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1

Temporal changes in kin structure through a population cycle in a territorial bird, the red grouse Lagopus lagopus scoticus  

Microsoft Academic Search

Populations of red grouse (Lagopus lagopus scoticus) undergo regular multiannual cycles in abundance. The 'kinship hypothesis' posits that such cycles are caused by changes in kin structure among territorial males producing delayed density-dependent changes in aggres- siveness, which in turn influence recruitment and regulate density. The kinship hypothesis makes several specific predictions about the levels of kinship, aggressiveness and recruitment

STUART B. PIERTNEY; XAVIER LAMBIN; ANDREW D. C. MACCOLL; KERRY LOCK; PHILIP J. BACON; JOHN F. DALLAS; FIONA LECKIE; FRANCOIS MOUGEOT; PAUL A. RACEY; STEVE REDPATH; ROBERT MOSS

2008-01-01

2

Endocrine changes in photostimulated willow ptarmigan (Lagopus lagopus lagopus) and Svalbard ptarmigan (Lagopus mutus hyperboreus).  

PubMed

Changes in plasma luteinizing hormone (LH), testosterone, thyroxine (T4), and triiodothyronine (T3) and the height of supraorbital combs were compared in captive willow ptarmigan (Lagopus lagopus lagopus) and Svalbard ptarmigan (Lagopus mutus hyperboreus) exposed to an artificial annual cycle of daylength simulating that at 70 degrees N. Plasma LH and testosterone and comb height increased more slowly in Svalbard than in willow ptarmigan as daylength increased. In both species, plasma LH and testosterone fell abruptly, and the supraorbital combs regressed in June, marking the development of long-day refractoriness. Comparison with free-living Svalbard ptarmigan (K.-A. Stokkan, P. J. Sharp, and S. Unander (1986) Gen. Comp. Endocrinol. 61, 446-451) at 80 degrees N, showed a similar slow increase in reproductive function before the onset of the breeding season. However, maximum plasma LH levels and comb size were higher in free-living than in captive Svalbard ptarmigan. Furthermore, long-day refractoriness developed earlier in captive than in free-living Svalbard ptarmigan. In both species of ptarmigan, the development of long-day refractoriness was associated with increased plasma prolactin. This increase was larger and occurred earlier in the Svalbard than in the willow ptarmigan. Seasonal changes in thyroid hormones were not as marked as for the other hormones measured. In both species, plasma T4 tended to increase and plasma T3 to decrease as daylength increased. A small increase in plasma T3 was seen after the development of long-day refractoriness in both species. It is concluded that captivity depresses the photoperiodic response of Svalbard ptarmigan more than that of willow ptarmigan.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3371650

Stokkan, K A; Sharp, P J; Dunn, I C; Lea, R W

1988-04-01

3

Behavioural effects of cadmium (Cd) in free-living willow ptarmigan ( Lagopus lagopus )  

Microsoft Academic Search

The objective of this study was to examine effects of sublethal cadmium (Cd) contamination on parental behaviour and chick\\u000a survival in willow ptarmigan (Lagopus lagopus) in an area that does not have high environmental levels of Cd due to geology but have high environmental levels of Cd due\\u000a to anthropogenic deposition and acidification. One group of willow ptarmigan hens were

Hans Chr. Pedersen; Asgeir Lorås; Rolf A. Andersen; Bjørn M. Jenssen

2010-01-01

4

Late Pleistocene arctic fox ( Alopex lagopus) from Crimea, Ukraine  

Microsoft Academic Search

The teeth and bone fragments of Alopex lagopus of early Weichselian age from Mousterian layers of grotto Prolom 2 in Crimea have been studied. The Crimean fossil arctic fox was found to be smaller than the late Weichselian subspecies, A. l. rossicus, from the East European Plain, but it seems to be similar in dimensions to the recent insular subspecies,

Gennady Baryshnikov

2006-01-01

5

Sequence Polymorphism in Candidate Genes for Differences in Winter Plumage between Scottish and Scandinavian Willow Grouse (Lagopus lagopus)  

PubMed Central

Background Population variation in the degree of seasonal polymorphism is rare in birds, and the genetic basis of this phenomenon remains largely undescribed. Both sexes of Scandinavian and Scottish Willow grouse (Lagopus lagopus) display marked differences in their winter phenotypes, with Scottish grouse retaining a pigmented plumage year-round and Scandinavian Willow grouse molting to a white morph during winter. A widely studied pathway implicated in vertebrate pigmentation is the melanin system, for which functional variation has been characterised in many taxa. Methodology/Principal Findings We sequenced coding regions from four genes involved in melanin pigmentation (DCT, MC1R, TYR and TYRP1), and an additional control involved in the melanocortin pathway (AGRP), to investigate the genetic basis of winter plumage in Lagopus. Despite the well documented role of the melanin system in animal coloration, we found no plumage-associated polymorphism or evidence for selection in a total of ?2.6 kb analysed sequence. Conclusions/Significance Our results indicate that the genetic basis of alternating between pigmented and unpigmented seasonal phenotypes is more likely explained by regulatory changes controlling the expression of these or other loci in the physiological pathway leading to pigmentation.

Skoglund, Pontus; Hoglund, Jacob

2010-01-01

6

A multilocus assay reveals high nucleotide diversity and limited differentiation among Scandinavian willow grouse (Lagopus lagopus)  

PubMed Central

Background There is so far very little data on autosomal nucleotide diversity in birds, except for data from the domesticated chicken and some passerines species. Estimates of nucleotide diversity reported so far in birds have been high (~10-3) and a likely explanation for this is the generally higher effective population sizes compared to mammals. In this study, the level of nucleotide diversity has been examined in the willow grouse, a non-domesticated bird species from the order Galliformes, which also holds the chicken. The willow grouse (Lagopus lagopus) has an almost circumpolar distribution but is absent from Greenland and the north Atlantic islands. It primarily inhabits tundra, forest edge habitats and sub-alpine vegetation. Willow grouse are hunted throughout its range, and regionally it is a game bird of great cultural and economical importance. Results We sequenced 18 autosomal protein coding loci from approximately 15–18 individuals per population. We found a total of 127 SNP's, which corresponds to 1 SNP every 51 bp. 26 SNP's were amino acid replacement substitutions. Total nucleotide diversity (?t) was between 1.30 × 10-4 and 7.66 × 10-3 (average ?t = 2.72 × 10-3 ± 2.06 × 10-3) and silent nucleotide diversity varied between 4.20 × 10-4and 2.76 × 10-2 (average ?S = 9.22 × 10-3 ± 7.43 × 10-4). The synonymous diversity is approximately 20 times higher than in humans and two times higher than in chicken. Non-synonymous diversity was on average 18 times lower than the synonymous diversity and varied between 0 and 4.90 × 10-3 (average ?a = 5.08 × 10-4 ± 7.43 × 103), which suggest that purifying selection is strong in these genes. FST values based on synonymous SNP's varied between -5.60 × 10-4 and 0.20 among loci and revealed low levels of differentiation among the four localities, with an overall value of FST = 0.03 (95% CI: 0.006 – 0.057) over 60 unlinked loci. Non-synonymous SNP's gave similar results. Low levels of linkage disequilibrium were observed within genes, with an average r2 = 0.084 ± 0.110, which is expected for a large outbred population with no population differentiation. The mean per site per generation recombination parameter (?) was comparably high (0.028 ± 0.018), indicating high recombination rates in these genes. Conclusion We found unusually high levels of nucleotide diversity in the Scandinavian willow grouse as well as very little population structure among localities with up to 1647 km distance. There are also low levels of linkage disequilibrium within the genes and the population recombination rate is high, which is indicative of an old panmictic population, where recombination has had time to break up any haplotype blocks. The non-synonymous nucleotide diversity is low compared with the silent, which is in agreement with effective purifying selection, possibly due to the large effective population size.

Berlin, Sofia; Quintela, Maria; Hoglund, Jacob

2008-01-01

7

Effects of fasting and exogenous melatonin on annual rhythms in the blue fox ( Alopex lagopus)  

Microsoft Academic Search

The arctic fox (Alopex lagopus) is a winter-active inhabitant of the high arctic with extreme fluctuations in photoperiod and food availability. The blue fox is a semi-domesticated variant of the wild arctic fox reared for the fur industry. In this study, 48 blue foxes were followed for a year in order to determine the effects of exogenous melatonin and wintertime

Petteri Nieminen; Teija Pyykönen; Juha Asikainen; Jaakko Mononen; Anne-Mari Mustonen

2004-01-01

8

Reduced Metabolic Cost of Locomotion in Svalbard Rock Ptarmigan (Lagopus muta hyperborea) during Winter  

Microsoft Academic Search

The Svalbard rock ptarmigan, Lagopus muta hyperborea experiences extreme photoperiodic and climatic conditions on the Arctic archipelago of Svalbard. This species, however, is highly adapted to live in this harsh environment. One of the most striking adaptations found in these birds is the deposition, prior to onset of winter, of fat stores which may comprise up to 32% of body

John Lees; Robert Nudds; Karl-Arne Stokkan; Lars Folkow; Jonathan Codd; Paul A. Bartell

2010-01-01

9

Organochlorine-induced histopathology in kidney and liver tissue from Arctic fox ( Vulpes lagopus)  

Microsoft Academic Search

The effects of persistent organic pollutants on renal and liver morphology in farmed arctic fox (Vulpes lagopus) were studied under experimental conditions. Control animals received a diet containing pork (Sus scrofa) fat with low amounts of persistent organic pollutants, while the diet of the exposed animals contained whale blubber, ‘naturally’ contaminated with persistent organic pollutants. Polychlorinated biphenyls (PCB) and organochlorine

Christian Sonne; Hans Wolkers; Pall S. Leifsson; Bjørn Munro Jenssen; Eva Fuglei; Øystein Ahlstrøm; Rune Dietz; Maja Kirkegaard; Derek C. G. Muir; Even Jørgensen

2008-01-01

10

Chronic dietary exposure to environmental organochlorine contaminants induces thyroid gland lesions in Arctic foxes ( Vulpes lagopus)  

Microsoft Academic Search

The impact of dietary organochlorine (OC) exposure on thyroid gland pathology was studied in farmed male Arctic foxes (Vulpes lagopus). The exposed group (n=16) was fed a diet based on wild minke whale (Balaenoptera acutorostrata) blubber as a main fat source in order to mimic the exposure to OC cocktails in the Artic environment. This resulted in an exposure of

Christian Sonne; Hans Wolkers; Pall S. Leifsson; Tine Iburg; Bjørn Munro Jenssen; Eva Fuglei; Øystein Ahlstrøm; Rune Dietz; Maja Kirkegaard; Derek C. G. Muir; Even H. Jørgensen

2009-01-01

11

Leucocytozoon lovati infections in wild rock ptarmigan (Lagopus mutus) in Japan.  

PubMed

Leucocytozoon lovati infections were detected in free-flying rock ptarmigan (Lagopus mutus), an endangered species that inhabits alpine areas in Japan. Eight of nine adult birds tested positive for L. lovati infection. For comparison, two captive rock ptarmigans hatched in a breeding facility at the foot of the mountains were examined. Both were negative for L. lovati infection. This is the first report of L. lovati infection in the rock ptarmigan in Japan. PMID:15650105

Hagihara, Mio; Yamaguchi, Tsuyoshi; Kitahara, Masanobu; Hirai, Katsuya; Murata, Koichi

2004-10-01

12

Wooden blocks and straw as environmental enrichments for juvenile blue foxes ( Alopex lagopus )  

Microsoft Academic Search

.   This study was designed to evaluate the enrichment value of a wooden block (30 cm long×4 cm in diameter) and straw for growing\\u000a farm-bred male blue foxes (Alopex lagopus). Comparisons were made between animals provided with these enrichments at 7 weeks and 15 weeks of age. Various behavioural,\\u000a physiological, and haematological variables as well as fur and teeth characteristics were assessed. The foxes

H. T. Korhonen; L. Jauhiainen; P. Niemelä; R. Sauna-aho

2002-01-01

13

Pearsonema (syn Capillaria) plica associated cystitis in a Fennoscandian arctic fox (Vulpes lagopus: a case report.  

PubMed

The bladderworm Pearsonema (syn Capillaria) plica affects domestic dogs and wild carnivores worldwide. A high prevalence in red foxes (Vulpes vulpes) has been reported in many European countries. P. plica inhabits the lower urinary tract and is considered to be of low pathogenic significance in dogs mostly causing asymptomatic infections. However, a higher level of pathogenicity has been reported in foxes. A severe cystitis associated with numerous bladderworms was found in a captive arctic fox (Vulpes lagopus) originating from the endangered Fennoscandian arctic fox population. To our knowledge this is the first description of P. plica infection in an arctic fox. PMID:20540788

Fernández-Aguilar, Xavier; Mattsson, Roland; Meijer, Tomas; Osterman-Lind, Eva; Gavier-Widén, Dolores

2010-01-01

14

Glomerulopathy with renal tubular oxalosis in Japanese rock ptarmigan (Lagopus mutus).  

PubMed

Seven adult Japanese rock ptarmigan (Lagopus mutus) that died on a rearing farm and appeared to have suffered from glomerulopathy with renal tubular oxalosis were examined pathologically. Macroscopically, the kidneys showed enlargement of varying degrees. Histologically, the precipitation of a fibril-like substance in the mesangial area of the renal glomeruli was the most important and common lesion seen in the kidney. Calcification of glomeruli was observed in severe cases. In addition, oxalate precipitation in the lumen of the renal tubules was associated with glomerular lesions. The primary renal lesion may have been glomerulonephropathy, which was subsequently associated with tubular oxalosis as the secondary renal lesion. PMID:16236572

Yoshikawa, Keiichi; Nakamura, Kikuyasu; Aoyagi, Takahiro; Yamada, Manabu

2005-10-01

15

Surgical implantation of radio transmitters in arctic foxes (Alopex lagopus) on Svalbard, Norway.  

PubMed

Twelve captive wild-caught adult arctic foxes (Alopex lagopus) were anesthetized a total of 24 times for an equal number of surgical procedures involving implantation of heart rate (HR) and core body temperature transmitters (Tb) between October 1995 and April 1997. Xylazine-ketamine and medetomidine-ketamine anesthesia was used, resulting in an unacceptably high death rate. One out of four foxes anesthetized with xylazine-ketamine died, whereas two of nine foxes anesthetized with medetomidine-ketamine died out of a total of 20 surgical procedures. Durations of the surgeries for implantation of Tb transmitters and HR transmitters were 73 +/- 7 min and 95 +/- 13 min, respectively. PMID:12564532

Fuglei, Eva; Mercer, James B; Arnemo, Jon M

2002-12-01

16

An Arctic fox (Alopex lagopus) captures a Least Auklet (Aethia pusilla) in the Aleutian Islands.  

NSDL National Science Digital Library

During the 100-150 years since they were introduced to the Aleutian Islands, the Arctic fox (Alopex lagopus) and Norway rat (Rattus norvegicus) have extirpated native seabirds from most of the islands through predation. Burrow nesting species have been particularly affected. The Least Auklet (Aethia pusilla) is an abundant seabird species in the Aleutian Islands. The introduction of foxes and rats to many islands and the subsequent loss of seabirds have indirectly affected other characteristics of island ecosystems, such as soil nutrient levels, plant community composition, and predominant nutrient sources (terrestrial versus marine). This photograph originally appeared on the cover of Ecological Monographs (76:1) in February of 2006.

Degange, Anthony

2010-02-16

17

Arctic Fox (Alopex lagopus) Diet in Karupelv Valley, East Greenland, during a Summer with Low Lemming Density  

Microsoft Academic Search

We investigated the diet of arctic foxes (Alopex lagopus) in the Karupelv valley, East Greenland, during the summer of 1997. Despite a low density, lemmings were the most utilized prey, comprising 65.3% of dry fecal weight in fresh feces. This demonstrates the importance of lemming species as prey for arctic foxes all through a lemming cycle. Birds, arctic hare (Lepus

FREDRIK DALERUM; ANDERS ANGERBJÖRN

2000-01-01

18

Population genetic structure of rock ptarmigan Lagopus mutus in Northern and Western Europe.  

PubMed

Alpine species may be losing habitat because of global warming. Setting management priorities for such species is thus urgent and cannot be achieved without data on population structure. We studied the structure of rock ptarmigan (Lagopus mutus) populations in the Pyrenees, Alps and Norway, using six microsatellites. We found that rock ptarmigan in the Pyrenees were genetically impoverished compared with those in the Alps and Norway, and displayed a greater divergence (Pyrenees vs. Alps or Norway: theta(ST) = 0.16, Alps vs. Norway, theta(ST) = 0.04). In the Alps, despite a weak genetic differentiation between localities up to 200 km apart (theta(ST) = 0.011), a significant isolation-by-distance (IBD) effect was detected. When computed for each sex separately this IBD effect was significant for males but not for females, suggesting that males are highly philopatric. PMID:12859645

Caizergues, A; Bernard-Laurent, A; Brenot, J-F; Ellison, L; Rasplus, J Y

2003-08-01

19

Two Eimeria species isolated from wild Japanese rock ptarmigans (Lagopus mutus japonicus) in Japan.  

PubMed

Fecal samples were collected from 64 Japanese rock ptarmigans (Lagopus mutus japonicus) at 13 locations in the alpine zone of Japan and examined for internal parasites. We found 2 morphologically different types of eimerian oocysts. Based on morphological characteristics, one was identified as Eimeria uekii, which had already been found from Japanese rock ptarmigans in 1981, and the other was likely a new type of Eimeria. The new type of eimerian oocysts required a longer sporulation time than E. uekii. The prevalence of both eimerian oocysts in Japanese rock ptarmigans was 62.5%, while that of E. uekii was 60.9% and the new type 29.7%. Mixed infection of both types was found in 28.1%. PMID:17019072

Ishihara, Sayuri; Shiibashi, Takashi; Sato, Yukita; Murata, Koichi; Nogami, Sadao

2006-09-01

20

Mineral density and biomechanical properties of bone tissue from male Arctic foxes ( Vulpes lagopus) exposed to organochlorine contaminants and emaciation  

Microsoft Academic Search

We investigated the impact from dietary OC (organochlorine) exposure and restricted feeding (emaciation) on bone mineral density (BMD; g hydroxy-apatite cm?2) in femoral, vertebrate, skull and baculum osteoid tissue from farmed Arctic blue foxes (Vulpes lagopus). For femur, also biomechanical properties during bending (displacement [mm], load [N], energy absorption [J] and stiffness [N\\/mm]) were measured. Sixteen foxes (EXP) were fed

Christian Sonne; Hans Wolkers; Frank F. Rigét; Jens-Erik Beck Jensen; Jenni Teilmann; Bjørn Munro Jenssen; Eva Fuglei; Øystein Ahlstrøm; Rune Dietz; Derek C. G. Muir; Even H. Jørgensen

2009-01-01

21

Foods of arctic foxes (Alopex lagopus) during winter and spring in western Alaska  

USGS Publications Warehouse

During 1986-1991, carcasses of 619 arctic fares (Alopex lagopus) collected from local trappers and at biological field camps on the Yukon-Kuskokwim Delta in western Alaska from November through May were analyzed to determine gastrointestinal contents, age, sex, and body condition. Prey in declining order of importance were small mammals (95% tundra voles, Microtus oeconomus), birds, marine mammals, and fishes. Foxes with small mammal remains in their stomachs were captured farther from the Bering Sea coast ((X) over bar = 5.2 km) than those without small-mammal remains (2.8 km); foxes consuming remains of marine mammals were closer to the coast (1.9 km) than others (4.9 km). Although eggshells had a poor likelihood of occurrence in stomachs, they were found in all months and years. In 1986 and 1987, foxes consumed fewer small mammals than in other years. Mean ages of foxes captured in 1986 (3.7 years) and 1987 (3.2) were greater than in all ether years (1.5). Capture of adults was more common as winter progressed. Indexes of subcutaneous fat decreased annually in April-May and were highest in 1991, when occurrence of carrion of marine mammals was highest.

Anthony, M.; Barten, N. K.; Seiser, P. E.

2000-01-01

22

Reduced Metabolic Cost of Locomotion in Svalbard Rock Ptarmigan (Lagopus muta hyperborea) during Winter  

PubMed Central

The Svalbard rock ptarmigan, Lagopus muta hyperborea experiences extreme photoperiodic and climatic conditions on the Arctic archipelago of Svalbard. This species, however, is highly adapted to live in this harsh environment. One of the most striking adaptations found in these birds is the deposition, prior to onset of winter, of fat stores which may comprise up to 32% of body mass and are located primarily around the sternum and abdominal region. This fat, while crucial to the birds' survival, also presents a challenge in that the bird must maintain normal physiological function with this additional mass. In particular these stores are likely to constrain the respiratory system, as the sternum and pelvic region must be moved during ventilation and carrying this extra load may also impact upon the energetic cost of locomotion. Here we demonstrate that winter birds have a reduced cost of locomotion when compared to summer birds. A remarkable finding given that during winter these birds have almost twice the body mass of those in summer. These results suggest that Svalbard ptarmigan are able to carry the additional winter fat without incurring any energetic cost. As energy conservation is paramount to these birds, minimising the costs of moving around when resources are limited would appear to be a key adaptation crucial for their survival in the barren Arctic environment.

