mating system of dunnocks in New Zealand. Our results differ from the well-known Cambridge dunnock study and can help our understanding of the evolution and maintenance of various breeding systems in the animal kingdom.

  7. Y-chromosome descent clusters and male differential reproductive success: young lineage expansions dominate Asian pastoral nomadic populations

    PubMed Central

    Balaresque, Patricia; Poulet, Nicolas; Cussat-Blanc, Sylvain; Gerard, Patrice; Quintana-Murci, Lluis; Heyer, Evelyne; Jobling, Mark A

    2015-01-01

    High-frequency microsatellite haplotypes of the male-specific Y-chromosome can signal past episodes of high reproductive success of particular men and their patrilineal descendants. Previously, two examples of such successful Y-lineages have been described in Asia, both associated with Altaic-speaking pastoral nomadic societies, and putatively linked to dynasties descending, respectively, from Genghis Khan and Giocangga. Here we surveyed a total of 5321 Y-chromosomes from 127 Asian populations, including novel Y-SNP and microsatellite data on 461 Central Asian males, to ask whether additional lineage expansions could be identified. Based on the most frequent eight-microsatellite haplotypes, we objectively defined 11 descent clusters (DCs), each within a specific haplogroup, that represent likely past instances of high male reproductive success, including the two previously identified cases. Analysis of the geographical patterns and ages of these DCs and their associated cultural characteristics showed that the most successful lineages are found both among sedentary agriculturalists and pastoral nomads, and expanded between 2100 BCE and 1100 CE. However, those with recent origins in the historical period are almost exclusively found in Altaic-speaking pastoral nomadic populations, which may reflect a shift in political organisation in pastoralist economies and a greater ease of transmission of Y-chromosomes through time and space facilitated by the use of horses. PMID:25585703

  8. Experimentally-elevated testosterone, female parental care, and reproductive success in a songbird, the Dark-eyed Junco (Junco hyemalis).

    PubMed

    O'Neal, Dawn M; Reichard, Dustin G; Pavilis, Katie; Ketterson, Ellen D

    2008-09-01

    In male dark-eyed juncos (Junco hyemalis), experimentally elevated testosterone (T) decreases male parental care and offspring survival, but results in higher overall fitness through greater mating success. To help address the ensuing question of what prevents selection from favoring higher levels of T in male juncos, we manipulated T in female juncos. A previous study demonstrated no effect of experimentally elevated T on female incubation behavior, suggesting that female parental behavior might be insensitive to T. In this study we asked whether experimentally elevated T mediates other female parental behaviors and whether variation in T-mediated parental behavior might influence reproductive success. We videotaped free-living control- and T-females during nesting to quantify brooding behavior when young were 3 days old and provisioning behavior when young were 6 days old. Nest defense was measured by quantifying responses to a mounted predator placed near the nest. Reproductive success was assessed via fecundity, nestling quality, and nest survival. T-females spent less time than control females brooding but did not differ in provisioning rate. T-females performed fewer dives at the predator mount and, unlike controls, failed to increase defense as nesting progressed. T-females also had lower daily nest survival and lower nest success (odds of producing at least one fledgling). We conclude that some aspects of female parental behavior are sensitive to experimentally elevated T while others are not and consider the implications for the evolution of T-mediated characters in both sexes.

  9. Limited mate availability decreases reproductive success of fragmented populations of Linnaea borealis, a rare, clonal self-incompatible plant

    PubMed Central

    Scobie, A. R.; Wilcock, C. C.

    2009-01-01

    Background and Aims Small populations of rare plant species are increasingly reported to have high levels of reproductive failure. The objective of this study was to understand the principal constraints on sexual reproduction in small fragmented populations of a rare clonal self-incompatible plant. Methods The pollinator spectrum, diversity of flower colour, natural pollination and fruit-set levels of L. borealis were examined in Scotland. Artificially crossed seed production was compared within and between different flower colour types and patches. Key Results Linnaea borealis was pollinated by a diverse spectrum of insect species and the principal pollinators were muscid, syrphid and empid flies which mostly moved only small distances (<0·25 m) between flowers when foraging. Natural pollination levels were high, indicating high pollinator effectiveness, but fruit set was very low in most patches. Flower colour diversity was low in most patches and only those with a diversity of flower colour types had high fruiting success. Pollination experiments showed L. borealis to be highly self-incompatible and artificial crosses within and between patches and flower colour types confirmed that low fruit success was the result of a lack of compatible mates and limited pollen movement between them. Evidence of isolation from pollen exchange was apparent at as little as 6 m and severe at 30 m and beyond. Conclusions Limited mate availability and isolation from pollen exchange compromise the reproductive success of fragmented populations of L. borealis in Scotland. A diversity of compatible mates situated within close proximity (<6 m) is the key requirement to ensure high natural fruiting success. This study emphasizes that an understanding of the breeding system, pollinator spectrum and potential for interconnectivity via pollinator movement are fundamental to identify isolation distances and to establish when conservation intervention is necessary for rare species. PMID

  10. Nest success and reproductive ecology of the Texas Botteri’s Sparrow (Peucaea botterii texana) in exotic and native grasses

    USGS Publications Warehouse

    Miller, Katherine S.; McCarthy, Erin M.; Woodin, Marc C.; Withers, Kim

    2013-01-01

    Very little information is available for Peucaea botterii texana (Texas Botteri’s Sparrow) and nothing is known about its nesting ecology, in part due to its cryptic behavior and nesting strategies. Our goal was to examine the nesting ecology of Texas Botteri’s Sparrows and compare reproductive success between exotic and native grass- lands. We searched for and monitored nests in 2004 and 2005 on the King Ranch in southern Texas. We found no relationship in reproductive effort, nest characteristics, and plant species richness around the nest between grassland types. Vegetation surrounding Texas Botteri's Sparrow nests was significantly taller and denser in native grasslands than in exotic grasslands. Further research on nesting ecology for the Texas Botteri’s Sparrow is necessary to determine its habitat needs and its role as an indicator of grassland quality.

  11. Reproductive success of non-rewarding Cypripedium japonicum benefits from low spatial dispersion pattern and asynchronous flowering

    PubMed Central

    Sun, Hai-Qin; Cheng, Jin; Zhang, Fu-Min; Luo, Yi-Bo; Ge, Song

    2009-01-01

    Background and Aims Outcrossing animal-pollinated plants, particularly non-rewarding species, often experience pollinator limitation to reproduction. Pollinator visitation is affected by various factors, and it is hypothesized that reproduction in non-rewarding plants would benefit from low spatial flower abundance and asynchronous flowering. In order to test this hypothesis, the influence of spatial pattern and flowering phenology on male and female reproductive success (RS) was investigated in a non-rewarding orchid, Cypripedium japonicum, in central China over two flowering seasons. Methods The probabilities of intrafloral self-pollination and geitonogamy caused by pollinator behaviours were estimated from field observations. Pollinator limitation was evaluated by hand-pollination experiments. RS was surveyed in different spatial flower dispersal patterns and local flower densities. The effects of flowering phenological traits on RS were assessed by univariate and multivariate regression analyses. Key Results Hand-pollination experiments revealed that fruit production was strongly pollen limited throughout the entire reproductive season – over two seasons, 74·3 % of individuals set fruit following hand pollination, but only 5·2–7·7 % did so under natural conditions. Intrafloral self-pollination and geitonogamy within the potential clones might be rare. Both male and female fitness were substantially lower in clustered plants than in those growing singly. An increase in local conspecific flower density significantly and negatively influenced male RS, but had no effect on female RS. Phenotypic selection analysis indicated that individuals flowering earlier have the greatest probability of RS. Over 85 % of sampled flowering individuals had a flowering synchrony value >0·7; however, highly synchronous flowering was not advantageous for RS, as indicated by the negative directional selection differentials and gradients, and by the positive quadratic selection

  12. Human disturbance influences reproductive success and growth rate in California sea lions (Zalophus californianus).

    PubMed

    French, Susannah S; González-Suárez, Manuela; Young, Julie K; Durham, Susan; Gerber, Leah R

    2011-03-16

    The environment is currently undergoing changes at both global (e.g., climate change) and local (e.g., tourism, pollution, habitat modification) scales that have the capacity to affect the viability of animal and plant populations. Many of these changes, such as human disturbance, have an anthropogenic origin and therefore may be mitigated by management action. To do so requires an understanding of the impact of human activities and changing environmental conditions on population dynamics. We investigated the influence of human activity on important life history parameters (reproductive rate, and body condition, and growth rate of neonate pups) for California sea lions (Zalophus californianus) in the Gulf of California, Mexico. Increased human presence was associated with lower reproductive rates, which translated into reduced long-term population growth rates and suggested that human activities are a disturbance that could lead to population declines. We also observed higher body growth rates in pups with increased exposure to humans. Increased growth rates in pups may reflect a density dependent response to declining reproductive rates (e.g., decreased competition for resources). Our results highlight the potentially complex changes in life history parameters that may result from human disturbance, and their implication for population dynamics. We recommend careful monitoring of human activities in the Gulf of California and emphasize the importance of management strategies that explicitly consider the potential impact of human activities such as ecotourism on vertebrate populations.

  13. Human Disturbance Influences Reproductive Success and Growth Rate in California Sea Lions (Zalophus californianus)

    PubMed Central

    French, Susannah S.; González-Suárez, Manuela; Young, Julie K.; Durham, Susan; Gerber, Leah R.

    2011-01-01

    The environment is currently undergoing changes at both global (e.g., climate change) and local (e.g., tourism, pollution, habitat modification) scales that have the capacity to affect the viability of animal and plant populations. Many of these changes, such as human disturbance, have an anthropogenic origin and therefore may be mitigated by management action. To do so requires an understanding of the impact of human activities and changing environmental conditions on population dynamics. We investigated the influence of human activity on important life history parameters (reproductive rate, and body condition, and growth rate of neonate pups) for California sea lions (Zalophus californianus) in the Gulf of California, Mexico. Increased human presence was associated with lower reproductive rates, which translated into reduced long-term population growth rates and suggested that human activities are a disturbance that could lead to population declines. We also observed higher body growth rates in pups with increased exposure to humans. Increased growth rates in pups may reflect a density dependent response to declining reproductive rates (e.g., decreased competition for resources). Our results highlight the potentially complex changes in life history parameters that may result from human disturbance, and their implication for population dynamics. We recommend careful monitoring of human activities in the Gulf of California and emphasize the importance of management strategies that explicitly consider the potential impact of human activities such as ecotourism on vertebrate populations. PMID:21436887

  14. Strong spatial genetic structure reduces reproductive success in the critically endangered plant genus Pseudomisopates.

    PubMed

    Amat, María E; Silvertown, Jonathan; Vargas, Pablo

    2013-01-01

    Clonal growth can be a double-edged sword for endangered species, because the short-term insurance against extinction may incur a longer-term hazard of creating small inbred populations with low fecundity. In the present study, we quantify the advantages and disadvantages of clonal growth regarding the fitness of the central Iberian monotypic endangered genus Pseudomisopates. Preliminary studies showed that the species is self-incompatible and exhibits extensive clonal growth with plants flowering profusely. However, seeds at many sites seemed to be unviable, and no seedlings have been observed in the field. A fully replicated nested sampling design (n = 100) was conducted to explore genetic (using seven SSR loci) and environmental factors potentially affecting seed viability, such as: 1) clonal and genetic diversity, 2) spatial genetic structure, and 3) environmental factors (shrub cover and grazing). Generalized Linear Mixed Models were fitted relating genetic and environmental variables to reproductive variables (seed viability and flower display). Our results indicate that the relatively low genotypic diversity of the population (PD = 0.23), as quantified by SSRs, and the strong spatial genetic structure observed are congruent with intense clonal growth. This clonal growth is enhanced by unfavorable environmental conditions, such as canopy closure and grazing. Under these circumstances, both flower display and mate availability decrease, thus hindering sexual reproduction. Indeed, a mixed reproductive system (clonal and sexual) to escape environmental stochasticity is crucial for the survival of Pseudomisopates, a species inhabiting a disturbance-prone ecosystem.

  15. Reproductive performance and weaning success in fur-chewing chinchillas (Chinchilla lanigera).

    PubMed

    Galeano, María G; Cantarelli, Verónica I; Ruiz, Rubén D; Fiol de Cuneo, Marta; Ponzio, Marina F

    2014-09-01

    In captive chinchillas, one of the most challenging behavioral problems is the development of a stress-related abnormal repetitive behavior (ARB) known as "fur-chewing". We investigated whether there is a relationship between the severity of fur-chewing behavior and reproductive function in male and female chinchillas. Regardless of the severity of abnormal behavior, fur-chewing males did not show significant differences in seminal quality (sperm concentration, motility and viability; integrity of sperm membrane and acrosome) and the response to the process of semen collection (the number of stimuli needed to achieve ejaculation) when compared to those with normal behavior. Also, females showing normal or fur-chewing behavior presented similar reproductive performance in terms of number of litters per female per year and litter size. However, pup survival rate was lower (p=0.05) in fur-chewing females than in normal females. These results seem to be consistent with data suggesting non-significant effects of ARBs on reproductive performance.

  16. [The sexual behavior, chemosignals and reproductive success in the male mice during activation of nonspecific immune response].

    PubMed

    Moshkin, M P; Kondratiuk, E Iu; Gerlinskaia, L A

    2009-01-01

    Hypothesis of reproductive compensation (Gowaty et al., 2007) suggests that constraining of free mating preference leads to reduction of the viability of progenies, which could be, partially, compensated by higher fecundity of the constrained parents. We consider infection as one of natural causes constraining female mating choice, because infection or immune response to infection can modulate male sexual demonstrations. Here we studied influence of LPS (bacterial endotoxin, activating non-specific immune response) on chemical attractiveness, sexual behavior and reproductive success in the outbreed male mice mated with the non-treated females. Single or repeated LPS administrations lead to increase of scent attractiveness of the male urine and soiled bedding for the non-estrus females. Injection of LPS (dose 50 mkg/kg) did not suppress the male sexual behavior. Time from pairing to successful mating correlates positively with the body mass of 16 day embryo. Embryos development, assessed by their body mass, was reduced in the females mated with the LPS-treated males. Higher level of plasma progesterone found in the females mated with the LPS-treated males, and shift of successful mating to the later time did not compensate reduction of embryo mass. At the same time the females mated with the LPS-treated males showed lower embryo lost in comparison with the females mated with the control males.

  17. Comparing the Sexual Reproductive Success of Two Exotic Trees Invading Spanish Riparian Forests vs. a Native Reference

    PubMed Central

    2016-01-01

    A widely accepted hypothesis in invasion ecology is that invasive species have higher survival through the early stages of establishment than do non-invasive species. In this study we explore the hypothesis that the sexual reproductive success of the invasive trees Ailanthus altissima (Mill.) Swingle and Robinia pseudoacacia L. is higher than that of the native Fraxinus angustifolia Vahl., all three species coexisting within the riparian forests of Central Spain. We compared different stages of the early life cycle, namely seed rain, seed infestation by insects, seed removal by local fauna, seed germination under optimal conditions and seedling abundance between the two invasive trees and the native, in order to assess their sexual reproductive success. The exotic species did not differ from the native reference (all three species displaying high seed rain and undergoing seed losses up to 50% due to seed removal by the local fauna). Even if the exotic R. pseudoacacia showed a high percentage of empty and insect-parasited seeds along with a low seedling emergence and the exotic A. altissima was the species with more viable seeds and of higher germinability, no differences were found regarding these variables when comparing them with the native F. angustifolia. Unsuitable conditions might have hampered either seedling emergence and survival, as seedling abundance in the field was lower than expected in all species -especially in R. pseudoacacia-. Our results rather suggest that the sexual reproductive success was not higher in the exotic trees than in the native reference, but studies focusing on long-term recruitment would help to shed light on this issue. PMID:27529695

  18. The role of weather in mediating the effect of mercury exposure on reproductive success in tree swallows.

    PubMed

    Hallinger, Kelly K; Cristol, Daniel A

    2011-08-01

    Mercury is a heavy metal that has contaminated countless ecosystems throughout the world. A large body of literature has documented reproductive, physiological, and behavioral impairments associated with mercury exposure in laboratory settings, but whether and how such effects are manifest in free-living populations remains poorly understood. The purpose of this study was to evaluate whether tree swallow (Tachycineta bicolor) breeding success at a site with high mercury exposure varied with ambient temperature or precipitation at various points in the breeding cycle. Tree swallows nesting along the South River had significantly elevated blood total mercury (mean ± SE: 3.03 ± 0.15 μg/g) compared to swallows breeding on reference sites (mean ± SE: 0.16 ± 0.005 μg/g). These high levels of mercury were associated with reduced hatching and fledging success, and contaminated birds produced approximately one less fledgling per nest than their reference counterparts. The magnitude of this difference was weather-dependent: unusually high ambient temperatures encountered early in the nestling period were associated with reduced reproductive output in contaminated, but not in reference, birds. In contrast, little effect of mercury on success of nestlings was observed when temperatures were cooler, and precipitation also had no detectable interaction with mercury. These results provide insight into mechanisms underlying reproductive effects of mercury. In addition, these findings underscore the importance of considering variable environmental conditions when assessing effects of contaminants on free-living wildlife. In particular, projections about the effects of global climate change on ecotoxicological impacts must take into account the kinds of weather-mediated effect demonstrated here.

  19. Effects of climate variation on timing of nesting, reproductive success, and offspring sex ratios of red-winged blackbirds.

    PubMed

    Weatherhead, Patrick J

    2005-06-01

    Predicting ecological consequences of climate change will be improved by understanding how species are affected by contemporary climate variation, particularly if analyses involve more than single ecological variables and focus on large-scale climate phenomena. I used 18 years of data from red-winged blackbirds (Agelaius phoeniceus) studied over a 25-year period in eastern Ontario to explore chronological and climate-related patterns of reproduction. Although blackbirds started nesting earlier in years with warmer springs, associated with low winter values of the North Atlantic Oscillation Index (NAOI), there was no advance in laying dates over the study. Nesting ended progressively later and the breeding season lasted longer over the study, however, associated with higher spring values of NAOI. As the length of the nesting season increased, offspring sex ratios became more female biased, apparently as a result of females adjusting the sex of the eggs they laid, rather than from sex-biased nestling mortality. Clutch size did not vary systematically over the study or with climate. Opposing trends of declining nest success and increasing productivity of successful nests over the study resulted in no chronological change in productivity per female. Higher productivity of successful nests was associated with higher winter NAOI values, possibly because synchrony between nesting and food availability was higher in years with high NAOI values. Other than the association between the start of nesting and spring temperatures, local weather (e.g., temperature, rainfall) patterns that linked NAOI with reproduction were not identified, suggesting that weather patterns may be complex. Because climate affected most aspects of red-winged blackbird reproduction examined, focusing on associations between climate and single variables (e.g., first-egg dates) will have limited value in predicting how future climates will affect populations.

  20. An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans

    PubMed Central

    Sparkman, Amanda M; Arnold, Stevan J; Bronikowski, Anne M

    2007-01-01

    Evolutionary theory predicts that differential reproductive effort and rate of reproductive senescence will evolve under different rates of external mortality. We examine the evolutionary divergence of age-specific reproduction in two life-history ecotypes of the western terrestrial garter snake, Thamnophis elegans. We test for the signature of reproductive senescence (decreasing fecundity with age) and increasing reproductive effort with age (increasing reproductive productivity per gram female) in replicate populations of two life-history ecotypes: snakes that grow fast, mature young and have shorter lifespans, and snakes that grow slow, mature late and have long lives. The difference between life-history ecotypes is due to genetic divergence in growth rate. We find (i) reproductive success (live litter mass) increases with age in both ecotypes, but does so more rapidly in the fast-growth ecotype, (ii) reproductive failure increases with age in both ecotypes, but the proportion of reproductive failure to total reproductive output remains invariant, and (iii) reproductive effort remains constant in fast-growth individuals with age, but declines in slow-growth individuals. This illustration of increasing fecundity with age, even at the latest ages, deviates from standard expectations for reproductive senescence, as does the lack of increases in reproductive effort. We discuss our findings in light of recent theories regarding the phenomenon of increased reproduction throughout life in organisms with indeterminate growth and its potential to offset theoretical expectations for the ubiquity of senescence. PMID:17251099

  1. Osprey distribution, abundance, reproductive success and contaminant burdens along lower Columbia River, 1997/1998 versus 2004

    USGS Publications Warehouse

    Henny, C.J.; Grove, R.A.; Kaiser, J.L.

    2008-01-01

    The osprey (Pandion haliaetus) population nesting along the lower portion of the Columbia River (river mile 29 to 286) increased from 94 in 1997 to 103 occupied nests in 1998 (9.6% annual rate of increase) to 225 occupied nests in 2004 (13.9% annual rate of increase). The more recent rate of population increase was associated with higher reproductive rates than in 1997/1998, and significantly lower egg concentrations of most organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). A comparison of observed egg residue concentrations in 2004 with effect-level information for ospreys indicated that reproduction at few, if any, nests was adversely affected. As recent as 1997/1998, dichlorodiphenyldichloroethylene (DDE) was still adversely affecting reproductive success for a portion of this population. Mercury was the only contaminant evaluated in both 1997/1998 and 2004 that showed a significant increase in eggs over time, but concentrations in 2004 (0.09 ??g g -1 ww) remained below established effect levels for birds (generally reported at 0.50 ??g g-1 ww or higher). The significant increase in mercury justifies the need for future monitoring. All contaminants mentioned that biomagnify up food chains can be effectively monitored in osprey eggs. The osprey has been shown to be an excellent sentinel species for long-term monitoring with their many useful traits described. ?? 2007 Springer Science+Business Media, LLC.

  2. Effects of predation, flooding, and contamination on reproductive success of California Clapper Rails (Rallus longirostris obsoletus) in San Francisco Bay

    USGS Publications Warehouse

    Schwarzbach, S.E.; Albertson, J.D.; Thomas, C.M.

    2006-01-01

    We assessed the reproductive success of the California Clapper Rail (Rallus longirostris obsoletus), an endangered subspecies restricted to San Francisco Bay, and the relative importance of predation, flooding, and contaminants as factors affecting that success. Our study was conducted in six tidal marshes in the northern and southern reaches of San Francisco Bay. This assessment, conducted in four breeding seasons (1991, 1992, 1998, 1999), determined that productivity of California Clapper Rails was much reduced over the natural potential. Only 69% of clapper rail eggs whose viability could be assessed were viable. Hatchability of eggs in North Bay and South Bay marshes was 65% and 70%, respectively. Only 45% of the nests successfully hatched at least one egg. Despite mean clutch sizes of 6.7 and 6.9 in the North and South bays, respectively, clapper rails produced only 1.9 and 2.5 young per nesting attempt. Flooding was a minor factor, reducing the number of eggs available to hatch by only 2.3%. Predation on eggs was a major factor affecting nest success, reducing productivity by a third. Failed eggs were examined for abnormal development and contaminant concentrations. Contamination appeared to adversely influence California Clapper Rail reproductive success, as evidenced by deformities; embryo hemorrhaging; embryo malpositions; a depressed rate of hatchability; excess concentrations of mercury, barium, and chromium over known avian embryotoxic thresholds; and a correlation of deformities with elevated concentrations of some trace elements in eggs that failed to hatch. Mercury was the only significant contaminant common to all marshes. ?? The American Ornithologists' Union, 2006.

  3. Individual Variability in Reproductive Success Determines Winners and Losers under Ocean Acidification: A Case Study with Sea Urchins

    PubMed Central

    Schlegel, Peter; Havenhand, Jon N.; Gillings, Michael R.; Williamson, Jane E.

    2012-01-01

    Background Climate change will lead to intense selection on many organisms, particularly during susceptible early life stages. To date, most studies on the likely biotic effects of climate change have focused on the mean responses of pooled groups of animals. Consequently, the extent to which inter-individual variation mediates different selection responses has not been tested. Investigating this variation is important, since some individuals may be preadapted to future climate scenarios. Methodology/Principal Findings We examined the effect of CO2-induced pH changes (“ocean acidification”) in sperm swimming behaviour on the fertilization success of the Australasian sea urchin Heliocidaris erythrogramma, focusing on the responses of separate individuals and pairs. Acidification significantly decreased the proportion of motile sperm but had no effect on sperm swimming speed. Subsequent fertilization experiments showed strong inter-individual variation in responses to ocean acidification, ranging from a 44% decrease to a 14% increase in fertilization success. This was partly explained by the significant relationship between decreases in percent sperm motility and fertilization success at ΔpH = 0.3, but not at ΔpH = 0.5. Conclusions and Significance The effects of ocean acidification on reproductive success varied markedly between individuals. Our results suggest that some individuals will exhibit enhanced fertilization success in acidified oceans, supporting the concept of ‘winners’ and ‘losers’ of climate change at an individual level. If these differences are heritable it is likely that ocean acidification will lead to selection against susceptible phenotypes as well as to rapid fixation of alleles that allow reproduction under more acidic conditions. This selection may ameliorate the biotic effects of climate change if taxa have sufficient extant genetic variation upon which selection can act. PMID:23300876

  4. Comparing the Reproductive Success of Yakima River Hatchery- and Wild-Origin Spring Chinook; Yakima/Klickitat Fisheries Project Monitoring and Evaluation, 2005-2006 Annual Report.

    SciTech Connect

    Schroder, S.L.; Pearsons, T.N.; Knudsen, C.M.

    2006-05-01

    Reproductive success in wild- and first generation hatchery-origin spring Chinook males was examined by allowing the fish to compete for spawning opportunities in two sections of an observation stream. Behavioral observations were used to characterize the frequency of aggression and courting activities. Microsatellite DNA from each male and fry collected from the observation stream were used in pedigree analyses to estimate reproductive success. The coefficient of variation in male reproductive success equaled 116 and 86% in the two populations. No differences were detected in reproductive success due to hatchery or wild origin. Nor were any behavioral differences found between hatchery and wild males. Although statistical power was low due to intrinsic variation a great deal of overlap existed in the reproductive success values of hatchery and wild males. Significant disparities existed among the males on their ability to produce offspring. Males achieving high reproductive success mated with numerous females, were socially dominant, aggressive, and tended to stay in localized areas, courting and spawning with females that were adjacent to one another.

  5. Variation in floral morphology and plant reproductive success in four Ipomoea species (Convolvulaceae) with contrasting breeding systems.

    PubMed

    Delgado-Dávila, R; Martén-Rodríguez, S; Huerta-Ramos, G

    2016-11-01

    This study tested the hypothesis that self-compatibility would be associated with floral traits that facilitate autonomous self-pollination to ensure reproduction under low pollinator visitation. In a comparison of two pairs of Ipomoea species with contrasting breeding systems, we predicted that self-compatible (SC) species would have smaller, less variable flowers, reduced herkogamy, lower pollinator visitation and higher reproductive success than their self-incompatible (SI) congeners. We studied sympatric species pairs, I. hederacea (SC)- I. mitchellae (SI) and I. purpurea (SC)-I. indica (SI), in Mexico, over two years. We quantified variation in floral traits and nectar production, documented pollinator visitation, and determined natural fruit and seed set. Hand-pollination and bagging experiments were conducted to determine potential for autonomous self-pollination and apomixis. Self-compatible Ipomoea species had smaller flowers and lower nectar production than SI species; however, floral variation and integration did not vary according to breeding system. Bees were primary pollinators of all species, but visitation rates were seven times lower in SC than SI species. SC species had a high capacity for autonomous self-pollination due to reduced herkogamy at the highest anther levels. Self-compatible species had two to six times higher fruit set than SI species. Results generally support the hypothesis that self-compatibility and autonomous self-pollination ensure reproduction under low pollinator visitation. However, high variation in morphological traits of SC Ipomoea species suggests they maintain variation through outcrossing. Furthermore, reduced herkogamy was associated with high potential for autonomous self-pollination, providing a reproductive advantage that possibly underlies transitions to self-compatibility in Ipomoea.