Lees, John; Nudds, Robert; Stokkan, Karl-Arne; Folkow, Lars; Codd, Jonathan

2010-01-01

23

Relative importance of male and territory quality in pairing success of male rock ptarmigan (Lagopus mutus)  

USGS Publications Warehouse

We studied pairing success in male rock ptarmigan (Lagopus mutus) in northern Alaska to learn whether males obtaining more females possessed phenotypic traits that influenced female choice directly, whether these traits permitted males to obtain territories favored by females, or whether both processes occurred. The number of females per male varied from zero to three. Several male and territory traits were significantly correlated with number of females per male. We used multiple regression to obtain a single measure of male quality and a single measure of territory quality. These measures of male and territory quality correlated with each other and with male pairing success. We used path analysis to separate direct effects of male quality on pairing success from indirect effects due to high-quality males obtaining high-quality territories. Both direct and indirect pathways had significant effects on pairing success, and direct and indirect effects of male traits on pairing success were about equal. This study illustrates an analytical approach for estimating the relative importance of direct and indirect causal relationships in natural systems.

Bart, Jonathan; Earnst, Susan L.

1999-01-01

24

Glacial vicariance and historical biogeography of rock ptarmigan (Lagopus mutus) in the Bering region.  

PubMed

In this paper, we address alternative hypotheses for the evolution of subspecies of rock ptarmigan (Lagopus mutus) endemic to the Aleutian Archipelago. To do this we examined patterns of genetic differentiation among populations of rock ptarmigan in the Aleutian Islands and parts of both Alaska and Siberia. Variation in mitochondrial control region sequences of 105 rock ptarmigan from 10 subspecies within the Bering region revealed three major phylogenetic lineages, two of which are endemic to the Aleutian Islands. Accordingly, haplotype and nucleotide diversities of rock ptarmigan within the archipelago are much higher than within mainland Alaska or Siberia. For Aleutian rock ptarmigan, analyses of molecular variance indicated significant genetic structuring and low estimates of gene flow among populations, despite small interisland distances within the archipelago. However, isolation by distance did not describe the pattern of gene flow or differentiation at this scale. Our estimates of divergence times of lineages suggest that Aleutian rock ptarmigan became isolated prior to the most recent Pleistocene glaciation event (late Wisconsin Stade) and that current patterns of genetic variation reflect the postglacial redistribution of divergent lineages and subsequent limited gene flow. In addition, genetic divergence among lineages was concordant with the distribution of plumage types among subspecies. The patterns of genetic variation described here for rock ptarmigan provide evidence for the role of glacial vicariance in contributing to genetic diversity within this and other Bering region species. PMID:10972767

Holder, K; Montgomerie, R; Friesen, V L

2000-09-01

25

Endocrine changes associated with fat deposition and mobilization in svalbard ptarmigan (Lagopus mutus hyperboreus).  

PubMed

Plasma concentrations of Triiodothyronine (T3), thyroxine (T4) and growth hormone (GH) have been measured in blood samples taken from Svalbard ptarmigans (Lagopus mutus hyperboreus), shot throughout 1 whole year at Svalbard (79 degrees N). Plasma T3 levels varied in a monophasic pattern with low levels in winter and a peak in August, whereas plasma T4 levels remained constant throughout the year. High plasma T3 levels coincide with molt and a large food intake while low plasma levels of T3 coincide with molt arrest and a low food intake. Plasma GH levels were highest in winter and lowest in May and September. The low plasma GH levels in early autumn coincide with elevated liver weights and maximum rate of fat deposition. High GH levels in midwinter coincide with low liver weights and the mobilization of fat stores. A possible relationship between molt, food intake, fat deposition/mobilization, and plasma levels of T3 and GH is discussed. PMID:3988037

Stokkan, K A; Harvey, S; Klandorf, H; Unander, S; Blix, A S

1985-04-01

26

The annual breeding cycle of the high-arctic Svalbard ptarmigan (Lagopus mutus hyperboreus).  

PubMed

Gonadal size, spermatogenesis, egg production, height of the supraorbital comb, moult, and plasma luteinizing hormone (LH) levels were measured during an annual cycle in wild Svalbard ptarmigans (Lagopus mutus hyperboreus). These birds live permanently at 77-81 degrees N where daylight is continuous from the beginning of April until mid September while the average ambient temperature is above freezing only between early June and mid September. The gonads and comb size began to enlarge in March coinciding with an increase in plasma LH, but sperm production and egg laying did not begin until the end of May and early June, respectively. This long lag between the onset of reproductive functions and the time of breeding reflects a slow rate of gonadal growth which may be caused by nonphotoperiodic, inhibitory input from the environment. Gonadal regression occurred in July and was associated with a steep decline in plasma LH levels indicating that the birds became long-day refractory. A moult from white to pigmented plumage occurred in females at the beginning and in males towards the end of the breeding season. This observation is consistent with the notion of an inhibitory effect of testosterone on moult in the males. Both sexes moulted simultaneously into white plumage in late September/early October. PMID:3956996

Stokkan, K A; Sharp, P J; Unander, S

1986-03-01

27

Organochlorine-induced histopathology in kidney and liver tissue from Arctic fox (Vulpes lagopus).  

PubMed

The effects of persistent organic pollutants on renal and liver morphology in farmed arctic fox (Vulpes lagopus) were studied under experimental conditions. Control animals received a diet containing pork (Sus scrofa) fat with low amounts of persistent organic pollutants, while the diet of the exposed animals contained whale blubber, 'naturally' contaminated with persistent organic pollutants. Polychlorinated biphenyls (PCB) and organochlorine pesticide (OCP) concentrations in the whale blubber were 488 and 395 ng/g wet weight, respectively. Animals were sacrificed and sampled when they were at their fattest (winter) as well as their lowest body weight (summer). The results show that PCB and OCP exposure causes renal (and probably also liver) lesions in arctic foxes. The prevalence of glomerular, tubular and interstitial lesions was significantly highest in the exposed group (chi-square: all p<0.05). The frequency of liver lesions (steatosis, intravascular granulocyte accumulations, interstitial cell infiltrations, lipid granulomas, portal fibrosis and bile duct hyperplasia) were also highest in the exposed group, although not significantly (chi-square: all p>0.05). The prevalence of lesions was not significantly different between lean (winter) and fat (summer) foxes for any of the lesions (chi-square: all p>0.05). We suggest that wild arctic foxes exposed to an environmental cocktail of persistent organic pollutants, such as PCBs and OCPs, in their natural diet are at risk for developing chronic kidney and liver damage. Whether such lesions may have an impact on age and health of the animals remains uncertain. PMID:18279914

Sonne, Christian; Wolkers, Hans; Leifsson, Pall S; Jenssen, Bjørn Munro; Fuglei, Eva; Ahlstrøm, Oystein; Dietz, Rune; Kirkegaard, Maja; Muir, Derek C G; Jørgensen, Even

2008-04-01

28

Seasonal differences in jump performance in the Svalbard rock ptarmigan (Lagopus muta hyperborea)  

PubMed Central

ABSTRACT Fat storage is essential to the survival of many bird species, providing energy reserves, but can have an effect on locomotor performance with an associated potential increase in predation risk. In particular, the ability to initiate flight through jumping is critical to predator avoidance and may be influenced by changes in body mass (Mb). Here we investigate seasonal differences in the jump take-off performance of high Arctic Svalbard rock ptarmigan (Lagopus muta hyperborea) resulting from around a 50% increase in Mb during winter as a result of fat deposition. Using force-plate data and videography, we reveal that, in the absence of alterations to take-off angle, winter Svalbard rock ptarmigan are unable to increase hind-limb power output during jumping to compensate for their increased Mb. As a result, peak take-off velocity is reduced by 42% and jump duration is also extended during winter. The consequences of reduced jumping performance upon Svalbard ptarmigan during winter may be relatively small given their low risk of predation during this season. It may be, however, that the observed reduction in jumping performance when fat may contribute to the sub-maximal pattern of fat acquisition observed in other bird species.

Lees, John J.; Folkow, Lars P.; Codd, Jonathan R.; Nudds, Robert L.

2014-01-01

29

Seasonal differences in jump performance in the Svalbard rock ptarmigan (Lagopus muta hyperborea).  

PubMed

Fat storage is essential to the survival of many bird species, providing energy reserves, but can have an effect on locomotor performance with an associated potential increase in predation risk. In particular, the ability to initiate flight through jumping is critical to predator avoidance and may be influenced by changes in body mass (Mb). Here we investigate seasonal differences in the jump take-off performance of high Arctic Svalbard rock ptarmigan (Lagopus muta hyperborea) resulting from around a 50% increase in Mb during winter as a result of fat deposition. Using force-plate data and videography, we reveal that, in the absence of alterations to take-off angle, winter Svalbard rock ptarmigan are unable to increase hind-limb power output during jumping to compensate for their increased Mb. As a result, peak take-off velocity is reduced by 42% and jump duration is also extended during winter. The consequences of reduced jumping performance upon Svalbard ptarmigan during winter may be relatively small given their low risk of predation during this season. It may be, however, that the observed reduction in jumping performance when fat may contribute to the sub-maximal pattern of fat acquisition observed in other bird species. PMID:24659246

Lees, John J; Folkow, Lars P; Codd, Jonathan R; Nudds, Robert L

2014-01-01

30

Two cysteine substitutions in the MC1R generate the blue variant of the arctic fox ( Alopex lagopus) and prevent expression of the white winter coat  

Microsoft Academic Search

We have characterized two mutations in the MC1R gene of the blue variant of the arctic fox (Alopex lagopus) that both incorporate a novel cysteine residue into the receptor. A family study in farmed arctic foxes verified that the dominant expression of the blue color phenotype cosegregates completely with the allele harboring these two mutations. Additionally to the altered pigment

Dag Inge Våge; Eva Fuglei; Kristin Snipstad; Janne Beheim; Veslemøy Malm Landsem; Helge Klungland

2005-01-01

31

Gastrointestinal helminths of Arctic foxes (Alopex lagopus) from different bioclimatological regions in Greenland.  

PubMed

Nine species of gastrointestinal helminths were recovered from 254 arctic foxes (Alopex lagopus) from 8 different localities in Greenland. Prevalences of infection with the helminth species differed from area to area: Toxascaris leonina (39-68%), Strongyloides stercoralis (0-14%), Mesocestoides lineatus (0-58%), Diphyllobothrium dendriticum (0-15%), Taenia ovis krabbei (0-70%), Cryptocotyle sp. (0-3%), Plagiorchis elegans (0-6%), and Polymorphus sp. (0-3%). Additionally, a Taenia species, which appears to be different from T. ovis krabbei, had a prevalence of 24% but only on the east coast of Greenland. In general, the composition of the helminth fauna of arctic foxes in Greenland showed distinct differences geographically. Thus, the diversity of helminth species in foxes caught in the northern districts of Greenland seems lower than in the southern districts; only nematode species with direct life cycles were represented equally in all parts of the country. The diversity of the surrounding fauna, and thereby the food items available for the foxes, seems to determine the spectrum of helminth species. Helminths requiring rodents as intermediate hosts were absent on the west coast, even in the areas in northwest Greenland in close proximity to the Canadian Archipelago. Foxes from air bases, which are known to feed intensively on garbage, harbored similar numbers of species compared to foxes from settlements in the same regions. The number of T. leonina in animals less than 1 yr of age was significantly higher than in older individuals. For M. lineatus, the prevalence of infection was found to increase and worm burdens to decrease with increasing host age. Infections with 2 or more helminth species were most frequent in older animals (47% in foxes > or = 4 yr old and 33% in foxes < 4 yr old). PMID:8627489

Kapel, C M; Nansen, P

1996-02-01

32

Is alloparenting helpful for Mednyi Island arctic foxes, Alopex lagopus semenovi?  

NASA Astrophysics Data System (ADS)

The Arctic Fox Alopex lagopus semenovi population on Mednyi Island is completely isolated and subsists largely by scavenging on seabird colonies, which have remained abundant and spatio-temporally predictable for many years. We compared population data at the beginning of 1976/1978 and some time after 1994-2005, finding an 85% decline in fox numbers due to disease, to assess the effect of population size on social structure. A total of 81 groups of known size and composition was observed during this 29-year period. Overall, helpers (usually non-lactating yearling females) occurred in 25.7% of groups, and in 32.4% of groups there were two or three lactating females. Female engagement in alloparental behaviour decreased, but not statistically significantly, after the decline in population density. Total food availability was apparently constant throughout the study period, and therefore, the amount available per individual was much higher later in the study. Both communally nursing females and helpers brought food and helped to guard the litter. However, the benefits of communal rearing were unclear. While cubs were left without guards significantly more rarely in the groups with an additional adult, the number of cubs weaned per lactating female was greater in groups with one (3.93 ± 1.60), as opposed to two or three (3.06 ± 0.92), lactating females. Survival of cubs to 1 year of age in the groups with two lactating females and/or with helpers was lower than that in the families with one lactating female without helpers (22.2% vs 32.2%). Fewer second-generation litters were born to foxes produced by composite families than to those produced by pairs. Reproductive adults producing by pairs had, on average, 1.23 (±1.72) second-generation litters. In groups that initially included additional adults, the average number of second-generation litters per reproductive female was 0.21 (±0.49) and 0.46 (±0.81) litters per male. Thus, according to three measures, increased group size had no apparent positive impact on reproductive success. The increased parental investment and enhanced guarding of the cubs in the larger families could be beneficial under conditions of high population density and a saturated biotope to which the island fox population was presumably adapted before the population crash in the late 1970s.

Kruchenkova, Elena P.; Goltsman, Michael; Sergeev, Sergei; MacDonald, David W.

2009-04-01

33

Allelic expression in intergeneric fox hybrids ( Alopex lagopus × Vulpes vulpes ). III. Regulation of the expression of the parental alleles at the Gpd locus linked to the X chromosome  

Microsoft Academic Search

The electrophoretic pattern of glucose-6-phosphate dehydrogenase (G6PD) was studied in 60 intergeneric fox hybrids (Alopex lagopus × Vulpes vulpes), 33 females and 27 males. It is shown that the structural gene for G6PD, designated Gpd, is located on the X chromosome in both Arctic and silver foxes. Analysis of G6PD patterns in the erythrocytes of hybrid females demonstrated that the

O. L. Serov; S. M. Zakijan; V. A. Kulichkov

1978-01-01

34

Seasonal emaciation causes tissue redistribution and an increased potential for toxicity of lipophilic pollutants in farmed arctic fox (Vulpes lagopus).  

PubMed

Many Arctic animals carry high body burdens of organochlorine contaminants (OCs) as a result of long-range transport of persistent pollutants. It has been shown that seasonal mobilization of body fat in these species results in increased blood concentration of OCs. The authors investigated OC assimilation, tissue distribution, and biotransformation in farmed Arctic fox (Vulpes lagopus) continuously fed a diet containing contaminated minke whale blubber or lard (control) from 8 wk of age in August 2003, until sampling when they were at their fattest (in November 2004) and leanest (in June 2005). Markedly higher tissue (liver, adrenals, brain, and blood) OC levels were found in June than in November despite low exposure to OCs during emaciation, suggesting that OCs had been redistributed from adipose tissues to vital organs. There were no differences in the activities of hepatic biotransforming enzymes between exposed fat and control fat foxes, except for 16?-hydroxylation, which was higher in exposed fat foxes. In emaciated foxes, ethoxyresorufin activity was higher in exposed than in control foxes, indicating an enhanced potential for toxicity of OCs with emaciation. Lower activities of 6?- and 2?-hydroxylation were found in lean than in fat foxes, irrespective of OC treatment. The results show that emaciation increase the toxic potential of accumulated OCs and emphasize that body adiposity must be considered when time-trend analyses, risk assessments, and effect studies are designed. Environ Toxicol Chem 2013;32:1784-1792. © 2013 SETAC. PMID:23606128

Helgason, Lisa B; Wolkers, Hans; Fuglei, Eva; Ahlstrøm, Oystein; Muir, Derek; Jørgensen, Even H

2013-08-01

35

Impact of historical founder effects and a recent bottleneck on MHC variability in Commander Arctic foxes (Vulpes lagopus)  

PubMed Central

Populations of Arctic foxes (Vulpes lagopus) have been isolated on two of the Commander Islands (Bering and Mednyi) from the circumpolar distributed mainland population since the Pleistocene. In 1970–1980, an epizootic outbreak of mange caused a severe population decline on Mednyi Island. Genes of the major histocompatibility complex (MHC) play a primary role in infectious disease resistance. The main objectives of our study were to compare contemporary variation of MHC class II in mainland and island Arctic foxes, and to document the effects of the isolation and the recent bottleneck on MHC polymorphism by analyzing samples from historical and contemporary Arctic foxes. In 184 individuals, we found 25 unique MHC class II DRB and DQB alleles, and identified evidence of balancing selection maintaining allelic lineages over time at both loci. Twenty different MHC alleles were observed in mainland foxes and eight in Bering Island foxes. The historical Mednyi population contained five alleles and all contemporary individuals were monomorphic at both DRB and DQB. Our data indicate that despite positive and diversifying selection leading to elevated rates of amino acid replacement in functionally important antigen-binding sites, below a certain population size, balancing selection may not be strong enough to maintain genetic diversity in functionally important genes. This may have important fitness consequences and might explain the high pathogen susceptibility in some island populations. This is the first study that compares MHC diversity before and after a bottleneck in a wild canid population using DNA from museum samples.

Ploshnitsa, Anna I; Goltsman, Mikhail E; Macdonald, David W; Kennedy, Lorna J; Sommer, Simone

2012-01-01

36

The digestion of bulbils (Polygonum viviparum L.) and berries (Vaccinium myrtillus L. and Empetrum sp.) by captive ptarmigan (Lagopus mutus).  

PubMed

1. The digestion of three foods favoured by ptarmigan (Lagopus mutus) in the wild was studied using captive birds. 2. Bulbils of Polygonum viviparum L. were a good source of metabolizable energy, protein and phosphorus, but were deficient in sodium. Berries of Vaccinium myrtillus L. were the most digestible of the three foods, contained enough protein and P for maintenance, but were probably deficient in Na. A diet of Empetrum sp. berries caused the birds to be in negative nitrogen and P balance, but provided adequate Na. Both species of berries were rich sources of soluble carbohydrate. 3. In the wild, ptarmigan eat a mixed diet, which presumably provides adequate Na, protein and P. 4. The relative proportions of the various end-products of N metabolism varied according to the protein content of the food. With the diet of Vaccinium berries (11 g N/kg dry matter) roughly equal amounts of ammonium salts and urates were excreted. With Polygonum bulbils (29 g N/kg dry matter) the quantities of ammonium salts and urates excreted were similar to those with Vaccinium berries, but some urea was also excreted and about half the N in the birds' droppings was in an unidentified form. 5. When eating Empetrum berries, ptarmigan digested lignin and tannins and excreted ornithurates. The benzoic acid moiety of the ornithuric acid molecule may have been derived partly from the digested lignin and tannins. PMID:1167787

Moss, R; Parkinson, J A

1975-03-01

37

Seasonal and daily variations in plasma melatonin in the high-arctic Svalbard ptarmigan (Lagopus mutus hyperboreus).  

PubMed

This study presents the daily rhythm of melatonin secretion throughout one year in a bird from the northern hemisphere, the Svalbard ptarmigan (Lagopus mutus hyperboreus), which lives naturally at 76-80 degrees N. Eight Svalbard ptarmigan were caged outdoors at 70 degrees N and blood sampled throughout one day each month for 13 months. At this latitude, daylight is continuous between May and August, but there is a short period of civil twilight around noon from late November to mid January. There was no daily rhythm in plasma melatonin in May-July. Plasma melatonin levels varied significantly throughout the day in all other months of the year, with the nighttime increase reflecting the duration of darkness. The highest mean plasma concentration occurred at midnight in March (110.1 +/- 16.5 pg/ml) and represented the annual peak in estimated daily production. Around the winter solstice, melatonin levels were significantly reduced at noon and elevated during the nearly 18 h of consecutive darkness, and the estimated mean daily production of melatonin was significantly reduced. Thus, at the times of the year characterized by light-dark cycles, melatonin may convey information concerning the length of the day and, therefore, progression of season. The nearly undetectable low melatonin secretion in summer and the reduced amplitude and production in midwinter indicate a flexible circadian system that may reflect an important adaptation to life in the Arctic. PMID:10447312

Reierth, E; Van't Hof, T J; Stokkan, K A

1999-08-01

38

Glomerular lipidosis accompanied by renal tubular oxalosis in wild and laboratory-reared Japanese rock ptarmigans (Lagopus mutus japonicus).  

PubMed

Glomerular lipidosis is a disease characterized by lipid accumulation in mesangial cells but that has not been fully investigated in avian species. We examined four wild and two laboratory-reared Japanese rock ptarmigans (Lagopus mutus japonicus)--an endangered avian species--presenting vacuolar deposits in the glomeruli. All cases had vacuolar deposits in the glomeruli. In the wild cases, fewer than 30% of all glomeruli were affected, compared with more than 90% in the laboratory-reared cases. In the wild cases, most deposits were mild and restricted to the mesangial areas of glomeruli. In the laboratory-reared cases, nearly all of the deposits covered entire glomeruli. Electron microscopy of mild deposits revealed vacuoles in the cytoplasm of mesangial cells. These vacuoles were positive for Sudan III, Sudan black B, oil red O, Nile blue, periodic acid-Schiff, Schultz test, and digitonin stain and were negative for performaric acid-Schiff stains. Based on these results, we diagnosed the glomerular lesion as glomerular lipidosis caused by uptake of low-density lipoprotein in mesangial cells. Except for one wild case, all cases exhibited renal tubular oxalosis. The severity of tubular oxalosis tended to be related to the severity of glomerular lipidosis: In cases of mild glomerular lipidosis, tubular oxalosis was also mild or absent. We therefore diagnosed the primary lesion as glomerular lipidosis accompanied by tubular oxalosis. The four wild cases came from different zones and therefore had no opportunities to interbreed and no common relatives. We believe these data support the hypothesis that glomerular lipidosis is a disease of the general population ofJapanese rock ptarmigans. This is the first report of glomerular lipidosis accompanied by renal tubular oxalosis in an avian species. PMID:22312998

Murai, Atsuko; Murakami, Mami; Sakai, Hiroki; Shimizu, Hiroaki; Murata, Koichi; Yanai, Tokuma

2011-12-01

39

Dietary contaminant exposure affects plasma testosterone, but not thyroid hormones, vitamin A, and vitamin E, in male juvenile arctic foxes (Vulpes lagopus).  

PubMed

Levels of persistent organic pollutants (POP), such as polychlorinated biphenyls (PCB), are high in many Arctic top predators, including the Arctic fox (Vulpes lagopus). The aim of this study was to examine possible endocrine-disruptive effects of dietary POP exposure in male juvenile Arctic foxes in a controlled exposure experiment. The study was conducted using domesticated farmed blue foxes (Vulpes lagopus) as a model species. Two groups of newly weaned male foxes received a diet supplemented with either minke whale (Baleneoptera acutorostrata) blubber that was naturally contaminated with POP (exposed group, n?=?5 or 21), or pork (Sus scrofa) fat (control group, n?=?5 or 21). When the foxes were 6 mo old and had received the 2 diets for approximately 4 mo (147 d), effects of the dietary exposure to POP on plasma concentrations of testosterone (T), thyroid hormones (TH), thyroid-stimulating hormone (TSH), retinol (vitamin A), and tocopherol (viramin E) were examined. At sampling, the total body concentrations of 104 PCB congeners were 0.1 ± 0.03 ?g/g lipid weight (l.w.; n?=?5 [mean ± standard deviation]) and 1.5 ± 0.17 ?g/g l.w. (n?=?5) in the control and exposed groups, respectively. Plasma testosterone concentrations in the exposed male foxes were significantly lower than in the control males, being approximately 25% of that in the exposed foxes. There were no between-treatment differences for TH, TSH, retinol, or tocopherol. The results suggest that the high POP levels experienced by costal populations of Arctic foxes, such as in Svalbard and Iceland, may result in delayed masculine maturation during adolescence. Sex hormone disruption during puberty may thus have lifetime consequences on all aspects of reproductive function in adult male foxes. PMID:23030655

Hallanger, Ingeborg G; Jørgensen, Even H; Fuglei, Eva; Ahlstrøm, Øystein; Muir, Derek C G; Jenssen, Bjørn Munro

2012-01-01

40

Geographical distribution and seasonality of the prevalence of Leucocytozoon lovati in Japanese rock ptarmigans (Lagopus mutus japonicus) found in the alpine regions of Japan.  

PubMed

In this study, we investigated the geographical distribution and seasonality of Leucocytozoon lovati infection in the Japanese rock ptarmigan (Lagopus mutus japonicus); this bird is one of the special natural monuments of Japan that inhabits the Japanese alpine regions. We examined blood samples from birds captured in the Kubiki, Hida, and Akaishi mountain ranges for three years from 2002 to 2005. Seventy-three blood samples from 42 males, 19 females, and 12 birds of unknown sex were used for this study. The rate of infection with L. lovati was 78.1% in the 73 birds examined. We demonstrated that the L. lovati infection was distributed across wide ranges of ptarmigan populations from the northern to the southern alpine zones. There was no sex bias in the prevalence ratio. The prevalence of L. lovati and the level of parasitization of the blood cells tended to increase from spring through summer; in contrast, a decrease was observed from summer through autumn. Although L. lovati infection was observed in a number of local populations inhabiting three mountainous regions, no infected birds were found in Mt. Johnen-dake and Mt. Maejohnen-dake. It is necessary to continue surveying the relationship between the population dynamics of the ptarmigan and the density of the arthropod vector from the perspective of in situ conservation of this endangered species. PMID:17339762

Murata, Koichi; Tamada, Asumi; Ichikawa, Yoko; Hagihara, Mio; Sato, Yukita; Nakamura, Hiroshi; Nakamura, Masahiko; Sakanakura, Takaaki; Asakawa, Mitsuhiko

2007-02-01

41

The metabolic cost of incline locomotion in the Svalbard rock ptarmigan (Lagopus muta hyperborea): the effects of incline grade and seasonal fluctuations in body mass.  

PubMed

In a terrestrial environment animals must locomote over varying terrain; despite this, the majority of studies of animal locomotion focus on level locomotion. The influence moving up an inclined surface has on the metabolic cost of locomotion and the efficiency with which animals perform positive work against gravity is still not well understood. Generally speaking, existing data sets lack consistency in the use of grades, further compounded by differences between species in terms of morphology and locomotor gait. Here we investigated the metabolic cost of locomotion using respirometry in the Svalbard ptarmigan (Lagopus muta hyperborea). The Svalbard ptarmigan provides a unique opportunity to investigate the cost of incline locomotion as it undergoes a seasonal fluctuation in body mass, which doubles in winter, meaning the requirement for positive mechanical work also fluctuates with season. We demonstrate that at the same degree of incline, the cost of lifting 1 kg by 1 vertical metre remains relatively constant between seasons despite the large differences in body mass from summer to winter. These findings are consistent with the notion that positive mechanical work alone dictates the cost of lifting above a certain body mass. However, our data indicate that this cost may vary according to the degree of incline and gait. PMID:23264484

Lees, John; Folkow, Lars; Stokkan, Karl-Arne; Codd, Jonathan

2013-04-15

42

Habitat loss and raptor predation: disentangling long- and short-term causes of red grouse declines  

Microsoft Academic Search

The number of red grouse ( Lagopus lagopus scoticus ) shot in the UK has declined by 50% during the 20th century. This decline has coincided with reductions in the area of suitable habitat and recoveries in the populations of some avian predators. Here we use long-term records of shooting bags and a large-scale manipulation of raptor density to disentangle

Simon J. Thirgood; Steve M. Redpath; Daniel T. Haydon; Peter Rothery; Ian Newton; Peter J. Hudson

2000-01-01

43

The association of grouse moor in Scotland with the illegal use of poisons to control predators  

Microsoft Academic Search

In the UK uplands, there is a conflict between the maintenance of high densities of red grouse (Lagopus lagopus scoticus) for sporting shoots and the conservation of birds of prey on grouse moors where shoots take place. Several authors have indicated that as a result of this conflict, illegal use of poisoned baits to control predators is more likely to

D. Philip Whitfield; David R. A McLeod; Jeff Watson; Alan H Fielding; Paul F Haworth

2003-01-01

44

An Experimental Evaluation of the Arctic Fox (Alopex lagopus) as a Seed Disperser  

Microsoft Academic Search

Arctic foxes are evaluated as seed dispersal vectors for Greenlandic plant species through a feeding experiment with subsequent scat analysis and germination test. Seeds of 22 common species with different morphology were tested. Passage time ranged between 4 and 48 h. No significant differences were detected in passage time for seeds with different morphology. Cerastium alpinum and Stellaria longipes had

Bente J. Graae; Sussie Pagh; Hans Henrik Bruun

2004-01-01

45

Handling during pregnancy in the blue fox (Alopex lagopus): the influence on the fetal gonadal function.  

PubMed

In previous studies it has been shown that handling produced stress in pregnant blue fox vixens increasing plasma level and adrenal in vitro production of cortisol. Moreover, this treatment increased plasma cortisol levels in the fetuses. The present study was designed to examine effects of a 1-min daily handling stress applied to pregnant blue fox vixens on fetal gonadal steroidogenesis. Plasma concentrations of oestradiol and testosterone, gonadal content and gonadal in vitro production of these steroids, and response to exogenous hCG as well as gonadal weights, and anogenital distances were measured in control (C, n=69) and stressed (S, n=54) fetuses on 47-48 days of pregnancy. Maternal stress induced a suppression of gonadal steroidogenesis in the fetuses. The decreased testosterone content in the testes and oestradiol content in the ovaries were demonstrated in stressed fetuses compared with control (testosterone: 4.91+/-0.46 vs. 7.35+/-0.87 ng/both testes, P<0.05; oestradiol: 29.1+/-3.4 vs. 46.5+/-4.9 ng/both ovaries, P<0.05). The ovarian oestradiol in vitro production in female fetuses from stressed mothers was decreased in comparison with control (3.69+/-0.39 vs. 7.52+/-1.51 pg/ovary/h, P<0.05). The same difference was observed between stressed and control male fetuses in the testosterone testicular response to hCG (5.34+/-0.64 vs. 8.73+/-0.40 ng/testis/h, P<0.05). The ovarian weight from stressed fetuses was lower in comparison with control (12.9+/-0.7 vs. 16.8+/-0.6 mg, P<0.05). The anogenital distance in female fetuses from stressed vixens was also reduced (0.6+/-0.03 vs. 0.8+/-0.02 cm, P<0.01). These results indicate that prenatal stress resulted in a significant reduction of hormonal and morphometric measures of the reproductive system in blue fox fetuses with more drastic effects in female fetuses. PMID:12812765

Osadchuk, Ludmila V; Braastad, Bjarne O; Hovland, Anna-Lena; Bakken, Morten

2003-06-15

46

Evidence for energy savings from aerial running in the Svalbard rock ptarmigan (Lagopus muta hyperborea)  

PubMed Central

Svalbard rock ptarmigans were walked and run upon a treadmill and their energy expenditure measured using respirometry. The ptarmigan used three different gaits: a walking gait at slow speeds (less than or equal to 0.75 m s?1), grounded running at intermediate speeds (0.75 m s?1 < U < 1.67 m s?1) and aerial running at high speeds (greater than or equal to 1.67 m s?1). Changes of gait were associated with reductions in the gross cost of transport (COT; J kg?1 m?1), providing the first evidence for energy savings with gait change in a small crouched-postured vertebrate. In addition, for the first time (excluding humans) a decrease in absolute metabolic energy expenditure (rate of O2 consumption) in aerial running when compared with grounded running was identified. The COT versus U curve varies between species and the COT was cheaper during aerial running than grounded running, posing the question of why grounded running should be used at all. Existing explanations (e.g. stability during running over rocky terrain) amount to just so stories with no current evidence to support them. It may be that grounded running is just an artefact of treadmill studies. Research investigating the speeds used by animals in the field is sorely needed.

Nudds, R. L.; Folkow, L. P.; Lees, J. J.; Tickle, P. G.; Stokkan, K.-A.; Codd, J. R.

2011-01-01

47

Dual entrainment by light and food in the Svalbard ptarmigan (Lagopus mutus hyperboreus).  

PubMed

The possibility that feeding may act as a zeitgeber has been investigated in captive Svalbard ptarmigan by recording feeding or food-searching activity (FA) in birds given periodic access to food (PAF) under light-dark (LD) cycles or in continuous bright (LL) or dim light (DD) conditions. Except during LL, anticipatory attempts to feed always occurred prior to the food access interval with a relatively stable phase relationship to the interval. There was always a second bout of feeding toward the end of the food access interval, which apparently corresponds to the afternoon bout of feeding, seen under LD and ad libitum access to food. During PAF, this afternoon peak of activity disappeared. When the LD cycle was phase delayed while restricted access to food remained unchanged, the afternoon peak of feeding was temporarily reestablished but was transiently shifted forward to reattain its position within the food access interval. After termination of PAF, the afternoon bout of feeding was reestablished through phase-delaying transients, with an initial phase corresponding to the previous food access interval. The results suggest that FA of Svalbard ptarmigan is controlled by 2 separate circadian oscillators, both of which can be entrained by light and food: a putative morning oscillator, which controls the activity associated with the beginning of the photoperiod or the food access interval, and a putative evening oscillator, which induces increased activity toward the end of these intervals. In their natural environment at very high latitudes, Svalbard ptarmigan deposit fat when the day length declines rapidly in autumn. Entrained by feeding, they appear to enjoy a longer daily period of food-searching activity than if day length was the only zeitgeber. PMID:9783230

Reierth, E; Stokkan, K A

1998-10-01

48

Den use by arctic foxes (Alopex lagopus) in a subarctic region of western Alaska  

USGS Publications Warehouse

Distribution, abundance, and use of arctic fox dens located in coastal tundra communities of the Yukon-Kuskokwim delta were determined in studies from 1985 to 1990. Dens were denser and less complex than those described in studies conducted above the Arctic Circle. Eighty-three dens of varying complexity were found in the 52-km2 study area. Nineteen dens were used by arctic foxes for whelping or rearing pups. Three females relocated litters to multiple dens; a maximum of four dens were used concurrently by pups from one litter. Although red foxes were common in the region, their use of dens in the study area was minimal. Differences in vegetation at den sites and nearby unoccupied sites were minimal. Furthermore, den sites could not be distinguished from non-den sites during aerial surveys.

Anthony, R. M.

1996-01-01

49

Kinematics and Subpopulations' Structure Definition of Blue Fox (Alopex lagopus) Sperm Motility using the ISAS(®) V1 CASA System.  

PubMed

Over recent years, technological advances have brought innovation in assisted reproduction to the agriculture. Fox species are of great economical interest in some countries, but their semen characteristics have not been studied enough. To advance the knowledge of function of fox spermatozoa, five samples were obtained by masturbation, in the breeding season. Kinetic analysis was performed using ISAS(®) v1 system. Usual kinematic parameters (VCL, VSL, VAP, LIN, STR, WOB, ALH and BCF) were considered. To establish the standardization for the analysis of samples, the minimum number of cells to analyse and the minimum number of fields to capture were defined. In the second step, the presence of subpopulations in blue fox semen was analysed. The minimum number of cells to test was 30, because kinematic parameters remained constant along the groups of analysis. Also, the effectiveness of ISAS(®) D4C20 counting chamber was studied, showing that the first five squares presented equivalent results, while in the squares six and seven, the kinematic parameters showed a reduction in all of them, but not in the concentration or motility percentage. Kinematic variables were grouped into two principal components (PC). A linear movement characterized PC1, while PC2 showed an oscillatory movement. Three subpopulations were found, varying in structure among different animals. PMID:24890953

Soler, C; García, A; Contell, J; Segervall, J; Sancho, M

2014-08-01

50

A base substitution in the donor site of intron 12 of KIT gene is responsible for the dominant white coat colour of blue fox (Alopex lagopus).  

PubMed

The dominant white coat colour of farmed blue fox is inherited as a monogenic autosomal dominant trait and is suggested to be embryonic lethal in the homozygous state. In this study, the transcripts of KIT were identified by RT-PCR for a dominant white fox and a normal blue fox. Sequence analysis showed that the KIT transcript in normal blue fox contained the full-length coding sequence of 2919 bp (GenBank Acc. No KF530833), but in the dominant white individual, a truncated isoform lacking the entire exon 12 specifically co-expressed with the normal transcript. Genomic DNA sequencing revealed that a single nucleotide polymorphism (c.1867+1G>T) in intron 12 appeared only in the dominant white individuals and a 1-bp ins/del polymorphism in the same intron showed in individuals representing two different coat colours. Genotyping results of the SNP with PCR-RFLP in 185 individuals showed all 90 normal blue foxes were homozygous for the G allele, and all dominant white individuals were heterozygous. Due to the truncated protein with a deletion of 35 amino acids and an amino acid replacement (p.Pro623Ala) located in the conserved ATP binding domain, we propose that the mutant receptor had absent tyrosine kinase activity. These findings reveal that the base substitution at the first nucleotide of intron 12 of KIT gene, resulting in skipping of exon 12, is a causative mutation responsible for the dominant white phenotype of blue fox. PMID:24308634

Yan, S Q; Hou, J N; Bai, C Y; Jiang, Y; Zhang, X J; Ren, H L; Sun, B X; Zhao, Z H; Sun, J H

2014-04-01

51

Isolates of Encephalitozoon cuniculi from farmed blue foxes ( Alopex lagopus ) from Norway differ from isolates from Swiss domestic rabbits ( Oryctolagus cuniculus )  

Microsoft Academic Search

Encephalitozoon cuniculi has a wide host range among mammals, but whether it represents a homogeneous species is a subject of controversy. We have\\u000a isolated, cultivated (in human MRC-5 cells) and, for the first time, characterized by immunological and molecular biological\\u000a methods four isolates of E. cuniculi from Norwegian blue foxes with a history of encephalitozoonosis. The isolates were compared with

A. Mathis; J. Åkerstedt; J. Tharaldsen; Ø. Ødegaard; P. Deplazes

1996-01-01

52

Non-invasive faecal steroid monitoring of ovarian and adrenal activity in farmed blue fox ( Alopex lagopus) females during late pregnancy, parturition and lactation onset  

Microsoft Academic Search

In the semi-domesticated blue fox, handling stress may influence reproductive performance and increase perinatal pup loss. Ovarian and adrenal steroids were analysed in faecal samples collected from mid-gestation through the first week of lactation in 40 female blue foxes to characterize hormone patterns during this important reproductive period. Daily faecal samples were collected from 40 foxes during 30 pregnancies, one

Gorm Sanson; Janine L. Brown; Wenche Farstad

2005-01-01

53

Influence of Dietary Protein Level and the Amino Acids Methionine and Lysine on Leather Properties of Blue Fox (Alopex Lagopus) Pelts  

Microsoft Academic Search

The influence of dietary protein, methionine, and lysine on leather quality in blue fox pelts was studied. The pelt material originated from animals in two consecutive feeding trials (Exp. 1 and Exp. 2) with three protein levels: conventional, slightly lowered, and very low. The two lowest protein diets were fed as such or as supplemented with methionine or with lysine

Tuula Dahlman; Marja Mäntysalo; Palle V. Rasmussen; L. L. Skovløkke

2002-01-01

54

Influence of dietary protein level and the amino acids methionine and lysine on leather properties of blue fox (Alopex lagopus) pelts.  

PubMed

The influence of dietary protein, methionine, and lysine on leather quality in blue fox pelts was studied. The pelt material originated from animals in two consecutive feeding trials (Exp. 1 and Exp. 2) with three protein levels: conventional, slightly lowered, and very low. The two lowest protein diets were fed as such or as supplemented with methionine or with lysine (lysine only in Exp. 2). The following physical leather properties were measured: breaking load (BRL), tensile strength (TEN), relative elongation at break (PEB), straining of skins at pelting, and shrinkage at dressing. A decline in the dietary protein content reduced BRL and, hence, leather firmness, and increased straining and the corresponding shrinking in Exp. 1. The supplemented methionine tended to improve leather strength and elasticity by increasing TEN and PEB in Exp. 1, whereas lysine elicited no response. Methionine supplementation at the slightly lowered protein level increased BRL in both experiments by almost 10% as compared with the respective non-supplemented diet. We conclude that with high protein quality diets, a level of 200 g/kg DM (as digestible protein) appears to be adequate for producing pelts with firm, elastic leather, provided that an adequate amount of methionine is included in the diet. PMID:12553694

Dahlman, Tuula; Mäntysalo, Marja; Rasmussen, Palle V; Skovløkke, L L

2002-12-01

55

An alternative to killing? Treatment of reservoir hosts to control a vector and pathogen in a susceptible species.  

PubMed

Parasite-mediated apparent competition occurs when one species affects another through the action of a shared parasite. One way of controlling the parasite in the more susceptible host is to manage the reservoir host. Culling can cause issues in terms of ethics and biodiversity impacts, therefore we ask: can treating, as compared to culling, a wildlife host protect a target species from the shared parasite? We used Susceptible Infected Recovered (SIR) models parameterized for the tick-borne louping ill virus (LIV) system. Deer are the key hosts of the vector (Ixodes ricinus) that transmits LIV to red grouse Lagopus lagopus scoticus, causing high mortality. The model was run under scenarios of varying acaricide efficacy and deer densities. The model predicted that treating deer can increase grouse density through controlling ticks and LIV, if acaricide efficacies are high and deer densities low. Comparing deer treated with 70% acaricide efficacy with a 70% cull rate suggested that treatment may be more effective than culling if initial deer densities are high. Our results will help inform tick control policies, optimize the targeting of control methods and identify conditions where host management is most likely to succeed. Our approach is applicable to other host-vector-pathogen systems. PMID:22939093

Porter, R; Norman, R A; Gilbert, L

2013-02-01

56

Condition- and parasite-dependent expression of a male-like trait in a female bird  

PubMed Central

In many species, females display brightly coloured and elaborate traits similar to those that males use in intra- and inter-sexual selection processes. These female characters are sometimes related to fitness, and might function as secondary sexual characteristics that have evolved through sexual selection. Here, we used descriptive data from 674 females in 10 populations and an experimental removal of Trichostrongylus tenuis parasites in four populations, to examine the effects of season, age, condition, and parasites on the size of supra-orbital combs displayed by female red grouse Lagopus lagopus scoticus. We found that comb size (i) was greater during the breeding than the non-breeding season, (ii) was greater in adult than in young females, (iii) was positively correlated with body condition, and (iv) negatively correlated with parasite abundance. Experimentally, we showed that comb size increased proportionally to the number of worms removed after parasite dosing. Our findings provide a better understanding of proximate mechanisms behind the expression of a male-like trait in females, and we discuss its possible function as a female ornament.