  6. Successful frozen blastocyst transfers after failed fresh transfers in assisted reproductive technologies patients with hydrosalpinx.

    PubMed

    Sueldo, Carolina M; Milki, Amin A; Lathi, Ruth B

    2012-03-01

    Untreated hydrosalpinx is known to decrease in vitro fertilization success. We report on 4 patients with hydrosalpinx for whom fresh transfers of 11 good quality embryos did not produce a pregnancy; however, frozen blastocyst transfers in natural cycles resulted in several successful pregnancies, with an implantation rate of 60% (9/15 blastocysts implanted).

  7. Modulation of the adrenocortical response to acute stress with respect to brood value, reproductive success and survival in the Eurasian hoopoe.

    PubMed

    Schmid, Baptiste; Tam-Dafond, Laura; Jenni-Eiermann, Susanne; Arlettaz, Raphaël; Schaub, Michael; Jenni, Lukas

    2013-09-01

    Reproducing parents face the difficult challenge of trading-off investment in current reproduction against presumed future survival and reproduction. Glucocorticoids are supposed to mediate this trade-off because the adrenocortical response to stress disrupts normal reproductive behaviour in favour of self-maintenance and own survival. According to the brood-value hypothesis, individuals with a low survival probability until the next reproductive season have to invest in current reproduction, a process driven by a down-regulation of their adrenocortical response. If the adrenocortical response to stress effectively mediates the trade-off between current reproduction versus future survival and reproduction, we expect a negative relationship with reproductive success and a positive correlation of the adrenocortical stress response with survival. We studied the relationship between corticosterone secretion in parents and their current brood value, reproductive success and survival in a short-lived multi-brooded bird, the Eurasian hoopoe Upupa epops. The adrenocortical response to acute handling stress was correlated with the brood value within the individual (first and second broods of the year) and between individuals. Birds breeding late in the season mounted a lower total corticosterone response to acute stress than birds breeding earlier, while females showed lower levels than males. We observed a negative relationship between the adrenocortical stress response and rearing success or fledging success in females, as predicted by the brood-value hypothesis. However, we could not evidence a clear link between the adrenocortical stress response and survival. Future research testing the brood-value hypothesis and trade-offs between current reproduction and future survival should also measure free corticosterone and carefully differentiate between cross-sectional (i.e. between-individual) and individual-based experimental studies.

  8. Triennial Reproduction Symposium: the obstacle course to successful establishment of pregnancy in domestic livestock species.

    PubMed

    Utt, M D; Day, M L

    2013-07-01

    The 2012 Triennial Reproduction Symposium (TRS), "Impediments to Fertility in Domestic Animals," was held immediately before the Joint Annual Meeting of the American Society of Animal Science, American Dairy Science Association, Canadian Society of Animal Science, Western Section of the American Society of Animal Science, and the Asociación Mexicana de Producción Animal in Phoenix, AZ, in July, 2012. The theme of the symposium highlighted key impediments or opportunities in the process of creating a pregnancy, beginning with male and female gametes and ending with a viable fetus. The 2012 TRS was designed to focus on areas of current and exciting investigation across a variety of species and to include 8 presentations from a mix of established and early-career scientists. The TRS was also the venue for presentation of the 2012 L. E. Casida Award for Graduate Education; the recipient was R. D. Randel (Texas A&M University). The symposium provided an excellent opportunity for reproductive biologists to consider the broad spectrum of factors that limit fertility in domestic species and contemplate the current status of knowledge relative to several of the significant obstacles to pregnancy.

  9. Altered pairing behaviour and reproductive success in white ibises exposed to environmentally relevant concentrations of methylmercury

    PubMed Central

    Frederick, Peter; Jayasena, Nilmini

    2011-01-01

    Methylmercury (MeHg) is the most biologically available and toxic form of mercury, and can act as a powerful teratogen, neurotoxin and endocrine disruptor in vertebrates. However, mechanisms of endocrine impairment and net effects on demography of biota are poorly understood. Here, we report that experimental exposure of an aquatic bird over 3 years to environmentally relevant dietary MeHg concentrations (0.05–0.3 ppm wet weight) resulted in dose-related increases in male–male pairing behaviour (to 55% of males), and decreases in egg productivity (to 30%). Dosed males showed decreased rates of key courtship behaviours, and were approached less by courting females in comparison to control males. Within dosed groups, homosexual males showed a similar reduction when compared with dosed heterosexual males. We found an average 35 per cent decrease in fledgling production in high-dose birds over the study duration. These results are of interest because (i) MeHg exposure is experimentally tied to demographically important reproductive deficits, (ii) these effects were found at low, chronic exposure levels commonly experienced by wildlife, and (iii) effects on reproductive behaviour and sexual preference mediated by endocrine disruption represent a novel and probably under-reported mechanism by which contaminants may influence wild populations of birds. PMID:21123262

  10. Different pollinator assemblages ensure reproductive success of Cleisostoma linearilobatum (Orchidaceae) in fragmented holy hill forest and traditional tea garden.

    PubMed

    Zhou, Xiang; Liu, Qiang; Han, Jessie Yc; Gao, JiangYun

    2016-02-24

    Orchids are generally recognized to have specialist pollination systems and low fruit set is often thought to be characteristic of the family. In this study, we investigated the reproductive ecology of Cleisostoma linearilobatum, an epiphytic tropical orchid, in a holy hill forest fragment and a traditional tea garden in SW China using comparable methods. C. linearilobatum is self-compatible and dependent on insects for pollination. Fruit production in natural conditions was both pollinator- and resource-limited. However, the natural fruit set remained stable over multiple years at both sites. Pollination observations showed that C. linearilobatum has a generalized pollination system and seven insect species were observed as legitimate pollinators. Although the visit frequencies of different pollinators were different in the two sites, the pollinator assemblages ensured reproductive success of C. linearilobatum in both study sites over multiple years. The results partly explain why C. linearilobatum is so successful in the area, and also suggest that holy hill forest fragments and traditional tea gardens in Xishuangbanna are important in preserving orchids, especially those with generalist pollination.

  11. Different pollinator assemblages ensure reproductive success of Cleisostoma linearilobatum (Orchidaceae) in fragmented holy hill forest and traditional tea garden

    PubMed Central

    Zhou, Xiang; Liu, Qiang; Han, Jessie Yc; Gao, JiangYun

    2016-01-01

    Orchids are generally recognized to have specialist pollination systems and low fruit set is often thought to be characteristic of the family. In this study, we investigated the reproductive ecology of Cleisostoma linearilobatum, an epiphytic tropical orchid, in a holy hill forest fragment and a traditional tea garden in SW China using comparable methods. C. linearilobatum is self-compatible and dependent on insects for pollination. Fruit production in natural conditions was both pollinator- and resource-limited. However, the natural fruit set remained stable over multiple years at both sites. Pollination observations showed that C. linearilobatum has a generalized pollination system and seven insect species were observed as legitimate pollinators. Although the visit frequencies of different pollinators were different in the two sites, the pollinator assemblages ensured reproductive success of C. linearilobatum in both study sites over multiple years. The results partly explain why C. linearilobatum is so successful in the area, and also suggest that holy hill forest fragments and traditional tea gardens in Xishuangbanna are important in preserving orchids, especially those with generalist pollination. PMID:26907369

  12. Florivory and nectar-robbing perforations in flowers of pointleaf manzanita Arctostaphylos pungens (Ericaceae) and their effects on plant reproductive success

    PubMed Central

    Eliyahu, Dorit; McCall, Andrew C.; Lauck, Marina; Trakhtenbrot, Ana

    2015-01-01

    Damage to petals may have varying effects on the reproductive success of the plant. The variation may depend on the kind of damage to the corolla. Whether the damage is limited to the corolla, as is usually the case with nectar-robbing perforations, or extending to the reproductive parts of the flower, as in the case of florivory holes, might determine the extent of the effect on the plant's reproduction. We examined the various perforations in the flowers of Arctostaphylos pungens and correlated their presence with fruiting success. We found that though florivory holes were highly associated with damage to reproductive parts, fruiting success did not differ significantly between flowers with the two kinds of damage. Although nectar-robbing perforations were not associated with reduced number of fruit produced, they were significantly correlated with reduced number of fruit that contained seemingly viable seeds. The implications of our findings are discussed in the context of pollination and antagonism. PMID:26811740

  13. Influence of Snowmelt Timing on the Diet Quality of Pyrenean Rock Ptarmigan (Lagopus muta pyrenaica): Implications for Reproductive Success

    PubMed Central

    García-González, Ricardo; Aldezabal, Arantza; Laskurain, Nere Amaia; Margalida, Antoni; Novoa, Claude

    2016-01-01

    The Pyrenean rock ptarmigan (Lagopus muta pyrenaica) is the southernmost subspecies of the species in Europe and is considered threatened as a consequence of changes in landscape, human pressure, climate change, and low genetic diversity. Previous studies have shown a relationship between the date of snowmelt and reproductive success in the Pyrenean ptarmigan. It is well established that birds laying early in the breeding season have higher reproductive success, but the specific mechanism for this relationship is debated. We present an explicative model of the relationship between snowmelt date and breeding success mediated by food quality for grouse in alpine environments. From microhistological analyses of 121 faecal samples collected during three years in the Canigou Massif (Eastern Pyrenees), and the assessment of the chemical composition of the main dietary components, we estimated the potential quality of individual diets. Potential dietary quality was correlated with free-urate faecal N, a proxy of the digestible protein content ingested by ptarmigan, and both were correlated with phenological stage of consumed plants, which in turn depends on snowmelt date. Our findings suggest that the average snowmelt date is subject to a strong interannual variability influencing laying date. In years of early snowmelt, hens benefit from a longer period of high quality food resources potentially leading to a higher breeding success. On the contrary, in years of late snowmelt, hens begin their breeding period in poorer nutrient condition because the peaks of protein content of their main food items are delayed with respect to laying date, hence reducing breeding performance. We discuss the possible mismatch between breeding and snowmelt timing. PMID:26849356

  14. Fungal plant endosymbionts alter life history and reproductive success of aphid predators

    PubMed Central

    de Sassi, Claudio; Müller, Christine B; Krauss, Jochen

    2006-01-01

    Endosymbionts occur in most plant species and may affect interactions among herbivores and their predators through the production of toxic alkaloids. Here, we ask whether effects of mycotoxins produced by the symbiosis of the fungal endophyte Neotyphodium lolii and the grass Lolium perenne are transmitted to the aphidophagous ladybird Coccinella septempunctata when feeding on cereal aphids Rhopalosiphum padi on infected plants. The larval development of coccinellids was extended, while their survival was reduced when feeding exclusively on aphids from infected plants. Ladybirds developing on aphids from infected plants showed reduced fecundity and impaired reproductive performance. Body size and symmetries of ladybird adults were not affected by the endophytes. Consistently strong, negative effects of endophytes on the lifetime performance of ladybirds indicates that mycotoxins are transmitted along food chains, causing significant damage for top predators. Such cascading effects will influence the population dynamics of aphid predators in the long term and could feedback to the primary plant producers. PMID:16720406

  15. The age-specific force of natural selection and biodemographic walls of death

    PubMed Central

    Wachter, Kenneth W.; Evans, Steven N.; Steinsaltz, David

    2013-01-01

    W. D. Hamilton’s celebrated formula for the age-specific force of natural selection furnishes predictions for senescent mortality due to mutation accumulation, at the price of reliance on a linear approximation. Applying to Hamilton’s setting the full nonlinear demographic model for mutation accumulation recently developed by Evans, Steinsaltz, and Wachter, we find surprising differences. Nonlinear interactions cause the collapse of Hamilton-style predictions in the most commonly studied case, refine predictions in other cases, and allow walls of death at ages before the end of reproduction. Haldane’s principle for genetic load has an exact but unfamiliar generalization. PMID:23657010

  16. A comparison of American Oystercatcher reproductive success on barrier beach and river island habitats in coastal North Carolina

    USGS Publications Warehouse

    McGowan, C.P.; Simons, T.R.; Golder, W.; Cordes, J.

    2005-01-01

    American Oystercatcher (Haematopus palliatus) numbers along the east coast of the United States are declining in some areas and expanding in others. Researchers have suggested that movement from traditional barrier beach habitats to novel inland habitats and coastal marshes may explain some of these changes, but few studies have documented oystercatcher reproductive success in non-traditional habitats. This study compares the reproductive success of the American Oystercatcher on three river islands in the lower Cape Fear River of North Carolina with that of birds nesting on barrier island beach habitat of Cape Lookout National Seashore. There were 17.6 times more oystercatcher breeding pairs per kilometer on the river island habitat than barrier beach habitat. The Mayfield estimate of daily nest content survival was 0.97 (S.E. ?? 0.0039) on river islands, significantly higher than 0.92 (S.E. ?? 0.0059) on barrier islands. The primary identifiable cause of nest failure on the river islands was flooding while the main cause of nest failure on the barrier islands was mammalian predation. Fledging success was equally low at both study sites. Only 0.19 chicks fledged per pair in 2002, and 0.21 chicks fledged per pair in 2003 on the river islands and 0.14 chicks fledged per pair in 2002 and 0.20 chicks fledged per pair in 2003 on the barrier islands. Many questions are still unanswered and more research is needed to fully understand the causes of chick mortality and the functional significance of non-traditional nesting habitats for the American Oystercatcher in the eastern United States.

  17. Grasshopper sparrow reproductive success and habitat use on reclaimed surface mines varies by age of reclamation

    USGS Publications Warehouse

    Wood, Petra; Ammer, Frank K.

    2015-01-01

    We studied 3 mountaintop mining–valley fill (MTMVF) complexes in southern West Virginia, USA to examine grasshopper sparrow (Ammodramus savannarum pratensis) demographic response to different age classes of mine land reclamation. For 71 nests monitored during the 2001–2002 breeding seasons, overall nest success (36%) was within the range of nest success rates previously reported for this species, but it was highest on more recently reclaimed sites (56%). Nest density and clutch size did not differ (P > 0.30) among reclamation age classes, whereas number of fledglings was greater (P = 0.01) on more recently reclaimed sites. We measured vegetation variables at 70 nest subplots and at 96 systematic subplots to compare nest vegetation with vegetation available on the plots. We found that nests occurred in areas with more bare ground near the nest, greater vegetation height–density surrounding the nest site, lower grass height, and fewer woody stems, similar to previous studies. As postreclamation age increased, vegetation height–density and maximum grass height increased, and sericea (Lespedeza cuneata) became more dominant. Nest success declined with increasing vegetation height–density at the nest. The grasslands available on these reclaimed mine complexes are of sufficient quality to support breeding populations of grasshopper sparrows, but nest success decreased on the older reclaimed areas. Without active management, grasslands on reclaimed MTMVF mines become less suitable for nesting grasshopper sparrows about 10 years after reclamation.

  18. Testing wetland features to increase amphibian reproductive success and species richness for mitigation and restoration.

    PubMed

    Shulse, Christopher D; Semlitsch, Raymond D; Trauth, Kathleen M; Gardner, James E

    2012-07-01

    Aquatic habitat features can directly influence the abundance, species richness, and quality of juvenile amphibians recruited into adult populations. We examined the influences of within-wetland slope, vegetation, and stocked mosquito fish (Gambusia affinis) on amphibian metamorph production and species richness during the first two years post-construction at 18 experimental wetlands in northeast Missouri (U.S.A.) grasslands. We used an information theoretic approach (AICc) to rank regression models representing total amphibian metamorph production, individual amphibian species metamorph production, and larval amphibian species richness. Total amphibian metamorph production was greatest at shallow-sloped, fish-free wetlands during the first year, but shallow-sloped wetlands with high vegetation cover were best the second year. Species richness was negatively associated with fish and positively associated with vegetation in both survey years. Leopard frog (Rana blairi/sphenocephala complex) metamorph quality, based on average metamorph size, was influenced by slope and the number of cohorts in the wetland. However, the tested variables had little influence on the size of American toads (Bufo americanus) or boreal chorus frogs (Pseudacris maculata). Our results indicate that wetlands designed to act as functional reproductive habitat for amphibians should incorporate shallows, high amounts of planted or naturally established vegetation cover, and should be fish-free.

  19. Effects of different male remating intervals on the reproductive success of Choristoneura rosaceana males and females.

    PubMed

    Marcotte, Mireille; Delisle, Johanne; McNeil, Jeremy N

    2007-02-01

    The mass of the spermatophore transferred by a previously mated Choristoneura rosaceana male increases with time elapsed since the last mating but, even after 4 days, it never reaches the mass of the spermatophore of a virgin male. However, spermatophore mass is clearly not a good indicator of the male reproductive investment as the quantity of sperm in the second ejaculate of a previously mated male is the same as that of his first, if he is allowed a 2 (eupyrene sperm) to 3 day (apyrene sperm) recovery period. The interval between the first two matings had no influence on female fecundity or longevity but significantly affected fertility if the male had only 1 day to recover. The length of the post-copulatory refractory period was also shorter in females mated with previously mated males than in those mated with virgins, regardless of the male's remating interval. Furthermore, a significant variation in the eupyrene sperm content of the spermatophore transferred by virgin males had no influence on the length of the female refractory period. Globally, these results support the hypothesis that a factor, other than sperm numbers in the spermatheca, is responsible for maintaining the inhibition of pheromone production in this species.

  20. Habitat Selection and Reproductive Success of Lewis's Woodpecker (Melanerpes lewis) at Its Northern Limit

    PubMed Central

    Zhu, Xiang; Srivastava, Diane S.; Martin, Kathy

    2012-01-01

    Lewis's Woodpecker (Melanerpes lewis) has experienced population declines in both Canada and the United States and in 2010 was assigned a national listing of threatened in Canada. We conducted a two-year study (2004–2005) of this species at its northern range limit, the South Okanagan Valley in British Columbia, Canada. Our main objective was to determine whether the habitat features that influenced nest-site selection also predicted nest success, or whether other factors (e.g. cavity dimensions, clutch initiation date or time of season) were more important. Nest tree decay class, density of suitable cavities and total basal area of large trees were the best predictors of nest-site selection, but these factors were unrelated to nesting success. Estimates of demographic parameters (mean ± SE) included daily nest survival rate (0.988±0.003, years combined), nest success (0.52±0.08), clutch size (5.00±0.14 eggs), female fledglings per successful nest (1.31±0.11), and annual productivity (0.68±0.12 female fledglings per nest per year). Although higher nest survival was associated with both early and late initiated clutches, early-initiated clutches allowed birds to gain the highest annual productivity as early clutches were larger. Nests in deep cavities with small entrances experienced lower predation risk especially during the peak period of nest predation. We concluded that nest-site selection can be predicted by a number of easily measured habitat variables, whereas nest success depended on complicated ecological interactions among nest predators, breeding behaviors, and cavity features. Thus, habitat-based conservation strategies should also consider ecological factors that may not be well predicted by habitat. PMID:23028525

  1. Early-life disease exposure and associations with adult survival, cause of death, and reproductive success in preindustrial humans

    PubMed Central

    Hayward, Adam D.; Rigby, Francesca L.; Lummaa, Virpi

    2016-01-01

    A leading hypothesis proposes that increased human life span since 1850 has resulted from decreased exposure to childhood infections, which has reduced chronic inflammation and later-life mortality rates, particularly from cardiovascular disease, stroke, and cancer. Early-life cohort mortality rate often predicts later-life survival in humans, but such associations could arise from factors other than disease exposure. Additionally, the impact of early-life disease exposure on reproduction remains unknown, and thus previous work ignores a major component of fitness through which selection acts upon life-history strategy. We collected data from seven 18th- and 19th-century Finnish populations experiencing naturally varying mortality and fertility levels. We quantified early-life disease exposure as the detrended child mortality rate from infectious diseases during an individual’s first 5 y, controlling for important social factors. We found no support for an association between early-life disease exposure and all-cause mortality risk after age 15 or 50. We also found no link between early-life disease exposure and probability of death specifically from cardiovascular disease, stroke, or cancer. Independent of survival, there was no evidence to support associations between early-life disease exposure and any of several aspects of reproductive performance, including lifetime reproductive success and age at first birth, in either males or females. Our results do not support the prevailing assertion that exposure to infectious diseases in early life has long-lasting associations with later-life all-cause mortality risk or mortality putatively linked to chronic inflammation. Variation in adulthood conditions could therefore be the most likely source of recent increases in adult life span. PMID:27457937

  2. Evaluation of the effect of implanted depleted uranium on male reproductive success, sperm concentration, and sperm velocity

    SciTech Connect

    Arfsten, Darryl P. . E-mail: darryl.arfsten@wpafb.af.mil; Schaeffer, David J.; Johnson, Eric W.; Robert Cunningham, J.; Still, Kenneth R.; Wilfong, Erin R.

    2006-02-15

    Depleted uranium (DU) projectiles have been used in battle in Iraq and the Balkans and will continue to be a significant armor-penetrating munition for the US military. As demonstrated in the Persian Gulf War, battle injury from DU projectiles and shrapnel is a possibility, and removal of embedded DU fragments from the body is not always practical because of their location in the body or their small size. Previous studies in rodents have demonstrated that implanted DU mobilizes and translocates to the gonads, and natural uranium may be toxic to spermatazoa and the male reproductive tract. In this study, the effects of implanted DU pellets on sperm concentration, motility, and male reproductive success were evaluated in adult (P1) Sprague-Dawley rats implanted with 0, 12, or 20, DU pellets of 1x2 mm or 12 or 20 tantalum (Ta) steel pellets of 1x2 mm. Twenty DU pellets of 1x2 mm (760 mg) implanted in a 500-g rat are equal to approximately 0.2 pound of DU in a 154-lb (70-kg) person. Urinary analysis found that male rats implanted with DU were excreting uranium at postimplantation days 27 and 117 with the amount dependent on dose. No deaths or evidence of toxicity occurred in P1 males over the 150-day postimplantation study period. When assessed at postimplantation day 150, the concentration, motion, and velocity of sperm isolated from DU-implanted animals were not significantly different from those of sham surgery controls. Velocity and motion of sperm isolated from rats treated with the positive control compound {alpha}-chlorohydrin were significantly reduced compared with sham surgery controls. There was no evidence of a detrimental effect of DU implantation on mating success at 30-45 days and 120-145 days postimplantation. The results of this study suggest that implantation of up to 20 DU pellets of 1x2 mm in rats for approximately 21% of their adult lifespan does not have an adverse impact on male reproductive success, sperm concentration, or sperm velocity.

  3. Oil collecting bees and Byrsonima cydoniifolia A. Juss. (Malpighiaceae) interactions: the prevalence of long-distance cross pollination driving reproductive success.

    PubMed

    Sazan, Morgana S; Bezerra, Antonio Diego M; Freitas, Breno M

    2014-03-01

    Oil-collecting bees are the natural pollinators of oil-flower plants, but little is known about the pollination process and the effectiveness of their pollination service to the reproductive success of their host plants. In species of Byrsonima the reproductive system have been described as auto-compatible or self-incompatible. We studied the reproductive system of Byrsonima cydoniifolia, the fructification by means of short, medium and long-distance cross pollinations, the morphology and floral biology and the pollination interactions with species of oil-collecting bees. By means of controlled pollinations we found self-incompatibility caused by abortion of most self-pollinated flowers and demonstrated that the prevailing cross pollination ensuring the reproductive success of B. cydoniifolia is the long-distance cross pollination and Centridini bees; Epicharis nigrita, particularly, are the pollinators promoting the gene flow between genetically distinct populations.

  4. Early Blooming’s Challenges: Extended Flowering Season, Diverse Pollinator Assemblage and the Reproductive Success of Gynodioecious Daphne laureola

    PubMed Central

    ALONSO, CONCHITA

    2004-01-01

    • Background and aims The scarcity and unpredictability of active pollinators during late winter in temperate areas tends to favour extended flowering seasons and increased floral longevity in early blooming species, which are usually pollinated by diverse sets of insects. Daphne laureola is a gynodioecious woody perennial that flowers from January to April in southern Spain, a period characterized by cold temperatures, frequent rains and irregular snowfalls. • Methods Pollinators were excluded at four different times during the flowering season in order to determine the effect of decreased exposure to pollinators on fruit set in female and hermaphrodite individuals. The role of nocturnal and diurnal pollination on reproductive success in each gender was simultaneously evaluated by selective exclusion. • Key results A 50 % reduction in the flowering period decreased fruit set of females by 50 %, whereas the corresponding decrease in self‐compatible hermaphrodites was only approx. 25 %. Day‐active hymenopterans and lepidopterans were infrequent visitors, and nocturnal pollinators were inefficient, suggesting that pollen beetles, Meligethes elongatus, were the main pollinators of D. laureola in the study region. • Conclusions Beetles were less abundant in pollenless females, although discrimination did not apparently result in pollination limitation of female reproduction. A preference of beetles for sunny locations emphasized the relevance of abiotic conditions for pollination of this early blooming shrub. PMID:14602664

  5. Social status does not predict responses to Seoul virus infection or reproductive success among male Norway rats.

    PubMed

    Hinson, Ella R; Hannah, Michele F; Norris, Douglas E; Glass, Gregory E; Klein, Sabra L

    2006-03-01

    Trade-offs exist among life history strategies that are used to increase survival and reproduction; such that, males that engage in more competitive behaviors may be more susceptible to infection. Hantaviruses are transmitted horizontally between rodents through the passage of virus in saliva during wounding and male rodents are more likely to be infected with hantaviruses than females. To determine whether a trade-off exists between dominance and susceptibility to Seoul virus infection, male Long Evans rats were group housed (3/cage) with a female rat and aggressive and subordinate behaviors were monitored during a 10 day group housing condition. After behavioral testing, males were individually housed, inoculated with Seoul virus, and blood, saliva, and fecal samples were collected. Dominant males initiated more aggressive encounters than subordinate males. Dominant and subordinate males, however, had similar steroid hormone concentrations, anti-Seoul virus IgG responses, and weight gain over the course of infection. A similar proportion of dominant and subordinate males shed virus in saliva and feces during infection. Using microsatellite DNA markers paternity was assigned to pups derived during the group housing period. In contrast to our initial hypothesis, dominant and subordinate males sired a similar percentage of pups. Taken together, host social status may not predict reproductive success or susceptibility to hantaviruses in rodent reservoir populations.

  6. Proposed method for evaluating the effects of PCBs in sediment on egg mass viability and reproductive success in frogs

    SciTech Connect

    Schmidt, C.S.; Henning, M.H.; Ebert, E.S.

    1995-12-31

    A proposed study design for evaluating the effect of PCBs in the sediments of a large New England river on reproductive success in frogs is described. Depending on field conditions and species abundance, the study will use either bullfrogs, Rana catesbiana; spring peepers, Hyla pickeringii; or green frogs, Rana claymitans as the study model. A selected number of gravid females will be collected from both the target area and a reference area matched with respect to a number of key variables including, but not limited to, stream flow, temperature, pH, substrate type, depth, surrounding land use, and organic carbon content of sediments. The gravid frogs will be transferred to a laboratory, where the egg masses will be stripped following induced ovulation, and then fertilized using semen from males collected in the field. Egg masses will be maintained under static renewal conditions for a period up to and including 7 days post hatch, during which mortality and gross morphological appearance will be evaluated. In the event that statistically significant differences in these endpoints are noted, a dose response model will be developed to relate observed effects to previously determined PCB concentrations in egg masses and maternal tissues. The results of this study will be of significant utility in evaluating reproductive toxicity of PCBs in ecological risk assessment.