Martinez-Padilla, J.; Vergara, P.; Perez-Rodriguez, L.; Mougeot, F.; Casas, F.; Ludwig, S. C.; Haines, J. A.; Zeineddine, M.; Redpath, S. M.

2011-01-01

57

A model to test how ticks and louping ill virus can be controlled by treating red grouse with acaricide.  

PubMed

Ticks are the most important vectors of disease-causing pathogens in Europe. In the U.K., Ixodes ricinus L. (Ixodida: Ixodidae) transmits louping ill virus (LIV; Flaviviridae), which kills livestock and red grouse, Lagopus lagopus scoticus Lath. (Galliformes: Phasianidae), a valuable game bird. Tick burdens on grouse have been increasing. One novel method to reduce ticks and LIV in grouse may be acaricide treatment. Here, we use a mathematical model parameterized with empirical data to investigate how the acaricide treatment of grouse might theoretically control ticks and LIV in grouse. Assuming a situation in which ticks and LIV impact on the grouse population, the model predicts that grouse density will depend on deer density because deer maintain the tick population. In low deer densities, no acaricide treatment is predicted to be necessary because abundances of grouse will be high. However, at higher deer densities, the model predicts that grouse densities will increase only if high numbers of grouse are treated, and the efficacy of acaricide is high and lasts 20 weeks. The qualitative model predictions may help to guide decisions on whether to treat grouse or cull deer depending on deer densities and how many grouse can be treated. The model is discussed in terms of practical management implications. PMID:23088727

Porter, R; Norman, R A; Gilbert, L

2013-09-01

58

Effects of lead shot ingestion in willow grouse  

Microsoft Academic Search

Willow grouse (Lagopus lagopus) is the most popular game bird in Norway and hunted extensively. Ingestion of lead shot pellets as grit with consequently adverse effects is therefore a distinct possibility as this has been observed in other upland game birds. The present experiment was carried out to study the possible effects of ingested lead shot pellets on willow grouse.

Norvald Fimreite

1984-01-01

59

Intra-sexual competition alters the relationship between testosterone and ornament expression in a wild territorial bird.  

PubMed

In a reliable signalling system, individual quality is expected to mediate the costs associated with ornamental displays, with relatively lower costs being paid by individuals of higher quality. These relative costs should depend not only on individual quality, but also on levels of intra-sexual competition. We explored the current and delayed effects that testosterone implants have on bird ornamentation in populations with contrasted population densities, as a proxy for intra-sexual competition. In a replicated experiment, we manipulated testosterone in 196 yearling male red grouse Lagopus lagopus scoticus in autumn in populations of high and low levels of intra-sexual competition. Males were assigned to one of three exogenous testosterone (T) treatments: empty implants (T0), small T implants (T1) or larger T implants (T2). We monitored subsequent changes in testosterone levels, ornament size and carotenoid-based colouration, carotenoid levels and body condition from autumn to spring. Testosterone implants increased testosterone levels, comb redness and comb size, and decreased body condition but these effects depended on levels of intra-sexual competition. Specifically, T2-implanted birds increased testosterone levels and comb size more, and reduced body condition more, in populations where intra-sexual competition was low. In the following spring, testosterone levels of T2-treated birds kept increasing in populations where intra-sexual competition was high but not in populations where intra-sexual competition was low. Our results highlight that levels of intra-sexual competition alter the relationship between testosterone levels and ornament expression, influencing their condition-dependence; they also indicate that the outcome of standard hormone manipulation conducted in free-living animals vary depending on the population context. PMID:24698833

Martínez-Padilla, J; Pérez-Rodríguez, L; Mougeot, F; Ludwig, S; Redpath, S M

2014-05-01

60

Bone lead levels and lead isotope ratios in red grouse from Scottish and Yorkshire moors.  

PubMed

Leg and foot bones of adult and juvenile red grouse (Lagopus lagopus scoticus) were collected from hunter-shot birds on two Scottish estates (Glendye and Invermark) and one Yorkshire estate in September, 2003. The lead content of bones was measured by atomic absorption spectrophotometry, and corresponding stable lead isotopes (Pb(204, 206, 207, 208)) by inductively coupled plasma mass spectrometry. At the Glendye (N=111) and Invermark (N=85) estates, relatively few birds (5.4% and 3.5%, respectively) had highly elevated bone lead concentrations (>20 microg/g dry weight). In bones of these highly exposed birds, a combination of Pb(206):Pb(207) and Pb(208):Pb(207)ratios was consistent with ingestion of lead gunshot available in Europe. By contrast, Yorkshire grouse experienced a high incidence (65.8%) of bone lead >20 microg/g. The Pb(206):Pb(207) and Pb(208):Pb(207)ratios in bones of these highly exposed birds were consistent with a combined exposure to ingested lead gunshot and lead from galena mining in the region. Lead isotope ratios also indicated that lead from UK gasoline combustion and fallout from atmospheric particles was not a likely source of elevated lead in bones of either Scottish or Yorkshire grouse. Suggested management options for the three moors include adopting nontoxic shot for all game shooting on the estates, allowing heather (Calluna vulgaris) vegetation to grow tall in lead shot fall-out zones to reduce physical access to high densities of lead shot already present, and provision of calcareous grit across moors to reduce lead assimilation from all ingested sources of lead. PMID:19264349

Thomas, Vernon G; Scheuhammer, Anton M; Bond, Della E

2009-05-15

61

Platinum Group Elements in the Feathers of Raptors and Their Prey  

Microsoft Academic Search

Platinum (Pt), palladium (Pd), and rhodium (Rh) concentrations were determined in the feathers of three raptor species in\\u000a Sweden, the sparrowhawk (Accipiter nisus), the peregrine falcon (Falco peregrinus), and the gyrfalcon (Falco rusticolus), as well as the main prey of the sparrowhawk (the house sparrow, Passer domesticus) and the gyrfalcon (the willow grouse, Lagopus lagopus).\\u000a \\u000a \\u000a \\u000a The analysis of feathers from

K. H. Jensen; S. Rauch; G. M. Morrison; P. Lindberg

2002-01-01

62

Effects of food availability on dispersal and cub sex ratio in the Mednyi Arctic fox  

Microsoft Academic Search

Since the Pleistocene, Arctic foxes, Alopex lagopus, on Mednyi Island in the North Pacific have been isolated in a small area with rich food resources and no other terrestrial carnivores. This situation provides an unusually simple system within which the effect of food dispersion on demography and social organisation was examined. We studied the composition, location and dispersal of 67

Mikhail Goltsman; Elena P. Kruchenkova; Sergei Sergeev; Paul J. Johnson; David W. Macdonald

2005-01-01

63

Contrasting Population Trends at Two Razorbill Colonies in Atlantic Canada: Additive Effects of Fox Predation and Hunting Mortality? Comparaison de la tendance de deux colonies de Petits Pingouins dans les provinces de l'Atlantique : la prédation par le renard et la mortalité par la chasse ont-elles un effet cumulatif?  

Microsoft Academic Search

We developed a stochastic, stage-based, matrix-projection population model to assess population viability and estimate the impact of mortality caused by hunting, illegal and incidental to the murre (Uria sp.) hunt, and fox (Alopex lagopus) predation on Razorbill (Alca torda) populations breeding on the Gannet Islands, Labrador, the \\

Jennifer L. Lavers; Ian L. Jones; Gregory J. Robertson; Antony W. Diamond

2009-01-01

64

Bioenergetics of the Snowy Owl (Nyctea scandiaca).  

National Technical Information Service (NTIS)

The snowy owl, Nyctea scandiaca, is a permanent resident in the arctic tundra of both North America and Eurasia. Besides the snowy owl only the common raven (Corvus corax) and rock ptarmigan (Lagopus mutus) inhabit the arctic tundra in winter. When food i...

J. A. Gessaman

1972-01-01

65

Orienting and freezing responses in incubating ptarmigan hens.  

PubMed

Behavior studies and telemetric recordings of heart and respiration rates were performed on five wild and two captive, incubating, willow ptarmigan hens (Lagopus lagopus lagopus) and on four wild, incubating, Svalbard ptarmigan hens (Lagopus mutus hyperboreus). Sounds and sight of approaching humans, egg predators, or dogs near the nests elicited behavior in the hens which we have interpreted as an orienting response (OR) followed by freezing behavior. During both types of behavioral responses, heart rate was reduced from 204 +/- 39 (mean +/- SE) to 119 +/- 26 beats per minute and respiration from 25 +/- 2 to 12 +/- 3 breaths per minute. In wild incubating willow ptarmigan, further approach led to tachycardia and increased respiration. Some birds maintained freezing behavior, while others became restless before flying off. Two of the four incubating Svalbard ptarmigan hens showed the OR followed by freezing behavior accompanied by decreased heart and respiration rates. The other two birds showed flight response, restless behavior accompanied by increased heart and respiration rates. Flight behavior was also typical for willow ptarmigan incubating in captivity. Repeated auditory provocation of incubating hens caused progressive decrement in behavioral and cardiac responses that is interpreted as habituation of the OR. PMID:4059382

Gabrielsen, G W; Blix, A S; Ursin, H

1985-06-01

66

Enhancement of local species richness in tundra by seed dispersal through guts of muskox and barnacle goose  

Microsoft Academic Search

The potential contribution of vertebrate-mediated seed rain to the maintenance of plant community richness in a High Arctic\\u000a ecosystem was investigated. We analyzed viable seed content in dung of the four numerically most important terrestrial vertebrates\\u000a in Northeast Greenland – muskox (Ovibos moschatus), barnacle goose (Branta leucopsis), Arctic fox (Alopex lagopus) and Arctic hare (Lepus arcticus). High numbers of plant

Hans Henrik Bruun; Rebekka Lundgren; Marianne Philipp

2008-01-01

67

The dispersion of arctic breeding birds according to snow-free patch dimensions during the spring thaw in the north-eastern Taimyr Peninsula, Russia  

Microsoft Academic Search

The dispersion of passerines, ptarmiganLagopus mutus and waders in relation to available snowfree patches is described after spring arrival but prior to the main thaw at Pronchishcheva\\u000a Lake, north-eastern Taimyr, in June 1991. The numbers of ptarmigan and passerines were proportional to patch perimeter but\\u000a disproportionately more birds occurred on smaller patches. In contrast, wader numbers were proportional to patch

Ron W. Summers; Les G. Underhill

1996-01-01

68

Fatal pox infection in a rough-legged hawk  

USGS Publications Warehouse

Natural pox infection occurred in a free-living rough-legged hawk (Buteo lagopus) in northeastern North Dakota. Gross, histological and electron microscopic findings were typical of pox infection, and characteristic lesions developed in red-tailed hawks (Buteo jamaicensis) but not in great horned owls (Bubo virginianus) following inoculation with case material. Death of the rough-legged hawk was attributed to starvation resulting from inability to capture prey and to blood loss from foot lesions.

Pearson, G. L.; Pass, D. A.; Beggs, E. C.

1975-01-01

69

Habitat Associations and Population Trends of Two Hawks in an Urbanizing Grassland Region in Colorado  

Microsoft Academic Search

Despite increasing interest in the ecological effects of urbanization, relatively little is known about its effects in grasslands. We examined population trends and habitat associations of two predators, the rough-legged hawk (Buteo lagopus) and the red-tailed hawk (B. jamaicensis), in a rapidly urbanizing grassland region at the western edge of the North American Great Plains. Count data indicate that rough-legged

Eric Schmidt; Carl E. Bock

2005-01-01

70

Historical biogeography and a mitochondrial DNA phylogeny of grouse and ptarmigan.  

PubMed

We sequenced 2690 nucleotides of mitochondrial DNA (mtDNA) including the entire control region (CR), partial 12S and 16S ribosomal RNAs, NADH dehydrogenase subunit 2, and cytochrome b genes from representatives of all the 17 living species of grouse and ptarmigan (Aves; Galliformes; subfamily Tetraoninae). Substitution rates and phylogenetic signals were variable among genes, with the CR being more informative than protein-coding and rRNA genes. Phylogenetic trees, computed with the CR or the concatenated sequences, indicate that: (1) genus Bonasa is monophyletic and basal within the subfamily, (2) all the other currently recognized genera of Tetraoninae are monophyletic, except Dendragapus; (3) D. obscurus is related to Centrocercus urophasianus and divergent from former D. canadensis and D. falcipennis, which, accordingly, may be ascribed to the distinct genus Falcipennis; (4) Tympanuchus, Dendragapus, and Centrocercus form a clade comprising taxa distributed exclusively in North America; and (5) the North American species of Bonasa (B. umbellus) and Lagopus (L. leucurus) are basal to their Eurasian and Holarctic congeneric species. These findings, and a dispersal-vicariance analysis, support a North American origin of the subfamily and of all the genera of Tetraoninae, with the possible exception of Tetrao. Present species distributions might have been attained by at least three dispersal events from North America to Eurasia, involving the ancestors to Palearctic Bonasa, the ancestors to circumpolar Lagopus mutus/L. lagopus, and the clade leading to Tetrao/Falcipennis. According to a "standard calibration" of the mtDNA molecular clock (2% sequence divergence per million years), Bonasa split about 5-6 million years ago, the other genera diverged during the upper Pliocene, and most of the congeneric species with North American and Eurasian distributions (Bonasa, Lagopus, and Falcipennis) originated during the lower Pleistocene, well before the last interruption of the Beringian land bridge. PMID:11421655

Lucchini, V; Höglund, J; Klaus, S; Swenson, J; Randi, E

2001-07-01

71

Introduced predator removal from islands. Exxon Valdez oil spill restoration project final report  

SciTech Connect

In order to restore black oystercatchers (Haematopus bachmani) and pigeon guillemots (Cepphus columba), 2 species injured by the T/V Exxon Valdez oil spill, the introduced predator, artic fox (Alopex lagopus), was removed from 2 islands near the western edge of the trajectory of the oil. Surveys indicated that although adequate nesting habitat was available at Simeonof and Chernabura, oystercatcher and guillemot population densities were much lower than at nearby fox-free islands. Elimination of foxes is expected to dramatically increase populations of these injured species as well as other native birds.

Byrd, G.V.; Bailey, E.P.; Stahl, W.

1996-05-01

72

Adoption in rock and white-tailed ptarmigan  

USGS Publications Warehouse

Reports of adoption in birds are widespread, but few studies report rates of adoption or possible mechanisms for this phenomenon, particularly in the Order Galliformes. We report incidents of adoption in Rock Ptarmigan (Lagopus muta) and White-tailed Ptarmigan (L. leucura) from two sites in western Canada. Adoption rates for White-tailed Ptarmigan on Vancouver Island, British Columbia, and the Ruby Ranges, Yukon Territory were 13% (n = 16 broods) and 4% (n = 27), respectively, while rates for Rock Ptarmigan were 14% (n = 29) in the Ruby Ranges. Low brood densities may result in lower rates of adoption for ptarmigan. ?? 2009 The Wilson Ornithological Society.

Wong, M. M. L.; Fedy, B. C.; Wilson, S.; Martin, K. M.

2009-01-01

73

Pholeter anterouterus Fischthal & Nasir, 1974 (Digenea: Opisthorchiidae) redescribed, together with remarks on the genera Pholeter Odhner, 1914 and Phocitrema Goto & Ozaki, 1930 and their relationship to the centrocestine heterophyids.  

PubMed

Photoleter anterouterus Fischthal & Nasir, 1974, from Pelecanus occidentalis Linnaeus and Pelecanus erythrorhynchos Gmelin from Florida, USA and the ventro-genital complexes of Photeleter gastrophilus (Kossack, 1910) from Delphinus delphis Linnaeus from Queensland, Australia and of Phocitrema fusiforme Goto & Ozaki, 1930 from Alopex lagopus (Linnaeus) and Phoca vitulina Linnaeus from Alaska are redescribed. The genus Photoleter Odhner, 1914 is emended and compared with Phocitrema Goto & Ozaki, 1930 and both genera are compared with members of, and as a result transferred from the family Opisthorchiidae Looss, 1899 to, the subfamily Centrocestinae Looss, 1899, family Heterophyidae Odhner, 1914. PMID:876682

Pearson, J C; Courtney, C H

1977-06-01

74

From 'third pole' to north pole: a Himalayan origin for the arctic fox.  

PubMed

The 'third pole' of the world is a fitting metaphor for the Himalayan-Tibetan Plateau, in allusion to its vast frozen terrain, rivalling the Arctic and Antarctic, at high altitude but low latitude. Living Tibetan and arctic mammals share adaptations to freezing temperatures such as long and thick winter fur in arctic muskox and Tibetan yak, and for carnivorans, a more predatory niche. Here, we report, to our knowledge, the first evolutionary link between an Early Pliocene (3.60-5.08 Myr ago) fox, Vulpes qiuzhudingi new species, from the Himalaya (Zanda Basin) and Kunlun Mountain (Kunlun Pass Basin) and the modern arctic fox Vulpes lagopus in the polar region. A highly hypercarnivorous dentition of the new fox bears a striking resemblance to that of V. lagopus and substantially predates the previous oldest records of the arctic fox by 3-4 Myr. The low latitude, high-altitude Tibetan Plateau is separated from the nearest modern arctic fox geographical range by at least 2000 km. The apparent connection between an ancestral high-elevation species and its modern polar descendant is consistent with our 'Out-of-Tibet' hypothesis postulating that high-altitude Tibet was a training ground for cold-environment adaptations well before the start of the Ice Age. PMID:24920475

Wang, Xiaoming; Tseng, Zhijie Jack; Li, Qiang; Takeuchi, Gary T; Xie, Guangpu

2014-07-22

75

Gyrfalcon diet in central west Greenland during the nestling period  

USGS Publications Warehouse

We studied food habits of Gyrfalcons (Falco rusticolus) nesting in central west Greenland in 2000 and 2001 using three sources of data: time-lapse video (3 nests), prey remains (22 nests), and regurgitated pellets (19 nests). These sources provided different information describing the diet during the nesting period. Gyrfalcons relied heavily on Rock Ptarmigan (Lagopus mutus) and arctic hares (Lepus arcticus). Combined, these species contributed 79-91% of the total diet, depending on the data used. Passerines were the third most important group. Prey less common in the diet included waterfowl, arctic fox pups (Alopex lagopus), shorebirds, gulls, alcids, and falcons. All Rock Ptarmigan were adults, and all but one arctic hare were young of the year. Most passerines were fledglings. We observed two diet shifts, first from a preponderance of ptarmigan to hares in mid-June, and second to passerines in late June. The video-monitored Gyrfalcons consumed 94-110 kg of food per nest during the nestling period, higher than previously estimated. Using a combination of video, prey remains, and pellets was important to accurately document Gyrfalcon diet, and we strongly recommend using time-lapse video in future diet studies to identify biases in prey remains and pellet data.

Booms, Travis; Fuller, Mark R.

2003-01-01

76

Gyrfalcon diet in central west Greenland during the nesting period  

USGS Publications Warehouse

We studied food habits of Gyrfalcons (Falco rusticolus) nesting in central west Greenland in 2000 and 2001 using three sources of data: time-lapse video (3 nests), prey remains (22 nests), and regurgitated pellets (19 nests). These sources provided different information describing the diet during the nesting period. Gyrfalcons relied heavily on Rock Ptarmigan (Lagopus mutus) and arctic hares (Lepus arcticus). Combined, these species contributed 79-91% of the total diet, depending on the data used. Passerines were the third most important group. Prey less common in the diet included waterfowl, arctic fox pups (Alopex lagopus), shorebirds, gulls, alcids, and falcons. All Rock Ptarmigan were adults, and all but one arctic hare were young of the year. Most passerines were fledglings. We observed two diet shifts, first from a preponderance of ptarmigan to hares in mid-June, and second to passerines in late June. The video-monitored Gyrfalcons consumed 94-110 kg of food per nest during the nestling period, higher than previously estimated. Using a combination of video, prey remains, and pellets was important to accurately document Gyrfalcon diet, and we strongly recommend using time-lapse video in future diet studies to identify biases in prey remains and pellet data.

Booms, T. L.; Fuller, M. R.

2003-01-01

77

Cospeciation and horizontal transmission of avian sarcoma and leukosis virus gag genes in galliform birds.  