  7. First evidence of successful natural reproduction by planted lake trout in Lake Huron

    USGS Publications Warehouse

    Nester, Robert T.; Poe, Thomas P.

    1984-01-01

    Twenty-two lake trout (Salvelinus namaycush) swim-up fry, 24-27 mm long, were captured with emergent fry traps and a tow net in northwestern Lake Huron on a small nearshore reef off Alpena, Michigan, between May 10 and June 1, 1982. These catches represent the first evidence of successful production of swim-up fry by planted, hatchery-reared lake trout in Lake Huron since the lake trout rehabilitation program began in 1973.

  8. Sexual conflict over care: antagonistic effects of clutch desertion on reproductive success of male and female penduline tits.

    PubMed

    Szentirmai, I; Székely, T; Komdeur, J

    2007-09-01

    A fundamental tenet of sexual conflict theory is that one sex may increase its reproductive success (RS) even if this harms the other sex. Several studies supported this principle by showing that males benefit from reduced paternal care whereas females suffer from it. By investigating penduline tits Remiz pendulinus in nature, we show that parental conflict may be symmetric between sexes. In this small passerine a single female (or male) cares for the offspring, whereas about 30% of clutches are deserted by both parents. Deserting parents enhance their RS by obtaining multiple mates, and they reduce the RS of their mates due to increased nest failure. Unlike most other species, however, the antagonistic interests are symmetric in penduline tits, because both sexes enhance their own RS by deserting, whilst harming the RS of their mates. We argue that the strong antagonistic interests of sexes explain the high frequency of biparental desertion.

  9. Individual Quality Explains Variation in Reproductive Success Better than Territory Quality in a Long-Lived Territorial Raptor

    PubMed Central

    Zabala, Jabi; Zuberogoitia, Iñigo

    2014-01-01

    Evolution by natural selection depends on the relationship between individual traits and fitness. Variation in individual fitness can result from habitat (territory) quality and individual variation. Individual quality and specialization can have a deep impact on fitness, yet in most studies on territorial species the quality of territory and individuals are confused. We aimed to determine if variation in breeding success is better explained by territories, individual quality or a combination of both. We analysed the number of fledglings and the breeding quality index (the difference between the number of fledglings of an individual/breeding pair and the average number of fledglings of the monitored territories in the same year) as part of a long term (16 years) peregrine falcon (Falco peregrinus) monitoring program with identification of individuals. Using individual and territory identities as correlates of quality, we built Generalised Linear Models with Mixed effects, in which random factors depicted different hypotheses for sources of variation (territory/individual quality) in the reproductive success of unique breeding pairs, males and females, and assessed their performance. Most evidence supported the hypothesis that variation in breeding success is explained by individual identity, particularly male identity, rather than territory. There is also some evidence for inter year variations in the breeding success of females and a territory effect in the case of males. We argue that, in territorial species, individual quality is a major source of variation in breeding success, often masked by territory. Future ecological and conservation studies on habitat use should consider and include the effect of individuals, in order to avoid misleading results. PMID:24599280

  10. Variation in alfalfa leafcutting bee (Hymenoptera: Megachilidae) reproductive success according to location of nests in United States commercial domiciles.

    PubMed

    Pitts-Singer, Theresa L

    2013-04-01

    The alfalfa leafcutting bee, Megachile rotundata F., is used extensively to pollinate alfalfa for seed production in western North America. However, it usually is not possible to sustain bee populations in the United States. In the managed pollination system, variable microenvironments are experienced by developing M. rotundata during the nesting season that may influence bee reproductive success. In this study, bee cells were produced in a small alfalfa field and collected from domiciles according to nesting boards and different portions of boards. Examination of cells showed that the production of live overwintering prepupae, diseased larvae, other dead eggs and larvae, and cells attacked by natural enemies varied according to board orientations and positions, and portions of the boards. Northeast-facing board samples were significantly heavier and had more pollen balls and chalkbrood compared with southwest-facing boards. Lower boards in stacks had significantly more chalkbrood than upper boards. Outer portions of boards had significantly more live prepupae and less chalkbrood than middle and inner portions, and outer and middle portions had less summer-emerging bees. These results suggest that reproductive success could be altered by changing the orientation of boards within domiciles or changing the designs of domiciles. To accurately assess the quality of bee populations managed in the commercial loose cell system, a sample of bees should be taken from a pooled sample from all boards in each domicile. Each domicile sample should then be evaluated according to its proportional contribution to the whole field's progeny production (e.g., by weight or volume).

  11. Spatial and temporal patterns of larval dispersal in a coral-reef fish metapopulation: evidence of variable reproductive success.

    PubMed

    Pusack, Timothy J; Christie, Mark R; Johnson, Darren W; Stallings, Christopher D; Hixon, Mark A

    2014-07-01

    Many marine organisms can be transported hundreds of kilometres during their pelagic larval stage, yet little is known about spatial and temporal patterns of larval dispersal. Although traditional population-genetic tools can be applied to infer movement of larvae on an evolutionary timescale, large effective population sizes and high rates of gene flow present serious challenges to documenting dispersal patterns over shorter, ecologically relevant, timescales. Here, we address these challenges by combining direct parentage analysis and indirect genetic analyses over a 4-year period to document spatial and temporal patterns of larval dispersal in a common coral-reef fish: the bicolour damselfish (Stegastes partitus). At four island locations surrounding Exuma Sound, Bahamas, including a long-established marine reserve, we collected 3278 individuals and genotyped them at 10 microsatellite loci. Using Bayesian parentage analysis, we identified eight parent-offspring pairs, thereby directly documenting dispersal distances ranging from 0 km (i.e., self-recruitment) to 129 km (i.e., larval connectivity). Despite documenting substantial dispersal and gene flow between islands, we observed more self-recruitment events than expected if the larvae were drawn from a common, well-mixed pool (i.e., a completely open population). Additionally, we detected both spatial and temporal variation in signatures of sweepstakes and Wahlund effects. The high variance in reproductive success (i.e., 'sweepstakes') we observed may be influenced by seasonal mesoscale gyres present in the Exuma Sound, which play a prominent role in shaping local oceanographic patterns. This study documents the complex nature of larval dispersal in a coral-reef fish, and highlights the importance of sampling multiple cohorts and coupling both direct and indirect genetic methods in order disentangle patterns of dispersal, gene flow and variable reproductive success.

  12. Effects of suspended sediment on the reproductive success of the tricolor shiner, a crevice-spawning minnow

    USGS Publications Warehouse

    Burkhead, N.M.; Jelks, H.L.

    2001-01-01

    Excessive sedimentation of rivers and creeks has been linked to increasing levels of imperilment in the diverse fish fauna of the southeastern United States. In particular, benthic-spawning fishes have decreased in both numbers and range. The tricolor shiner Cyprinella trichroistia is a crevice-spawning minnow that is widespread in the eastern Mobile River drainage above the Fall Line. While they are less sensitive to perturbation than the federally threatened blue shiner C. caerulea, tricolor shiners have decreased in numbers and range during the past few decades. This experiment examined the effects of 0 (control), 100, 300, and 600 mg/L initial concentrations of suspended sediment on the reproductive success of the tricolor shiner. Increasing levels of suspended sediment caused decreasing levels of reproductive success (fewer spawns and fewer eggs laid when spawning occurred). Increasing levels of suspended sediment also delayed the onset of spawning, resulting in distinct frequency distributions of clear eggs, eyed eggs, and larvae across treatments. Mortality of eggs and larvae was not a factor in the experiment. We examined daily sediment concentration data recorded at three sites in the upper Coosa River over the April-August spawning season of 1963. By weighting our experimental results by the number of days above each sediment concentration, we estimated that 20% fewer eggs were laid than would have been laid if conditions had been like those of the controls. Albeit our model is simplistic, it provides insight into how excessive sedimentation contributes to population extirpation. Mitigation of suspended sediments is an important management action for the conservation of southern Appalachian fishes that spawn in benthic habitats.

  13. Factors affecting the reproductive success of American Oystercatchers Haematopus palliatus on the outer banks of North Carolina

    USGS Publications Warehouse

    Schulte, Shiloh A.; Simons, Theodore R.

    2015-01-01

    We used an information-theoretic approach to assess the factors affecting the reproductive success of American Oystercatchers Haematopus palliatus on the Outer Banks of North Carolina. We evaluated survival with respect to nesting island, year, time of season, brood age, distance to tide (m), presence of off-road vehicles and proximity of foraging habitat. The daily nest survival (mean 0.981, standard error [SE] 0.002) was affected by year and island, and declined over the nesting season. Mammals were responsible for 54% of identified nest failures. Daily brood survival (mean 0.981, SE 0.002) varied by island and increased non-linearly with age, with highest mortality in the seven days after hatching. Model results indicate direct access to foraging sites has a positive effect on brood survival, whereas presence of off-road vehicles has a negative effect. We studied chick behavior and survival using radio telemetry and direct observation and found that vehicles caused mortality and affected behavior and resource use by oystercatcher chicks. We identified the source of mortality for 37 radio-tagged chicks. Six (16%) were killed by vehicles, 21 (57%) by predators, and 10 (27%) by exposure and starvation. From 1995 to 2008, 25 additional oystercatcher chicks were found dead, 13 (52%) killed by vehicles. Chicks on beaches closed to vehicles used beach and intertidal zones more frequently than chicks on beaches open to vehicles. Chick predators included Great Horned Owls Bubo virginianus, Fish Crows Corvus ossifragus, cats Felis catus, mink Mustela vison, raccoons Procyon lotor, and ghost crabs Ocypode albicans. The factors affecting reproductive success differed between the incubation and chick-rearing stages.  Management actions that influence chick survival will have a larger effect on total productivity than actions affecting nest survival.

  14. Early reproductive success of western bluebirds and ash-throated flycatchers: a landscape-contaminant perspective.

    PubMed

    Fair, Jeanne M; Myers, Orrin B

    2002-01-01

    Eggshell quality, clutch size, sex ratio, and hatching success of western bluebirds (Sialia mexicana) and ash-throated flycatchers (Myiarchus cinerascens) were studied on a landscape-soil contaminant gradient at Los Alamos National Laboratory (LANL) in New Mexico from 1997 to 1999. A variety of contaminants (heavy metals, chemicals, insecticides, polychlorinated biphenyls (PCBs), organochlorines, and radioactive isotopes) range across different spatial scales and concentrations on LANL land. This study is an example of a monitoring program over a large area with varying degree of contamination that is used to highlight locations of concern for future research. There were two locations where the flycatcher had a lower hatching success. The bluebirds at Sandia wetland, a location of concern for PCBs. had a thinner eggshell thickness index (RATCLIFFE) and the eggs were smaller than at other locations. The flycatcher had thinner eggshells than bluebirds, which could add to sensitivity to exposure to contaminants. There was no variation in clutch size or sex ratio between locations or areas closer to contaminant release sites for both species. Percent females in the clutch ranged from 0 to 100% in the WEBL and from 33 to 67% for ATFL.

  15. Impacts of Water Level Fluctuations on Kokanee Reproduction in Flathead Lake; Effects of Operation of Kerr and Hungry Horse Dam on Reproductive Success, 1983 Annual Report.

    SciTech Connect

    Decker-Hess, Janet; McMullin, Steve L.

    1983-11-01

    ) found live eggs and fry only in shoreline spawning areas wetted by groundwater seeps. Impacts of the operation of Kerr Dam on lakeshore spawning have not been quantified. Recent studies have revealed that operation of Hungry Horse Dam severely impacted successful kokanee spawning and incubation in the Flathead River above Flathead Lake (Graham et al. 1980, McMullin and Graham 1981, Fraley and Graham 1982 and Fraley and McMullin 1983). Flows from Hungry Horse Dam to enhance kokanee reproduction in the river system have been voluntarily met by the Bureau of Reclamation since 1981. In lakeshore spawning areas in other Pacific Northwest systems, spawning habitat for kokanee and sockeye salmon was characterized by seepage or groundwater flow where suitable substrate composition existed (Foerster 1968). Spawning primarily occurred in shallower depths (<6 m) where gravels were cleaned by wave action (Hassemer and Rieman 1979 and 1980, Stober et al. 1979a). Seasonal drawdown of reservoirs can adversely affect survival of incubating kokanee eggs and fry spawned in shallow shoreline areas. Jeppon (1955 and 1960) and Whitt (1957) estimated 10-75 percent kokanee egg loss in shoreline areas of Pend Oreille Lake, Idaho after regulation of the upper three meters occurred in 1952. After 20 years of operation, Bowler (1979) found Pend Oreille shoreline spawning to occur in fewer areas with generally lower numbers of adults. In studies on Priest Lake, Idaho, Bjornn (1957) attributed frozen eggs and stranded fry to winter fluctuations of the upper three meters of the lake. Eggs and fry frozen during winter drawdown accounted for a 90 percent loss to shoreline spawning kokanee in Donner Lake, California (Kimsey 1951). Stober et al. (1979a) determined irrigation drawdown of Banks Lake, Washington reduced shoreline survival during five of the seven years the system was studied. The goal of this phase of the study was to evaluate and document effects of the operation of Kerr Dam on kokanee

  16. Assisted reproductive technology--IVF treatment in Ireland: a study of couples with successful outcomes.

    PubMed

    Mahon, Evelyn; Cotter, Noelle

    2014-09-01

    This article describes the experiences of twelve Irish couples who had successful IVF treatment in Ireland. Irish Medical guidelines specify that IVF may only be used when no other treatment is likely to be effective. This article is based on data drawn from a longitudinal research study by Cotter (2009) which tells the stories of 34 couples who sought fertility treatment. Initially, the women assumed that they would become pregnant when they stopped using contraception. As a couple, it was the 'right time' for them to have a child--they were ready, socially and financially. For several months they were patient, hoping it would happen naturally. With envy and some despair they watched as their friends had babies. Infertility came as a shock to most of them. They were reluctant to talk about it to anyone, and over time their anxieties were accompanied by feelings of regret, stigma and social exclusion. They finally sought medical treatment. The latter involved a series of diagnostic treatments, which eventually culminated in IVF which offered them a final chance of having a 'child of their own'. While IVF can be clinically assessed in terms of cycle success rates, their stories showed treatment as a series of discoveries, as an extensive range of diagnostic tests and procedures helped to reveal to them where their problems might lie. They described their treatments as a series of sequential 'hurdles' that they had to overcome, which further strengthened their resolve to try IVF. Much more knowledgeable at that stage, they embraced IVF as a final challenge with single minded dedication while drawing on all their psychological and biological resources to promote a successful outcome. Of the 34 couples who took part in the study, twelve got pregnant. Unfortunately, two children died shortly after birth but eighteen babies survived (see Table I). The findings suggest that health policy should raise awareness of infertility, and advise women to become aware of it

  17. Reproductive success, developmental anomalies and environmental contaminants in double-crested cormorants (Phalacrocorax auritus)

    USGS Publications Warehouse

    Larson, J.M.; Karasov, W.H.; Sileo, L.; Stromborg, K.L.; Hanbidge, B.A.; Giesy, J.P.; Jones, P.D.; Tillitt, D.E.; Verbrugge, D.A.

    1996-01-01

    To test an association between environmental contaminants and the prevalence of congenital anomalies in colonial waterbirds, we collected representative eggs for chemical analysis from double-crested cormorant nests at colonies in Lake Michigan, Wisconsin, USA, and Lake Winnipegosis, Manitoba, Canada, and periodically revisited the nests to determine the hatching success, survivorship of hatchlings, and number of deformed hatchlings in the remainder of each clutch. Total concentrations of polychlorinated biphenyls (PCBs) in eggs were determined by capillary gas chromatography. The combined activity of planar chlorinated hydrocarbons (PCHs) in the eggs was measured in an in vitro bioassay based on the induction of ethoxyresorufin-O-deethylase (EROD) activity in rat hepatoma cells. The combined EROD induction activity was expressed as 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQ). Total concentrations of PCBs and TCDD-EQ were seven to eight times greater in eggs from Lake Michigan (7.8 μg/g and 138 pg/g, respectively) than in those from Lake Winnipegosis (1.0 μg/g and 19 pg/g, respectively). The proportion of eggs hatching at the Lake Michigan colony (59%) was less (p < 0.05) than at Lake Winnipegosis (70%), and the prevalence of hatchlings with deformed bills was greater (p < 0.001) at Lake Michigan (0.79 vs. 0.06%). However, within the Lake Michigan colony, concentrations of PCBs and TCDD-EQ were not correlated with either hatching success or the occurrence of deformities in nestlings.

  18. Reproductive success and habitat characteristics of Golden-winged Warblers in high-elevation pasturelands

    USGS Publications Warehouse

    Wood, Petra; Aldinger, Kyle R.

    2016-01-01

    The Golden-winged Warbler (Vermivora chrysoptera) is one of the most rapidly declining vertebrate species in the Appalachian Mountains. It is the subject of extensive range-wide research and conservation action. However, little is known about this species' breeding ecology in high-elevation pasturelands, a breeding habitat with conservation potential considering the U.S. Natural Resource Conservation Service's Working Lands for Wildlife program targeting private lands in the Appalachian Mountains. We located 100 nests of Golden-winged Warblers in pastures in and around the Monongahela National Forest in West Virginia during 2008–2012. Daily nest survival rate (mean ± SE  =  0.962 ± 0.006), clutch size (4.5 ± 0.1), and number of young fledged per nest attempt (2.0 ± 0.2) and successful nest (4.0 ± 0.1) fell within the range of values reported in other parts of the species' range and were not significantly affected by year or the presence/absence of cattle grazing. Classification tree analysis revealed that nests were in denser vegetation (≥52%) and closer to forest edges (<36.0 m) and shrubs (<7.0 cm) than random locations within the male's territory. Successful nests had significantly more woody cover (≥9%) within 1 m than failed nests. Our results suggest that cattle grazing at 1.2–2.4 ha of forage/animal unit with periodic mowing can create and maintain these characteristics without interfering with the nesting of Golden-winged Warblers. High-elevation pasturelands may provide a refuge for remaining populations of Golden-winged Warblers in this region.

  19. Reproductive success, developmental anomalies, and environmental contaminants in double-crested cormorants (Phalacrocorax auritus)

    SciTech Connect

    Larson, J.M.; Karasov, W.H.; Sileo, L.; Stromborg, K.L.; Giesy, J.P.; Jones, P.D.; Tillitt, D.E.; Verbrugge, D.A.; Hanbidge, B.A.

    1996-04-01

    To test an association between environmental contaminants and the prevalence of congenital anomalies in colonial waterbirds, the authors collected representative eggs for chemical analysis from double-crested cormorant nests at colonies in Lake Michigan, Wisconsin, USA, and Lake Winnipegosis, Manitoba, Canada, and periodically revisited the nests to determine the hatching success, survivorship of hatchlings, and number of deformed hatchlings in the remainder of each clutch. Total concentrations of polychlorinated biphenyls (PCBs) in eggs were determined by capillary gas chromatography. The combined activity of planar chlorinated hydrocarbons (PCHs) in the eggs was measured in an in vitro bioassay based on the induction of ethoxyresorufin-O-deethylase (EROD) activity in rat hepatoma cells. The combined EROD induction activity was expressed as 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQ). Total concentrations of PCBs and TCDD-EQ were seven to eight times greater in eggs from Lake Michigan (7.8 {micro}g/g and 138 pg/g, respectively) than in those from Lake Winnipegosis (1.0 {micro}g/g and 19 pg/g, respectively). The proportion of eggs hatching at the Lake Michigan colony (59%) was less (p < 0.05) than at Lake Winnipegosis (70%), and the prevalence of hatchlings with deformed bills was greater (p < 0.001) at Lake Michigan (0.79 vs. 0.06%). However, within the Lake Michigan colony, concentrations of PCBs and TCDD-EQ were not correlated with either hatching success or the occurrence of deformities in nestlings.

  20. Female and male genetic effects on offspring paternity: additive genetic (co)variances in female extra-pair reproduction and male paternity success in song sparrows (Melospiza melodia).

    PubMed

    Reid, Jane M; Arcese, Peter; Keller, Lukas F; Losdat, Sylvain

    2014-08-01

    Ongoing evolution of polyandry, and consequent extra-pair reproduction in socially monogamous systems, is hypothesized to be facilitated by indirect selection stemming from cross-sex genetic covariances with components of male fitness. Specifically, polyandry is hypothesized to create positive genetic covariance with male paternity success due to inevitable assortative reproduction, driving ongoing coevolution. However, it remains unclear whether such covariances could or do emerge within complex polyandrous systems. First, we illustrate that genetic covariances between female extra-pair reproduction and male within-pair paternity success might be constrained in socially monogamous systems where female and male additive genetic effects can have opposing impacts on the paternity of jointly reared offspring. Second, we demonstrate nonzero additive genetic variance in female liability for extra-pair reproduction and male liability for within-pair paternity success, modeled as direct and associative genetic effects on offspring paternity, respectively, in free-living song sparrows (Melospiza melodia). The posterior mean additive genetic covariance between these liabilities was slightly positive, but the credible interval was wide and overlapped zero. Therefore, although substantial total additive genetic variance exists, the hypothesis that ongoing evolution of female extra-pair reproduction is facilitated by genetic covariance with male within-pair paternity success cannot yet be definitively supported or rejected either conceptually or empirically.

  1. The effects of patch shape and connectivity on nest site selection and reproductive success of the Indigo Bunting.

    SciTech Connect

    Weldon, Aimee Jean

    2004-07-01

    Description – Ph.D Dissertation. North Carolina State University. Raleigh, North Carolina. 135 pp. Abatract - Habitat fragmentation and its associated effects have been blamed for the recent population declines of many Neotropical migratory bird species. Increased predation and parasitism resulting from edge-related effects have been implicated for poor nesting success in many studies, mostly of forest interior species. However, little attention has been devoted to disturbance-dependent birds. In this study, I examine how patch shape and connectivity in fragmented landscapes affects the reproductive success of disturbance-dependent bird species, specifically the Indigo Bunting (Passerina cyanea). I conducted my study in a landscape-scale experimental system of similar-area habitat patches that differed in connectivity and in shape. Shapes differed between edgy and rectangular forms, where edgy patches contained 50% more edge than rectangular patches. I tested whether edgy patches function as ecological traps for species with strong edge preferences, by leading them to select dangerous habitats. Indigo Buntings preferentially selected edgy patches over rectangular patches, but experienced significantly lower reproductive success in edgy patches early in the season. Although predation pressure intensified in rectangular patches late in the season, seasonal fecundity was still significantly lower in edgy patches, providing the first empirical evidence that edges can function as ecological traps for Indigo Buntings. A second objective of my study was to evaluate the efficacy of conservation corridors for disturbance-dependent bird species. Conservation corridors have become a popular strategy to preserve biodiversity and promote gene flow in fragmented landscapes, but corridors may also have negative consequences. I tested the hypothesis that corridors can increase nest predation risk in connected patches relative to unconnected patches. Nest predation rates

  2. Long-Term Prophylactic Antibiotic Treatment: Effects on Survival, Immunocompetence and Reproduction Success of Parasemia plantaginis (Lepidoptera: Erebidae).

    PubMed

    Dickel, Franziska; Freitak, Dalial; Mappes, Johanna

    2016-01-01

    Hundreds of insect species are nowadays reared under laboratory conditions. Rearing of insects always implicates the risk of diseases, among which microbial infections are the most frequent and difficult problems. Although there are effective prophylactic treatments, the side effects of applied antibiotics are not well understood. We examined the effect of prophylactic antibiotic treatment on the overwintering success of wood tiger moth (Parasemia plantaginis) larvae, and the postdiapause effect on their life-history traits. Four weeks before hibernation larvae were treated with a widely used antibiotic (fumagillin). We monitored moths' survival and life-history traits during the following 10 mo, and compared them to those of untreated control larvae. Prophylactic antibiotic treatment had no effect on survival but we show effects on some life-history traits by decreasing the developmental time of treated larvae. However, we also revealed relevant negative effects, as antibiotic treated individuals show a decreased number of laid eggs and also furthermore a suppressed immunocompetence. These results implicate, that a prophylactic medication can also lead to negative effects on life-history traits and reproductive success, which should be seriously taken in consideration when applying a prophylactic treatment to laboratory reared insect populations.

  3. Direct-to-consumer advertising of success rates for medically assisted reproduction: a review of national clinic websites

    PubMed Central

    Vail, Andy; Roberts, Stephen A

    2017-01-01

    Objectives To establish how medically assisted reproduction (MAR) clinics report success rates on their websites. Setting Websites of private and NHS clinics offering in vitro fertilisation (IVF) in the UK. Participants We identified clinics offering IVF using the Choose a Fertility Clinic facility on the website of the Human Fertilisation and Embryology Authority (HFEA). Of 81 clinics identified, a website could not be found for 2, leaving 79 for inclusion in the analysis. Primary and secondary outcome measures Outcome measures reported by clinic websites. The numerator and denominator included in the outcome measure were of interest. Results 53 (67%) websites reported their performance using 51 different outcome measures. It was most common to report pregnancy (83% of these clinics) or live birth rates (51%). 31 different ways of reporting pregnancy and 9 different ways of reporting live birth were identified. 11 (21%) reported multiple birth or pregnancy rates. 1 clinic provided information on adverse events. It was usual for clinics to present results without relevant contextual information such as sample size, reporting period, the characteristics of patients and particular details of treatments. Conclusions Many combinations of numerator and denominator are available for the purpose of reporting success rates for MAR. The range of reporting options available to clinics is further increased by the possibility of presenting results for subgroups of patients and for different time periods. Given the status of these websites as advertisements to patients, the risk of selective reporting is considerable. Binding guidance is required to ensure consistent, informative reporting. PMID:28082363

  4. Long-Term Prophylactic Antibiotic Treatment: Effects on Survival, Immunocompetence and Reproduction Success of Parasemia plantaginis (Lepidoptera: Erebidae)

    PubMed Central

    Dickel, Franziska; Freitak, Dalial; Mappes, Johanna

    2016-01-01

    Hundreds of insect species are nowadays reared under laboratory conditions. Rearing of insects always implicates the risk of diseases, among which microbial infections are the most frequent and difficult problems. Although there are effective prophylactic treatments, the side effects of applied antibiotics are not well understood. We examined the effect of prophylactic antibiotic treatment on the overwintering success of wood tiger moth (Parasemia plantaginis) larvae, and the postdiapause effect on their life-history traits. Four weeks before hibernation larvae were treated with a widely used antibiotic (fumagillin). We monitored moths’ survival and life-history traits during the following 10 mo, and compared them to those of untreated control larvae. Prophylactic antibiotic treatment had no effect on survival but we show effects on some life-history traits by decreasing the developmental time of treated larvae. However, we also revealed relevant negative effects, as antibiotic treated individuals show a decreased number of laid eggs and also furthermore a suppressed immunocompetence. These results implicate, that a prophylactic medication can also lead to negative effects on life-history traits and reproductive success, which should be seriously taken in consideration when applying a prophylactic treatment to laboratory reared insect populations. PMID:27271967

  5. Environmentally relevant concentrations of DE-71 and HBCD alter eggshell thickness and reproductive success of American kestrels.