PubMed

In a study of the evolution and distribution of avian retroviruses, we found avian sarcoma and leukosis virus (ASLV) gag genes in 26 species of galliform birds from North America, Central America, eastern Europe, Asia, and Africa. Nineteen of the 26 host species from whom ASLVs were sequenced were not previously known to contain ASLVs. We assessed congruence between ASLV phylogenies based on a total of 110 gag gene sequences and ASLV-host phylogenies based on mitochondrial 12S ribosomal DNA and ND2 sequences to infer coevolutionary history for ASLVs and their hosts. Widespread distribution of ASLVs among diverse, endemic galliform host species suggests an ancient association. Congruent ASLV and host phylogenies for two species of Perdix, two species of Gallus, and Lagopus lagopus and L. mutus also indicate an old association with vertical transmission and cospeciation for these ASLVs and hosts. An inference of horizontal transmission of ASLVs among some members of the Tetraoninae subfamily (grouse and ptarmigan) is supported by ASLV monophyletic groups reflecting geographic distribution and proximity of hosts rather than host species phylogeny. We provide a preliminary phylogenetic taxonomy for the new ASLVs, in which named taxa denote monophyletic groups. PMID:10756010

Dimcheff, D E; Drovetski, S V; Krishnan, M; Mindell, D P

2000-05-01

78

Cospeciation and Horizontal Transmission of Avian Sarcoma and Leukosis Virus gag Genes in Galliform Birds  

PubMed Central

In a study of the evolution and distribution of avian retroviruses, we found avian sarcoma and leukosis virus (ASLV) gag genes in 26 species of galliform birds from North America, Central America, eastern Europe, Asia, and Africa. Nineteen of the 26 host species from whom ASLVs were sequenced were not previously known to contain ASLVs. We assessed congruence between ASLV phylogenies based on a total of 110 gag gene sequences and ASLV-host phylogenies based on mitochondrial 12S ribosomal DNA and ND2 sequences to infer coevolutionary history for ASLVs and their hosts. Widespread distribution of ASLVs among diverse, endemic galliform host species suggests an ancient association. Congruent ASLV and host phylogenies for two species of Perdix, two species of Gallus, and Lagopus lagopus and L. mutus also indicate an old association with vertical transmission and cospeciation for these ASLVs and hosts. An inference of horizontal transmission of ASLVs among some members of the Tetraoninae subfamily (grouse and ptarmigan) is supported by ASLV monophyletic groups reflecting geographic distribution and proximity of hosts rather than host species phylogeny. We provide a preliminary phylogenetic taxonomy for the new ASLVs, in which named taxa denote monophyletic groups.

Dimcheff, Derek E.; Drovetski, Sergei V.; Krishnan, Mallika; Mindell, David P.

2000-01-01

79

Cadmium toxicity among wildlife in the Colorado Rocky Mountains  

USGS Publications Warehouse

Cadmium is known to be both extremely toxic and ubiquitous in natural environments. It occurs in almost all soils, surface waters and plants, and it is readily mobilized by human activities such as mining. As a result, cadmium has been named as a potential health threat to wildlife species; however, because it exists most commonly in the environment as a trace constituent, reported incidences of cadmium toxicity are rare. Here we have measured trace metals in the food web and tissues of white-tailed ptarmigan (Lagopus leucurus) in Colorado. Our results suggest that cadmium toxicity may be more common among natural populations of vertebrates than has been appreciated to date and that cadmium toxicity may often go undetected or unrecognized. In addition, our research shows that ingestion of even trace quantities of cadmium can influence not only the physiology and health of individual organisms, but also the demographics and the distribution of species.

Larison, J. R.; Likens, G. E.; Fitzpatrick, J. W.; Crock, J. G.

2000-01-01

80

Prevalence of Rabies Virus in Foxes Trapped in the Canadian Arctic  

PubMed Central

Brains and salivary glands of 521 trapped arctic foxes (Alopex lagopus) submitted from four different settlement areas in the Northwest Territories were examined for rabies by the standard fluorescent antibody and mouse inoculation tests. Rabies antigen was present in 44 of 201 (21.9%) brains from foxes trapped in the Sachs Harbour area, but submissions from Cambridge Bay (127), Spence Bay (93) and Gjoa Haven (100) were negative. Virus was also present in salivary glands from 43 (97.7%) of these 44 positive foxes. The arctic fox continues to be the main wildlife reservoir of rabies in the Canadian Arctic and foxes in the prodromal stage of the disease pose a particular threat to the trapper. Preexposure vaccination should always be a consideration in this occupational group.

Secord, D. C.; Bradley, J. A.; Eaton, R. D.; Mitchell, D.

1980-01-01

81

Herbivores Influence the Growth, Reproduction, and Morphology of a Widespread Arctic Willow  

PubMed Central

Shrubs have expanded in Arctic ecosystems over the past century, resulting in significant changes to albedo, ecosystem function, and plant community composition. Willow and rock ptarmigan (Lagopus lagopus, L. muta) and moose (Alces alces) extensively browse Arctic shrubs, and may influence their architecture, growth, and reproduction. Furthermore, these herbivores may alter forage plants in such a way as to increase the quantity and accessibility of their own food source. We estimated the effect of winter browsing by ptarmigan and moose on an abundant, early-successional willow (Salix alaxensis) in northern Alaska by comparing browsed to unbrowsed branches. Ptarmigan browsed 82–89% of willows and removed 30–39% of buds, depending on study area and year. Moose browsed 17–44% of willows and browsed 39–55% of shoots. Browsing inhibited apical dominance and activated axillary and adventitious buds to produce new vegetative shoots. Ptarmigan- and moose-browsed willow branches produced twice the volume of shoot growth but significantly fewer catkins the following summer compared with unbrowsed willow branches. Shoots on browsed willows were larger and produced 40–60% more buds compared to unbrowsed shoots. This process of shoot production at basal parts of the branch is the mechanism by which willows develop a highly complex “broomed” architecture after several years of browsing. Broomed willows were shorter and more likely to be re-browsed by ptarmigan, but not moose. Ptarmigan likely benefit from the greater quantity and accessibility of buds on previously browsed willows and may increase the carrying capacity of their own habitat. Despite the observed tolerance of willows to browsing, their vertical growth and reproduction were strongly inhibited by moose and ptarmigan. Browsing by these herbivores therefore needs to be considered in future models of shrub expansion in the Arctic.

Christie, Katie S.; Ruess, Roger W.; Lindberg, Mark S.; Mulder, Christa P.

2014-01-01

82

Comparative tissue distribution of metals in birds in Sweden using ICP-MS and laser ablation ICP-MS.  

PubMed

Cadmium, copper, lead, palladium, platinum, rhodium, and zinc profiles were investigated along feather shafts of raptor and other bird species by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The distribution of external versus internal metal contamination of feathers was investigated. The species examined were peregrine falcon (Falco peregrinus), sparrowhawk ( Accipiter nisus), willow grouse (Lagopus lagopus), and house sparrow (Passer domesticus) in Sweden. For habitat comparisons, total Cu, Pb, Zn, and Cd concentrations were analyzed by ICP-MS in feathers of the examined species as well as captive peregrine falcon. For investigation of metal distribution and correlation in different biological materials of raptors, total concentrations of Cu, Pb, Cd, and Zn were also investigated by ICP-MS in feathers, eggs, blood, feces, liver, and kidney of wild peregrine falcon from southwestern Sweden. Laser ablation of feathers revealed that Pb contamination is both external and internal, Zn contamination is internal, and Cd and Cu contamination is predominantly internal, with a few externally attached particles of high concentration. Pb, Cu, and Cd signal intensities were highest in urban habitats and contamination was mainly external in feathers. The background signal intensity of Zn was also higher in birds from urban habitats. The laser ablation profile of PGE (Pt, Pd, Rh) demonstrated that PGE contamination of feathers consists almost exclusively of externally attached PGE-containing particles, with little evidence of internally deposited PGE.Generally, total metal concentrations in feathers were highest in sparrowhawk and house sparrow due to their urban habitat. Total Cu, Zn, and Cd concentrations were highest in liver and kidney due to binding to metallothionein, while the total Pb concentration was highest in feces due to the high excretion rate of Pb. A decreasing temporal trend for Pb in feathers, showing that Pb levels in feathers have decreased since the introduction of nonleaded petrol, is also discussed. PMID:15386152

Ek, Kristine H; Morrison, Gregory M; Lindberg, Peter; Rauch, Sébastien

2004-08-01

83

Platinum group elements in the feathers of raptors and their prey.  

PubMed

Platinum (Pt), palladium (Pd), and rhodium (Rh) concentrations were determined in the feathers of three raptor species in Sweden, the sparrowhawk ( Accipiter nisus), the peregrine falcon ( Falco peregrinus), and the gyrfalcon ( Falco rusticolus), as well as the main prey of the sparrowhawk (the house sparrow, Passer domesticus) and the gyrfalcon (the willow grouse, Lagopus lagopus). The analysis of feathers from 1917-1999 revealed a clear temporal trend, with significantly higher Rh concentrations in sparrowhawk and peregrine falcon after 1986. There is evidence for increasing platinum group element (PGE) concentrations from 1917 to 1999 in peregrine falcon and sparrowhawk. This suggests that feathers reflect increased PGE concentrations in the environment over this time period. Mean concentrations of PGE in feathers of raptors after 1986 ranged from 0.3 to 1.8 ng x g(-1) for Pt, 0.6 to 2.1 ng x g(-1) for Pd (indicative values), and 0.1 to 0.6 ng x g(-1) for Rh. House sparrows in urban areas had significantly higher Pt and Pd concentrations than urban sparrowhawks. The higher Pd concentrations in relation to Pt and Rh may indicate the greater mobility of Pd in the environment. Although PGE concentrations are generally higher in birds living in urban areas, no significant spatial trend could be established. This is partly due to the widespread distribution of automobiles and partly because birds forage and integrate PGE exposure over large areas. Laser ablation analysis demonstrates that PGE contamination of feathers is predominantly external, consisting of small particles in the nanometer size range. Other indications of external contamination are that Pt and Pd levels are significantly higher in the vane than in the shaft and that PGE relative ratios (except Pd) reflect urban particles. PMID:11910463

Jensen, K H; Rauch, S; Morrison, G M; Lindberg, P

2002-04-01

84

Territory occupancy rate of goshawk and gyrfalcon: no evidence of delayed numerical response to grouse numbers.  

PubMed

Two recent studies on territory occupancy rates of goshawk Accipiter gentilis and gyrfalcon Falco rusticolus report a 2-3-year-delayed numerical response to grouse numbers, which is a requirement for a hypothesis of predator-generated grouse cycles. The time lags were assumed to reflect the average age of sexual maturity in the raptor species. In southern Norway, however, subadult (two-year-old) goshawk hens occupied only 18-25% of territories where occupancy was not recorded in the preceding year, and there was no significant relationship between the proportion of subadults among recruits and grouse indices two years earlier. We argue that territory occupancy rates are not appropriate indices of total raptor population levels, but rather reflect the proportion of territorial pairs that attempt to nest. Because this depends on the body condition of the hens, fluctuations in other important winter resident prey species (most important for the goshawk) and winter weather (most important for the gyrfalcon) should also be addressed. During 1988-2006, the annual proportion of goshawk territories with recorded nesting attempts in southern Norway was most closely related to the preceding autumn's population indices of black grouse Tetrao tetrix and mountain hare Lepus timidus, whereas the annual proportion of gyrfalcon territories with observations of falcons or with confirmed breeding attempts in central Norway were best explained by population indices of willow grouse Lagopus lagopus and ptarmigan L. mutus from the previous autumn, and by December temperatures. Hence, our studies do not support the predation hypothesis for grouse cycles. PMID:17549523

Selås, Vidar; Kålås, John Atle

2007-09-01

85

Distribution of Ground-Nesting Marine Birds Along Shorelines in Glacier Bay, Southeastern Alaska: An Assessment Related to Potential Disturbance by Back-Country Users  

USGS Publications Warehouse

With the exception of a few large colonies, the distribution of ground-nesting marine birds in Glacier Bay National Park in southeastern Alaska is largely unknown. As visitor use increases in back-country areas of the park, there is growing concern over the potential impact of human activities on breeding birds. During the 2003i??05 breeding seasons, the shoreline of Glacier Bay was surveyed to locate ground-nesting marine birds and their nesting areas, including wildlife closures and historical sites for egg collection by Alaska Native peoples. The nesting distribution of four common ground-nesting marine bird species was determined: Arctic Tern (Sterna paradisaea), Black Oystercatcher (Haematopus bachmani), Mew Gull (Larus canus), and Glaucous-winged Gull (Larus glaucescens). Observations of less abundant species also were recorded, including Herring Gull (Larus argentatus), Red-throated Loon (Gavia stellata), Canada Goose (Branta canadensis), Willow Ptarmigan (Lagopus lagopus), Semipalmated Plover (Charadrius semipalmatus), Spotted Sandpiper (Actitis macularia), Least Sandpiper (Calidris minutilla), Parasitic Jaeger (Stercorarius parasiticus), and Aleutian Tern (Sterna aleutica). Nesting distribution for Arctic Terns was largely restricted to the upper arms of the bay and a few treeless islets in the lower bay, whereas Black Oystercatchers were more widely distributed along shorelines in the park. Mew Gulls nested throughout the upper bay in Geikie Inlet and in Fingers and Berg Bays, and most Glaucous-winged Gull nests were found at wildlife closures in the central and lower bays. Several areas were identified where human disturbance could affect breeding birds. This study comprises the first bay-wide survey for the breeding distribution of ground-nesting marine birds in Glacier Bay National Park, providing a minimum estimate of their numbers and distribution within the park. This information can be used to assess future human disturbance and track natural changes in nesting bird distribution over time.

Arimitsu, M. L.; Piatt, J. F.; Romano, M. D.

2007-01-01

86

Effect of high altitude and in vivo adenosine/(&bgr;)-adrenergic receptor blockade on ATP and 2,3BPG concentrations in red blood cells of avian embryos  

PubMed

In chick embryos, developmental changes of the blood oxygen tension control hemoglobin (Hb) oxygen affinity via modulation of ATP and 2, 3BPG concentrations in red blood cells. Hypoxia, which is a normal developmental condition for late chick embryos, causes a decrease of the red cell ATP concentration (and increase of red cell oxygen affinity) as well as activation of 2,3BPG synthesis via cyclic AMP-dependent signaling. Adenosine and catecholamines have been implicated as signaling substances in these red cell responses. To assess the extent to which adenosine and catecholamines are involved in vivo in the control of red cell ATP/2,3BPG concentrations, day 13 chick embryos were treated for 24 h with adenosine A(2) and/or (&bgr;)-adrenergic receptor blockers and red cell ATP and 2,3BPG levels were determined. The data suggest that adaptive effects later in development in chick embryos induced by adenosine and catecholamines are vital. We have also tested whether avian embryos of the free-living, high-altitude, native white-tailed ptarmigan (Lagopus leucurus) alter their organic phosphate pattern in red cells in response to incubation at different altitudes. Embryos incubated at 3600-4100 m decrease their red cell ATP concentration much more rapidly than embryos of the same clutch incubated at 1600 m. From these data it can be inferred that the oxygen affinity of high altitude embryos will be adjusted to the altitude at which the eggs are incubated. PMID:10504314

Dragon; Carey; Martin; Baumann

1999-10-01

87

Depredation of common eider, Somateria mollissima, nests on a central Beaufort Sea barrier island: A case where no one wins  

USGS Publications Warehouse

Along the central Beaufort Sea, Pacific Common Eiders (Somateria mollissima v-nigra) nest on unvegetated, barrier islands; often near nesting Glaucous Gulls (Larus hyperboreus). Nest-site choice likely reflects a strategy of predator avoidance: nesting on islands to avoid mammalian predators and near territorial gulls to avoid other avian predators. We observed a nesting colony of Common Eiders from first nest initiation through nesting termination on Egg Island near Prudhoe Bay, Alaska (2002 - 2003). Resident gulls depredated many eider nests, mostly during initiation. All nests failed when an Arctic Fox (Alopex lagopus) visited the island and flushed hens from their nests, exposing the eggs to depredation by the fox and gulls (resident and non-resident). Common Eiders actively defended nests from gulls, but not from foxes. Likely all three species (i.e., eiders, gulls, and foxes) ultimately achieved negligible benefit from their nest-site selection or predatory activity: (a) island nesting provided no safety from mammalian predators for eiders or gulls, (b) for Common Eiders, nesting near gulls increased egg loss, (c) for Glaucous Gulls, nesting near colonial eiders may have reduced nest success by attracting the fox, and (d) for Arctic Foxes, the depredation was of questionable value, as most eggs were cached and probably not recoverable (due to damage from fall storms). Thus, the predator-prey interactions we observed appear to be a case where little or no fitness advantage was realized by any of the species involved.

Reed, J. A.; Lacroix, D. L.; Flint, P. L.

2007-01-01

88

A comparative analysis of MC4R gene sequence, polymorphism, and chromosomal localization in Chinese raccoon dog and Arctic fox.  

PubMed

Numerous mutations of the human melanocortin receptor type 4 (MC4R) gene are responsible for monogenic obesity, and some of them appear to be associated with predisposition or resistance to polygenic obesity. Thus, this gene is considered a functional candidate for fat tissue accumulation and body weight in domestic mammals. The aim of the study was comparative analysis of chromosome localization, nucleotide sequence, and polymorphism of the MC4R gene in two farmed species of the Canidae family, namely the Chinese raccoon dog (Nycterutes procyonoides procyonoides) and the arctic fox (Alopex lagopus). The whole coding sequence, including fragments of 3'UTR and 5'UTR, shows 89% similarity between the arctic fox (1276 bp) and Chinese raccoon dog (1213 bp). Altogether, 30 farmed Chinese raccoon dogs and 30 farmed arctic foxes were searched for polymorphisms. In the Chinese raccoon dog, only one silent substitution in the coding sequence was identified; whereas in the arctic fox, four InDels and two single-nucleotide polymorphisms (SNPs) in the 5'UTR and six silent SNPs in the exon were found. The studied gene was mapped by FISH to the Chinese raccoon dog chromosome 9 (NPP9q1.2) and arctic fox chromosome 24 (ALA24q1.2-1.3). The obtained results are discussed in terms of genome evolution of species belonging to the family Canidae and their potential use in animal breeding. PMID:22047079

Skorczyk, Anna; Flisikowski, Krzysztof; Switonski, Marek

2012-05-01

89

Behavioral interactions of penned red and arctic foxes  

USGS Publications Warehouse

Expansion of the geographical distribution of red foxes (Vulpes vulpes) into the far north tundra region may lead to competition between arctic (Alopex lagopus) and red foxes for space and resources. Behavioral interactions between red and arctic foxes were evaluated during 9 trials conducted in a 4.05-ha enclosure near Woodworth, North Dakota. Each trial consisted of introducing a male-female pair of arctic foxes into the enclosure and allowing them to acclimate for approximately a week before releasing a female red fox into the enclosure, followed by her mate a few days later. In 8 of 9 trials, red foxes were dominant over arctic foxes during encounters. Activity of the arctic foxes decreased upon addition of red foxes. Arctic foxes tried unsuccessfully to defend preferred den, resting, and feeding areas. Even though the outcome of competition between red and arctic foxes in the Arctic is uncertain, the more aggressive red fox can dominate arctic foxes in direct competition for den sites and other limited resources.

Rudzinski, D. R.; Graves, H. B.; Sargeant, A. B.; Storm, G. L.

1982-01-01

90

Molecular detection of Leucocytozoon lovati from probable vectors, black flies (Simuliudae) collected in the alpine regions of Japan.  

PubMed

Probable arthropod vectors of avian blood protozoa, Leucocytozoon lovati, were collected in the alpine regions of Japan, the habitats of the host birds of Japanese rock ptarmigan (Lagopus mutus japonicus). Seven alpine regions of Japan, Asahidake, Chogatake, Tateyama, Jiigatake, Norikura, Kitadake, and Senjyogatake were investigated for black fly collection during 2004 to 2007. The collected 490 insects were morphologically identified as six species of female black flies, including Prosimulium hirtipes group (n = 59), Prosimulium mutata (n = 13), Prosimulium yezoense (n = 10), Similium japonicum (n = 359), Similium uchidai (n = 39), and Twinnia japonensis (n = 10). Extracted DNAs from individual black fly species were utilized for the amplification of the partial mitochondrial cytochrome b gene sequences of Leucocytozoon lovati previously reported. Four S. japonicum, two S. uchidai, and two P. hirtipes group studied were positive for the nested PCR among 490 black flies collected (1.6%; 8/490). All amplified sequences from the black flies were completely identical to those of L. lovati previously detected from Japanese rock ptarmigan. Our results suggest that at least three species of black flies, S. japonicum, S. uchidai, and P. hirtipes group, studied in this area could be regarded as potential vectors for L. lovati in the rock ptarmigan. This is the first detection case of Leucocytozoon from black flies of Japan. PMID:18791737

Sato, Yukita; Tamada, Asumi; Mochizuki, Yayoi; Nakamura, Shino; Okano, Emiko; Yoshida, Chihiro; Ejiri, Hiroko; Omori, Sumie; Yukawa, Masayoshi; Murata, Koichi

2009-01-01

91

Phylogenetic comparison of Leucocytozoon spp. from wild birds of Japan.  

PubMed

Eight species of Japanese birds were found to be infected with Leucocytozoon species using microscopic analysis. We used PCR and sequence analysis of the mitochondrial cytochrome b gene (cyt b) to compare the genetic background among these detected protozoa species. In 20 individuals of 22 samples, a single amplified band was detected from 6 of 8 bird species; 9 Japanese rock ptarmigans (Lagopus mutus japonicus), 4 large-billed crows (Corvus macrorhynchos), 2 carrion crows (C. corone), 2 scops owls (Otus scops), 1 Japanese grosbeak (Eophona personata), and 2 brown-eared bulbuls (Hypsipetes amaurotis), respectively. Phylogenetic analysis based on the partial cyt b sequences revealed that all Leucocytozoon isolates in Japan closely grouped with other Leucocytozoon species previously reported in the literature. Among the Japanese isolates, the phylogenetic tree suggested that L. lovati from the Japanese rock ptarmigan may be basal to the parasites found in other bird species. Our study is the first to identify the molecular relationships among Leucocytozoon parasites in the avifauna of Japan. PMID:17283401

Sato, Yukita; Hagihara, Mio; Yamaguchi, Tsuyoshi; Yukawa, Masayoshi; Murata, Koichi

2007-01-01

92

Virological investigation of avian influenza virus on postglacial species of phasianidae and tetraonidae in the italian alps.  