    PubMed

    Fernie, Kim J; Shutt, J Laird; Letcher, Robert J; Ritchie, Ian J; Bird, David M

    2009-03-15

    Polybrominated diphenyl ethers (PBDEs) and total alpha-hexabromocyclododecane (HBCD) are flame-retardant additives that are commonly used in household and commercial applications. PBDE congeners, which are comprised of technical mixtures such as DE-71, are globally persistent and their concentrations are increasing in many species. Captive American kestrels (Falco sparverius) were exposed by diet to vehicle (safflower oil), or one of two environmentally relevant concentrations of DE-71 and unintentionally to HBCD. This exposure resulted in the birds laying eggs that contain PBDE and HBCD concentrations currently found in wild herring gull (Larus argentatus) and peregrine falcon (F. peregrinus) eggs, and compared to control kestrels, resulted in delayed egg laying and smaller eggs being laid, caused thinner eggshells and differential weight loss during embryonic development, and reduced fertility and reproductive success. The thickness of the eggshell declined as the concentrations of all measured PBDE and the total amount of a-HBCD congeners (except BDE-183 and BDE-209) increased; increasing concentrations of BDE-153, BDE-154, BDE-28, BDE-17, delayed egg laying, reduced eggshell mass (plus sigmaPBDEs), and reduced fledging success (BDE-153 and BDE-154 only). BDE-153 is the dominant congener recently found in peregrine eggs. The results of this study are consistent with the PBDE-associated brood reduction in wild European peregrines and may partially explain the decline of kestrels in North America.

  6. Breeding phenology and reproductive success of the Brandt's Cormorant at three nearshore colonies in central California, 1997-2001

    USGS Publications Warehouse

    Jones, Nathan M.; McChesney, Gerard; Parker, Michael W.; Yee, Julie L.; Carter, Harry R.; Golightly, Richard T.

    2008-01-01

    Brandt's Cormorant (Phalacrocorax penicillatus) breeding effort, phenology and success were studied in 1997-2001 at three colonies spanning approximately 200 km of the central California coast: Point Reyes (PR); Devil's Slide Rock and Mainland (DS); and Castle-Hurricane Colony Complex (CH). Breeding effort was reduced at all three colonies in the 1998 El Niño event. Mean clutch initiation dates differed significantly among colonies, with cormorants at the southernmost colony (CH) laying earliest, and those at the northernmost colony (PR) laying latest. Productivity at individual colonies varied greatly among years (range 0.7-2.5 fledglings per pair). Overall colony means were lowest (1.6 fledglings/pair) during the 1998 El Niño event and highest (2.5 fledglings/pair) in the 1999 La Niña event. Productivity at CH (1.7 fledglings/pair) was significantly lower than at PR (2.2 fledglings/pair), and interannual variation was greatest at CH. Late-nesting birds laid fewer eggs, hatched fewer chicks, and fledged fewer chicks per pair than early-nesters. The rapid rate of growth at some nearshore colonies in central California suggests immigration from elsewhere, most likely the large offshore colony at the South Farallon Islands. Variation in timing of breeding and reproductive success among colonies demonstrates a value in maintaining multiple study locations when assessing Brandt's Cormorant population parameters in the California Current System.

  7. Acute exposure to gas-supersaturated water does not affect reproductive success of female adult chinook salmon late in maturation

    USGS Publications Warehouse

    Gale, William L.; Maule, A.G.; Postera, A.; Peters, M.H.

    2004-01-01

    At times, total dissolved gas concentrations in the Columbia and Snake rivers have been elevated due to involuntary spill from high spring runoff and voluntary spill used as a method to pass juvenile salmonids over dams. The goal of this project was to determine if acute exposure to total dissolved gas supersaturation (TDGS) affects the reproductive performance of female chinook salmon late in their maturation. During this study, adult female spring chinook salmon were exposed to mean TDGS levels of 114.1 % to 125.5%. We ended exposures at first mortality, or at the appearance of impending death. Based on this criterion, exposures lasted from 10 to 68 h and were inversely related to TDGS. There was no effect of TDGS on pre-spawning mortality or fecundity when comparing treatment fish to experimental controls or the general hatchery population four to six weeks after exposures. Egg quality, based on egg weight and egg diameter, did not differ between treatment and control fish. Fertilization rate and survival to eyed-stage was high (>94%) for all groups. With the exception of Renibacterium salmoninarum (the causative agent of bacterial kidney disease; BKD), no viral or bacterial fish pathogens were isolated from experimental fish. The prevalence (about 45%) and severity of R. salmoninarum did not differ among the groups or the general hatchery population. We conclude that these acute exposures to moderate levels of gas-supersaturated water-perhaps similar to that experienced by immigrating adult salmon as they approach and pass a hydropower dam on the Columbia River-did not affect reproductive success of female chinook salmon late in their maturation. These results are most applicable to summer and fall chinook salmon, which migrate in the summer/fall and spawn shortly after reaching their natal streams. Published in 2004 by John Wiley and Sons, Ltd.

  8. Successful survival, growth, and reproductive potential of quagga mussels in low calcium lake water: is there uncertainty of establishment risk?

    PubMed Central

    Ruhmann, Emma K.; Acharya, Kumud; Chandra, Sudeep; Jerde, Christopher L.

    2015-01-01

    The risk of quagga mussel (Dreissena rostriformis bugensis Andrusov 1897) establishment into water-bodies of the western US has expanded the geographic concern regarding the ecological and economic impacts this species will have in aquatic ecosystems. Thresholds based on calcium concentrations, an element critical for mussel growth and physiology, have been used as a primary predictor of quagga mussel establishment success to aid management decisions. We evaluated the invasion potential of quagga mussels in low calcium waters using laboratory experiments to compare the survival, growth and reproductive potential of adult mussels held for 90 days at low (9 and 12 ppm), moderate (15 to 32 ppm) and high (72 ppm) calcium water concentrations. In conjunction with adult experiments, veliger stage survival, growth and settlement were evaluated under similar low, moderate, and high calcium water treatments. Adult mussels survived, grew and showed reproductive potential in low calcium water (12 ppm). Veligers were also able to survive, grow and settle in low calcium water. Higher levels of natural seston biomass appeared to improve adult mussel life history performance in low calcium water. Survival curve analysis predicted that 99% adult mortality could occur in <170 days at 9 ppm and 12 ppm, however water with >15 ppm could have adults surviving more than a year. The results from these bioassays provide further evidence that quagga mussels have higher risk of establishment in low calcium lakes if habitats exist that have slightly elevated calcium. These results should help emphasize the vulnerability of water-body in the 12 to 15 ppm calcium range that could potentially be at risk of establishing sustainable quagga mussel populations. Furthermore, these results provide insights into the uncertainty of using a single parameter in assigning establishment risk given the complexity of variables in specific water-bodies that influence life history performance of introduced

  9. Men with a complete absence of normal sperm morphology exhibit high rates of success without assisted reproduction

    PubMed Central

    Kovac, Jason R; Smith, Ryan P; Cajipe, Miguel; Lamb, Dolores J; Lipshultz, Larry I

    2017-01-01

    In couples with infertility, abnormal strict morphology of 0% normal forms (NF) is a criterion to proceed rapidly to in vitro fertilization (IVF). Since no data currently exist, we investigated the outcomes for men with 0% NF to determine reproductive success without the use of assisted reproductive technologies (ART). A cohort of 24 men with 0% NF were identified (2010–2013) with 27 randomly selected men with ≥4% NF as controls. Patient charts were reviewed with men contacted and administered an Institutional Review Board (IRB)-approved telephone questionnaire to ascertain outcomes. After a median follow-up time of 2.5 years, 29.2% of men with 0% NF did not require ART for their first pregnancy (controls = 55.6%, P ≤ 0.05). When all pregnancies were analyzed together, men with 0% NF achieved twenty pregnancies of which 75% did not require IVF (controls = thirty pregnancies; 76.7% did not require IVF). The average age of men and female partners was similar between men with 0% NF and ≥4% NF. All men had normal follicle-stimulating hormone (FSH), testosterone, prolactin, sex hormone-binding globulin (SHBG), and estradiol. Although, global semen parameters were worse in men with 0% NF, when a first pregnancy was a natural conception (NC), 100% of men with 0% NF (n = 7/7) and 37.5% of controls (n = 3/8) went on to have a subsequent pregnancy via NC. Men with 0% NF conceived without IVF in 29.2% of cases compared to 55.6% of controls. Strict morphology should not be used to predict fertilization, pregnancy, or live birth potential. In men with 0% NF, alternative modalities should be considered before immediate IVF. PMID:27751992

  10. Men with a complete absence of normal sperm morphology exhibit high rates of success without assisted reproduction.

    PubMed

    Kovac, Jason R; Smith, Ryan P; Cajipe, Miguel; Lamb, Dolores J; Lipshultz, Larry I

    2017-01-01

    In couples with infertility, abnormal strict morphology of 0% normal forms (NF) is a criterion to proceed rapidly to in vitro fertilization (IVF). Since no data currently exist, we investigated the outcomes for men with 0% NF to determine reproductive success without the use of assisted reproductive technologies (ART). A cohort of 24 men with 0% NF were identified (2010-2013) with 27 randomly selected men with ≥4% NF as controls. Patient charts were reviewed with men contacted and administered an Institutional Review Board (IRB)-approved telephone questionnaire to ascertain outcomes. After a median follow-up time of 2.5 years, 29.2% of men with 0% NF did not require ART for their first pregnancy (controls = 55.6%, P ≤ 0.05). When all pregnancies were analyzed together, men with 0% NF achieved twenty pregnancies of which 75% did not require IVF (controls = thirty pregnancies; 76.7% did not require IVF). The average age of men and female partners was similar between men with 0% NF and ≥4% NF. All men had normal follicle-stimulating hormone (FSH), testosterone, prolactin, sex hormone-binding globulin (SHBG), and estradiol. Although, global semen parameters were worse in men with 0% NF, when a first pregnancy was a natural conception (NC), 100% of men with 0% NF (n = 7/7) and 37.5% of controls (n = 3/8) went on to have a subsequent pregnancy via NC. Men with 0% NF conceived without IVF in 29.2% of cases compared to 55.6% of controls. Strict morphology should not be used to predict fertilization, pregnancy, or live birth potential. In men with 0% NF, alternative modalities should be considered before immediate IVF.

  11. The novel POSEIDON stratification of 'Low prognosis patients in Assisted Reproductive Technology' and its proposed marker of successful outcome.

    PubMed

    Humaidan, Peter; Alviggi, Carlo; Fischer, Robert; Esteves, Sandro C

    2016-01-01

    In reproductive medicine little progress has been achieved regarding the clinical management of patients with a reduced ovarian reserve or poor ovarian response (POR) to stimulation with exogenous gonadotropins -a frustrating experience for clinicians as well as patients. Despite the efforts to optimize the definition of this subgroup of patients, the existing POR criteria unfortunately comprise a heterogeneous population and, importantly, do not offer any recommendations for clinical handling. Recently, the POSEIDON group ( Patient- Oriented Strategies Encompassing Individualize D Oocyte Number) proposed a new stratification of assisted reproductive technology (ART) in patients with a reduced ovarian reserve or unexpected inappropriate ovarian response to exogenous gonadotropins. In brief, four subgroups have been suggested based on quantitative and qualitative parameters, namely, i. Age and the expected aneuploidy rate; ii. Ovarian biomarkers (i.e. antral follicle count [AFC] and anti-Müllerian hormone [AMH]), and iii. Ovarian response - provided a previous stimulation cycle was performed. The new classification introduces a more nuanced picture of the "low prognosis patient" in ART, using clinically relevant criteria to guide the physician to most optimally manage this group of patients. The POSEIDON group also introduced a new measure for successful ART treatment, namely, the ability to retrieve the number of oocytes needed for the specific patient to obtain at least one euploid embryo for transfer. This feature represents a pragmatic endpoint to clinicians and enables the development of prediction models aiming to reduce the time-to-pregnancy (TTP). Consequently, the POSEIDON stratification should not be applied for retrospective analyses having live birth rate (LBR) as endpoint. Such an approach would fail as the attribution of patients to each Poseidon group is related to specific requirements and could only be made prospectively. On the other hand, any

  12. Adaptation of a stage-projection model for species with multiple year reproductive cycles

    USGS Publications Warehouse

    Gilbert, James R.; Udevitz, Mark S.

    1997-01-01

    We apply stage projection matrices to multiple age and reproductive categories, deriving the stable age - reproductive category distribution for populations with multi-year reproductive cycles and identifying conditions for the existence of a dominant latent root. Given the stable distribution of age and reproductive category and the number of female young for each reproductive category, the age specific fecundity rates can be calculated. For species with multi-year reproductive cycles, the fecundity rate associated with the stable age distribution is often not a smooth function of age, but fluctuates as a larger or smaller fraction of females becomes available to breed. We suggest that fecundity rates for species with multi-year reproductive cycles be defined in terms of litter size and probabilities of conception and successful gestation rather than average fecundity.

  13. Observations on the removal of brood inoculated with Tropilaelaps mercedesae (Mesostigmata: Laelapidae) and the mite’s reproductive success in Apis mellifera colonies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study assessed the response of Apis mellifera to brood deliberately infested with Tropilaelaps mercedesae. The reproductive success of T. mercedesae in mite-inoculated and naturally infested brood was also compared. The presence of T. mercedesae inside brood cells significantly affected brood ...

  14. Breeding site selection by coho salmon (Oncorhynchus kisutch) in relation to large wood additions and factors that influence reproductive success

    USGS Publications Warehouse

    Clark, Steven M.; Dunham, Jason B.; McEnroe, Jeffery R.; Lightcap, Scott W.

    2014-01-01

    The fitness of female Pacific salmon (Oncorhynchus spp.) with respect to breeding behavior can be partitioned into at least four fitness components: survival to reproduction, competition for breeding sites, success of egg incubation, and suitability of the local environment near breeding sites for early rearing of juveniles. We evaluated the relative influences of habitat features linked to these fitness components with respect to selection of breeding sites by coho salmon (Oncorhynchus kisutch). We also evaluated associations between breeding site selection and additions of large wood, as the latter were introduced into the study system as a means of restoring habitat conditions to benefit coho salmon. We used a model selection approach to organize specific habitat features into groupings reflecting fitness components and influences of large wood. Results of this work suggest that female coho salmon likely select breeding sites based on a wide range of habitat features linked to all four hypothesized fitness components. More specifically, model parameter estimates indicated that breeding site selection was most strongly influenced by proximity to pool-tail crests and deeper water (mean and maximum depths). Linkages between large wood and breeding site selection were less clear. Overall, our findings suggest that breeding site selection by coho salmon is influenced by a suite of fitness components in addition to the egg incubation environment, which has been the emphasis of much work in the past.

  15. Reproductive success of individuals with different fruit production patterns. What does it mean for the predator satiation hypothesis?

    PubMed

    Zywiec, Magdalena; Holeksa, Jan; Ledwoń, Mateusz; Seget, Piotr

    2013-06-01

    The predator satiation hypothesis states that synchronous periodic production of seeds is an adaptive strategy evolved to reduce the pressure of seed predators. The seed production pattern is crucial to the predator satiation hypothesis, but there are few studies documenting the success of individuals that are in synchrony and out of synchrony with the whole population. This study is based on long-term data on seed production of Sorbus aucuparia and specialised pre-dispersal seed predation by Argyresthia conjugella, in a subalpine spruce forest in the Western Carpathians (Poland). At the population level, we tested whether functional and numerical responses of predators to the variation of fruit production operate. At the individual level, we tested whether individuals with higher interannual variability in their own seed crops and higher synchrony with the population have higher percentages of uninfested fruits. The intensity of pre-dispersal seed predation was high (average 70 %; range 19-100 %). There were both functional and numerical responses of predators to the variation of fruit production at the population level. We found that individuals that were expected to be preferred under seed predator pressure had higher reproductive success. With increasing synchrony of fruit production between individual trees and the population, the percentage of infested fruits decreased. There was also a negative relationship between the interannual variation in individual fruit production and the percentage of infested fruits. These results confirm selection for individuals with a masting strategy. However, the population does not seem well adapted to strong seed predation pressure and we suggest that this may be a result of prolonged diapause of A. conjugella.

  16. Effects of parental age and food availability on the reproductive success of Heermann's gulls in the Gulf of California.

    PubMed

    Vieyra, Leticia; Velarde, Enriqueta; Ezcurra, Exequiel

    2009-04-01

    Parental age, body condition, and food availability have been found to influence breeding parameters in seabirds, such as clutch size, number of chicks hatched and fledged, hatching, fledging, and reproductive success. In this paper we analyze the influence of parental age and body condition estimated by body mass, and food availability estimated from catch per unit effort (CPUE) statistics for Pacific sardine (Sardinops caeruleus) + northern anchovy (Engraulis mordax) by the local fishing fleet, on the breeding parameters of the Heermann's Gull (Larus heermanni; a vulnerable species according to Mexican federal law) nesting in Isla Rasa, Gulf of California, Mexico. Results are based on data from 1123 recaptures of known-age individuals, ranging from 4 to 13 years of age, during seven observation years between 1989 and 1997. Ages of mated male and female gulls were positively correlated. Breeding parameters showed their lowest values in 1992, an El Niño year in which the birds also showed significantly lower individual masses for both males and females, and in which the local CPUE of sardine + anchovies was lowest. All breeding parameters increased significantly with parental age and were highest at 10-12 years. No significant statistical interactions were found between food availability and parental age on the breeding parameters. Through a path analysis we found that there is a strong chained relationship between variables: food availability, which is strongly driven by oceanographic conditions, affects both the survival of eggs into hatchlings and the survival of hatchlings into fledglings. This external factor and parental age, a biological factor intrinsic to each nesting couple, explain 41% of the observed between-nest variation in fledgling success.

  17. Age-specific MRI templates for pediatric neuroimaging

    PubMed Central

    Sanchez, Carmen E.; Richards, John E.; Almli, C. Robert

    2012-01-01

    This study created a database of pediatric age-specific MRI brain templates for normalization and segmentation. Participants included children from 4.5 through 19.5 years, totaling 823 scans from 494 subjects. Open-source processing programs (FSL, SPM, ANTS) constructed head, brain and segmentation templates in 6 month intervals. The tissue classification (WM, GM, CSF) showed changes over age similar to previous reports. A volumetric analysis of age-related changes in WM and GM based on these templates showed expected increase/decrease pattern in GM and an increase in WM over the sampled ages. This database is available for use for neuroimaging studies (blindedforreview). PMID:22799759

  18. Body growth considerations in age-specific dosimetry. Final report

    SciTech Connect

    Eckerman, K.F.

    1993-09-30

    This report describes the manner in which the age-specific dosimetric calculations of the International Commission on Radiological Protection (ICRP) addressed changes in organ size that occur with age. The approach involves an interpolation of dosimetric information derived for six reference individuals using the inverse of the total body mass as the interpolation variable. An alternative formulation is investigated that employs a functional representation of the organ mass as a function of age in conjunction with an explicit formulation of the dosimetric factors in terms of organ mass. Using an exponential-logistic growth function as suggested by Walker, this report demonstrates, through application to the dosimetry of radioiodines in the thyroid, that the alternative formulation can be formulated and implemented. Although either approach provides a workable basis for age-specific dosimetry, it is clear that the functional representation of organ growth has some attractive features. However, without question, the major difficulty is the quality and quantity of data available to address the age- and gender-specific parameters in the dosimetric formulations.

  19. Digit ratio (2D:4D), dominance, reproductive success, asymmetry, and sociosexuality in the BBC Internet Study.

    PubMed

    Manning, John T; Fink, Bernhard

    2008-01-01

    Digit ratio (2D:4D) may be a correlate of prenatal sex steroids, and has been linked to traits, which are influenced by fetal testosterone and estrogen. Here we consider such links in a large Internet study of sex differences (the BBC Internet Study) in which finger lengths were self-measured. Consistent with lab-based findings the 2D:4D in this study shows sexual dimorphism, ethnic differences and higher dimorphism of right 2D:4D than left, thereby indicating that 2D:4D does measure real between-participant variation. High error in self-measurement of fingers reduces effect sizes. However, the large sample size gives assurance that significant effects are likely to be real. We controlled for ethnicity and sexual orientation by considering White heterosexuals only (153,429 participants). Sexual dimorphism was confirmed in 2D:4D and for the difference of right-left 2D:4D. After Bonferroni correction we found highly significant relationships with low effect sizes as follows. In males and females there were negative associations between 2D:4D and dominance. In males there were negative associations between 2D:4D and family size and factors associated with reproductive success. For females these associations were positive. For asymmetry we found U-shaped relationships with 2D:4D in both males and females. We found no relationship between 2D:4D and promiscuity (sociosexuality). In total, we considered 48 relationships and found 29 to be significant. We compare our findings with a similar study reported by Putz et al. (2004), which found only 2 out of 57 correlations to be significant and discuss possible reasons for the discrepancies between the studies.

  20. Effects of contaminant exposure on reproductive success of ospreys (Pandion haliaetus) nesting in Delaware River and Bay, USA

    USGS Publications Warehouse

    Toschik, P.C.; Rattner, B.A.; McGowan, P.C.; Christman, M.C.; Carter, Daniel B.; Hale, R.C.; Matson, C.W.; Ottinger, M.A.

    2005-01-01

    Despite serious water-quality problems and pollutant loading and retention, Delaware River and Bay (USA) provide important wildlife habitat. In 2002, we conducted a comprehensive evaluation of contaminant exposure and reproduction of ospreys (Pandion haliaetus) breeding in Delaware River and Bay. Sample eggs were collected from 39 nests and analyzed for organochlorine pesticides, polychlorinated biphenyls (PCBs), and mercury; a subset of 15 eggs was analyzed for perfluorinated compounds and polybrominated diphenyl ethers (PBDEs). The fate of each nest was monitored weekly. Concentrations of 10 organochlorine pesticides or metabolites, total PCBs, and several toxic PCB congeners were greater (p < 0.05) in eggs collected between the Chesapeake and Delaware Canal (C and D Canal) and Trenton (Delaware River and northern Bay) compared to other sites. Concentrations of p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE; 0.785-3.84 mug/g wet wt) and total PCBs (5.50-14.5 mug/g wet wt) in eggs collected between the C and D Canal and Trenton were similar to levels recently found in the Chesapeake Bay. In all study segments, at least one young fledged from 66 to 75% of nests. Productivity for Delaware Inland Bays (reference area) and southern Delaware Bay was 1.17 and 1.42 fledglings/active nest, respectively; north of the C and D Canal, productivity was 1.00 fledgling/active nest, which is marginally adequate to maintain the population. Using these data, a logistic regression model found that contaminant concentrations (p,p'-DDE, heptachlor epoxide, chlordane and metabolites, and total PCBs) were predictive of hatching success. Several perfluorinated compounds and PBDEs were detected in eggs at concentrations approaching 1 mug/g wet weight. These findings provide evidence that contaminants continue to be a significant stressor on osprey productivity in the northern Delaware River and Bay.

  1. Reproductive failure in Arabidopsis thaliana under transient carbohydrate limitation: flowers and very young siliques are jettisoned and the meristem is maintained to allow successful resumption of reproductive growth.

    PubMed

    Lauxmann, Martin A; Annunziata, Maria G; Brunoud, Géraldine; Wahl, Vanessa; Koczut, Andrzej; Burgos, Asdrubal; Olas, Justyna J; Maximova, Eugenia; Abel, Christin; Schlereth, Armin; Soja, Aleksandra M; Bläsing, Oliver E; Lunn, John E; Vernoux, Teva; Stitt, Mark

    2016-04-01

    The impact of transient carbon depletion on reproductive growth in Arabidopsis was investigated by transferring long-photoperiod-grown plants to continuous darkness and returning them to a light-dark cycle. After 2 days of darkness, carbon reserves were depleted in reproductive sinks, and RNA in situ hybridization of marker transcripts showed that carbon starvation responses had been initiated in the meristem, anthers and ovules. Dark treatments of 2 or more days resulted in a bare-segment phenotype on the floral stem, with 23-27 aborted siliques. These resulted from impaired growth of immature siliques and abortion of mature and immature flowers. Depolarization of PIN1 protein and increased DII-VENUS expression pointed to rapid collapse of auxin gradients in the meristem and inhibition of primordia initiation. After transfer back to a light-dark cycle, flowers appeared and formed viable siliques and seeds. A similar phenotype was seen after transfer to sub-compensation point irradiance or CO2 . It also appeared in a milder form after a moderate decrease in irradiance and developed spontaneously in short photoperiods. We conclude that Arabidopsis inhibits primordia initiation and aborts flowers and very young siliques in C-limited conditions. This curtails demand, safeguarding meristem function and allowing renewal of reproductive growth when carbon becomes available again.

  2. Effects of experimentally sustained elevated testosterone on incubation behaviour and reproductive success in female great tits (Parus major).

    PubMed

    de Jong, Berber; Lens, Luc; Amininasab, Seyed Mehdi; van Oers, Kees; Darras, Veerle M; Eens, Marcel; Pinxten, Rianne; Komdeur, Jan; Groothuis, Ton G G

    2016-05-01

    In many seasonally breeding birds, female and male testosterone (T) levels peak at the start of the breeding season, coinciding with pair bonding and nesting activities. Shortly after the onset of egg laying, T levels slowly decline to baseline levels in both sexes, but more rapidly so in females. During this period, T in males may still function to facilitate territorial behaviour, mate guarding and extra pair copulations, either via short lasting peaks or elevated basal levels of the hormone. In some species, however, males become insensitive to increased T after the onset of egg laying. It has been postulated that in these species bi-parental care is essential for offspring survival, as T is known to inhibit paternal care. However, only very few studies have analysed this for females. As females are heavily involved in parental care, they too might become insensitive to T after egg laying. Alternatively, because territorial defence, mate guarding and extra pair copulations are expected to be less important for females than for males, they may not have had the need to evolve a mechanism to become insensitive to T during the period of maternal care, because their natural T levels are never elevated during this part of the breeding season anyway. We tested these alternative hypotheses in female great tits (Parus major). Male great tits have previously been shown to be insensitive to T after egg laying with regard to nestling feeding behaviour (but not song rate). When females had started nest building, we experimentally elevated their T levels up to the nestling feeding phase, and measured incubation behaviour (only females incubate) and reproductive success. T did not significantly affect nest building or egg laying behaviour, although egg laying tended to be delayed in T females. Females with experimentally enhanced T maintained lower temperature during incubation but did not spend less time incubating. This might explain the reduced hatching success of their

  3. Country- and age-specific optimal allocation of dengue vaccines.

    PubMed

    Ndeffo Mbah, Martial L; Durham, David P; Medlock, Jan; Galvani, Alison P

    2014-02-07

    Several dengue vaccines are under development, and some are expected to become available imminently. Concomitant with the anticipated release of these vaccines, vaccine allocation strategies for dengue-endemic countries in Southeast Asia and Latin America are currently under development. We developed a model of dengue transmission that incorporates the age-specific distributions of dengue burden corresponding to those in Thailand and Brazil, respectively, to determine vaccine allocations that minimize the incidence of dengue hemorrhagic fever, taking into account limited availability of vaccine doses in the initial phase of production. We showed that optimal vaccine allocation strategies vary significantly with the demographic burden of dengue hemorrhagic fever. Consequently, the strategy that is optimal for one country may be sub-optimal for another country. More specifically, we showed that, during the first years following introduction of a dengue vaccine, it is optimal to target children for dengue mass vaccination in Thailand, whereas young adults should be targeted in Brazil.

  4. Effective population size of steelhead trout: influence of variance in reproductive success, hatchery programs, and genetic compensation between life-history forms.

    PubMed

    Araki, Hitoshi; Waples, Robin S; Ardren, William R; Cooper, Becky; Blouin, Michael S

    2007-03-01

    The effective population size is influenced by many biological factors in natural populations. To evaluate their relative importance, we estimated the effective number of breeders per year (Nb) and effective population size per generation (Ne) in anadromous steelhead trout (Oncorhynchus mykiss) in the Hood River, Oregon (USA). Using demographic data and genetic parentage analysis on an almost complete sample of all adults that returned to the river over 15 years (>15,000 individuals), we estimated Nb for 13 run years and Ne for three entire generations. The results are as follows: (i) the ratio of Ne to the estimated census population size (N) was 0.17-0.40, with large variance in reproductive success among individuals being the primary cause of the reduction in Ne/N; (ii) fish from a traditional hatchery program (Htrad: nonlocal, multiple generations in a hatchery) had negative effects on Nb, not only by reducing mean reproductive success but also by increasing variance in reproductive success among breeding parents, whereas no sign of such effects was found in fish from supplementation hatchery programs (Hsupp: local, single generation in a hatchery); and (iii) Nb was relatively stable among run years, despite the widely fluctuating annual run sizes of anadromous adults. We found high levels of reproductive contribution of nonanadromous parents to anadromous offspring when anadromous run size is small, suggesting a genetic compensation between life-history forms (anadromous and nonanadromous). This is the first study showing that reproductive interaction between different life-history forms can buffer the genetic impact of fluctuating census size on Ne.