PubMed

Land-based birds, belonging to Galliformes order are considered to be potential intermediaries in the emergence of new strains of influenza A viruses (AIVs), but the viral circulation in these birds remains largely unknown. To gain insights into the circulation of AIV in the wild Galliformes populations in Italian Alps, we conducted a virological survey on rock partridge (Alectoris graeca saxatilis) belonging to Phasianidae family and on tetraonids including rock ptarmigan (Lagopus mutus helveticus) and black grouse (Tetrao tetrix tetrix). In 2003 and 2004, during the hunting seasons, 79 wild Galliformes, categorised into age and sex classes, were hunted in the Sondrio Province (Central Alps). Cloacal swabs were collected from 11 rock partridges and from 68 tetraonids including 23 alpine rock ptarmigans and 45 black grouses. We tested cloacal swabs by a high sensitive reverse transcription- (RT-) PCR detecting the matrix gene of AIV. No AIV was detected in the investigated samples, thus, suggesting the lack of AIV circulation in these relict populations in the study period. In terms of threatened species conservation, during wildlife management activities, it is very important to exclude the introduction of AIV-carrier birds in shared territories, a fact representing a health risk for these populations. PMID:24167732

Delogu, Mauro; Ghetti, Giulia; Gugiatti, Alessandro; Cotti, Claudia; Piredda, Isabella; Frasnelli, Matteo; De Marco, Maria A

2013-01-01

93

Persistent organochlorine levels in six prey species of the gyrfalcon Falco rusticolus in Iceland.  

PubMed

Our previous investigations have revealed very high levels of organochlorines (OCs) in the Icelandic gyrfalcon Falco rusticolus, a resident top predator. We now examine six potential prey species of birds, both resident and migratory, in order to elucidate the most likely route of the OCs to the gyrfalcon. The ptarmigan Lagopus mutus, the most important prey of the gyrfalcon, contained very low levels of OCs. Bioaccumulation of polychlorinated biphenyls (PCBs) and DDTs in mallards Anas platyrhynchos, tufted ducks Aythya fuligula, golden plovers Pluvialis apricaria, purple sandpipers Calidris maritima, and black guillemots Cepphus grylle reflected their position in the foodchain. The differences in OC-levels seem nevertheless too high just to reflect the different food-chain levels of these species in Iceland. The winter grounds of the migratory golden plovers and tufted ducks appear to be more contaminated than the Icelandic terrestrial habitat of ptarmigans or the freshwater habitat as reflected in mallards, both resident species. However, spending the winter on the coast in Iceland, results in high levels of contaminants in purple sandpipers and black guillemots. Our results indicate OC contamination of the marine ecosystem in Iceland while the terrestrial and freshwater ecosystems are little affected. It is postulated that gyrfalcons receive the major part of the observed contamination from prey other than ptarmigan, especially birds associated with the marine ecosystem and also from migratory birds. PMID:11234542

Olafsdóttir, K; Petersen, A E; Magnúsdóttir, E V; Björnsson, T; Jóhannesson, T

2001-01-01

94

Heptachlor seed treatment contaminates hawks, owls, and eagles of Columbia Basin, Oregon  

USGS Publications Warehouse

We evaluated organochlorine residues in 12 species of hawks. owls, and eagles from the Columbia Basin of Oregon between 1978 and 1981. Companion studies showed that heptachlor epoxide (HE) induced adult mortality and reduced productivity of the Canada Goose (Branta canadensis) and American Kestrel (Falco sparverius).ln this study, brain tissue from raptors found dead and sample eggs from 90 nests were analyzed for organochlorines. The primary concern was HE that entered raptor food chains through the ingestion of heptachlor-treated seed by their prey. HE residues were detected in eggs from 9 of 10 species and ranged as high as 4.75 ppm (wet wt), but no definite effects of HE on productivity were readily apparent from the limited series of nests. However, the hazard of heptachlor seed treatments to birds of prey was demonstrated by the occurrence of lethal residues of HE in brain tissue of 3 Golden Eagles (Aquila chrysaetos) and 1 Rough-legged Hawk (Buteo lagopus). Other organochlorine pesticides were present in the eggs and significant relationships were found between DDE and eggshell thickness for the Swainson's Hawk (Buteo swainsoni) and Western Screech-Owl (Otus kennicotti), although shell thinning (9.6% and 7.4%) was below the generally accepted range where reproductive problems have been known to occur.

Henny, C.J.; Blus, L.J.; Kaiser, T.E.

1984-01-01

95

Spatial and temporal variability of nitrogen oxide and methane fluxes from a fertilized tree plantation in Costa Rica  

NASA Astrophysics Data System (ADS)

Nitric oxide (NO), nitrous oxide (N2O), and methane (CH4) are naturally produced and consumed by soil biogeochemical processes. Naturally high variation between trace gas fluxes may temporarily increase due to agricultural management. We studied spatial and temporal variability of fluxes in the context of a 3-year field experiment established to identify and quantify N2O fluxes and controlling factors using automated field measurements. We measured trace gas fluxes, soil temperature, and moisture from fertilized and unfertilized balsa (Ochroma lagopus) plantations. Combining spatial and temporal sampling we evaluate if automatically measured time series of N2O emissions are representative of overall mean fluxes from fertilized loam under balsa. Soil trace gas fluxes were measured manually at 36 randomly distributed sampling locations per plot. Mean plot emissions were evaluated against fluxes measured by seven chambers commonly used for routine bimonthly manual measurements and against N2O emissions measured by two automated chambers at 4.6-hour sampling intervals. Trace gas fluxes were highly variable over 40 × 40 m plots. Nitrogen oxide fluxes were mainly spatially independent. Fertilization increased nitrogen oxide emissions but did not introduce spatial dependency of flux data. Within about 6 weeks fluxes approached pre-fertilization level again. Given high spatial variation of nitrogen oxide fluxes we find that automatically measured N2O fluxes represent the nature of the flux response well and are in the range of fluxes indicated by spatial sampling. When soils were relatively dry fertilization inhibited CH4 uptake.

Weitz, A. M.; Keller, M.; Linder, E.; Crill, P. M.

1999-12-01

96

Mother knows best: functionally referential alarm calling in white-tailed ptarmigan.  

PubMed

Functionally referential alarm calls have stimulus specificity, distinct acoustic structure, and elicit different escape responses that are appropriate to the threat. The mechanisms by which escape responses are evoked are not fully understood and may range from eliciting innate responses to conveying representational information. White-tailed ptarmigan (Lagopus leucurus) are a long-lived alpine tundra grouse, which are preyed upon by aerial and terrestrial predators. We investigated the hypothesis that alarm calls of ptarmigan hens with chicks are functionally referential. We recorded hens' alarm calls in response to naturally occurring and model predators in California's Sierra Nevada alpine tundra for two summer seasons. We conducted playback experiments in the field to determine chick responses to alarm calls. Alarm calls commenced with an extended 'alerting' note followed by a series of staccato notes grouped into elements. Fundamental and dominant frequencies in element notes were significantly higher in terrestrial compared to aerial threat alarm calls. Playbacks of terrestrial threat alarm calls elicited an upright/alert position by chicks (75 % of responses). In response to aerial threat alarm call playbacks, chicks flattened to the ground and froze (80 % of responses). To our knowledge, this study provides the first empirical evidence of functionally referential alarm calling, including the responses of the receivers, in an avian species in the wild. PMID:24132414

Ausmus, Desa M; Clarke, Jennifer A

2014-05-01

97

Association of wintering raptors with Conservation Reserve Enhancement Program grasslands in Pennsylvania  

USGS Publications Warehouse

Conservation grasslands can provide valuable habitat resource for breeding songbirds, but their value for wintering raptors has received little attention. We hypothesized that increased availability of grassland habitat through the Conservation Reserve Enhancement Program (CREP) has resulted in an increase or redistribution in numbers of four species of raptors in Pennsylvania since 2001. We tested this by analyzing winter raptor counts from volunteer surveys, conducted from 2001 to 2008, for Red-tailed Hawks (Buteo jamaicensis), Rough-legged Hawks (Buteo lagopus), Northern Harriers (Circus cyaneus), and American Kestrels (Falco sparverius). During that period, numbers of wintering Northern Harriers increased by more than 20% per year. Log-linear Poisson regression models show that all four species increased in the region of Pennsylvania that had the most and longest-established conservation grasslands. At the county scale (N= 67), Bayesian spatial models showed that spatial and temporal population trends of all four species were positively correlated with the amount of conservation grassland. This relationship was particularly strong for Northern Harriers, with numbers predicted to increase by 35.7% per year for each additional 1% of farmland enrolled in CREP. Our results suggest that conservation grasslands are likely the primary cause of the increase in numbers of wintering Northern Harriers in Pennsylvania since 2001. ?? 2010 The Authors. Journal of Field Ornithology ?? 2010 Association of Field Ornithologists.

Wilson, A.; Brittingham, M.; Grove, G.

2010-01-01

98

Winter raptor use of the Platte and North Platte River Valleys in south central Nebraska  

USGS Publications Warehouse

Winter distribution and abundance of raptors were monitored within the Platte and North Platte river valleys. Data were collected along 265 km of census routes along the Platte and North Platte rivers during the winters of 1978-1979 and 1979-1980. Observations recorded during the second winter involved less observation time and were at somewhat different periods. There were 1574 sightings of 15 species representing 3 raptor families. Number of raptors observed on 54 days from 15 November to 13 February 1978-1979 was 48.3 per 100 km. In 20 days of observation from 5 December to 6 March 1979-1980, 39.7 raptors were observed per 100 km. Small mammal indices were 21 and 12 captures per 1000 trap nights during November 1978 and 1979, respectively. Raptors were sighted most frequently in riverine habitat and least in pasture and tilled fields. American kestrels (Falco sparverius) (11.1 individuals/100 km), red-tailed hawks (Buteo jamaicensis) (9.9), and bald eagles (Haliaeetus leucocephalus) (9.6) were the most frequently sighted raptors. Northern harrier (Circus cyaneus), rough-legged hawk (B. lagopus), and prairie falcon (P. mexicanus) sightings were 3.4, 3.4, and 1.7, respectively. Nine species were seen at a frequency of less than 1.0 individuals/100 km. Improved foraging conditions throughout the region resulted in fewer raptors sighted in 1979-1980.

Lingle, G. R.

1989-01-01

99

Winter habitat associations of diurnal raptors in Californias Central Valley  

USGS Publications Warehouse

The wintering raptors of California's Central Valley are abundant and diverse. Despite this, little information exists on the habitats used by these birds in winter. We recorded diurnal raptors along 19 roadside survey routes throughout the Central Valley for three consecutive winters between 2007 and 2010. We obtained data sufficient to determine significant positive and negative habitat associations for the White-tailed Kite (Elanus leucurus), Bald Eagle {Haliaeetus leucocephalus), Northern Harrier (Circus cyaneus), Red-tailed Hawk (Buteo jamaicensis), Ferruginous Hawk (Buteo regalis), Rough-legged Hawk (Buteo lagopus), American Kestrel (Falco sparverius), and Prairie Falcon (Falco mexicanus). The Prairie Falcon and Ferruginous and Rough-legged hawks showed expected strong positive associations with grasslands. The Bald Eagle and Northern Harrier were positively associated not only with wetlands but also with rice. The strongest positive association for the White-tailed Kite was with wetlands. The Red-tailed Hawk was positively associated with a variety of habitat types but most strongly with wetlands and rice. The American Kestrel, Northern Harrier, and White-tailed Kite were positively associated with alfalfa. Nearly all species were negatively associated with urbanized landscapes, orchards, and other intensive forms of agriculture. The White-tailed Kite, Northern Harrier, Redtailed Hawk, Ferruginous Hawk, and American Kestrel showed significant negative associations with oak savanna. Given the rapid conversion of the Central Valley to urban and intensive agricultural uses over the past few decades, these results have important implications for conservation of these wintering raptors in this region.

Pandolrno, E. R.; Herzog, M. P.; Hooper, S. L.; Smith, Z.

2011-01-01

100

Serum lipid concentrations in six canid and four ursid species in four zoos.  

PubMed

Serum lipid levels were measured in healthy captive wild canids and ursids, and the values were compared with previously published data. Serum lipid levels were evaluated in blood samples collected from eight African wild dogs (Lycaon pictus), three arctic foxes (Alopex lagopus), nine gray wolves (Canis lupus), four maned wolves (Chrysocyon brachyurus), two Mexican wolves (Canis lupus baleiyi), nine red wolves (Canis rufus), two brown bears (Ursus arctos), six polar bears (Ursus maritimus), six spectacled bears (Tremarctos ornatus), and five sun bears (Ursus malayanus). Samples were analyzed for total cholesterol, triacylglycerides, high-density lipoprotein-cholesterol, and low-density lipoprotein-cholesterol. Although the results showed a great variation among species, circulating lipids appeared especially high, sometimes extremely so, in the spectacled bears, polar bears, sun bears, and maned wolves compared with all other species sampled. The study provides a substantial basis for comparing lipid levels in presumed healthy animals and indicates a need for controlled study of the effects of diet on circulating lipid levels. PMID:15193071

Crissey, Susan D; Ange, Kimberly D; Slifka, Kerri A; Sadler, William; Kahn, Stephen; Ward, Ann M

2004-03-01

101

Gull eggs--food of high organic pollutant content?  

PubMed

A wide range and occasionally high levels of persistent organic pollutants (POPs) are reported in Arctic regions, especially among top predators. Polar bears (Ursus maritimus), arctic foxes (Alopex lagopus) and some gull species (Larus spp.) often have high levels of these fat-soluble pollutants. Gulls deposit significant levels of these contaminants in their eggs. In northern regions, gull eggs are part of the traditional human diet. In the present study we have investigated the levels of POPs in gull eggs in order to determine the tolerable weekly intake (TWI) for humans. Concentrations of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were measured in 214 gull eggs collected in the spring of 2001-02. The eggs were collected from four gull species (herring gulls (Larus argentatus), great black-backed gulls (L. marinus), lesser black-backed gulls (L. fuscus) and glaucous gulls (L. hyperboreus)) at 12 different locations in Northern Norway, on the Faroe Islands and on Svalbard. The pollutant levels in gull eggs were found to be 65.5 +/- 26.9 pg toxic equivalent (TE) for dioxin and PCB g(-1) wet weight. Based on these findings and the TWI-value determined by the EU Scientific Committee on Food it is advised that children, young women and pregnant and nursing women should not eat gull eggs. Other people should limit their intake of eggs to an absolute minimum, considering the health risks associated with gull egg intake. PMID:15931427

Pusch, Kerstin; Schlabach, Martin; Prinzinger, Roland; Wing Gabrielsen, Geir

2005-06-01

102

Genetic characterisation of Toxoplasma gondii in wildlife from North America revealed widespread and high prevalence of the fourth clonal type.  

PubMed

Little is known of the genetic diversity of Toxoplasma gondii circulating in wildlife. In the present study wild animals, from the USA were examined for T. gondii infection. Tissues of naturally exposed animals were bioassayed in mice for isolation of viable parasites. Viable T. gondii was isolated from 31 animals including, to our knowledge for the first time, from a bald eagle (Haliaeetus leucocephalus), five gray wolves (Canis lupus), a woodrat (Neotoma micropus), and five Arctic foxes (Alopex lagopus). Additionally, 66 T. gondii isolates obtained previously, but not genetically characterised, were revived in mice. Toxoplasma gondii DNA isolated from these 97 samples (31+66) was characterised using 11 PCR-restriction fragment length polymorphism (RFLP) markers (SAG1, 5'- and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico). A total of 95 isolates were successfully genotyped. In addition to clonal Types II, and III, 12 different genotypes were found. These genotype data were combined with 74 T. gondii isolates previously characterised from wildlife from North America and a composite data set of 169 isolates comprised 22 genotypes, including clonal Types II, III and 20 atypical genotypes. Phylogenetic network analysis showed limited diversity with dominance of a recently designated fourth clonal type (Type 12) in North America, followed by the Type II and III lineages. These three major lineages together accounted for 85% of strains in North America. The Type 12 lineage includes previously identified Type A and X strains from sea otters. This study revealed that the Type 12 lineage accounts for 46.7% (79/169) of isolates and is dominant in wildlife of North America. No clonal Type I strain was identified among these wildlife isolates. These results suggest that T. gondii strains in wildlife from North America have limited diversity, with the occurrence of only a few major clonal types. PMID:21802422

Dubey, J P; Velmurugan, G V; Rajendran, C; Yabsley, M J; Thomas, N J; Beckmen, K B; Sinnett, D; Ruid, D; Hart, J; Fair, P A; McFee, W E; Shearn-Bochsler, V; Kwok, O C H; Ferreira, L R; Choudhary, S; Faria, E B; Zhou, H; Felix, T A; Su, C

2011-09-01

103

Detection probability of cliff-nesting raptors during helicopter and fixed-wing aircraft surveys in western Alaska  

USGS Publications Warehouse

We conducted repeated aerial surveys for breeding cliff-nesting raptors on the Yukon Delta National Wildlife Refuge (YDNWR) in western Alaska to estimate detection probabilities of Gyrfalcons (Falco rusticolus), Golden Eagles (Aquila chrysaetos), Rough-legged Hawks (Buteo lagopus), and also Common Ravens (Corvus corax). Using the program PRESENCE, we modeled detection histories of each species based on single species occupancy modeling. We used different observers during four helicopter replicate surveys in the Kilbuck Mountains and five fixed-wing replicate surveys in the Ingakslugwat Hills near Bethel, AK. During helicopter surveys, Gyrfalcons had the highest detection probability estimate (p^;p^ 0.79; SE 0.05), followed by Golden Eagles (p^=0.68; SE 0.05), Common Ravens (p^=0.45; SE 0.17), and Rough-legged Hawks (p^=0.10; SE 0.11). Detection probabilities from fixed-wing aircraft in the Ingakslugwat Hills were similar to those from the helicopter in the Kilbuck Mountains for Gyrfalcons and Golden Eagles, but were higher for Common Ravens (p^=0.85; SE 0.06) and Rough-legged Hawks (p^=0.42; SE 0.07). Fixed-wing aircraft provided detection probability estimates and SEs in the Ingakslugwat Hills similar to or better than those from helicopter surveys in the Kilbucks and should be considered for future cliff-nesting raptor surveys where safe, low-altitude flight is possible. Overall, detection probability varied by observer experience and in some cases, by study area/aircraft type.

Booms, T. L.; Schempf, P. F.; McCaffery, B. J.; Lindberg, M. S.; Fuller, M. R.

2010-01-01

104

Importance of the National Petroleum Reserve-Alaska for aquatic birds  

USGS Publications Warehouse

We used data from aerial surveys (1992–2010) of >100,000 km2 and ground surveys (1998–2004) of >150 km2 to estimate the density and abundance of birds on the North Slope of Alaska (U.S.A.). In the ground surveys, we used double sampling to estimate detection ratios. We used the aerial survey data to compare densities of birds and Arctic fox (Vulpes lagopus), the major nest predator of birds, on the North Slope, in Prudhoe Bay, and in nearby areas. We partitioned the Prudhoe Bay oil field into 2 × 2 km plots and determined the relation between density of aquatic birds and density of roads, buildings, and other infrastructure in these plots. Abundance and density (birds per square kilometer) of 3 groups of aquatic birds—waterfowl, loons, and grebes; shorebirds; and gulls, terns, and jaegers—were highest in the National Petroleum Reserve–Alaska (NPRA) and lowest in the Arctic National Wildlife Refuge. Six other major wetlands occur in the Arctic regions of Canada and Russia, but the largest population of aquatic birds was in the NPRA. Aquatic birds were concentrated in the northern part of the NPRA. For example, an area that covered 18% of the NPRA included 53% of its aquatic birds. The aerial surveys showed that bird density was not lower and fox density was not higher in Prudhoe Bay than in surrounding areas. Density of infrastructure did not significantly affect bird density for any group of species. Our results establish that the NPRA is one of the most important areas for aquatic birds in the Arctic. Our results and those of others also indicate that oil production, as practiced in Prudhoe Bay, does not necessarily lead to substantial declines in bird density or productivity in or near the developed areas.

Bart, Jonathan; Platte, Robert M.; Andres, Brad; Brown, Stephen; Johnson, James A.; Larned, William

2013-01-01

105

Signatures of large-scale and local climates on the demography of white-tailed ptarmigan in Rocky Mountain National Park, Colorado, USA  

NASA Astrophysics Data System (ADS)

Global climate change may impact wildlife populations by affecting local weather patterns, which, in turn, can impact a variety of ecological processes. However, it is not clear that local variations in ecological processes can be explained by large-scale patterns of climate. The North Atlantic oscillation (NAO) is a large-scale climate phenomenon that has been shown to influence the population dynamics of some animals. Although effects of the NAO on vertebrate population dynamics have been studied, it remains uncertain whether it broadly predicts the impact of weather on species. We examined the ability of local weather data and the NAO to explain the annual variation in population dynamics of white-tailed ptarmigan (Lagopus leucurus) in Rocky Mountain National Park, USA. We performed canonical correlation analysis on the demographic subspace of ptarmigan and local-climate subspace defined by the empirical orthogonal function (EOF) using data from 1975 to 1999. We found that two subspaces were significantly correlated on the first canonical variable. The Pearson correlation coefficient of the first EOF values of the demographic and local-climate subspaces was significant. The population density and the first EOF of local-climate subspace influenced the ptarmigan population with 1-year lags in the Gompertz model. However, the NAO index was neither related to the first two EOF of local-climate subspace nor to the first EOF of the demographic subspace of ptarmigan. Moreover, the NAO index was not a significant term in the Gompertz model for the ptarmigan population. Therefore, local climate had stronger signature on the demography of ptarmigan than did a large-scale index, i.e., the NAO index. We conclude that local responses of wildlife populations to changing climate may not be adequately explained by models that project large-scale climatic patterns.