  5. Age-specific reference values for serum FSH and estradiol levels throughout the reproductive period.

    PubMed

    Grisendi, Valentina; Spada, Elena; Argento, Cindy; Plebani, Maddalena; Milani, Silvano; Seracchioli, Renato; Volpe, Annibale; La Marca, Antonio

    2014-06-01

    High serum day 3 FSH levels are associated with poor ovarian reserve and reduced fertility, but the interpretation of FSH values according to age is still not univocal. The purpose of this study was to determine age-dependent reference values in women with regular menstrual cycles and FSH as a guide for specialists. The study was performed at the Department of Mother-Infant of a University-based tertiary care centre. One-hundred ninety-two healthy normal menstruating women were recruited for the study. All patients attended the department on menstrual cycle day 3 for a blood sample for FSH and estradiol determination. A linear relationship between FSH or estradiol serum levels and age was observed. The FSH level increased by 0.11 IU for every year of age (1 IU for every 9 years of age). The values of FSH and estradiol corresponding to the 5th, 25th, 50th, 75th, 95th centiles for any specific age have been calculated. Serum FSH levels need to be interpreted according to age-dependent reference values. Serum FSH levels on 95th centile for any age may represent a warning sign for reduced ovarian reserve.

  6. Comparing the Reproductive Success of Yakima River Hatchery- and Wild-Origin Spring Chinook; Yakima/Klickitat Fisheries Project Monitoring and Evaluation, 2001-2002 Annual Report.

    SciTech Connect

    Schroder, Steven L.; Knudsen, Curtis M.; Watson, Bruce D.

    2003-05-01

    In 2001 hatchery- and wild-origin spring chinook were placed into an observation stream located at the Cle Elum Supplementation Research Facility to compare their reproductive success. Two groups containing both wild- and hatchery fish of both sexes were brought into the stream and allowed to spawn. Their longevity, spawning participation, and reproductive success were assessed. In addition, wild- and hatchery-origin precocious males were also introduced into one of the sections and allowed to spawn. We found that hatchery and wild males generally lived longer than females. In one group hatchery and wild females lived for similar periods of time while in the other wild females lived longer than hatchery fish. Wild females were also more successful at burying their eggs and the eggs they buried had higher survival rates. This result occurred in both groups of fish. Spawning participation in males was estimated by using two statistics referred to as percent gonad depletion (PGD) and percent testes retention (PRT). Both of these measures assumed that loss of testes weight in males would reflect their spawning participation and therefore could be used to estimate reproductive success. Hatchery and wild males had similar PGD and PRT values. One of these measures, PRT, was negatively associated with male reproductive success, confirming the idea that reduction in testes weight can be used as a surrogate measure of a male's ability to produce offspring Fry from the observation stream were collected throughout the emergence period that ran from January through May. Proportionate sub-samples of these fish were removed and microsatellite DNA was extracted from them. Pedigree analyses were performed to ascertain which adult fish had produced them. These analyses disclosed that wild males were more successful at producing progeny in one of the groups. No difference occurred in the other group. Precocial males and jacks fathered fewer progeny than did fish maturing at ages 4

  7. Nutritional stress in Northern gannets during an unprecedented low reproductive success year: can extreme sea surface temperature event and dietary change be the cause?

    PubMed

    Franci, Cynthia D; Vézina, François; Grégoire, François; Rail, Jean-François; Verreault, Jonathan

    2015-03-01

    Reproductive success of seabirds is tightly associated with availability of their prey for which the spatiotemporal distribution may be influenced by sea surface temperature (SST) fluctuations. The objective of this study was to investigate whether Northern gannets (Morus bassanus) from the largest colony in North America (Bonaventure Island, Quebec, Canada) were in negative nutritional state during the unprecedented low reproductive success year of 2012, and whether this was associated with changes in SST anomalies and diet. The incubation period of gannets in 2012 was characterized by a significant decline, from early to late incubation, in plasma triglyceride levels that was associated with an increase in plasma corticosterone levels. However, no changes in plasma glycerol and β-hydroxybutyrate levels were noted. SST anomalies recorded in this area (south of the Gulf of St. Lawrence) during the breeding period were consistently higher in 2012 compared to the previous year (a better reproductive success year). Based on signatures of stable carbon (δ(13)C) and nitrogen (δ(15)N) isotopes in gannet red blood cells and in whole fish homogenates of three major preys (mackerel, herring, and capelin), a minor dietary shift was noted between those years and incubation periods. In light of these findings, it is suggested that the extreme warm-water perturbation event that prevailed in the Gulf of St. Lawrence during summer 2012 was associated with a rapid deterioration of nutritional condition of Bonaventure Island gannets during the incubation. These suboptimal physiological changes likely contributed to the dramatic decline in reproductive success reported in this colony.

  8. Successful Reproduction Requires the Function of Arabidopsis YELLOW STRIPE-LIKE1 and YELLOW STRIPE-LIKE3 Metal-Nicotianamine Transporters in Both Vegetative and Reproductive Structures

    SciTech Connect

    Chu, H.; Chiecko, J; Punshon, T; Lanzirotti, A; Lahner, B; Salt, D; Walker, E

    2010-01-01

    Several members of the Yellow Stripe-Like (YSL) family of proteins are transporters of metals that are bound to the metal chelator nicotianamine or the related set of mugineic acid family chelators known as phytosiderophores. Here, we examine the physiological functions of three closely related Arabidopsis (Arabidopsis thaliana) YSL family members, AtYSL1, AtYSL2, and AtYSL3, to elucidate their role(s) in the allocation of metals into various organs of Arabidopsis. We show that AtYSL3 and AtYSL1 are localized to the plasma membrane and function as iron transporters in yeast functional complementation assays. By using inflorescence grafting, we show that AtYSL1 and AtYSL3 have dual roles in reproduction: their activity in the leaves is required for normal fertility and normal seed development, while activity in the inflorescences themselves is required for proper loading of metals into the seeds. We further demonstrate that the AtYSL1 and AtYSL2 proteins, when expressed from the AtYSL3 promoter, can only partially rescue the phenotypes of a ysl1ysl3 double mutant, suggesting that although these three YSL transporters are closely related and have similar patterns of expression, they have distinct activities in planta. In particular, neither AtYSL1 nor AtYSL2 is able to functionally complement the reproductive defects exhibited by ysl1ysl3 double mutant plants.

  9. Positive effect of the yellow morph on female reproductive success in the flower colour polymorphic Iris lutescens (Iridaceae), a deceptive species.

    PubMed

    Imbert, E; Wang, H; Conchou, L; Vincent, H; Talavera, M; Schatz, B

    2014-09-01

    The deceptive Iris lutescens (Iridaceae) shows a heritable and striking flower colour polymorphism, with both yellow- and purple-flowered individuals growing sympatrically. Deceptive species with flower colour polymorphism are mainly described in the family Orchidaceae and rarely found in other families. To explain the maintenance of flower colour polymorphism in I. lutescens, we investigated female reproductive success in natural populations of southern France, at both population and local scales (within populations). Female reproductive success was positively correlated with yellow morph frequency, at both the population scale and the local scale. Therefore, we failed to observe negative frequency-dependent selection (NFDS), a mechanism commonly invoked to explain flower colour polymorphism in deceptive plant species. Flower size and local flower density could also affect female reproductive success in natural populations. Pollinator behaviour could explain the positive effect of the yellow morph, and our results suggest that flower colour polymorphism might not persist in I. lutescens, but alternative explanations not linked to pollinator behaviour are discussed. In particular, NFDS, although an appealingly simple explanation previously demonstrated in orchids, may not always contribute to maintaining flower colour polymorphism, even in deceptive species.

  10. Mercury and selenium concentrations in leatherback sea turtles (Dermochelys coriacea): population comparisons, implications for reproductive success, hazard quotients and directions for future research.

    PubMed

    Perrault, Justin R; Miller, Debra L; Garner, Jeanne; Wyneken, Jeanette

    2013-10-01

    Leatherback sea turtles (Dermochelys coriacea) are long-distance migrants that travel thousands of km from foraging grounds to breeding and nesting grounds. These extensive journeys are fueled by ingestion of an estimated 300-400 kg of prey/d and likely result in exposure to high concentrations of environmental toxicants (e.g., mercury compounds). Increased bodily concentrations of mercury and its compounds in nesting female turtles may have detrimental effects on reproductive success. Leatherbacks have relatively low reproductive success compared with other sea turtles (global average hatching success ~50-60%). To assess toxicants and necessary nutrients as factors affecting leatherback turtle reproductive success at Sandy Point National Wildlife Refuge (SPNWR), St. Croix, U.S. Virgin Islands, we collected blood from nesting female leatherbacks and tissues from their hatchlings (blood from live turtles, liver and yolk sac from dead turtles). We compared the concentrations in those tissues to hatching and emergence success. We found that on SPNWR, hatching and emergence success were more closely related to seasonal factors than to total mercury and selenium concentrations in both nesting females and hatchlings. Selenium concentrations of nesting females were positively correlated with those of their hatchlings. Mercury and selenium in the liver of hatchlings were positively correlated with one another. Turtles with greater remigration intervals tended to have higher blood selenium concentrations, suggesting that selenium accumulates in leatherbacks through time. Through hazard quotients, we found evidence that selenium may be at or above concentrations that may cause physiologic harm to hatchlings. We also found evidence that population level differences exist for these trace elements. The concentrations of mercury and selenium established in this manuscript form a baseline for future toxicant studies.

  11. Benefits of a Ball and Chain: Simple Environmental Enrichments Improve Welfare and Reproductive Success in Farmed American Mink (Neovison vison)

    PubMed Central

    Meagher, Rebecca K.; Ahloy Dallaire, Jamie; Campbell, Dana L. M.; Ross, Misha; Møller, Steen H.; Hansen, Steffen W.; Díez-León, María; Palme, Rupert; Mason, Georgia J.

    2014-01-01

    Can simple enrichments enhance caged mink welfare? Pilot data from 756 sub-adults spanning three colour-types (strains) identified potentially practical enrichments, and suggested beneficial effects on temperament and fur-chewing. Our main experiment started with 2032 Black mink on three farms: from each of 508 families, one juvenile male-female pair was enriched (E) with two balls and a hanging plastic chain or length of hose, while a second pair was left as a non-enriched (NE) control. At 8 months, more than half the subjects were killed for pelts, and 302 new females were recruited (half enriched: ‘late E’). Several signs of improved welfare or productivity emerged. Access to enrichment increased play in juveniles. E mink were calmer (less aggressive in temperament tests; quieter when handled; less fearful, if male), and less likely to fur-chew, although other stereotypic behaviours were not reduced. On one farm, E females had lower cortisol (inferred from faecal metabolites). E males tended to copulate for longer. E females also weaned more offspring: about 10% more juveniles per E female, primarily caused by reduced rates of barrenness (‘late E’ females also giving birth to bigger litters on one farm), effects that our data cautiously suggest were partly mediated by reduced inactivity and changes in temperament. Pelt quality seemed unaffected, but E animals had cleaner cages. In a subsidiary side-study using 368 mink of a second colour-type (‘Demis’), similar temperament effects emerged, and while E did not reduce fur-chewing or improve reproductive success in this colour-type, E animals were judged to have better pelts. Overall, simple enrichments were thus beneficial. These findings should encourage welfare improvements on fur farms (which house 60-70 million mink p.a.) and in breeding centres where endangered mustelids (e.g. black-footed ferrets) often reproduce poorly. They should also stimulate future research into more effective practical

  12. Evaluation of the Reproductive Success of Wild and Hatchery Steelhead in Hatchery and Natural and Hatchery Environments : Annual Report for 2008.

    SciTech Connect

    Quinn, Thomas P.; Seamons, todd; Hauser, Lorenz; Naish, Kerry

    2008-12-05

    This report summarizes the field, laboratory, and analytical work from December 2007 through November 2008 on a research project that investigates interactions and comparative reproductive success of wild and hatchery origin steelhead (Oncorhynchus mykiss) trout in Forks Creek, a tributary of the Willapa River in southwest Washington. First, we continued to successfully sample hatchery and wild (i.e., naturally spawned) adult and wild smolt steelhead at Forks Creek. Second, we revealed microsatellite genotype data for adults and smolts through brood year 2008. Finally, four formal scientific manuscripts were published in 2008 and two are in press, one is in revision and two are in preparations.

  13. Variation in probability of first reproduction of Weddell seals

    USGS Publications Warehouse

    Hadley, G.L.; Rotella, J.J.; Garrott, R.A.; Nichols, J.D.

    2006-01-01

    Summary 1. For many species, when to begin reproduction is an important life-history decision that varies by individual and can have substantial implications for lifetime reproductive success and fitness. 2. We estimated age-specific probabilities of first-time breeding and modelled variation in these rates to determine age at first reproduction and understand why it varies in a population of Weddell seals in Erebus Bay, Antarctica. We used multistate mark?recapture modelling methods and encounter histories of 4965 known-age female seals to test predictions about age-related variation in probability of first reproduction and the effects of annual variation, cohort and population density. 3. Mean age at first reproduction in this southerly located study population (7.62 years of age, SD =1.71) was greater than age at first reproduction for a Weddell seal population at a more northerly and typical latitude for breeding Weddell seals (mean =4?5 years of age). This difference suggests that age at first reproduction may be influenced by whether a population inhabits the core or periphery of its range. 4. Age at first reproduction varied from 4 to 14 years, but there was no age by which all seals recruited to the breeding population, suggesting that individual heterogeneity exists among females in this population. 5. In the best model, the probability of breeding for the first time varied by age and year, and the amount of annual variation varied with age (average variance ratio for age-specific rates =4.3%). 6. Our results affirmed the predictions of life-history theory that age at first reproduction in long-lived mammals will be sensitive to environmental variation. In terms of life history evolution, this variability suggests that Weddell seals display flexibility in age at first reproduction in order to maximize reproductive output under varying environmental conditions. Future analyses will attempt to test predictions regarding relationships between environmental

  14. Factors affecting reproductive success and life history parameters of Bracon hebetor Say (Hymenoptera: Braconidae) from three host-associated populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Augmentative releases of native natural enemies are viable strategies for suppression of crop pests. Appropriate mass rearing and release strategies rely on a thorough understanding of the reproductive biology of the natural enemy. In the present study, we evaluated the effects of parasitoid source ...

  15. Factors affecting reproductive success and life history parameters of Bracon hebetor Say (Hymenoptera: Braconidae) from three host-associated populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Augmentative releases of native natural enemies are viable strategies for suppression of crop pests. Appropriate mass rearing and release strategies rely on a thorough understanding of the reproductive biology of the natural enemy. In the present study, we evaluated the effects of parasitoid sourc...

  16. The effect of differential reproductive success on population genetic structure: correlations of life history with matrilines in humpback whales of the gulf of maine.

    PubMed

    Rosenbaum, H C; Weinrich, M T; Stoleson, S A; Gibbs, J P; Baker, C S; DeSalle, R

    2002-01-01

    To examine whether demographic and life-history traits are correlated with genetic structure, we contrasted mtDNA lineages of individual humpback whales (Megaptera novaeangliae) with sighting and reproductive histories of female humpback whales between 1979 and 1995. Maternal lineage haplotypes were obtained for 323 whales, either from direct sequencing of the mtDNA control region (n = 159) or inferred from known relationships along matrilines from the sequenced sample of individuals (n = 164). Sequence variation in the 550 bp of the control region defined a total of 19 maternal lineage haplotypes that formed two main clades. Fecundity increased significantly over the study period among females of several lineages among the two clades. Individual maternal lineages and other clades were characterized by significant variation in fecundity. The detected heterogeneity of reproductive success has the potential to substantially affect the frequency and distribution of maternal lineages found in this population over time. There were significant yearly effects on adult resighting rates and calf survivorship based on examination of sighting histories with varying capture-recapture probability models. These results indicate that population structure can be influenced by interactions or associations between reproductive success, genetic structure, and environmental factors in a natural population of long-lived mammals.

  17. Breeding resource distribution affects selection gradients on male phenotypic traits: experimental study on lifetime reproductive success in the bitterling fish (Rhodeus amarus).

    PubMed

    Reichard, Martin; Ondracková, Markéta; Bryjová, Anna; Smith, Carl; Bryja, Josef

    2009-02-01

    The spatial distribution of breeding resources can have pronounced demographic and evolutionary consequences. We used 20 experimental groups of the bitterling (Rhodeus amarus), an annual fish with a promiscuous, resource-based mating system, and extended breeding season to investigate how the spatial distribution (clumped or regular) of bitterling oviposition sites (live freshwater mussels) affected offspring production, variation in reproductive success, and directional selection on phenotypic traits over their entire reproductive lifetime. We did not detect any effect of resource distribution on offspring production or variation in reproductive success among individual fish, although variation between replicates was higher with a clumped distribution. This finding is discussed with regard to the incidence of alternative mating behaviors (sneaking) within the limitations imposed by our experimental design. Breeding resource distribution had a significant effect on selection on male phenotypic traits. Stronger directional selection on traits associated with intrasexual competition for fertilizations, gonad mass (an indicator of sperm competition), and the extent of red, carotenoid-based pigment in the iris (an index of dominance status), was detected with a clumped resource distribution. With a regular resource distribution, a stronger positive selection on male body size was detected. We discuss the implications of our results for natural populations.

  18. Laying date and polygyny as determinants of annual reproductive success in male collared flycatchers ( Ficedula albicollis): a long-term study

    NASA Astrophysics Data System (ADS)

    Herényi, Márton; Garamszegi, László Zsolt; Hargitai, Rita; Hegyi, Gergely; Rosivall, Balázs; Szöllősi, Eszter; Török, János

    2014-04-01

    Annual reproductive success (ARS) is one of the main components of lifetime reproductive success, a reliable measure of individual fitness. Previous studies often dealt with ARS and variables potentially affecting it. Among them, long-term studies that consider multiple factors at the same time are particularly important in understanding the adaptive value of different phenotypes. Here, we used an 18-year dataset to quantify the ARS of male collared flycatchers ( Ficedula albicollis) on the basis of recruited offspring. We simultaneously assessed the effect of start of breeding, age, polygyny, body size and the expression of forehead patch (a sexually selected trait). The success of early breeding individuals was appreciably higher than late birds; however, breeding too early was also disadvantaged, and males that bred around the yearly median breeding date had the highest ARS. Polygynous males were more successful in years with good food supply, while in years with low food availability, they did not produce more recruits than monogamous males. The age of males, their forehead patch size and body size did not affect the number of recruits. Our findings support the importance of breeding date and suggest stabilizing selection on it in the long term. We also show that polygyny is not always advantageous for males, and its fitness pay-off may depend on environmental quality.

  19. The presence of co-flowering species facilitates reproductive success of Pedicularis monbeigiana (Orobanchaceae) through variation in bumble-bee foraging behaviour

    PubMed Central

    Liao, Kuo; Gituru, Robert W.; Guo, You-Hao; Wang, Qing-Feng

    2011-01-01

    Background and Aims The presence of co-flowering species can alter pollinator foraging behaviour and, in turn, positively or negatively affect the reproductive success of the focal species. Such interactions were investigated between a focal species, Pedicularis monbeigiana, and a co-flowering species, Vicia dichroantha, which was mediated by behaviour alteration of the shared bumble-bee pollinator. Methods Floral display size and floral colour change of P. monbeigiana were compared between pure (P. monbeigiana only) and mixed (P. monbeigiana and V. dichroantha) plots in two populations. Pollinator visitation rates, interspecific floral switching and successive within-plant pollinator visits were recorded. In addition, supplemental pollination at plant level was performed, and the fruit set and seed set were analysed in pure and mixed plots with different densities of P. monbeigiana. Key Results Pollinator visitation rates were dramatically higher in mixed plots than in pure plots. The higher pollinator visitation rates were recorded in both low- and high-density plots. In particular, successive flower visits within an individual plant were significantly lower in mixed plots. Supplemental pollination significantly increased fruit set and seed set of individuals in pure plots, while it only marginally increased seed set per fruit of plants in mixed plots. Conclusions The presence of V. dichroantha can facilitate pollination and increase female reproductive success of P. monbeigiana via both quantity (mitigating pollinator limitation) and quality (reducing geitonogamy) effects. This study suggests that successive pollinator movements among flowers within a plant, as well as pollinator visitation rates and interspecific flower switching, may be important determinants of the direction and mechanisms of interaction between species. PMID:21831855

  20. Evaluating the interacting influences of pollination, seed predation, invasive species and isolation on reproductive success in a threatened alpine plant.

    PubMed

    Krushelnycky, Paul D

    2014-01-01

    Reproduction in rare plants may be influenced and limited by a complex combination of factors. External threats such as invasive species and landscape characteristics such as isolation may impinge on both pollination and seed predation dynamics, which in turn can strongly affect reproduction. I assessed how patterns in floral visitation, seed predation, invasive ant presence, and plant isolation influenced one another and ultimately affected viable seed production in Haleakalā silverswords (Argyroxiphium sandwicense subsp. macrocephalum) of Hawai'i. Floral visitation was dominated by endemic Hylaeus bees, and patterns of visitation were influenced by floral display size and number of plants clustered together, but not by floral herbivory or nearest flowering neighbor distance. There was also some indication that Argentine ant presence impacted floral visitation, but contradictory evidence and limitations of the study design make this result uncertain. Degree of seed predation was associated only with plant isolation, with the two main herbivores partitioning resources such that one preferentially attacked isolated plants while the other attacked clumped plants; total seed predation was greater in more isolated plants. Net viable seed production was highly variable among individuals (0-55% seed set), and was affected mainly by nearest neighbor distance, apparently owing to low cross-pollination among plants separated by even short distances (>10-20 m). This isolation effect dominated net seed set, with no apparent influence from floral visitation rates, percent seed predation, or invasive ant presence. The measured steep decline in seed set with isolation distance may not be typical of the entire silversword range, and may indicate that pollinators in addition to Hylaeus bees could be important for greater gene flow. Management aimed at maintaining or maximizing silversword reproduction should focus on the spatial context of field populations and outplanting

  1. Reproductive and post-reproductive life history of wild-caught Drosophila melanogaster under laboratory conditions.

    PubMed

    Klepsatel, P; Gáliková, M; De Maio, N; Ricci, S; Schlötterer, C; Flatt, T

    2013-07-01

    The life history of the fruit fly (Drosophila melanogaster) is well understood, but fitness components are rarely measured by following single individuals over their lifetime, thereby limiting insights into lifetime reproductive success, reproductive senescence and post-reproductive lifespan. Moreover, most studies have examined long-established laboratory strains rather than freshly caught individuals and may thus be confounded by adaptation to laboratory culture, inbreeding or mutation accumulation. Here, we have followed the life histories of individual females from three recently caught, non-laboratory-adapted wild populations of D. melanogaster. Populations varied in a number of life-history traits, including ovariole number, fecundity, hatchability and lifespan. To describe individual patterns of age-specific fecundity, we developed a new model that allowed us to distinguish four phases during a female's life: a phase of reproductive maturation, followed by a period of linear and then exponential decline in fecundity and, finally, a post-ovipository period. Individual females exhibited clear-cut fecundity peaks, which contrasts with previous analyses, and post-peak levels of fecundity declined independently of how long females lived. Notably, females had a pronounced post-reproductive lifespan, which on average made up 40% of total lifespan. Post-reproductive lifespan did not differ among populations and was not correlated with reproductive fitness components, supporting the hypothesis that this period is a highly variable, random 'add-on' at the end of reproductive life rather than a correlate of selection on reproductive fitness. Most life-history traits were positively correlated, a pattern that might be due to genotype by environment interactions when wild flies are brought into a novel laboratory environment but that is unlikely explained by inbreeding or positive mutational covariance caused by mutation accumulation.

  2. Embryonic exposure to dimethoate and/or deltamethrin impairs sexual development and programs reproductive success in adult male offspring mice.

    PubMed

    Ben Slima, A; Ben Abdallah, F; Keskes-Ammar, L; Mallek, Z; El Feki, A; Gdoura, R

    2012-05-01

    Pesticides can be toxic to desirable plants and animals, including humans. The aim of this study was to investigate the reproductive effects of low doses of pesticides on male offspring of exposed pregnant mice. Three groups of five female mice were treated daily by oral gavage with dimethoate (5 mg kg(-1) per day), deltamethrin (5 mg kg(-1) per day) and their mixture at 5 mg kg(-1) per day from day 3 to day 21 of pregnancy. Fertility, sexual behaviour and a number of reproductive endpoints, such as organ weights, sperm evaluations and testicular histology, were examined on four adult male offspring of exposed pregnant mice. When compared with control, a dose of deltamethrin 5 mg kg j(-1) causes a decrease in the absolute and relative weight of the testes of exposed mice and it affects their fertility by reducing the density, mobility and vitality of sperm and increasing the number of abnormal forms of these cells (P ≤ 0.01). The same results were obtained in mice exposed to a dose of 5 mg kg j(-1) combination of dimethoate and deltamethrin. This study demonstrated that deltamethrin and combination of dimethoate and deltamethrin caused a decrease in the absolute and relative weight of the testes, which affected the sperm parameters of male offspring of exposed mice to a low dose of these pesticides during pregnancy.

  3. Ecological risk assessment in a large river-reservoir. 8: Experimental study of the effects of polychlorinated biphenyls on reproductive success in mink

    SciTech Connect

    Halbrook, R.S.; Aulerich, R.J.; Bursian, S.J.; Lewis, L.

    1999-04-01

    As a component of an ecological risk assessment of Poplar Creek (located on the Oak Ridge Reservation [ORR]) and the Clinch River (a large river-reservoir system), fish from Poplar Creek, the Clinch River, and Atlantic Ocean were fed to ranch mink to evaluate reproductive success. Five diets, each composed of 75% fish and 25% normal ranch mink chow, were prepared. Two diets served as reference diets and contained 75% Atlantic Ocean fish or 75% Clinch River fish collected above the ORR. The fish portion of the remaining three diets contained 25, 50, and 75% fish collected from Poplar Creek and 50, 25, and 0% ocean fish, respectively. Five mink groups (eight females and two males each) were each fed one of the prepared diets for 196 days. Polychlorinated biphenyl concentrations were determined in diets and various mink tissues, ethoxyresorufin-O-deethylase (EROD) activity was determined in liver tissue, and reproductive success was evaluated. Concentrations of PCB were greatest in the diet composed of 75% Poplar Creek fish and in tissues from mink fed this diet and their offspring. There was a trend toward decreased adult female and kit weights and reduced mean litter size in mink fed diets containing 75% Poplar Creek fish; however, at 6 weeks of age, kit survival was similar among diet groups. Liver EROD activity significantly increased in adult female mink fed 50 and 75% Poplar Creek fish diets. Estimated dietary concentrations of PCBs were similar to or slightly lower than concentrations associated with adverse effects in experimentally dosed mink. Mercury (Hg) concentrations previously reported in these same mink were below that associated with adverse effects, and there was no indication of additive or synergistic effects from exposure to PCBs plus Hg. It is unlikely that population-level reproductive effects would be observed in mink consuming fish from Poplar Creek on the ORR.