Wang, Guiming; Hobbs, Thompson; Galbraith, Hector; Giesen, Kenneth

2002-06-01

106

Impact of transient climate change upon Grouse population dynamics in the Italian Alps  

NASA Astrophysics Data System (ADS)

Understanding the effect of short to medium term weather condition, and of transient global warming upon wildlife species life history is essential to predict the demographic consequences therein, and possibly develop adaptation strategies, especially in game species, where hunting mortality may play an important role in population dynamics. We carried out a preliminary investigation of observed impact of weather variables upon population dynamics indexes of three alpine Grouse species (i.e. Rock Ptarmigan, Lagopus Mutus, Black Grouse, Tetrao Tetrix, Rock Partridge, Alectoris Graeca), nested within central Italian Alps, based upon 15 years (1995-2009) of available censuses data, provided by the Sondrio Province authority. We used a set of climate variables already highlighted within recent literature for carrying considerable bearing on Grouse population dynamics, including e.g. temperature at hatching time and during winter, snow cover at nesting, and precipitation during nursing period. We then developed models of Grouses' population dynamics by explicitly driving population change according to their dependence upon the significant weather variables and population density and we evaluated objective indexes to assess the so obtained predictive power. Eventually, we develop projection of future local climate, based upon locally derived trends, and upon projections from GCMs (A2 IPCC storyline) already validated for the area, to project forward in time (until 2100 or so) the significant climatic variables, which we then use to force population dynamics models of the target species. The projected patterns obtained through this exercise are discussed and compared against those expected under stationary climate conditions at present, and preliminary conclusions are drawn.

Pirovano, Andrea; Bocchiola, Daniele

2010-05-01

107

Molecular identification of blood source animals from black flies (Diptera: Simuliidae) collected in the alpine regions of Japan.  

PubMed

One of vector-borne avian protozoa, Leucocytozoon lovati, has been found in the Japanese rock ptarmigans (Lagopus mutus japonicus), the endangered bird species distributed in the alpine regions in Japan. Vector arthropod species of L. lovati has also been estimated as Simuliidae black flies distributed in the same habitat of the host bird, however, possible blood meals of the black flies were not identified yet. To reveal host animals of black flies, we estimated the blood resources by using molecular techniques. Black flies were collected at Mt. Chogatake, one of the alpine regions of Japan in which Japanese rock ptarmigans live in June 2005. The analyzed 144 specimens were morphologically identified into five species including Simulium japonicum (n = 87), Prosimulium hirtipes (n = 48), Prosimulium yezoense (n = 3), Twinnia japonensis (n = 3), and Cnephia mutata (n = 3). Individually extracted DNA from the black flies was subjected to polymerase chain reaction (PCR) amplification targeting the partial mitochondrial cytochrome b gene of birds or mammals to identify the blood meals. Of 144 black flies examined, 34 specimens were PCR positive for avian hosts (23.6%). No mammalian-derived bloods were detected from the samples studied through. Sequences amplified from 11 black flies consist of S. japonicum, P. hirtipes, and C. mutata showed high similarity to that of the Japanese rock ptarmigan. Therefore, present results conclusively suggest that these three species of black flies might suck the bloods of Japanese rock ptarmigans and could be the vector for L. lovati infection among this endangered bird species of Japan. PMID:19936792

Imura, Takayuki; Sato, Yukita; Ejiri, Hiroko; Tamada, Asumi; Isawa, Haruhiko; Sawabe, Kyoko; Omori, Sumie; Murata, Koichi; Yukawa, Masayoshi

2010-01-01

108

Characterization and Physical Mapping of Ribosomal RNA Gene Families in Plantago  

PubMed Central

• Background and Aims The organization of rRNA genes in cultivated Plantago ovata Forsk. and several of its wild allies was analysed to gain insight into the phylogenetic relationships of these species in the genus which includes some 200 species. • Methods Specific primers were designed to amplify the internal transcribed spacer (ITS1 and ITS2) regions from seven Plantago species and the resulting fragments were cloned and sequenced. Similarly, using specific primers, the 5S rRNA genes from these species were amplified and subsequently cloned. Fluorescence in-situ hybridization (FISH) was used for physical mapping of 5S and 45S ribosomal RNA genes. • Results The ITS1 region is 19–29?bp longer than the ITS2 in different Plantago species. The 5S rRNA gene-repeating unit varies in length from 289 to 581?bp. Coding regions are highly conserved across species, but the non-transcribed spacers (NTS) do not match any database sequences. The clone from the cultivated species P. ovata was used for physical mapping of these genes by FISH. Four species have one FISH site while three have two FISH sites. In P. lanceolata and P. rhodosperma, the 5S and 45S (18S-5·8S-25S) sites are coupled. • Conclusions Characterization of 5S and 45S rRNA genes has indicated a possible origin of P. ovata, the only cultivated species of the genus and also the only species with x = 4, from a species belonging to subgenus Psyllium. Based on the studies reported here, P. ovata is closest to P. arenaria, although on the basis of other data the two species have been placed in different subgenera. FISH mapping can be used as an efficient tool to help determine phylogenetic relationships in the genus Plantago and show the interrelationship between P. lanceolata and P. lagopus.

DHAR, MANOJ K.; FRIEBE, BERND; KAUL, SANJANA; GILL, BIKRAM S.

2006-01-01

109

Alpine plant community trends on the elk summer range of Rocky Mountain National Park, Colorado: an analysis of existing data  

USGS Publications Warehouse

The majority of the elk (Cervus elaphus) population of Rocky Mountain National Park in Colorado summer in the parka??s high elevation alpine and subalpine meadows and willow krummholz. The parka??s population of white-tailed ptarmigan (Lagopus leucurus altipetens) depends on both dwarf and krummholz willows for food and cover. Concern about the effects of elk herbivory on these communities prompted the monitoring of 12 vegetation transects in these regions from 1971 to 1996. Over this 25-year period, data were collected on plant species cover and frequency and shrub heights. These data have not been statistically analyzed for trends in measured variable over time to determine changes in species abundance. Krummholz willow species (Salix planifolia, S. brachycarpa) declined 17-20 percent in cover and about 25 centimeters in height over the study period. Graminoids (particularly Deschampsia caespitosa, Carex, and Poa) increased slightly from 1971 to 1996. No significant increases of nonnative plant species were observed. An increase in presence of bare ground over the 25-year period warrants continued measurement of these transects. Lack of good data on elk density, distribution, or sue levels precluded correlating changes in plant species cover, frequency, or heights with elk population trends. I recommend development of a more rigorously designed monitoring program that includes these transects as well as other chosen on a random or stratified design and consistent measurement protocol and sampling intervals. Some method of quantifying elk use, either through measurement of plant utilization, pellet counts, or census-type surveys, would allow correlation of changes in plant species over time with changes in elk distribution and density on the parka??s alpine and subalpine regions.

Zeigenfuss, Linda C.

2006-01-01

110

Importance of the national petroleum reserve-alaska for aquatic birds.  

PubMed

We used data from aerial surveys (1992-2010) of >100,000 km(2) and ground surveys (1998-2004) of >150 km(2) to estimate the density and abundance of birds on the North Slope of Alaska (U.S.A.). In the ground surveys, we used double sampling to estimate detection ratios. We used the aerial survey data to compare densities of birds and Arctic fox (Vulpes lagopus), the major nest predator of birds, on the North Slope, in Prudhoe Bay, and in nearby areas. We partitioned the Prudhoe Bay oil field into 2 × 2 km plots and determined the relation between density of aquatic birds and density of roads, buildings, and other infrastructure in these plots. Abundance and density (birds per square kilometer) of 3 groups of aquatic birds-waterfowl, loons, and grebes; shorebirds; and gulls, terns, and jaegers-were highest in the National Petroleum Reserve-Alaska (NPRA) and lowest in the Arctic National Wildlife Refuge. Six other major wetlands occur in the Arctic regions of Canada and Russia, but the largest population of aquatic birds was in the NPRA. Aquatic birds were concentrated in the northern part of the NPRA. For example, an area that covered 18% of the NPRA included 53% of its aquatic birds. The aerial surveys showed that bird density was not lower and fox density was not higher in Prudhoe Bay than in surrounding areas. Density of infrastructure did not significantly affect bird density for any group of species. Our results establish that the NPRA is one of the most important areas for aquatic birds in the Arctic. Our results and those of others also indicate that oil production, as practiced in Prudhoe Bay, does not necessarily lead to substantial declines in bird density or productivity in or near the developed areas. Prioridades para la Conservación de Aves en el Norte de Alaska. PMID:23937114

Bart, Jonathan; Platte, Robert M; Andres, Brad; Brown, Stephen; Johnson, James A; Larned, William

2013-12-01

111

Predation pressure by avian predators suggests summer limitation of small-mammal populations in the Canadian Arctic.  

PubMed

Predation has been suggested to be especially important in simple food webs and less productive ecosystems such as the arctic tundra, but very few data are available to evaluate this hypothesis. We examined the hypothesis that avian predators could drive the population dynamics of two cyclic lemming species in the Canadian Arctic. A dense and diverse suite of predatory birds, including the Snowy Owl (Bubo scandiacus), the Rough-legged Hawk (Buteo lagopus), and the Long-tailed Jaeger (Stercorarius longicaudus), inhabits the arctic tundra and prey on collared (Dicrostonyx groenlandicus) and brown (Lemmus trimucronatus) lemmings during the snow-free period. We evaluated the predation pressure exerted by these predators by combining their numerical (variation in breeding and fledgling numbers) and functional (variation in diet and daily consumption rates) responses to variations in lemming densities over the 2004-2010 period. Breeding density and number of fledglings produced by the three main avian predators increased sharply without delay in response to increasing lemming densities. The proportion of collared lemmings in the diet of those predators was high at low lemming density (both species) but decreased as lemming density increased. However, we found little evidence that their daily consumption rates vary in relation to changes in lemming density. Total consumption rate by avian predators initially increased more rapidly for collared lemming but eventually leveled off at a much higher value for brown lemmings, the most abundant species at our site. The combined daily predation rate of avian predators exceeded the maximum daily potential growth rates of both lemming species except at the highest recorded densities for brown lemmings. We thus show, for the first time, that predation pressure exerted without delay by avian predators can limit populations of coexisting lemming species during the snow-free period, and thus, that predation could play a role in the cyclic dynamic of these species in the tundra. PMID:24649646

Therrien, J F; Gauthier, G; Korpimäki, E; Bêty, J

2014-01-01

112

Falcon versus grouse: flight adaptations of a predator and its prey  

USGS Publications Warehouse

Several falcons were trained to fly along a 500 m course to a lure. The air speeds of the more consistent performers averaged about 1.5 times their calculated minimum power speeds, and occasionally reached 2.1 times the minimum power speed. Wing beat frequencies of all the falcons were above those estimated from earlier field observations, and the same was true of wild Sage Grouse Centrocercus urophasianus, a regular falconer's quarry in the study area. Measurements of grouse killed by falcons showed that their wings were short, with broad slotted tips, whereas the falcons' wings were longer in relation to their body mass, and tapered. The short wings of grouse result in fast flight, high power requirements, and reduced capacity for aerobic flight. Calculations indicated that the grouse should fly faster than the falcons, and had the large amount of flight muscle needed to do so, but that the falcons would be capable of prolonged aerobic flight, whereas the grouse probably would not. We surmise that Sage Grouse cannot fly continuously without incurring an oxygen debt, and are therefore not long-distance migrants, although this limitation is partly due to their large size, and would not apply to smaller galliform birds such as ptarmigan Lagopus spp. The wing action seen in video recordings of the falcons was not consistent with the maintenance of constant circulation. We call it 'chase mode' because it appears to be associated with a high level of muscular exertion, without special regard to fuel economy. It shows features in common with the 'bounding' flight of passerines.

Pennycuick, C.J.; Fuller, M.R.; Oar, J.J.; Kirkpatrick, S.J.

1994-01-01

113

High exposure rates of anticoagulant rodenticides in predatory bird species in intensively managed landscapes in Denmark.  

PubMed

The extensive use of anticoagulant rodenticides (ARs) for rodent control has led to widespread secondary exposure in nontarget predatory wildlife species. We investigated exposure rates and concentrations of five ARs in liver samples from five raptors and six owls from Denmark. A total of 430 birds were analysed. ARs were detected in 84-100 % of individual birds within each species. Multiple AR exposure was detected in 73 % of all birds. Average number of substances detected in individual birds was 2.2 with no differences between owls and raptors. Difenacoum, bromadiolone, and brodifacoum were the most prevalent substances and occurred in the highest concentrations. Second-generation ARs made up 96 % of the summed AR burden. Among the six core species (sample size >30), summed AR concentrations were lower in rough-legged buzzard (Buteo lagopus) and long-eared owl (Asio otus) than in barn owl (Tyto alba), buzzard (B. buteo), kestrel (Falco tinnunculus), and tawny owl (Strix aluco). There was a strong tendency for seasonal variations in the summed AR concentration with levels being lowest during autumn, which is probably related to an influx of less-exposed migrating birds from northern Scandinavia during autumn. High hepatic AR residue concentrations (>100 ng/g wet weight), which have been associated with symptoms of rodenticide poisoning and increased mortality, were recorded high frequencies (12.9-37.4 %) in five of the six core species. The results suggest that the present use of ARs in Denmark, at least locally, may have adverse effects on reproduction and, ultimately, population status in some raptors and owls. PMID:22588365

Christensen, Thomas Kjær; Lassen, Pia; Elmeros, Morten

2012-10-01

114

Factors influencing nesting success of king eiders on northern Alaska's Coastal Plain  

USGS Publications Warehouse

King eider (Somateria spectabilis) populations have declined markedly in recent decades for unknown reasons. Nest survival is one component of recruitment, and a female's chance of reproductive success increases with her ability to choose an appropriate nesting strategy. We estimated variation in daily nest survival of king eiders at 2 sites, Teshekpuk and Kuparuk, Alaska, USA, 2002-2005. We evaluated both a priori and exploratory competing models of nest survival that considered importance of nest concealment, seclusion, and incubation constancy as strategies to avoid 2 primary egg predators, avian (Larus spp., Stercorarius spp., and Corvus corax) and fox (Alopex lagopus). We used generalized nonlinear techniques to examine factors affecting nest survival rates and information-theoretic approaches to select among competing models. Estimated nest survival, accounting for a nest visitation effect, varied considerably across sites and years (0.21-0.57); however, given our small sample size, much of this variation maybe attributable to sampling variation (??process = 0.007, 95% CI: 0.003-0.070). Nest survival was higher at Kuparuk than Teshekpuk in all years; however, due to the correlative nature of our data, we cannot determine the underlying causes with any certainty. We found mixed support for the concealed breeding strategy, females derived no benefit from nesting in areas with more willow (Salix spp.; measure of concealment) except that the observer effect diminished as willow cover increased. We suggest these patterns are due to conflicting predation pressures. Nest survival was not higher on islands (measure of seclusion) or with increased incubation constancy but was higher post-fox removal, indicating that predator control on breeding grounds could be a viable management option. Nest survival was negatively affected by our nest visitations, most likely by exposing the nest to avian scavengers. We recommend precautions be taken to limit the effects of nest visits in future studies and to consider them as a possible negative bias in estimated nest survival. Future models of the impacts of development within the breeding grounds of king eider should consider the influence of humans in the vicinity of nests.

Bentzen, R. L.; Powell, A. N.; Suydam, R. S.

2008-01-01

115

Predator behaviour and predation risk in the heterogeneous Arctic environment.  

PubMed

1. Habitat heterogeneity and predator behaviour can strongly affect predator-prey interactions but these factors are rarely considered simultaneously, especially when systems encompass multiple predators and prey. 2. In the Arctic, greater snow geese Anser caerulescens atlanticus L. nest in two structurally different habitats: wetlands that form intricate networks of water channels, and mesic tundra where such obstacles are absent. In this heterogeneous environment, goose eggs are exposed to two types of predators: the arctic fox Vulpes lagopus L. and a diversity of avian predators. We hypothesized that, contrary to birds, the hunting ability of foxes would be impaired by the structurally complex wetland habitat, resulting in a lower predation risk for goose eggs. 3. In addition, lemmings, the main prey of foxes, show strong population cycles. We thus further examined how their fluctuations influenced the interaction between habitat heterogeneity and fox predation on goose eggs. 4. An experimental approach with artificial nests suggested that foxes were faster than avian predators to find unattended goose nests in mesic tundra whereas the reverse was true in wetlands. Foxes spent 3.5 times more time between consecutive attacks on real goose nests in wetlands than in mesic tundra. Their attacks on goose nests were also half as successful in wetlands than in mesic tundra whereas no difference was found for avian predators. 5. Nesting success in wetlands (65%) was higher than in mesic tundra (56%) but the difference between habitats increased during lemming crashes (15%) compared to other phases of the cycle (5%). Nests located at the edge of wetland patches were also less successful than central ones, suggesting a gradient in accessibility of goose nests in wetlands for foxes. 6. Our study shows that the structural complexity of wetlands decreases predation risk from foxes but not avian predators in arctic-nesting birds. Our results also demonstrate that cyclic lemming populations indirectly alter the spatial distribution of productive nests due to a complex interaction between habitat structure, prey-switching and foraging success of foxes. PMID:18248387

Lecomte, Nicolas; Careau, Vincent; Gauthier, Gilles; Giroux, Jean-François

2008-05-01

116

Intrapopulation Variability Shaping Isotope Discrimination and Turnover: Experimental Evidence in Arctic Foxes  

PubMed Central

Background Tissue-specific stable isotope signatures can provide insights into the trophic ecology of consumers and their roles in food webs. Two parameters are central for making valid inferences based on stable isotopes, isotopic discrimination (difference in isotopic ratio between consumer and its diet) and turnover time (renewal process of molecules in a given tissue usually measured when half of the tissue composition has changed). We investigated simultaneously the effects of age, sex, and diet types on the variation of discrimination and half-life in nitrogen and carbon stable isotopes (?15N and ?13C, respectively) in five tissues (blood cells, plasma, muscle, liver, nail, and hair) of a top predator, the arctic fox Vulpes lagopus. Methodology/Principal Findings We fed 40 farmed foxes (equal numbers of adults and yearlings of both sexes) with diet capturing the range of resources used by their wild counterparts. We found that, for a single species, six tissues, and three diet types, the range of discrimination values can be almost as large as what is known at the scale of the whole mammalian or avian class. Discrimination varied depending on sex, age, tissue, and diet types, ranging from 0.3‰ to 5.3‰ (mean ?=?2.6‰) for ?15N and from 0.2‰ to 2.9‰ (mean ?=?0.9‰) for ?13C. We also found an impact of population structure on ?15N half-life in blood cells. Varying across individuals, ?15N half-life in plasma (6 to 10 days) was also shorter than for ?13C (14 to 22 days), though ?15N and ?13C half-lives are usually considered as equal. Conclusion/Significance Overall, our multi-factorial experiment revealed that at least six levels of isotopic variations could co-occur in the same population. Our experimental analysis provides a framework for quantifying multiple sources of variation in isotopic discrimination and half-life that needs to be taken into account when designing and analysing ecological field studies.

Lecomte, Nicolas; Ahlstr?m, ?ystein; Ehrich, Dorothee; Fuglei, Eva; Ims, Rolf A.; Yoccoz, Nigel G.

2011-01-01

117

Benefiting from a migratory prey: spatio-temporal patterns in allochthonous subsidization of an Arctic predator.  