  4. Nest-site selection and reproductive success of greater sage-grouse in a fire-affected habitat of northwestern Nevada

    USGS Publications Warehouse

    Lockyer, Zachary B.; Coates, Peter S.; Casazza, Michael L.; Espinosa, Shawn; Delehanty, David J.

    2015-01-01

    Identifying links between micro-habitat selection and wildlife reproduction is imperative to population persistence and recovery. This information is particularly important for landscape species such as greater sage-grouse (Centrocercus urophasianus; sage-grouse). Although this species has been widely studied, because environmental factors can affect sage-grouse populations, local and regional studies are crucial for developing viable conservation strategies. We studied the habitat-use patterns of 71 radio-marked sage-grouse inhabiting an area affected by wildfire in the Virginia Mountains of northwestern Nevada during 2009–2011 to determine the effect of micro-habitat attributes on reproductive success. We measured standard vegetation parameters at nest and random sites using a multi-scale approach (range = 0.01–15,527 ha). We used an information-theoretic modeling approach to identify environmental factors influencing nest-site selection and survival, and determine whether nest survival was a function of resource selection. Sage-grouse selected micro-sites with greater shrub canopy cover and less cheatgrass (Bromus tectorum) cover than random sites. Total shrub canopy, including sagebrush (Artemisia spp.) and other shrub species, at small spatial scales (0.8 ha and 3.1 ha) was the single contributing selection factor to higher nest survival. These results indicate that reducing the risk of wildfire to maintain important sagebrush habitats could be emphasized in sage-grouse conservation strategies in Nevada. Managers may seek to mitigate the influx of annual grass invasion by preserving large intact sagebrush-dominated stands with a mixture of other shrub species. For this area of Nevada, the results suggest that ≥40% total shrub canopy cover in sage-grouse nesting areas could yield improved reproductive success

  5. Polychlorinated biphenyls in adult black bass and yellow perch were not associated with their reproductive success in the upper Hudson River, New York, USA.

    PubMed

    Maceina, Michael J; Sammons, Steven M

    2013-07-01

    Although production and use of polychlorinated biphenyls (PCBs) ceased nearly 35 yr ago, questions still remain concerning the potential chronic effects these compounds may have on wild fish, including their reproductive success. In the upper Hudson River, New York, USA, fish were exposed to PCBs primarily from 2 manufacturing plants located approximately 320 km upstream of New York City, New York, from the 1940s to 1977. The authors collected yellow perch (Perca flavescens), smallmouth bass (Micropterus dolomieu), and largemouth bass (M. salmoides) using electrofishing, measured PCBs in these adults, and estimated abundance and size of their offspring at age 1 yr (age-1 fish). Fish were collected annually from 2004 to 2009 from 1 control site upstream of the PCB discharge sites and from 2 sites downstream from where PCBs were released. These sites (pools) are separated by a series of dams, locks, and canals. Muscle tissue wet weight PCB and lipid-based PCB concentrations in adults in the 2 PCB exposure pools averaged approximately 1 to 3 µg/g and 100 to 500 µg/g, respectively. Age-1 abundances were not related to adult PCB concentrations but were inversely related to river flow. Size of age-1 fish was slightly greater at the PCB-exposure sites. Levels of PCBs in yellow perch, largemouth bass, and smallmouth bass in the upper Hudson River did not impair or reduce recruitment or reproductive success.

  6. Differential courtship activity and alterations of reproductive success of competing gupply males as an indicator for low concentrations of aquatic pollutants

    SciTech Connect

    Schroeder, J.H.; Peters, K.

    1988-09-01

    Differential courtship activity of guppy males competing for the same females was used as a bioindicator for low concentrations of water-borne pollutants in a previous study. Patterns of male sexual activity were chosen because they determine reproductive success. The mean difference between courtship activities of two male competitors determines the relative fitness of the male in question. Accordingly, the decrease in mean differential courtship after exposure to aquatic contaminants was predicted to cause a corresponding change in the relative reproductive success. The present study completed the previous one by repeating the experiment with a 10% addition of wastewater drawn from the last clearing basin of a Munich purification plant this time using virgin (non-inseminated) females which were receptive to male courtship. The females subsequently were allowed to produce as many offspring as possible. The number of young guppies sired by individual male competitors could easily be traced by the use of sex-linked phenotypic color patterns as markers. The purpose of these two studies was to show that the quantification of sexual activities of male guppies is useful for monitoring environmental alterations which affect fitness characters.

  7. Age-specific nomograms for follicle stimulating hormone and anti-Mullerian hormone: A pilot study in Ile-Ife, Nigeria

    PubMed Central

    Okunola, Omoladun Temitope; Ajenifuja, Olusegun Kayode; Loto, Morebise Olabisi; Salawu, Afolabi; Omitinde, Oluseyi Stephen; Akande, Joel; Oke, Elizabeth

    2016-01-01

    Background: Assessment of ovarian reserve is one of the steps in the management of infertile couples. Follicle Stimulating hormone (FSH) and anti-Müllerian hormone (AMH) are commonly used ovarian reserve markers in Africa. However, there is paucity of age-specific reference values for FSH and AMH among the African population. Objective: This study aimed at conducting a pilot study for generation of age-specific nomograms for FSH and AMH among fertile women in Ile-Ife, Nigeria. Materials and Methods: A pilot cross-sectional study that involved 65 fertile women within the age range of 18-45 yr were prospectively and consecutively recruited from November 2014 to January 2015. Peripheral blood samples were taken for basal serum FSH and random serum AMH. The samples were processed using enzyme linked immunosorbent (ELISA) assays. Results: Age-specific FSH nomogram showed a gradual increase which became steeper at age 35 yr with an average yearly increase of 0.2 IU/L in basal serum FSH, while age-specific AMH nomogram showed a peak at 25 yr and then; an average yearly decrease of 0.11 ng/ml in random serum AMH from 25 yr. Conclusion: The age-specific nomograms generated by this pilot study suggest that AMH may be an earlier marker of reduced ovarian reserve; which if validated by future multicenter population based studies may facilitate counseling of women on their reproductive potentials. PMID:28066837

  8. Effects of inbreeding on reproductive success, performance, litter size, and survival in captive red wolves (Canis rufus).

    PubMed

    Rabon, David R; Waddell, William

    2010-01-01

    Captive-breeding programs have been widely used in the conservation of imperiled species, but the effects of inbreeding, frequently expressed in traits related to fitness, are nearly unavoidable in small populations with few founders. Following its planned extirpation in the wild, the endangered red wolf (Canis rufus) was preserved in captivity with just 14 founders. In this study, we evaluated the captive red wolf population for relationships between inbreeding and reproductive performance and fitness. Over 30 years of managed breeding, the level of inbreeding in the captive population has increased, and litter size has declined. Inbreeding levels were lower in sire and dam wolves that reproduced than in those that did not reproduce. However, there was no difference in the inbreeding level of actual litters and predicted litters. Litter size was negatively affected by offspring and paternal levels of inbreeding, but the effect of inbreeding on offspring survival was restricted to a positive influence. There was no apparent relationship between inbreeding and method of rearing offspring. The observable effects of inbreeding in the captive red wolf population currently do not appear to be a limiting factor in the conservation of the red wolf population. Additional studies exploring the extent of the effects of inbreeding will be required as inbreeding levels increase in the captive population.

  9. Effects of human disturbance on waterbird nesting and reproductive success at restoration pond SF2, south San Francisco Bay, California

    USGS Publications Warehouse

    Ackerman, Joshua T.; Herzog, Mark P.; Hartman, Christopher A.

    2014-01-01

    To determine the effects that human disturbance may have on waterbirds nesting on these newly constructed islands in Pond SF2, we assessed the potential effects of human disturbance features (specifically, access trails, viewing platforms, internal pond berms, exterior levees, and highways) on breeding waterbirds in 2011 and 2012. We found no clear pattern of potential disturbance features on a group of reproductive factors, including nest survival, nest initiation date, and clutch size. Because all the islands were constructed greater than 90 meters from the nearest disturbance feature, Pond SF2 alone did not provide adequate variation in the distance of disturbance features to detect potential detrimental effects for islands closer to disturbance features in other areas of the SBSP Restoration Project. If there is a need for SBSP Restoration Project Management Team to understand how close islands can be built to disturbance features in the future, we suggest a more comprehensive study that includes multiple ponds, other than SF2, with islands at varying distances to disturbance features.

  10. Observations on the removal of brood inoculated with Tropilaelaps mercedesae (Acari: Laelapidae) and the mite's reproductive success in Apis mellifera colonies.

    PubMed

    Khongphinitbunjong, Kitiphong; de Guzman, Lilia I; Buawangpong, Ninat; Rinderer, Thomas E; Frake, Amanda M; Chantawannakul, Panuwan

    2014-01-01

    This study assessed the response of Apis mellifera to brood deliberately infested with Tropilaelaps mercedesae. The reproductive success of T. mercedesae in mite-inoculated and naturally infested brood was also compared. The presence of T. mercedesae inside brood cells significantly affected brood removal. Thai A. mellifera removed 52.6 ± 8.2 % of the brood inoculated with T. mercedesae as compared to 17.2 ± 1.8 and 5.7 ± 1.1 % removal rates for the groups of brood with their cell cappings opened and closed without mite inoculation and the control brood (undisturbed, no mite inoculation), respectively. Brood removal peaked during the second and third days post inoculation when test brood was at the prepupal stage. Overall, non-reproduction (NR) of foundress T. mercedesae was high. However, when NR was measured based on the criteria used for Varroa, the naturally infested pupae (NIP) supported the highest NR (92.8 %). Newly sealed larvae inoculated with Tropilaelaps collected from newly sealed larvae (NSL) had 78.2 % NR and those inoculated with Tropilaelaps collected from tan-bodied pupae (TBP) had 76.8 % NR. Since Tropilaelaps is known to have a short development period and nearly all progeny reach adulthood by the time of host emergence, we also used two Tropilaelaps-specific criteria to determine NR. Foundresses that did not produce progeny and those that produced only one progeny were considered NR. Using these two criteria, NR decreased tremendously but showed similar trends with means of 65, 40 and 33 % for NIP, NSL and TBP, respectively. High NR in the NIP group may indicate increased hygienic behavior in Thai A. mellifera colonies. The removal of infested prepupae or tan-bodied pupae will likely decrease the reproductive potential of Tropilaelaps. Our study suggests that brood removal may be one of the resistance mechanisms towards T. mercedesae by naturally adapted Thai A. mellifera.

  11. Limitations on reproductive success in endemic Aquilegia viscosa (Ranunculaceae) relative to its widespread congener Aquilegia vulgaris: the interplay of herbivory and pollination.

    PubMed

    Lavergne, Sébastien; Debussche, Max; Thompson, John D

    2005-01-01

    Plant reproduction can be strongly affected by herbivory and different features of pollination ecology, such as pollinator visitation rates and capacity for self-pollination. The purpose of this study is to compare the relative impact of herbivory and pollination on maternal reproductive success in endemic Aquilegia viscosa and its widespread congener Aquilegia vulgaris. We conducted herbivore exclusion experiments in two populations of each species in 2 different years and showed that the maternal fertility of A. viscosa was significantly more limited by floral predation and pre-dispersal seed predation than its widespread congener. In the absence of herbivory, A. viscosa retained significantly lower maternal fertility than A. vulgaris. Experimental pollinations in an insect-free glasshouse showed that the two species have an equal seed/ovule ratio both in the absence of pollinators and in the presence of non-limiting outcross pollination. Pollinator visitation rates were significantly higher in populations of A. vulgaris than in populations of A. viscosa. In addition, path analyses showed that spur length, an important trait for pollinator attraction in Aquilegia, and, indirectly sepal and petal width, contribute positively to the seed/ovule ratio in A. vulgaris, but not in A. viscosa. These results indicate that maternal fertility of endemic A. viscosa is strongly reduced by flower and seed predation despite low rates of pollinator visitation, and that pollen or resource limitation in the wild may further reduce maternal fertility. Finally, floral trait variation appears to be decoupled from fertility variation in endemic A. viscosa, which possibly constrains the evolution of reproductive traits in this species.

  12. Investigation of Neospora caninum seroprevalence and potential impact on reproductive success in semi-free-ranging Père David's deer (Elaphurus davidianus)

    PubMed Central

    Bapodra, Priya; Wolfe, Barbara A

    2015-01-01

    This study aimed to determine the prevalence and reproductive impact of Neospora caninum in a herd of semi-free-ranging Père David's deer (Elaphurus davidianus) at a conservation facility, following a suspected abortion storm in 2008. Serum samples (n=103) collected from 60 individuals between 2002 and 2011 were evaluated using competitive ELISA for the detection of N. caninum-specific antibodies. Of the 103 samples, 73 (70.9 per cent) were positive for N. caninum antibodies, with a mean±sd competitive inhibition (CI) of 77.6±19.8 per cent. Thirty (29.1 per cent) samples were seronegative, with mean CI of 15.2±9.70 per cent. A significant negative linear relationship was noted between the proportion of seropositive animals and age (R2=0.228, P<0.001). Calving rates of adult females from 2005 to 2011 ranged from 15.4 per cent to 52 per cent (mean 35.5±11.3 per cent), and did not correlate with mean CI values (Spearman's rank correlation coefficient=0.072, P=0.878). While both horizontal and transplacental transmission are likely contributing to persistent herd seropositivity, the role of N. caninum in reproductive success in this and other populations of endangered ungulates remains to be explored. PMID:26392906

  13. Receptivity of female Neohelice granulata (Brachyura, Varunidae): different strategies to maximize their reproductive success in contrasting habitats

    NASA Astrophysics Data System (ADS)

    Sal Moyano, María Paz; Luppi, Tomás; Gavio, María Andrea; Vallina, Micaela; McLay, Colin

    2012-12-01

    The extent of the receptive period may determine the mating strategies employed by female crabs to obtain mates. Here, we studied the receptivity of female Neohelice granulata (Dana, 1851) in the laboratory, including the form of the vulvae and the anatomy of the seminal receptacle (SR). We examined the factors that influence the duration of receptivity by comparing two populations inhabiting contrasting habitats: Mar Chiquita Coastal lagoon (MCL), which is an oligo-polyhaline estuary, and San Antonio Oeste (SAO), which is an eu-hyperhaline marine bay. Non-receptive females have immobile vulva opercula, while receptive females have mobile opercula. Histological sections of the SR showed that the degree of epithelium secretions was associated with the receptive stage of females, and they may be involved in the maintenance of viable sperm and in the dehiscence of spermatophores. The existence of a special tissue at the junction of the oviduct and the SR was described and proposed as an internal mechanism influencing the timing of ovulation. The duration of receptivity was dependent on the SR load and the capacity to lay eggs. Thus, females with empty SR exhibited longer receptivity and did not lay eggs, while those with full SR exhibited shorter receptivity and always laid eggs. Interpopulation differences showed that females from SAO had shorter receptivity and heavier SR and laid eggs more frequently than females from MCL. Based on our results, we suggest that N. granulata females can adjust the duration of their receptivity and control the moment of fertilization according to different internal mechanisms related to the morphology of the vulvae, the fullness of the SR and anatomical attributes of the SR. An important consequence of this control is greater sperm competition. The extent of the receptive period and the number of times that a female could become receptive in a single reproductive season may also depend on the habitat characteristics.

  14. Effects of reduced salinity on survival, growth, reproductive success, and energetics of the euryhaline polychaete Capitella sp. I.

    PubMed

    Pechenik; Berard; Kerr

    2000-11-01

    Physiological adjustment to water of reduced salinity requires energy expenditure. In this study we sought to determine the fitness costs associated with such adjustment in the euryhaline polychaete Capitella sp. I, and the extent to which such costs could be explained by increased rates of energy expenditure. In a series of experiments conducted at 20 degrees C, salinity was reduced from 30 per thousand to either 25, 20, 15, 12, or 10 per thousand within 72 h after the larvae had been induced to metamorphose. Juveniles were reared on fine, organic-rich sediment. Over the next 15-30 days, we determined survival, growth, fecundity, and rates of respiration and feeding (via fecal pellet production). Larval salinity tolerance was also determined. Juvenile survival at salinities as low as 12-15 per thousand was comparable to that at 30 per thousand. The lower limit of salinity tolerance was 10-12 per thousand at 20 degrees C for both larvae and juveniles. Juveniles grew significantly more slowly at 12-15 per thousand in six of the seven experiments. Fecundity, however, was generally highest at intermediate salinities of 20-25 per thousand, and comparable at 30 and 15 per thousand. No individuals released embryos at 12 per thousand over the approximately 30-day observation periods in any of the three experiments in which the worms were reared at this low salinity. Reduced growth rates were not explained by differences in rates of respiration at different salinities: at reduced salinity, respiration rates were either statistically equivalent to (P>0.10) or significantly below (P<0.05) those recorded for animals maintained at 30 per thousand. Lower growth rates at lower salinities were best explained by reduced feeding rates. Further studies are required to determine whether digestive efficiency, growth hormone concentrations, or reproductive hormone concentrations are also altered by low salinity in this species.

  15. Natural hybrids in Atlantic eels (Anguilla anguilla, A. rostrata): evidence for successful reproduction and fluctuating abundance in space and time.

    PubMed

    Albert, Vicky; Jónsson, Bjarni; Bernatchez, Louis

    2006-06-01

    The outcome of natural hybridization is highly variable and depends on the nonexclusive effects of both pre- and post-mating reproductive barriers. The objective of this study was to address three specific questions regarding the dynamics of hybridization between the American and European eels (Anguilla rostrata and Anguilla anguilla). Using 373 AFLP loci, 1127 eels were genotyped, representing different life stages from both continents, as well as multiple Icelandic locations. We first evaluated the extent of hybridization and tested for the occurrence of hybrids beyond the first generation. Second, we tested whether hybrids were randomly distributed across continents and among Icelandic sampling sites. Third, we tested for a difference in the proportion of hybrids between glass eel and yellow eel stages in Iceland. Our results provided evidence for (i) an overall hybrid proportion of 15.5% in Iceland, with values ranging from 6.7% to 100% depending on life stages and locations; (ii) the existence of hybrids beyond the first generation; (iii) a nonrandom geographic distribution of hybrids in the North Atlantic; and (iv) a higher proportion of first and later generation hybrids in yellow eels compared to glass eels, as well as a significant latitudinal gradient in the proportion of hybrids in Icelandic freshwater. We propose that the combined effect of both differential survival of hybrids and variation in hybridization rate through time best explain these patterns. We discuss the possibility that climate change, which is impacting many environmental features in the North Atlantic, may have a determinant effect on the outcome of natural hybridization in Atlantic eels.

  16. Aquaporins Are Critical for Provision of Water during Lactation and Intrauterine Progeny Hydration to Maintain Tsetse Fly Reproductive Success

    PubMed Central

    Benoit, Joshua B.; Hansen, Immo A.; Attardo, Geoffrey M.; Michalková, Veronika; Mireji, Paul O.; Bargul, Joel L.; Drake, Lisa L.; Masiga, Daniel K.; Aksoy, Serap

    2014-01-01

    Tsetse flies undergo drastic fluctuations in their water content throughout their adult life history due to events such as blood feeding, dehydration and lactation, an essential feature of the viviparous reproductive biology of tsetse. Aquaporins (AQPs) are transmembrane proteins that allow water and other solutes to permeate through cellular membranes. Here we identify tsetse aquaporin (AQP) genes, examine their expression patterns under different physiological conditions (blood feeding, lactation and stress response) and perform functional analysis of three specific genes utilizing RNA interference (RNAi) gene silencing. Ten putative aquaporins were identified in the Glossina morsitans morsitans (Gmm) genome, two more than has been previously documented in any other insect. All organs, tissues, and body parts examined had distinct AQP expression patterns. Two AQP genes, gmmdripa and gmmdripb ( = gmmaqp1a and gmmaqp1b) are highly expressed in the milk gland/fat body tissues. The whole-body transcript levels of these two genes vary over the course of pregnancy. A set of three AQPs (gmmaqp5, gmmaqp2a, and gmmaqp4b) are expressed highly in the Malpighian tubules. Knockdown of gmmdripa and gmmdripb reduced the efficiency of water loss following a blood meal, increased dehydration tolerance and reduced heat tolerance of adult females. Knockdown of gmmdripa extended pregnancy length, and gmmdripb knockdown resulted in extended pregnancy duration and reduced progeny production. We found that knockdown of AQPs increased tsetse milk osmolality and reduced the water content in developing larva. Combined knockdown of gmmdripa, gmmdripb and gmmaqp5 extended pregnancy by 4–6 d, reduced pupal production by nearly 50%, increased milk osmolality by 20–25% and led to dehydration of feeding larvae. Based on these results, we conclude that gmmDripA and gmmDripB are critical for diuresis, stress tolerance and intrauterine lactation through the regulation of water and/or other

  17. Female ageing and reproductive outcome in assisted reproduction cycles

    PubMed Central

    Tan, Tse Yeun; Lau, Matthew Sie Kuei; Loh, Seong Feei; Tan, Heng Hao

    2014-01-01

    INTRODUCTION Fertility in women declines with increasing age. With the deferment of marriage and childbearing, couples are turning to assisted reproductive technology to counteract this decline. We aimed to evaluate the results of in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) in women of different age groups, and highlight the cost-effectiveness of IVF treatment in these groups while assessing its implications on the national healthcare provision model. METHODS Retrospective analysis of 3,412 stimulated IVF/ICSI cycles in a hospital-based IVF centre was performed from January 2008 to December 2010. Patients were stratified into seven age groups: < 30 years; 30–35 years; 36–37 years; 38 years; 39 years; 40–44 years; and ≥ 45 years. RESULTS Age had a significant effect on the number of cycles leading to embryo transfer (p < 0.001). The number of oocytes retrieved decreased across the various age groups (p < 0.001) and was the highest among women aged < 30 (mean 18.5 ± 10.3) years. With increasing age, there was a trend toward a lower fertilisation rate. Age also had a significant effect on the rates of clinical pregnancy, live birth and multiple pregnancies (p < 0.001). CONCLUSION Patients aged < 30 years had the best IVF outcomes, reflecting optimal reproductive capacity. Age-related decline in fertility starts after 30 years. Women opting for IVF should be counselled about age-specific success rates while taking into account individual risk factors. PMID:25017405

  18. Role of evolutionary and ecological factors in the reproductive success and the spatial genetic structure of the temperate gorgonian Paramuricea clavata.

    PubMed

    Mokhtar-Jamaï, Kenza; Coma, Rafel; Wang, Jinliang; Zuberer, Frederic; Féral, Jean-Pierre; Aurelle, Didier

    2013-06-01

    Dispersal and mating features strongly influence the evolutionary dynamics and the spatial genetic structure (SGS) of marine populations. For the first time in a marine invertebrate, we examined individual reproductive success, by conducting larval paternity assignments after a natural spawning event, combined with a small-scale SGS analysis within a population of the gorgonian Paramuricea clavata. Thirty four percent of the larvae were sired by male colonies surrounding the brooding female colonies, revealing that the bulk of the mating was accomplished by males from outside the studied area. Male success increased with male height and decreased with increasing male to female distance. The parentage analyses, with a strong level of self-recruitment (25%), unveiled the occurrence of a complex family structure at a small spatial scale, consistent with the limited larval dispersal of this species. However, no evidence of small scale SGS was revealed despite this family structure. Furthermore, temporal genetic structure was not observed, which appears to be related to the rather large effective population size. The low level of inbreeding found suggests a pattern of random mating in this species, which disagrees with expectations that limited larval dispersal should lead to biparental inbreeding. Surface brooding and investment in sexual reproduction in P. clavata contribute to multiple paternity (on average 6.4 fathers were assigned per brood), which enhance genetic diversity of the brood. Several factors may have contributed to the lack of biparental inbreeding in our study such as (i) the lack of sperm limitation at a small scale, (ii) multiple paternity, and (iii) the large effective population size. Thus, our results indicate that limited larval dispersal and complex family structure do not necessarily lead to biparental inbreeding and SGS. In the framework of conservation purposes, our results suggested that colony size, proximity among colonies and the

  19. Pollen limitation and reduced reproductive success are associated with local genetic effects in Prunus virginiana, a widely distributed self-incompatible shrub

    PubMed Central

    Suarez-Gonzalez, Adriana; Good, Sara V.

    2014-01-01

    Background and Aims A vast quantity of empirical evidence suggests that insufficient quantity or quality of pollen may lead to a reduction in fruit set, in particular for self-incompatible species. This study uses an integrative approach that combines field research with marker gene analysis to understand the factors affecting reproductive success in a widely distributed self-incompatible species, Prunus virginiana (Rosaceae). Methods Twelve patches of P. virginiana distributed within three populations that differed in degree of disturbance were examined. Two of the sites were small (7–35 km2) remnants of forest in an intensively used agricultural landscape, while the third was continuous (350 km2) and less disturbed. Field studies (natural and hand cross-pollinations) were combined with marker gene analyses (microsatellites and S-locus) in order to explore potential factors affecting pollen delivery and consequently reproductive success at landscape (between populations) and fine scales (within populations). Key Results Reductions in reproductive output were found in the two fragments compared with the continuous population, and suggest that pollen is an important factor limiting fruit production. Genetic analyses carried out in one of the fragments and in the continuous site suggest that even though S-allele diversity is high in both populations, the fragment exhibits an increase in biparental inbreeding and correlated paternity. The increase in biparental inbreeding in the fragment is potentially attributable to variation in the density of individuals and/or the spatial distribution of genotypes among populations, both of which could alter mating dynamics. Conclusions By using a novel integrative approach, this study shows that even though P. virginiana is a widespread species, fragmented populations can experience significant reductions in fruit set and pollen limitation in the field. Deatiled examination of one fragmented population suggests that these

  20. Integument coloration signals reproductive success, heterozygosity, and antioxidant levels in chick-rearing black-legged kittiwakes

    USGS Publications Warehouse

    Leclaire, S.; White, J.; Arnoux, E.; Faivre, B.; Vetter, N.; Hatch, Shyla A.; Danchin, E.

    2011-01-01

    Carotenoid pigments are important for immunity and as antioxidants, and carotenoid-based colors are believed to provide honest signals of individual quality. Other colorless but more efficient antioxidants such as vitamins A and E may protect carotenoids from bleaching. Carotenoid-based colors have thus recently been suggested to reflect the concentration of such colorless antioxidants, but this has rarely been tested. Furthermore, although evidence is accruing for multiple genetic criteria for mate choice, carotenoid-based colors have rarely been shown to reflect both phenotypic and genetic quality. In this study, we investigated whether gape, tongue, eye-ring, and bill coloration of chick-rearing black-legged kittiwakes Rissa tridactyla reflected circulating levels of carotenoids and vitamins A and E. We further investigated whether integument coloration reflected phenotypic (body condition and fledging success) and genetic quality (heterozygosity). We found that the coloration of fleshy integuments was correlated with carotenoid and vitamin A levels and fledging success but only in males. Furthermore, the coloration of tongue and eye-ring was correlated with heterozygosity in both males and females. Integument colors might therefore be reliable signals of individual quality used by birds to adjust their parental care during the chick-rearing period. ?? Springer-Verlag 2011.

  1. Integument coloration signals reproductive success, heterozygosity, and antioxidant levels in chick-rearing black-legged kittiwakes

    NASA Astrophysics Data System (ADS)

    Leclaire, Sarah; White, Joël; Arnoux, Emilie; Faivre, Bruno; Vetter, Nathanaël; Hatch, Scott A.; Danchin, Étienne

    2011-09-01

    Carotenoid pigments are important for immunity and as antioxidants, and carotenoid-based colors are believed to provide honest signals of individual quality. Other colorless but more efficient antioxidants such as vitamins A and E may protect carotenoids from bleaching. Carotenoid-based colors have thus recently been suggested to reflect the concentration of such colorless antioxidants, but this has rarely been tested. Furthermore, although evidence is accruing for multiple genetic criteria for mate choice, carotenoid-based colors have rarely been shown to reflect both phenotypic and genetic quality. In this study, we investigated whether gape, tongue, eye-ring, and bill coloration of chick-rearing black-legged kittiwakes Rissa tridactyla reflected circulating levels of carotenoids and vitamins A and E. We further investigated whether integument coloration reflected phenotypic (body condition and fledging success) and genetic quality (heterozygosity). We found that the coloration of fleshy integuments was correlated with carotenoid and vitamin A levels and fledging success but only in males. Furthermore, the coloration of tongue and eye-ring was correlated with heterozygosity in both males and females. Integument colors might therefore be reliable signals of individual quality used by birds to adjust their parental care during the chick-rearing period.

  2. Assessment of survival rates and reproductive success of captive bred milky stork released at Kuala Gula Bird Sanctuary, Perak

    NASA Astrophysics Data System (ADS)

    Faiq, H.; Safie, M. Y.; Shukor, M. N.

    2016-11-01

    A release programme of captive bred Milky Storks was initiated to increase population size in the wild. Population size depends on the survival rate and breeding success of individuals in the population. Among factors that affect survival rate and breeding success are population age class and sex ratio. The main objective of this study was to estimate the survival rate of Mycteria cinerea that has been released in Kuala Gula Bird Sanctuary since 2007. The estimation of the survival rate was done across gender and age class. This study was conducted in 2012 at Kuala Gula Bird Sanctuary. The presence of M. cinerea individuals were recorded at the sanctuary and identified to background information, such as date of birth, gender and date of release. Females of M. cinerea were estimated to have a higher survival rate (30.0%) than male (16.7%). Across gender, each individual was assigned into 4 different age classes, namely less than 1 year, between 1 and 2 years, between 2 and 3 years, and more than 3 years. The survival rate of individuals less than 1 year was about 50%, between 1 and 2 years was 25%, between 2 and 3 years was 9.1%, and more than 3 years was 0%. This study was intended to facilitate future release programmeme on which gender and age class to emphasize.

  3. Comparing the Reproductive Success of Yakima River Hatchery- and Wild-Origin Spring Chinook; Yakima/Klickitat Fisheries Project Monitoring and Evaluation, 2004-2005 Annual Report.

    SciTech Connect

    Schroder, S.L.; Pearsons, T.N.; Knudsen, C.M.

    2005-05-01

    A growing body of literature suggests that adult salmon produced by artificial culture are not as reproductively successful as wild fish when they spawn under natural conditions. Behavioral, morphological, and physiological divergences have been observed between hatchery and wild fish. These disparities are the likely proximate causes of the differences seen in the reproductive success of hatchery and wild salmonids. Two evolutionary paradigms have been proposed to explain why salmonids cultured in hatcheries are genetically and phenotypically different from wild cohorts. The first proposes that natural selection has been significantly relaxed in hatcheries. Consequently, fish that normally would have perished because of the possession of unsuitable traits are able to survive. If these traits have a genetic basis, they may become established in a hatchery population and cause its productivity to be less than expected if the fish are once again exposed to natural selection pressures. The second theorizes that environmental and social conditions in hatcheries are less variable than in the natural environment and that these conditions will remain relatively constant from one generation to the next. In this circumstance, selection for genetic traits that adapt fish to artificial culture will become prevalent in the population. Such traits may be mal-adaptive under natural conditions. Many of the studies that have compared the reproductive success (RS) of hatchery and wild fish, however, have used non-local hatchery fish that have experienced multiple generations of hatchery culture. Few efforts have been made where both the hatchery and wild fish have originated from the same population. When such studies have been performed differences in the competency of the fish to produce offspring have not been detected or are not as great as those expressed when non-local hatchery fish have been used. The hatchery spring Chinook produced by the Yakima Fisheries Project

  4. Effect of the Operation of Kerr and Hungry Horse Dams on the Reproductive Success of Kokanee in the Flathead System; Technical Addendum to the Final Report.

    SciTech Connect

    Beattie, Will; Tohtz, Joel

    1990-03-01

    This addendum to the Final Report presents results of research on the zooplankton and fish communities of Flathead Lade. The intent of the Study has been to identify the impacts of hydroelectric operations at Kerr and Hungry Horse Dam on the reproductive success of kokanee an to propose mitigation for these impacts. Recent changes in the trophic ecology of the lake, have reduced the survival of kokanee. In the last three year the Study has been redirected to identify, if possible, the biological mechanisms which now limit kokanee survival, and to test methods of enhancing the kokanee fishery by artificial supplementation. These studies were necessary to the formulation of mitigation plans. The possibility of successfully rehabilitating the kokanee population, is the doubt because of change in the trophic ecology of the system. This report first presents the results of studies of the population dynamics of crustacean zooplankton, upon which planktivorous fish depend. A modest effort was directed to measuring the spawning escapement of kokanee in 1988. Because of its relevance to the study, we also report assessments of 1989 kokanee spawning escapement. Hydroacoustic assessment of the abundance of all fish species in Flathead Lake was conducted in November, 1988. Summary of the continued efforts to document the growth rates and food habits of kokanee and lake whitefish are included in this report. Revised kokanee spawning and harvest estimates, and management implications of the altered ecology of Flathead Lake comprise the final sections of this addendum. 83 refs., 20 figs., 25 tabs.

  5. Climate change has indirect effects on resource use and overlap among coexisting bird species with negative consequences for their reproductive success

    USGS Publications Warehouse

    Martin, Thomas E.; Auer, Sonya K.

    2013-01-01

    Climate change can modify ecological interactions, but whether it can have cascading effects throughout ecological networks of multiple interacting species remains poorly studied. Climate-driven alterations in the intensity of plant–herbivore interactions may have particularly profound effects on the larger community because plants provide habitat for a wide diversity of organisms. Here we show that changes in vegetation over the last 21 years, due to climate effects on plant–herbivore interactions, have consequences for songbird nest site overlap and breeding success. Browsing-induced reductions in the availability of preferred nesting sites for two of three ground nesting songbirds led to increasing overlap in nest site characteristics among all three bird species with increasingly negative consequences for reproductive success over the long term. These results demonstrate that changes in the vegetation community from effects of climate change on plant–herbivore interactions can cause subtle shifts in ecological interactions that have critical demographic ramifications for other species in the larger community.

  6. Wild jackdaws' reproductive success and their offspring's stress hormones are connected to provisioning rate and brood size, not to parental neophobia.

    PubMed

    Greggor, Alison L; Spencer, Karen A; Clayton, Nicola S; Thornton, Alex

    2017-03-01

    Many species show individual variation in neophobia and stress hormones, but the causes and consequences of this variation in the wild are unclear. Variation in neophobia levels could affect the number of offspring animals produce, and more subtly influence the rearing environment and offspring development. Nutritional deficits during development can elevate levels of stress hormones that trigger long-term effects on learning, memory, and survival. Therefore measuring offspring stress hormone levels, such as corticosterone (CORT), helps determine if parental neophobia influences the condition and developmental trajectory of young. As a highly neophobic species, jackdaws (Corvus monedula) are excellent for exploring the potential effects of parental neophobia on developing offspring. We investigated if neophobic responses, alongside known drivers of fitness, influence nest success and offspring hormone responses in wild breeding jackdaws. Despite its consistency across the breeding season, and suggestions in the literature that it should have importance for reproductive fitness, parental neophobia did not predict nest success, provisioning rates or offspring hormone levels. Instead, sibling competition and poor parental care contributed to natural variation in stress responses. Parents with lower provisioning rates fledged fewer chicks, chicks from larger broods had elevated baseline CORT levels, and chicks with later hatching dates showed higher stress-induced CORT levels. Since CORT levels may influence the expression of adult neophobia, variation in juvenile stress responses could explain the development and maintenance of neophobic variation within the adult population.

  7. Inter-provincial migration in Spain: temporal trends and age-specific patterns.

    PubMed

    Garcia Coll, A; Stillwell, J

    1999-01-01

    "This paper provides interpretation of the changing patterns of internal migration in Spain at the inter-provincial scale, and new analysis of age-specific migration during the 1980s using a 10% sample of anonymised records from the 1991 census. Schedules of age-specific gross migration rates are constructed and classified according to their shape and level relative to the national schedule, and the relationships between in-migration and out-migration rates are examined for four selected age groups to demonstrate how aggregate patterns of inter-provincial migration conceal a wide diversity of age specific experience."

  8. Effect of oral infection with Kashmir bee virus and Israeli acute paralysis virus on bumblebee (Bombus terrestris) reproductive success.

    PubMed

    Meeus, Ivan; de Miranda, Joachim R; de Graaf, Dirk C; Wäckers, Felix; Smagghe, Guy

    2014-09-01

    Israeli acute paralysis virus (IAPV) together with Acute bee paralysis virus (ABPV) and Kashmir bee virus (KBV) constitute a complex of closely related dicistroviruses. They are infamous for their high mortality after injection in honeybees. These viruses have also been reported in non-Apis hymenopteran pollinators such as bumblebees, which got infected with IAPV when placed in the same greenhouse with IAPV infected honeybee hives. Here we orally infected Bombus terrestris workers with different doses of either IAPV or KBV viral particles. The success of the infection was established by analysis of the bumblebees after the impact studies: 50days after infection. Doses of 0.5×10(7) and 1×10(7) virus particles per bee were infectious over this period, for IAPV and KBV respectively, while a dose of 0.5×10(6) IAPV particles per bee was not infectious. The impact of virus infection was studied in micro-colonies consisting of 5 bumblebees, one of which becomes a pseudo-queen which proceeds to lay unfertilized (drone) eggs. The impact parameters studied were: the establishment of a laying pseudo-queen, the timing of egg-laying, the number of drones produced, the weight of these drones and worker mortality. In this setup KBV infection resulted in a significant slower colony startup and offspring production, while only the latter can be reported for IAPV. Neither virus increased worker mortality, at the oral doses used. We recommend further studies on how these viruses transmit between different pollinator species. It is also vital to understand how viral prevalence can affect wild bee populations because disturbance of the natural host-virus association may deteriorate the already critically endangered status of many bumblebee species.

  9. Reproductive success and chlorinated hydrocarbon contamination of resident great blue herons (Ardea herodias) from coastal British Columbia, Canada, 1977 to 2000.

    PubMed

    Harris, M L; Elliott, J E; Butler, R W; Wilson, L K

    2003-01-01

    Over the period 1977-2000, eggs of Pacific great blue heron (Ardea herodias fannini) were collected from 23 colonies along the southern coast of British Columbia, Canada, and analyzed for persistent organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs). Concentrations of OC pesticides in eggs declined sharply in the late 1970s, after which there were minimal changes. The sums of PCB congeners were not reduced appreciably during the 1980s and 1990s, but Aroclor 1260 concentrations suggested a sharp decline in PCB contamination of eggs in the late 1970s, similar to that shown for OC pesticides. Eggs collected along or near the Fraser River delta showed higher levels of most pesticides compared to other monitored colonies. Although the delta lands support a long-standing agricultural economy, the primary factors influencing OC levels in the delta colonies were thought to be driven by estuarine processes. We suggest two possible influencing factors were: 1) a greater rate of bioaccumulation in the estuary due to the deposition of particulates collected over a vast area encompassed by the Fraser River watershed; or 2) a higher rate of biomagnification in the estuary due to species differences at lower trophic levels of the heron food chain. Eggs from urban colonies contained higher levels of PCBs. The congener pattern was not clearly different from that observed in less contaminated eggs from rural and pulp mill-influenced colonies, except that colonies in Vancouver had greater proportions of PCB-66, suggesting a local source of Aroclor 1242. Productivity in the coastal heron colonies was highly variable over the period of study, with 71% of recorded colony-wide reproductive failures occurring in colonies near pulp mills. However, the predominant factors influencing reproductive success were probably disturbance by humans and bald eagles, combined with loss and degradation of nesting habitat, and not sublethal toxicity.

  10. The reproductive success of lake herring in habitats near shipping channels and ice-breaking operations in the St. Marys River, Michigan, USA

    USGS Publications Warehouse

    Blouin, Marc A.; Kostich, M.M.; Todd, T.N.; Savino, J.F.

    1998-01-01

    A study of the reproductive success of lake herring (Coregonus artedi) in the St. Marys River was conducted in the winters and springs of 1994, 1995, and 1996. The St. Marys River connects Lake Superior to the lower Great Lakes making it an important route for ship traffic. Recent pressure by commercial carriers to extend the shipping season by breaking ice earlier in spring, has raised concerns over the possible adverse effects on lake herring reproduction in the river caused by increased turbidity associated with vessel passage. Lake herring spawn in fall and their eggs overwinter under ice cover on the bottom of the St. Marys River. Hatching occurs in the spring after ice-out when water temperatures rise. Specialized incubators were used to hold fertilized lake herring eggs at four experimental sites, chosen to represent the range of various bottom substrate types of the St. Marys River from boulder rock reefs to soft sediments. In winter, incubators were placed under the ice on the bottom of the river at three sites each year. After ice-out, sites were relocated, and the incubators were retrieved and opened to determine the number of live and dead lake herring eggs and larvae. Survival was consistent from year to year at each site with the lowest survival percentage found at the site with the softest sediments, directly adjacent to the St. Marys River channel and downstream of the mouth of the Charlotte River. River bottom type and geographic location were the most important factors in determining egg survival. Sampling for indigenous larval lake herring was done throughout the spring hatching season in the areas adjacent to the incubator sites using nets and a diver-operated suction sampler. Result indicate that a small population (3) of larval lake herring was present throughout the sampling areas during the springs of 1994, 1995, and 1996 in the St. Marys River.

  11. The novel POSEIDON stratification of ‘Low prognosis patients in Assisted Reproductive Technology’ and its proposed marker of successful outcome

    PubMed Central

    Humaidan, Peter; Alviggi, Carlo; Fischer, Robert; Esteves, Sandro C.

    2016-01-01

    In reproductive medicine little progress has been achieved regarding the clinical management of patients with a reduced ovarian reserve or poor ovarian response (POR) to stimulation with exogenous gonadotropins -a frustrating experience for clinicians as well as patients. Despite the efforts to optimize the definition of this subgroup of patients, the existing POR criteria unfortunately comprise a heterogeneous population and, importantly, do not offer any recommendations for clinical handling. Recently, the POSEIDON group ( Patient- Oriented Strategies Encompassing Individualize D Oocyte Number) proposed a new stratification of assisted reproductive technology (ART) in patients with a reduced ovarian reserve or unexpected inappropriate ovarian response to exogenous gonadotropins. In brief, four subgroups have been suggested based on quantitative and qualitative parameters, namely, i. Age and the expected aneuploidy rate; ii. Ovarian biomarkers (i.e. antral follicle count [AFC] and anti-Müllerian hormone [AMH]), and iii. Ovarian response - provided a previous stimulation cycle was performed. The new classification introduces a more nuanced picture of the “low prognosis patient” in ART, using clinically relevant criteria to guide the physician to most optimally manage this group of patients. The POSEIDON group also introduced a new measure for successful ART treatment, namely, the ability to retrieve the number of oocytes needed for the specific patient to obtain at least one euploid embryo for transfer. This feature represents a pragmatic endpoint to clinicians and enables the development of prediction models aiming to reduce the time-to-pregnancy (TTP). Consequently, the POSEIDON stratification should not be applied for retrospective analyses having live birth rate (LBR) as endpoint. Such an approach would fail as the attribution of patients to each Poseidon group is related to specific requirements and could only be made prospectively. On the other hand, any

  12. Out of sight but not out of harm’s way: Human disturbance reduces reproductive success of a cavity-nesting seabird

    PubMed Central

    Watson, Hannah; Bolton, Mark; Monaghan, Pat

    2014-01-01

    While negative effects of human disturbance on animals living above the ground have been widely reported, few studies have considered effects on animals occupying cavities or burrows underground. It is generally assumed that, in the absence of direct visual contact, such species are less vulnerable to disturbance. Seabird colonies can support large populations of burrow- and cavity-nesting species and attract increasing numbers of tourists. We investigated the potential effects of recreational disturbance on the reproductive behaviour of the European storm petrel Hydrobates pelagicus, a nocturnally-active cavity-nesting seabird. Reproductive phenology and outcome of nests subject to high and low levels of visitor pressure were recorded in two consecutive years. Hatching success did not differ between disturbance levels, but overall nestling mortality was significantly higher in areas exposed to high visitor pressure. Although visitor numbers were consistent throughout the season, the magnitude and rate of a seasonal decline in productivity were significantly greater in nests subject to high disturbance. This study presents good evidence that, even when humans do not pose a direct mortality risk, animals may perceive them as a predation risk. This has implications for the conservation and management of a diverse range of burrow- and cavity-dwelling animals. Despite this reduction in individual fitness, overall colony productivity was reduced by ⩽1.6% compared with that expected in the absence of visitors. While the colony-level consequences at the site in question may be considered minor, conservation managers must evaluate the trade-off between potential costs and benefits of public access on a site- and species-specific basis. PMID:24899731

  13. DNA alterations and effects on growth and reproduction in Daphnia magna during chronic exposure to gamma radiation over three successive generations.

    PubMed

    Parisot, Florian; Bourdineaud, Jean-Paul; Plaire, Delphine; Adam-Guillermin, Christelle; Alonzo, Frédéric

    2015-06-01

    This study examined chronic effects of external Cs-137 gamma radiation on Daphnia magna exposed over three successive generations (F0, F1 and F2) to environmentally relevant dose rates (ranging from 0.007 to 35.4 mGy h(-1)). Investigated endpoints included survival, growth, reproduction and DNA alterations quantified using random-amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). Results demonstrated that radiation effects on survival, growth and reproduction increased in severity from generation F0 to generation F2. Mortality after 21 days at 35.4 mGy h(-1) increased from 20% in F0 to 30% in F2. Growth was affected by a slight reduction in maximum length at 35.4 mGy h(-1) in F0 and by reductions of 5 and 13% in growth rate, respectively, at 4.70 and 35.4 mGy h(-1) in F2. Reproduction was affected by a reduction of 19% in 21 day-fecundity at 35.4 mGy h(-1) in F0 and by a delay of 1.9 days in brood release as low as 0.070 mGy h(-1) in F2. In parallel, DNA alterations became significant at decreasing dose rates over the course of F0 (from 4.70 mGy h(-1) at hatching to 0.007 mGy h(-1) after ∼21 days) and from F0 to F2 (0.070 mGy h(-1) at hatching to 0.007 mGy h(-1) after ∼21 days), demonstrating their rapid accumulation in F0 daphnids and their transmission to offspring generations. Transiently more efficient DNA repair leading to some recovery at the organism level was suggested in F1, with no effect on survival, a slight reduction of 12% in 21 day-fecundity at 35.4 mGy h(-1) and DNA alterations significant at highest dose rates only. The study improved our understanding of long term responses to low doses of radiation at the molecular and organismic levels in a non-human species for a better radioprotection of aquatic ecosystems.

  14. Male reproductive proteins and reproductive outcomes.

    PubMed

    Ness, Roberta B; Grainger, David A

    2008-06-01

    Male reproductive proteins (MRPs), associated with sperm and semen, are the moieties responsible for carrying male genes into the next generation. Evolutionary biologists have focused on their capacity to control conception. Immunologists have shown that MRPs cause female genital tract inflammation as preparatory for embryo implantation and placentation. These observations argue that MRPs are critically important to reproductive success. Yet the impact of male reproductive proteins on obstetrical outcomes in women is largely unstudied. Epidemiologic and clinical observations suggest that shorter-duration exposure to MRPs prior to conception may elevate the risk for preeclampsia. A limited literature has also linked sexual behavior to bacterial vaginosis and preterm birth. We offer a clinical opinion that MRPs may have broad implications for successful reproduction, potentially involved in the composition of vaginal microflora, risks of preterm birth and preeclampsia, and success of assisted reproduction.

  15. Natural Reproductive Success and Demographic Effects of Hatchery-Origin Steelhead in Abernathy Creek, Washington : Annual Report 2008.

    SciTech Connect

    U.S. Fish & Wildlife Service, Abernathy Fish Technology Center

    2008-12-01

    program offers many genetic advantages over traditional adult-trapping programs for developing native broodstocks: (1) Large numbers of juveniles can be collected from the wild with only minimal impacts to naturally spawning populations because juvenile (age 0+parr)-to-adult survivals are typically very small (<1%) under natural conditions. (2) The genetic base of the broodstock (i.e. genetic effective population size) can be substantially larger for juveniles than adults because juveniles can theoretically represent the offspring of all adults that spawned successfully within a stream or watershed, as opposed to trapping only a small portion of returning adults for broodstock. (3) Collecting juveniles for broodstock can substantially reduce the risk of genetically 'swamping' naturally spawning populations with hatchery-origin fish (i.e. via a 'Ryman-Laikre effect') as occurs when hatchery-released fish represent the progeny of a relatively small number of trapped adults.

  16. Effect of the Operation of Kerr and Hungry Horse Dams on the Reproductive Success of Kokanee in the Flathead System, 1987 Final Report.

    SciTech Connect

    Beattie, Will; Zubik, Raymond; Clancey, Patrick

    1988-05-01

    Studies of kokanee reproductive success in the Flathead system from 1981 to 1987 have assessed the losses in fish production attributable to hydroelectric operations. We estimated that the Flathead Lake shoreline spawning stock has lost at least 50,000 fish annually, since Kerr Dam was completed in 1938. The Flathead River spawning stock has lost 95,000 spawners annually because of the operations of Hungry Horse Dam. Lakeshore spawning has been adversely affected because Flathead Lake has been drafted to minimum pool during the winter when kokanee eggs are incubating in shallow shoreline redds. Egg mortality from exposure and desiccation of kokanee redds has increased since the mid 1970's. When the lake was drafted more quickly and held longer at minimum pool. Escapement surveys in the early 1950's, and a creel survey in the early 1960's have provided a baseline to which the present escapement levels can be compared, and loss estimated. Main stem Flathead River spawning has also declined since the mid 1970's when fluctuating discharge from Hungry Horse Dam during the spawning and incubation season exposed redds at the river margin and increased mortality. This decline followed an increase in main stem spawning in the late 1950's through the mid 1960's attributable to higher winter water temperature and relatively stable discharge from Hungry Horse Dam. Spawning escapement in the main stem exceeded 300,000 kokanee in the early 1970's as a result. Spawning in spring-influenced sites has comprised 35 percent of the main stem escapement from 1979 to 1986. We took that proportion of the early 1970's escapement (105,000) as the baseline against which to measure historic loss. Agricultural and suburban development has contributed less significantly to degradation of kokanee spawning habitat in the river system and on the Flathead Lake shoreline. Their influence on groundwater quality and substrate composition has limited reproductive success in few sites. Studies of the

  17. Age-specific patterns of genetic variance in Drosophila melanogaster. II. Fecundity and its genetic covariance with age-specific mortality

    SciTech Connect

    Tatar, M.; Promislow, D.E.L.; Khazaeli, A.A.; Curtsinger, J.W.

    1996-06-01

    Under the mutation accumulation model of senescence, it was predicted that the additive genetic variance (V{sub A}) for fitness traits will increase with age. We measured age-specific mortality and fecundity from 65,134 Drosophila melanogaster and estimated genetic variance components, based on reciprocal crosses of extracted second chromosome lines. Elsewhere we report the results for mortality. Here, for fecundity, we report a biomodal pattern for V{sub A} with peaks at 3 days and at 17-31 days. Under the antagonistic pleiotropy model of senescence, it was predicted that negative correlations will exist between early and late life history traits. For fecundity itself we find positive genetic correlations among age classes >3 days but negative nonsignificant correlations between fecundity at 3 days and at older age classes. For fecundity vs. age-specific mortality, we find positive fitness correlations (negative genetic correlations) among the traits at all ages >3 days but a negative fitness correlation between fecundity at 3 days and mortality at the oldest ages (positive genetic correlations). For age-specific mortality itself we find overwhelmingly positive genetic correlations among all age classes. The data suggest that mutation accumulation may be a major source of standing genetic variance for senescence. 75 refs., 4 figs., 1 tab.

  18. Mating Systems, Reproductive Success, and Sexual Selection in Secretive Species: A Case Study of the Western Diamond-Backed Rattlesnake, Crotalus atrox

    PubMed Central

    Clark, Rulon W.; Schuett, Gordon W.; Repp, Roger A.; Amarello, Melissa; Smith, Charles F.; Herrmann, Hans-Werner

    2014-01-01

    Long-term studies of individual animals in nature contribute disproportionately to our understanding of the principles of ecology and evolution. Such field studies can benefit greatly from integrating the methods of molecular genetics with traditional approaches. Even though molecular genetic tools are particularly valuable for species that are difficult to observe directly, they have not been widely adopted. Here, we used molecular genetic techniques in a 10-year radio-telemetric investigation of the western diamond-backed rattlesnake (Crotalus atrox) for an analysis of its mating system and to measure sexual selection. Specifically, we used microsatellite markers to genotype 299 individuals, including neonates from litters of focal females to ascertain parentage using full-pedigree likelihood methods. We detected high levels of multiple paternity within litters, yet found little concordance between paternity and observations of courtship and mating behavior. Larger males did not father significantly more offspring, but we found evidence for size-specific male-mating strategies, with larger males guarding females for longer periods in the mating seasons. Moreover, the spatial proximity of males to mothers was significantly associated with reproductive success. Overall, our field observations alone would have been insufficient to quantitatively measure the mating system of this population of C. atrox, and we thus urge more widespread adoption of molecular tools by field researchers studying the mating systems and sexual selection of snakes and other secretive taxa. PMID:24598810

  19. Comparing the Reproductive Success of Yakima River Hatchery-and Wild-Origin Spring Chinook; Yakima/Klickitat Fisheries Project Monitoring and Evaluation, 2000-2001 Annual Report.

    SciTech Connect

    Schroder, S.L.; Knudsen, C.M.; Rau, J.A.

    2003-01-01

    In the Yakima Spring Chinook supplementation program, wild fish are brought into the Cle Elum Hatchery, artificially crossed, reared, transferred to acclimation sites, and released into the upper Yakima River as smolts. When these fish mature and return to the Yakima River most of them will be allowed to spawn naturally; a few, however, will be brought back to the hatchery and used for research purposes. In order for this supplementation approach to be successful, hatchery-origin fish must be able to spawn and produce offspring under natural conditions. Recent investigations on salmonid fishes have indicated that exposure to hatchery environments during juvenile life may cause significant behavioral, physiological, and morphological changes in adult fish. These changes appear to reduce the reproductive competence of hatchery fish. In general, males are more affected than females; species with prolonged freshwater rearing periods are more strongly impacted than those with shorter rearing periods; and stocks that have been exposed to artificial culture for multiple generations are more impaired than those with a relatively short exposure history to hatchery conditions.

  20. Effects of habitat disruption on the activity of nectarivorous bats (Chiroptera: Phyllostomidae) in a dry tropical forest: implications for the reproductive success of the neotropical tree Ceiba grandiflora.

    PubMed

    Quesada, Mauricio; Stoner, Kathryn E; Rosas-Guerrero, Víctor; Palacios-Guevara, Carolina; Lobo, Jorge A

    2003-05-01

    In the tropical dry forest of the central Pacific coast of Mexico the pollination and reproductive success of the bombacaceous tree Ceiba grandiflora was negatively affected by habitat disruption. Two of the three bat species that function as effective pollinators for this species ( Glossophaga soricina and Musonycteris harrisoni) visited flowers found in trees in disturbed habitats significantly less than trees found in undisturbed habitats. A similar pattern was observed for the effective bat pollinator, Leptonycteris curasoae; however the difference was not significant. The three nectarivorous bats that functioned as effective pollinators of C. grandiflora also visited flowers to exclusively feed on pollen by biting or pulling off an anther (see Fig. S1 of Electronic Supplementary Material). The number of pollen grains deposited on stigmas from flowers in undisturbed areas was significantly greater than from flowers in disturbed habitats. The greater visitation rate and the greater number of pollen grains deposited on flowers from trees in undisturbed forest resulted in a significantly greater fruit set for trees in these areas. Our study demonstrates the negative effect that habitat disruption has on bat pollinators in tropical dry forest ecosystems and documents the negative consequences for the plants they pollinate.

  1. Mating systems, reproductive success, and sexual selection in secretive species: a case study of the western diamond-backed rattlesnake, Crotalus atrox.

    PubMed

    Clark, Rulon W; Schuett, Gordon W; Repp, Roger A; Amarello, Melissa; Smith, Charles F; Herrmann, Hans-Werner

    2014-01-01

    Long-term studies of individual animals in nature contribute disproportionately to our understanding of the principles of ecology and evolution. Such field studies can benefit greatly from integrating the methods of molecular genetics with traditional approaches. Even though molecular genetic tools are particularly valuable for species that are difficult to observe directly, they have not been widely adopted. Here, we used molecular genetic techniques in a 10-year radio-telemetric investigation of the western diamond-backed rattlesnake (Crotalus atrox) for an analysis of its mating system and to measure sexual selection. Specifically, we used microsatellite markers to genotype 299 individuals, including neonates from litters of focal females to ascertain parentage using full-pedigree likelihood methods. We detected high levels of multiple paternity within litters, yet found little concordance between paternity and observations of courtship and mating behavior. Larger males did not father significantly more offspring, but we found evidence for size-specific male-mating strategies, with larger males guarding females for longer periods in the mating seasons. Moreover, the spatial proximity of males to mothers was significantly associated with reproductive success. Overall, our field observations alone would have been insufficient to quantitatively measure the mating system of this population of C. atrox, and we thus urge more widespread adoption of molecular tools by field researchers studying the mating systems and sexual selection of snakes and other secretive taxa.

  2. Reproductive success, early life stage development, and survival of westslope cutthroat trout (Oncorhynchus clarki lewisi) exposed to elevated selenium in an area of active coal mining.

    PubMed

    Rudolph, Barri-Lynn; Andreller, Iisak; Kennedy, Christopher J

    2008-04-15

    The effects of accumulated Se on the reproductive success and larval development of cutthroat trout (Oncorhynchus clarki lewis,) collected from a site of active coal mining in British Columbia were assessed. Eggs from 12 fish from an exposed site (Clode Pond) and 16 from a reference site (O'Rourke Lake) were field-collected and reared in the laboratory. Egg Se concentrations ranged from 12.3 to 16.7 and 11.8 to 140.0 microg/g dry weight (dw) from fish collected at the reference and exposed sites, respectively. Other studies, including those with this species, have not shown Se to affect egg viability; however, in the present study, eggs with Se concentrations > 86.3 microg/g dw were not successfully fertilized or were nonviable at fertilization, while eggs with concentrations > 46.8 and < 75.4 microg/g dw were fertilized (96% reached the eyed stage) but did not produce viable fry. A significant positive relationship between egg Se concentration and alevin mortality was observed. Deformities were analyzed in surviving fry which developed from eggs with Se concentrations between 11.8 and 20.6 microg/g dw. No relationship between Se concentration in eggs and deformities or edema was found in this range, suggesting that the no-effect threshold for deformity is > 20.6 microg/g dw. The present data, in conjunction with the data from several other studies in temperate fish, suggest that current Se thresholds are conservative for cold-water fish.

  3. Pollen gene flow, male reproductive success, and genetic correlations among offspring in a northern red oak (Quercus rubra L.) seed orchard

    PubMed Central

    Woeste, Keith

    2017-01-01

    Northern red oak is a high-value hardwood used for lumber, furniture and veneer. Intensively managed northern red oak seed orchards are required to obtain genetic gain for trait improvement. Data from conifer seed orchards and natural and managed stands of hardwood trees have shed light on the distance over which pollen can move, and underscore the need for managerial attention to seed orchard design, placement, and maintenance. We used eleven microsatellite markers to investigate pollen gene flow, female mate choice, and male reproductive success in a clonal seed orchard of northern red oak based on paternity analysis of seed orchard offspring in progeny tests. Nearly all (93%) offspring were sired by a male parent within the seed orchard. The mean number of male parents per year was 69.5, or 47.6% of all clones in the seed orchard. Female clones in the early phenology group had more offspring sired from extra-orchard pollen (13%) than clones in the intermediate (5%) and late (1%) phenology groups. Distance was the largest influence on pollination success, and pollination occurred most often by male trees in the same subline as the maternal tree. Males in the early phenology group sired more offspring overall in the progeny pool and more offspring per mother tree than males in the intermediate or late phenology groups. Average genetic correlations among all OP progeny ranged between 0.2557 and 0.3529 with a mean of 0.28±0.01. The importance of progeny test genotyping for northern red oak improvement likely is increasing with the demand for improved varieties. The current study demonstrated the feasibility of post hoc assembly of full-sib families for genetic analysis. PMID:28166543

  4. Reproductive success, early life stage development, and survival of westslope cutthroat trout (Oncorhynchus clarki lewisi) exposed to elevated selenium in an area of active coal mining

    SciTech Connect

    Barri-Lynn Rudolph; Iisak Andreller; Christopher J. Kennedy

    2008-04-15

    The effects of accumulated Se on the reproductive success and larval development of cutthroat trout (Oncorhynchus clarki lewisi) collected from a site of active coal mining in British Columbia were assessed. Eggs from 12 fish from an exposed site (Clode Pond) and 16 from a reference site (O'Rourke Lake) were field-collected and reared in the laboratory. Egg Se concentrations ranged from 12.3 to 16.7 and 11.8 to 140.0 {mu}g/g dry weight (dw) from fish collected at the reference and exposed sites, respectively. Other studies, including those with this species, have not shown Se to affect egg viability. However, in the present study, eggs with Se concentrations >86.3 {mu}g/g dw were not successfully fertilized or were nonviable at fertilization, while eggs with concentrations >46.8 and <75.4 {mu}g/g dw were fertilized (96% reached the eyed stage) but did not produce viable fry. A significant positive relationship between egg Se concentration and alevin mortality was observed. Deformities were analyzed in surviving fry which developed from eggs with Se concentrations between 11.8 and 20.6 {mu}g/g dw. No relationship between Se concentration in eggs and deformities or edema was found in this range, suggesting that the no-effect threshold for deformity is >20.6 {mu}g/g dw. The present data, in conjunction with the data from several other studies in temperate fish, suggest that current Se thresholds are conservative for cold-water fish. 25 refs., 3 figs.

  5. Pollen gene flow, male reproductive success, and genetic correlations among offspring in a northern red oak (Quercus rubra L.) seed orchard.

    PubMed

    Alexander, Lisa; Woeste, Keith

    2017-01-01

    Northern red oak is a high-value hardwood used for lumber, furniture and veneer. Intensively managed northern red oak seed orchards are required to obtain genetic gain for trait improvement. Data from conifer seed orchards and natural and managed stands of hardwood trees have shed light on the distance over which pollen can move, and underscore the need for managerial attention to seed orchard design, placement, and maintenance. We used eleven microsatellite markers to investigate pollen gene flow, female mate choice, and male reproductive success in a clonal seed orchard of northern red oak based on paternity analysis of seed orchard offspring in progeny tests. Nearly all (93%) offspring were sired by a male parent within the seed orchard. The mean number of male parents per year was 69.5, or 47.6% of all clones in the seed orchard. Female clones in the early phenology group had more offspring sired from extra-orchard pollen (13%) than clones in the intermediate (5%) and late (1%) phenology groups. Distance was the largest influence on pollination success, and pollination occurred most often by male trees in the same subline as the maternal tree. Males in the early phenology group sired more offspring overall in the progeny pool and more offspring per mother tree than males in the intermediate or late phenology groups. Average genetic correlations among all OP progeny ranged between 0.2557 and 0.3529 with a mean of 0.28±0.01. The importance of progeny test genotyping for northern red oak improvement likely is increasing with the demand for improved varieties. The current study demonstrated the feasibility of post hoc assembly of full-sib families for genetic analysis.

  6. ESTIMATING REPRODUCTIVE SUCCESS IN BIRDS

    EPA Science Inventory

    This presentation will focus on the statistical issues surrounding estimation of avian nest-survival. I first describe the natural history and breeding ecology of two North American songbirds, the Loggerhead Shrike (Lanius ludovicianus) and the Wood Thrush (Hylocichla mustelina)....

  7. A theory of the cancer age-specific incidence data based on extreme value distributions

    NASA Astrophysics Data System (ADS)

    Soto-Ortiz, Luis; Brody, James P.

    2012-03-01

    The incidence of cancers varies with age, if normalized this is called the age-specific incidence. A mathematical model that describes this variation should provide a better understanding of how cancers develop. We suggest that the age-specific incidence should follow an extreme value distribution, based on three widely accepted assumptions: (1) a tumor develops from a single cell, (2) many potential tumor progenitor cells exist in a tissue, and (3) cancer is diagnosed when the first of these many potential tumor cells develops into a tumor. We tested this by comparing the predicted distribution to the age-specific incidence data for colon and prostate carcinomas collected by the Surveillance, Epidemiology and End Results network of 17 cancer registries. We found that colon carcinoma age-specific incidence data is consistent with an extreme value distribution, while prostate carcinomas age-specific incidence data generally follows the distribution. This model indicates that both colon and prostate carcinomas only occur in a subset of the population (22% for prostate and 13.5% for colon.) Because of their very general nature, extreme value distributions might be applicable to understanding other chronic human diseases.

  8. Basis and implications of the CAP88 age-specific dose coefficients

    SciTech Connect

    Leggett, Richard Wayne; Scofield, Patricia A; Eckerman, Keith F

    2013-01-01

    Recent versions of CAP88 incorporate age-specific dose coefficients based on biokinetic and dosimetric models applied in Federal Guidance Report 13, Cancer Risk Coefficients for Environmental Exposure to Radionuclides (EPA 1999). With a few exceptions the models are those recommended in a series of reports by the International Commission on Radiological Protection (ICRP) on estimation of doses to the public from environmental radionuclides. This paper describes the basis for the ICRP s age-specific biokinetic and dosimetric models and examines differences with age in the derived dose coefficients and in estimates of dose per unit exposure based on those coefficients.

  9. Deriving age-specific incidence from prevalence with an ordinary differential equation.

    PubMed

    Brinks, Ralph; Landwehr, Sandra; Icks, Andrea; Koch, Michael; Giani, Guido

    2013-05-30

    This article describes new relationships between the age-specific incidence of, the prevalence of and mortality from a chronic disease. We express these relationships in terms of an ordinary differential equation and form the methodological basis for a novel approach to estimating incidences from age-specific prevalence data. We examine practical aspects of the relationships and a comparison with a known stochastic method in a simulation study. Finally, we apply the novel method to a data set of renal replacement therapy recorded from patients with chronic kidney failure in a region of Germany with approximately 310,000 inhabitants from 2002 to 2010.

  10. Proximate weather patterns and spring green-up phenology effect Eurasian beaver (Castor fiber) body mass and reproductive success: the implications of climate change and topography.

    PubMed

    Campbell, Ruairidh D; Newman, Chris; Macdonald, David W; Rosell, Frank

    2013-04-01

    Low spring temperatures have been found to benefit mobile herbivores by reducing the rate of spring-flush, whereas high rainfall increases forage availability. Cold winters prove detrimental, by increasing herbivore thermoregulatory burdens. Here we examine the effects of temperature and rainfall variability on a temperate sedentary herbivore, the Eurasian beaver, Castor fiber, in terms of inter-annual variation in mean body weight and per territory offspring production. Data pertain to 198 individuals, over 11 years, using capture-mark-recapture. We use plant growth (tree cores) and fAPAR (a satellite-derived plant productivity index) to examine potential mechanisms through which weather conditions affect the availability and the seasonal phenology of beaver forage. Juvenile body weights were lighter after colder winters, whereas warmer spring temperatures were associated with lighter adult body weights, mediated by enhanced green-up phenology rates. Counter-intuitively, we observed a negative association between rainfall and body weight in juveniles and adults, and also with reproductive success. Alder, Alnus incana, (n = 68) growth rings (principal beaver food in the study area) exhibited a positive relationship with rainfall for trees growing at elevations >2 m above water level, but a negative relationship for trees growing <0.5 m. We deduce that temperature influences beavers at the landscape scale via effects on spring green-up phenology and winter thermoregulation. Rainfall influences beavers at finer spatial scales through topographical interactions with plant growth, where trees near water level, prone to water logging, producing poorer forage in wetter years. Unlike most other herbivores, beavers are an obligate aquatic species that utilize a restricted 'central-place' foraging range, limiting their ability to take advantage of better forage growth further from water during wetter years. With respect to anthropogenic climate change, interactions between

  11. Monitoring the Reproductive Success of Naturally Spawning Hatchery and Natural Spring Chinook Salmon in the Wenatchee River, 2008-2009 Progress Report.

    SciTech Connect

    Ford, Michael J.; Williamson, Kevin S.

    2009-05-28

    We investigated differences in the statistical power to assign parentage between an artificially propagated and wild salmon population. The propagated fish were derived from the wild population, and are used to supplement its abundance. Levels of genetic variation were similar between the propagated and wild groups at 11 microsatellite loci, and exclusion probabilities were >0.999999 for both groups. The ability to unambiguously identify a pair of parents for each sampled progeny was much lower than expected, however. Simulations demonstrated that the proportion of cases the most likely pair of parents were the true parents was lower for propagated parents than for wild parents. There was a clear relationship between parentage assignment ability and the degree of linkage disequilibrium, the estimated effective number of breeders that produced the parents, and the size of the largest family within the potential parents. If a stringent threshold for parentage assignment was used, estimates of relative fitness were biased downward for the propagated fish. The bias appeared to be largely eliminated by either fractionally assigning progeny among parents in proportion to their likelihood of parentage, or by assigning progeny to the most likely set of parents without using a statistical threshold. We used a DNA-based parentage analysis to measure the relative reproductive success of hatchery- and natural-origin spring Chinook salmon in the natural environment. Both male and female hatchery-origin fish produced far fewer juvenile progeny per parent when spawning naturally than did natural origin fish. Differences in age structure, spawning location, weight and run timing were responsible for some of the difference in fitness. Male size and age had a large influence on fitness, with larger and older males producing more offspring than smaller or younger individuals. Female size had a significant effect on fitness, but the effect was much smaller than the effect of size on

  12. Drought-caused delay in nesting of Sonoran Desert birds and its facilitation of parasite- and predator-mediated variation in reproductive success

    USGS Publications Warehouse

    Chris McCreedy,; Van Riper, Charles

    2015-01-01

    As our understanding of climate change has increased, so has our awareness of the impacts of these changes on biotic systems. Climate models are nearly unanimous in their predictions for increased drought frequency in southwestern North America, and delays in nest initiation due to drought may influence nesting success and productivity for many Sonoran Desert bird species. In southeastern California and western Arizona in 2004–2009, we found negative correlations for 13 of 13 species between nest initiation date and rainfall accumulation during the preceding 4-month winter rainy season. Nesting was delayed more than 3 weeks for some species during extreme droughts in 2006 and 2007. During 2004–2009, we found a significant negative effect of nest initiation date on nest survival probability (β̂ = −0.031 ± 0.005 SE, P < 0.001) for the four species of greatest sample size. To investigate the role of nesting delay in nesting success and productivity, in 2010 we conducted a manipulative experiment with Black-tailed Gnatcatchers (Polioptila melanura; BTGN) and Verdins (Auriparus flaviceps; VERD). Following a wet winter, we delayed clutch initiation dates for treatment pairs to match first-egg dates that we observed during droughts in 2006 and 2007. Nest initiation date had a significant negative effect on nest survival of both species (BTGN: β̂ = −1.18 ± 0.27 SE, P < 0.001; VERD: β̂ = −2.33 ± 0.51 SE, P = 0.003). Treatment pairs were unable to overcome the lost period of high productivity in March and early April, and had lower productivity than control pairs over the entire breeding season. As nest predation and Brown-headed Cowbird (Molothrus ater) parasitism were the most common causes of nest failure, we conclude that the impacts of climate change–caused drought on annual reproductive output in the Sonoran Desert will be further compounded by parasitism and predation for Black-tailed Gnatcatchers and by predation for Verdins.

  13. Basis for the ICRP`s age-specific biokinetic model for uranium

    SciTech Connect

    Leggett, R.W.

    1994-12-01

    In an effort motivated largely by the Chernobyl nuclear accident, the International Commission on Radiological Protection (ICRP) is developing age-specific biokinetic models and dose coefficients for environmentally important radionuclides. This paper describes the ICRP`s age-specific biokinetic model for uranium. The model is constructed within a physiologically based framework originally developed for application to the alkaline earth elements but sufficiently general to apply to the larger class of bone-volume-seeking elements. Transfer rates for a reference adult are based mainly on: (1) measurements of uranium in blood and excreta of several human subjects who were intravenously injected with uranium; (2) postmortem measurements of uranium in tissues of some of those subjects; (3) postmortem measurements of uranium in tissues of occupationally and non-occupationally exposed subjects; (4) data on baboons, dogs, and smaller laboratory animals exposed to uranium for experimental purposes; and (5) consideration of the physiological processes thought to control retention and translocation of uranium in the body. Transfer rates for the adult are extended to children by application of a set of generic assumptions applied by the ICRP to calcium-like elements. These assumptions were derived mainly from observations of the age-specific biokinetics of the alkaline earth elements and lead in humans and laboratory animals but are consistent with available age-specific biokinetic data on uranium. 82 refs., 17 figs., 8 tabs.

  14. The Age Specific Incidence Anomaly Suggests that Cancers Originate During Development

    NASA Astrophysics Data System (ADS)

    Brody, James P.

    The accumulation of genetic alterations causes cancers. Since this accumulation takes time, the incidence of most cancers is thought to increase exponentially with age. However, careful measurements of the age-specific incidence show that the specific incidence for many forms of cancer rises with age to a maximum, and then decreases. This decrease in the age-specific incidence with age is an anomaly. Understanding this anomaly should lead to a better understanding of how tumors develop and grow. Here we derive the shape of the age-specific incidence, showing that it should follow the shape of a Weibull distribution. Measurements indicate that the age-specific incidence for colon cancer does indeed follow a Weibull distribution. This analysis leads to the interpretation that for colon cancer two subpopulations exist in the general population: a susceptible population and an immune population. Colon tumors will only occur in the susceptible population. This analysis is consistent with the developmental origins of disease hypothesis and generalizable to many other common forms of cancer.

  15. Hood River Steelhead Genetics Study; Relative Reproductive Success of Hatchery and Wild Steelhead in the Hood River, Final Report 2002-2003.

    SciTech Connect

    Blouin, Michael

    2003-05-01

    analysis, the relative total reproductive success (adult-to-adult production) of hatchery (H{sub old} or H{sub new}) and wild (W) fish for two populations, over multiple brood years. Our analyses of samples from fish that bred in the early to mid 1990's show that fish of 'old' hatchery stocks have much lower total fitness than wild fish (17% to 54% of wild fitness), but that 'new' stocks have fitness that is similar to that of wild fish (ranging from 85% to 108% of wild fitness, depending on parental gender and run year). Therefore, our results show that the decision to phase out the old, out-of-basin stocks and replace them with new, conservation hatchery stocks was well founded. We also conclude that the H{sub new} fish are leaving behind substantial numbers of wild-born offspring. The similar fitnesses of H{sub new} and W fish suggests that wild-born offspring of H{sub new} fish are unlikely to have negative genetic effects on the population when they in turn spawn in the wild. We will test this hypothesis once enough F2 offspring have returned. Another interesting result is that we were unable to match a large fraction of the unclipped, returning fish with parents from their brood year. Furthermore, we were missing more fathers than mothers. Because we sampled almost every possible anadromous parent, these results suggest that nonanadromous trout or precocious parr may be obtaining a substantial number of matings. Substantial reproduction by precocious parr could be one unintended consequence of the hatchery program.

  16. Medical innovation and age-specific trends in health care utilization: findings and implications.

    PubMed

    Wong, Albert; Wouterse, Bram; Slobbe, Laurentius C J; Boshuizen, Hendriek C; Polder, Johan J

    2012-01-01

    Health care utilization is expected to rise in the coming decades. Not only will the aggregate need for health care grow by changing demographics, so too will per capita utilization. It has been suggested that trends in health care utilization may be age-specific. In this paper, age-specific trends in health care utilization are presented for different health care sectors in the Netherlands, for the period 1981-2009. For the hospital sector we also explore the link between these trends and the state of medical technology. Using aggregated data from a Dutch health survey and a nationwide hospital register, regression analysis was used to examine age-specific trends in the probability of utilizing health care. To determine the influence of medical technology, the growth in age-specific probabilities of hospital care was regressed on the number of medical patents while adjusting for confounders related to demographics, health status, supply and institutional factors. The findings suggest that for most health care sectors, the trend in the probability of health care utilization is highest for ages 65 and up. Larger advances in medical technology are found to be significantly associated with a higher growth of hospitalization probability, particularly for the higher ages. Age-specific trends will raise questions on the sustainability of intergenerational solidarity in health care, as solidarity will not only be strained by the ageing population, but also might find itself under additional pressure as the gap in health care utilization between elderly and non-elderly grows over time. For hospital care utilization, this process might well be accelerated by advances in medical technology.

  17. Reproductive success, growth and survival of black-crowned night-heron (Nycticorax nycticorax) and snowy egret (Egretta thula) chicks in coastal Virginia

    USGS Publications Warehouse

    Erwin, R.M.; Haig, J.G.; Stotts, D.B.; Hatfield, J.S.

    1996-01-01

    We studied reproductive success, growth, and survival of Black-crowned Night-Heron (Nycticorax nycticorax) and Snowy Egret (Egretta thula) chicks in two mixed-species heronries on marsh islands in Chincoteague Bay, Accomack County, Virginia in 1992 and 1993. We attached radio transmitters with mortality sensors to the oldest chicks (A-chicks) in 11 to 22 nests of both species to monitor survival during the mid-to late nestling period and into the post-nesting dispersal period. For both species, we found significant differences between 1992 and 1993 in growth rates and survival. Mass growth rates of chicks were higher in 1993 than in 1992 for both species. Culmen-length growth rates varied significantly due to year-colony effects for night-herons, but only for hatching order for egrets. Differences in survival rates due to hatching order were found for the egrets in both years, but were found only in 1992 for night-herons. As with mass growth rates, survival of chicks was higher in 1993 than 1992. Survival of radio-marked A-chicks did not differ between species or years for the period from hatching to fledging or from fledging through the end of the study (ca. two months post-fledging). Survival ranged from 0.90 to 1.00 from the time radio transmitters were attached (ca. two weeks of age) until dispersal age (53-55 days for egrets; 55-60 days for night-herons). After birds left the colony, survival rates were lower during the next 40 to 55 days, ranging from 0.25 to 0.60. These results suggest that, at least for Snowy Egrets, Achicks may be buffered from annual variations in food conditions, but that growth and survival of other brood members may provide a barometer of local conditions. Despite problems of variability in measurement, some of these parameters show promise as bioindicators of estuarine conditions. We recommend that a costefficient wading-bird monitoring program would include: (1) estimating numbers of nesting birds of selected species (e.g. Snowy

  18. Effects of Hand-Rearing on Reproductive Success in Captive Large Cats Panthera tigris altaica, Uncia uncia, Acinonyx jubatus and Neofelis nebulosa.

    PubMed

    Hampson, Maja Coulthard; Schwitzer, Christoph

    2016-01-01

    Species Survival Plans and European Endangered Species Programmes have been developed for several species of endangered felids in order to build up captive reserve populations and support their conservation in the wild. The Siberian tiger (Panthera tigris altaica), snow leopard (Uncia uncia), cheetah (Acinonyx jubatus) and clouded leopard (Neofelis nebulosa) are managed in such ex situ conservation programmes. Many zoological institutions hand-rear offspring if rearing by the mother fails. Hand-rearing can cause behavioural problems, resulting in decreased copulation and lower breeding success in some species. In this study, studbook data subsets were examined: from 1901 to 2011; and 2000 to 2011. We analysed records from 4273 Siberian tigers, 2045 snow leopards, 3435 cheetahs, and 804 clouded leopards. We assessed the number of offspring produced, litter size, age at first reproduction, longevity, infant mortality and generational rearing of hand-reared versus parent-reared individuals. Hand-reared Siberian tigers (p<0.01; p = 0.0113), snow leopards (p<0.01), male cheetahs (p<0.01) and female clouded leopards (p<0.01) produced fewer offspring than parent-reared individuals. Hand-reared snow leopard breeding pairs had larger litters than parent-reared pairs (p = 0.0404). Hand-reared snow leopard females reproduced later in life (p<0.01). Hand-reared female Siberian tigers lived shorter lives, while hand-reared cheetahs lived longer (p<0.01; p = 0.0107). Infant mortality was higher in hand-reared snow leopards (p<0.01) and male cheetahs (p = 0.0395) in the 1901-2011 dataset and lower in hand-reared female Siberian tiger and male snow leopard cubs (p = 0.0404; p = 0.0349) in the 2000-2011 dataset. The rearing of the mother and subsequent rearing of offspring showed a significant relationship for all species (p<0.01 for Siberian tiger and snow leopard cubs; p<0.001 for cheetah and snow leopard cubs). Taking into account the limited carrying capacity of zoos, the

  19. Effects of Hand-Rearing on Reproductive Success in Captive Large Cats Panthera tigris altaica, Uncia uncia, Acinonyx jubatus and Neofelis nebulosa

    PubMed Central

    Hampson, Maja Coulthard; Schwitzer, Christoph

    2016-01-01

    Species Survival Plans and European Endangered Species Programmes have been developed for several species of endangered felids in order to build up captive reserve populations and support their conservation in the wild. The Siberian tiger (Panthera tigris altaica), snow leopard (Uncia uncia), cheetah (Acinonyx jubatus) and clouded leopard (Neofelis nebulosa) are managed in such ex situ conservation programmes. Many zoological institutions hand-rear offspring if rearing by the mother fails. Hand-rearing can cause behavioural problems, resulting in decreased copulation and lower breeding success in some species. In this study, studbook data subsets were examined: from 1901 to 2011; and 2000 to 2011. We analysed records from 4273 Siberian tigers, 2045 snow leopards, 3435 cheetahs, and 804 clouded leopards. We assessed the number of offspring produced, litter size, age at first reproduction, longevity, infant mortality and generational rearing of hand-reared versus parent-reared individuals. Hand-reared Siberian tigers (p<0.01; p = 0.0113), snow leopards (p<0.01), male cheetahs (p<0.01) and female clouded leopards (p<0.01) produced fewer offspring than parent-reared individuals. Hand-reared snow leopard breeding pairs had larger litters than parent-reared pairs (p = 0.0404). Hand-reared snow leopard females reproduced later in life (p<0.01). Hand-reared female Siberian tigers lived shorter lives, while hand-reared cheetahs lived longer (p<0.01; p = 0.0107). Infant mortality was higher in hand-reared snow leopards (p<0.01) and male cheetahs (p = 0.0395) in the 1901–2011 dataset and lower in hand-reared female Siberian tiger and male snow leopard cubs (p = 0.0404; p = 0.0349) in the 2000–2