PubMed

1.?Flows of nutrients and energy across ecosystem boundaries have the potential to subsidize consumer populations and modify the dynamics of food webs, but how spatio-temporal variations in autochthonous and allochthonous resources affect consumers' subsidization remains largely unexplored. 2.?We studied spatio-temporal patterns in the allochthonous subsidization of a predator living in a relatively simple ecosystem. We worked on Bylot Island (Nunavut, Canada), where arctic foxes (Vulpes lagopus L.) feed preferentially on lemmings (Lemmus trimucronatus and Dicrostonyx groenlandicus Traill), and alternatively on colonial greater snow geese (Anser caerulescens atlanticus L.). Geese migrate annually from their wintering grounds (where they feed on farmlands and marshes) to the Canadian Arctic, thus generating a strong flow of nutrients and energy across ecosystem boundaries. 3.?We examined the influence of spatial variations in availability of geese on the diet of fox cubs (2003-2005) and on fox reproductive output (1996-2005) during different phases of the lemming cycle. 4.?Using stable isotope analysis and a simple statistical routine developed to analyse the outputs of a multisource mixing model (SIAR), we showed that the contribution of geese to the diet of arctic fox cubs decreased with distance from the goose colony. 5.?The probability that a den was used for reproduction by foxes decreased with distance from the subsidized goose colony and increased with lemming abundance. When lemmings were highly abundant, the effect of distance from the colony disappeared. The goose colony thus generated a spatial patterning of reproduction probability of foxes, while the lemming cycle generated a strong temporal variation of reproduction probability of foxes. 6.?This study shows how the input of energy owing to the large-scale migration of prey affects the functional and reproductive responses of an opportunistic consumer, and how this input is spatially and temporally modulated through the foraging behaviour of the consumer. Thus, perspectives of both landscape and foraging ecology are needed to fully resolve the effects of subsidies on animal demographic processes and population dynamics. PMID:22268371

Giroux, Marie-Andrée; Berteaux, Dominique; Lecomte, Nicolas; Gauthier, Gilles; Szor, Guillaume; Bêty, Joël

2012-05-01

118

Some autecological characteristics of early to late successional tree species in Venezuela  

NASA Astrophysics Data System (ADS)

The breadth of the continuum concept of strategy with respect to succession was tested on 21 tree and shrub species common in either unlogged or logged stands, respectively, in the Forest Reserve of Caparo, Venezuela, by examining morphological, physiological and population characteristics. Based on a preliminary abundance analysis, `early', `mid' and `late' successional species as well as `generalists' were distinguished. Early successional species, i.e. Ochroma lagopus, Heliocarpus popayanensis and Cecropia peltata were similar in many autecological aspects, e.g. monolayered leaf arrangement, orthotropic architectural models, no adaptive reiteration, clumped distribution, but differed in gap association and distribution along a drainage gradient. Mid-successional species established themselves both in large and small gaps (> 300 m[sup2 ]; 80-300 m[sup2 ]) and showed a clumped to regular distribution pattern in logged areas; they exhibited more diverse crown and leaf characteristics than early successional species. Late successional species established themselves only in small gaps and understorey, and showed a regular spatial pattern in undisturbed areas. All late successional species displayed architectural models with plagiotropic lateral axes and showed a multilayered leaf arrangement. Adaptive reiteration was a common feature of late successional species which could be further subdivided into large, medium-sized and small trees, indicating different light requirements at maturity. Generalists were common treelet and shrub species in both disturbed and undisturbed sites where they are also capable of completing their life cycle. The light compensation point (LCP) of an individual plant was strongly influenced by its crown illuminance. Large late successional species showed the widest range of LCP values, reflecting the increasing light availability with increasing height in mature forest. On the basis of many autecological characteristics, it was found (i) that there is in fact a continuum of species strategies with respect to succession even among early and mid-successional species and (ii) that the latter group of species showed the widest breadth of autecological traits, reflecting the heterogeneous environment in which they establish and mature.

Kammesheidt, Ludwig

2000-01-01

119

Serosurvey for canine distemper virus, canine adenovirus, Leptospira interrogans, and Toxoplasma gondii in free-ranging canids in Scandinavia and Svalbard.  

PubMed

Prevalence of antibodies reactive to canine distemper virus (CDV), canine adenovirus type 1 (CAV-1), Leptospira interrogans serovars Canicola and Icterohaemorrhagiae, and Toxoplasma gondii were examined in free-ranging Scandinavian canids. Sampling included 275 red foxes (Vulpes vulpes) from mainland Norway, 60 arctic foxes (Vulpes lagopus) from the high-arctic islands of Svalbard, and 98 wolves (Canis lupus) from the joint Swedish-Norwegian population. Methods used included virus neutralization tests for CDV and CAV-1, a microscopic agglutination test for L. interrogans, and a direct agglutination test for T. gondii. High prevalence of antibody to CAV-1 was identified in red foxes (59.6%), wolves (67.7%), and arctic foxes (37.8%). The prevalence of antibody to CDV varied between 9.6% and 12.3% in the three species. Antibodies to L. interrogans serovar Icterohaemorrhagiae were found in 9.9% of the red foxes and 8.4% of the wolves sampled, whereas no antibody-positive arctic foxes were found. All animals were antibody-negative for L. interrogans serovar Canicola. Antibodies to T. gondii were found in 66.9, 51.7, and 18.6% of red foxes, arctic foxes and wolves, respectively. Significantly more adults than juveniles were antibody-positive for CDV in red foxes and arctic foxes, for CAV-1 in wolves, and for T. gondii in red foxes and wolves. There was a general tendency for adult female red foxes to have a higher prevalence of antibodies for CDV than adult males; this difference was statistically significant. The results indicate that CDV and CAV-1 are endemic in red foxes and wolves on the Scandinavian mainland and in arctic foxes on Svalbard. Although infection with L. interrogans serovar Icterohaemorrhagiae was relatively common in wild canids on mainland Norway, it was not found on Svalbard, where the maintenance host (Rattus norvegicus) is absent. All three species are commonly exposed to T. gondii through predation on infected intermediate hosts. PMID:20688639

Akerstedt, Johan; Lillehaug, Atle; Larsen, Inger-Lise; Eide, Nina E; Arnemo, Jon M; Handeland, Kjell

2010-04-01

120

A Cervid Vocal Fold Model Suggests Greater Glottal Efficiency in Calling at High Frequencies  

Microsoft Academic Search

Male Rocky Mountain elk (Cervus elaphus nelsoni) produce loud and high fundamental frequency bugles during the mating season, in contrast to the male European Red Deer (Cervus elaphus scoticus) who produces loud and low fundamental frequency roaring calls. A critical step in understanding vocal communication is to relate sound complexity to anatomy and physiology in a causal manner. Experimentation at

Ingo R. Titze; Tobias Riede

2010-01-01

121

Health effects from long-range transported contaminants in Arctic top predators: An integrated review based on studies of polar bears and relevant model species.  

PubMed

The aim of this review is to provide a thorough overview of the health effects from the complexed biomagnified mixture of long-range transported industrial organochlorines (OCs), polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFCs) and mercury (Hg) on polar bear (Ursus maritimus) health. Multiple scientific studies of polar bears indicate negative relationships between exposure to these contaminants and health parameters; however, these are all of a correlative nature and do not represent true cause-and-effects. Therefore, information from controlled studies of farmed Norwegian Arctic foxes (Vulpes lagopus) and housed East and West Greenland sledge dogs (Canis familiaris) were included as supportive weight of evidence in the clarification of contaminant exposure and health effects in polar bears. The review showed that hormone and vitamin concentrations, liver, kidney and thyroid gland morphology as well as reproductive and immune systems of polar bears are likely to be influenced by contaminant exposure. Furthermore, exclusively based on polar bear contaminant studies, bone density reduction and neurochemical disruption and DNA hypomethylation of the brain stem seemed to occur. The range of tissue concentration, at which these alterations were observed in polar bears, were ca. 1-70,000 ng/g lw for OCs (blood plasma concentrations of some PCB metabolites even higher), ca. 1-1000 ng/g lw for PBDEs and for PFCs and Hg 114-3052 ng/g ww and 0.1-50 microg/g ww, respectively. Similar concentrations were found in farmed foxes and housed sledge dogs while the lack of dose response designs did not allow an estimation of threshold levels for oral exposure and accumulated tissue concentrations. Nor was it possible to pinpoint a specific group of contaminants being more important than others nor analyze their interactions. For East Greenland polar bears the corresponding daily SigmaOC and SigmaPBDE oral exposure was estimated to be 35 and 0.34 microg/kg body weight, respectively. Furthermore, PFC concentrations, at which population effect levels could occur, are likely to be reached around year 2012 for the East Greenland polar bear subpopulation if current increasing temporal trends continue. Such proposed reproductive population effects were supported by physiological based pharmacokinetic (PBPK) modelling of critical body residues (CBR) with risk quotients >or=1 for SigmaPCB, dieldrin, SigmaPFC and SigmaOHC (organohalogen contaminant). The estimated daily TEQ for East Greenland polar bears and East Greenland sledge dogs were 32-281-folds above WHO SigmaTEQ guidelines for humans. Compared to human tolerable daily intake (TDI), these were exceeded for PCBs, dieldrin, chlordanes and SigmaHCH in East Greenland polar bears. Comparisons like these should be done with caution, but together with the CBR modelling and T-score estimations, these were the only available tools for polar bear risk evaluation. In conclusion, polar bears seem to be susceptible to contaminant induced stress that may have an overall sub-clinical impact on their health and population status via impacts on their immune and reproductive systems. PMID:20398940

Sonne, Christian

2010-07-01

122

Wing geometry as a tool for discrimination of Obsoletus group (Diptera: Ceratopogonidae: Culicoides) in France.  

PubMed

In Europe, Culicoides chiopterus, Culicoides dewulfi, Culicoides obsoletus and Culicoides scoticus, which belongs to the subgenus Avaritia and Obsoletus group are the most proficient Bluetongue and Schmallenberg vectors. Within this group, correct identification based on morphological traits is difficult but essential to assess disease transmission risk. The development of new tools has revolutionized taxonomy (i.e. geometric morphometrics and molecular biology). Wing morphology is of primary importance to entomologists interested in systematics. Here, we report phenotypic differentiation patterns among the species above mentioned using a landmark-based geometric morphometric approach that efficiently identified C. chiopterus and C. dewulfi. Wing shape of the C. scoticus sample exhibited large specific variability. Based on landmarks and phylogenetic analyses (Maximum Parsimony), we suggest that Obsoletus group in Europe includes only C. obsoletus and C. scoticus. C. dewulfi and C. chiopterus are clearly excluded. Their shape seems closer to C. obsoletus that is why we suggest that only these two species should be grouped in the Obsoletus group. In addition, the concordance between phenetic clusters and phylogenies inferred from molecular data based on a fragment of the mtDNA COI gene and rDNA 28S suggests the existence of a strong signal in wing shape. These findings encourage us to use this powerful tool in taxonomic studies. PMID:24514019

Henni, L Hajd; Sauvage, F; Ninio, C; Depaquit, J; Augot, D

2014-01-01

123

First Report of 13 Species of Culicoides (Diptera: Ceratopogonidae) in Mainland Portugal and Azores by Morphological and Molecular Characterization  

PubMed Central

The genus Culicoides (Diptera: Ceratopogonidae) contains important vectors of animal and human diseases, including bluetongue, African horse sickness and filariosis. A major outbreak of bluetongue occurred in mainland Portugal in 2004, forty eight years after the last recorded case. A national Entomological Surveillance Plan was initiated in mainland Portugal, Azores and the Madeira archipelagos in 2005 in order to better understand the disease and facilitate policy decisions. During the survey, the most prevalent Culicoides species in mainland Portugal was C. imicola (75.3%) and species belonging to the Obsoletus group (6.5%). The latter were the most prevalent in Azores archipelago, accounting for 96.7% of the total species identified. The Obsoletus group was further characterized by multiplex Polymerase Chain Reaction to species level showing that only two species of this group were present: C. obsoletus sensu strictu (69.6%) and C. scoticus (30.4%). Nine species of Culicoides were detected for the first time in mainland Portugal: C. alazanicus, C. bahrainensis, C. deltus, C. lupicaris, C. picturatus, C. santonicus, C. semimaculatus, C. simulator and C. subfagineus. In the Azores, C. newsteadi and C. circumscriptus were identified for the first time from some islands, and bluetongue vectors belonging to the Obsoletus group (C. obsoletus and C. scoticus) were found to be widespread.

Pereira da Fonseca, Isabel; Delecolle, Jean-Claude; Wilson, Anthony; Meireles, Jose; Lucientes, Javier; Ribeiro, Rita; Boinas, Fernando

2012-01-01

124

Host preferences of Palaearctic Culicoides biting midges: implications for transmission of orbiviruses.  

PubMed

Feeding success depends on host availability, host defensive reactions and host preferences. Host choice is a critical determinant of the intensity at which pathogens are transmitted. The aim of the current study was to describe host preferences of Palaearctic Culicoides species (Diptera: Ceratopogonidae) Latreille using traps baited with the five different host species of poultry, horse, cattle, sheep and goat. Collections were carried out nightly in July and August 2009 in western France with three replicates of a 5 × 5 randomized Latin square (five sites, five hosts). Moreover, an ultraviolet (UV) light/suction trap was operated during host-baited collections to correlate Culicoides biting rates and UV light/suction trap catches. A total of 660 Culicoides belonging to 12 species, but comprised mainly of Culicoides scoticus Downes and Kettle, Culicoides dewulfi Goetghebuer and Culicoides obsoletus Meigen, were collected on animal baits. Abundance was highest for the horse, which accounted for 95% of all Culicoides caught, representing 10 species. The horse, the largest bait, was the most attractive host, even when abundance data were corrected by weight, body surface or Kleiber's scaling factor. Culicoides obsoletus was the only dominant species attracted by birds. Both C. scoticus and C. dewulfi were collected mainly from the upper body of the horse. Finally, the quantification of host preferences allows for discussion of implications for the transmission of Culicoides-borne pathogens such as bluetongue virus. PMID:22985009

Viennet, E; Garros, C; Gardès, L; Rakotoarivony, I; Allène, X; Lancelot, R; Crochet, D; Moulia, C; Baldet, T; Balenghien, T

2013-09-01

125

A survey of Culicoides developmental sites on a farm in northern Spain, with a brief review of immature habitats of European species.  

PubMed

Culicoides species (Diptera: Ceratopogonidae) belonging to the Obsoletus and Pulicaris groups are considered to be the main vectors of bluetongue virus (BTV) in non Mediterranean Europe. Selected terrestrial microhabitats (n=17) on a farm in northern Spain were sampled repeatedly over a year-long period and characterized for use by Culicoides species for immature development. Concurrent use of CDC light traps showed the presence of 37 species and 66,575 specimens of adult Culicoides. A total of 28 species and 11,396 individuals emerged from laboratory-maintained soil samples. Culicoides obsoletus and Culicoides scoticus (pooled as Obsoletus complex) were particularly abundant (comprising 58.6% and 74.5% of the total collections in light traps and emergence traps respectively). Potential key vectors of animal viruses (such as BTV) were found in two main terrestrial types of microhabitats. In the case of C. obsoletus, different types of manure (old and composted manure, manure mixed with organic matter, and fresh manure) produced most of the specimens. In contrast, larvae of C. scoticus and Culicoides lupicaris were associated with soil substantially comprised of rotting leaf litter that included the parasitic plant Lathraea clandestina. Several species, Culicoides festivipennis, Culicoides punctatus and Culicoides brunnicans, were very common in mud at pond margins. Indeed, pond microhabitats and runoff below barn rooflines supported the greatest species richness. In the pond habitat, 49.4% of Culicoides specimens emerged from mud at the water edge, as opposed to 50 cm above (32.4%) and 1 meter above waterline (18%). Similar species richness, but statistically significant differences in abundance, were observed among the four pond microhabitats. Overall, the majority of the specimens were found in the upper layer (0-3 cm), except in manure, where they preferred deeper layers (>6 cm). Maximum peaks of abundance occurred in both light traps and soil samples in summer months, whereas increased captures in autumn were noticed only in light traps. Both trapping systems failed to collect adult Culicoides midges in the coldest months of December, January and February. The literature on immature habitats of species suspected in BTV transmission in Europe, the Pulicaris group and particularly the Obsoletus group, is briefly reviewed. PMID:22999100

González, Mikel; López, Sergio; Mullens, Bradley A; Baldet, Thierry; Goldarazena, Arturo

2013-01-16

126

Influence of biotic and abiotic factors on the distribution and abundance of Culicoides imicola and the Obsoletus Complex in Italy.  

PubMed

Culicoides imicola Kieffer (Culicoides, Diptera: Ceratopogonidae) is the principal vector of bluetongue virus (BTV) to ruminant livestock in southern Europe. The secondary potential vectors are Culicoides obsoletus (Meigen) and Culicoides scoticus Downes and Kettle of the Obsoletus Complex, Culicoides pulicaris (Linnaeus) of the Pulicaris Complex and Culicoides dewulfi Goetghebuer of the subgenus Avaritia Fox. Between 2000 and 2004 >38,000 light-trap collections were made for Culicoides across Italy including the islands of Sardinia and Sicily. Mapping of the 100 largest collections of C. imicola and of the Obsoletus Complex showed them to be disjunct overlapping in only 2% of the 200 municipalities selected. For each municipality the average values were calculated for minimum temperature, aridity index, altitude, terrain slope, normalised difference vegetation index (NDVI) and percentage forest cover. A factor analysis identified two principal factors ('biotic' and 'abiotic') and explained 84% of the total variability; a discriminant analysis classified correctly 87.5% of the observations. The results indicate adult populations of C. imicola to occur in more sparsely vegetated habitats that are exposed to full sunlight, whereas species of the Obsoletus Complex favour a more shaded habitat, with increased green leaf density. Heliophily and umbrophily, by shortening or lengthening the respective adult life cycles of these two vectors, will likely impact on the ability of each to transmit BTV and is discussed in the light of the current outbreak of BTV across the Mediterranean Basin. PMID:17997043

Conte, A; Goffredo, M; Ippoliti, C; Meiswinkel, R

2007-12-25

127

Larval development and emergence sites of farm-associated Culicoides in the United Kingdom.  

PubMed

Culicoides biting midges (Diptera: Ceratopogonidae) are the biological vectors of internationally important arboviruses of livestock including bluetongue virus (BTV). Information on the habitats used by Culicoides for larval development is valuable for establishing targeted vector control strategies and for improving local scale models of vector abundance. This study combines emergence trap collections of adult Culicoides identified using molecular markers and physiochemical measurements of habitats to investigate larval development sites of Palaearctic Culicoides in South East England. The known range of larval habitats for several Culicoides species is extended and the potential BTV vector species C. obsoletus and C. scoticus are confirmed to co-occur in many larval habitats. The presence of emerging C. obsoletus was favoured by increasing substrate moisture level [odds ratio (OR) 6.94 (2.30; 20.90)] and substrate pH [OR 4.80 (1.66; 13.90)] [bias-corrected Dxy : 0.68; area under the curve (AUC): 0.86] rather than any particular larval habitat type, as expected for a species with relatively wide larval habitat preference. Of the newly emerged sub-genus Avaritia individuals collected, 23% were observed to have a degree of abdominal pigmentation commonly inferred to indicate parity. If consistent across species and locations, this observation represents a potential source of error for age structure analyses of Culicoides populations. PMID:23458570

Harrup, L E; Purse, B V; Golding, N; Mellor, P S; Carpenter, S

2013-12-01

128

Towards the PCR-based identification of Palaearctic Culicoides biting midges (Diptera: Ceratopogonidae): results from an international ring trial targeting four species of the subgenus Avaritia  

PubMed Central

Background Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are biological vectors of internationally important arboviruses. To understand the role of Culicoides in the transmission of these viruses, it is essential to correctly identify the species involved. Within the western Palaearctic region, the main suspected vector species, C. obsoletus, C. scoticus, C. dewulfi and C. chiopterus, have similar wing patterns, which makes it difficult to separate and identify them correctly. Methods In this study, designed as an inter-laboratory ring trial with twelve partners from Europe and North Africa, we assess four PCR-based assays which are used routinely to differentiate the four species of Culicoides listed above. The assays based on mitochondrial or ribosomal DNA or microarray hybridisation were tested using aliquots of Culicoides DNA (extracted using commercial kits), crude lysates of ground specimens and whole Culicoides (265 individuals), and non-Culicoides Ceratopogonidae (13 individuals) collected from across Europe. Results A total of 800 molecular assays were implemented. The in-house assays functioned effectively, although specificity and sensitivity varied according to the molecular marker and DNA extraction method used. The Obsoletus group specificity was overall high (95-99%) while the sensitivity varied greatly (59.6-100%). DNA extraction methods impacted the sensitivity of the assays as well as the type of sample used as template for the DNA extraction. Conclusions The results are discussed in terms of current use of species diagnostic assays and the future development of molecular tools for the rapid differentiation of cryptic Culicoides species.

2014-01-01

129

Does covering of farm-associated Culicoides larval habitat reduce adult populations in the United Kingdom??  

PubMed Central

Culicoides biting midges (Diptera: Ceratopogonidae) are the biological vectors of a range of internationally important arboviruses of livestock, including bluetongue virus (BTV) and the recently emerging Schmallenberg virus (SBV). Culicoides species in the subgenus Avaritia (in the UK: Culicoides obsoletus Meigen, Culicoides scoticus Downes & Kettle, Culicoides dewulfi Goetghebuer and Culicoides chiopterus Meigen) have been implicated in BTV transmission in northern Europe and to a varying degree utilise cattle dung as a larval development substrate. The collection of cattle dung into heaps on farms provides a localised source of Culicoides emergence in close proximity to livestock. This study assesses the impact of covering dung heaps prior to the onset of adult Culicoides activity with the aim of reducing recruitment to the local adult populations at four livestock farms in England. Light suction trap catches of adult Culicoides from these farms were compared with those from four untreated control farms from a wide geographic range across the UK. It was demonstrated that implementing control of emergence from dung heaps did not have a significant impact upon the local adult subgenus Avaritia abundance at the treated farm holdings and that the onset of Culicoides activity was similarly unaffected. Use of this method in isolation is unlikely to have an effect in reducing the risk of BTV and SBV transmission. The implications of these results for control of farm-associated Culicoides in Europe are discussed.

Harrup, L.E.; Gubbins, S.; Barber, J.; Denison, E.; Mellor, P.S.; Purse, B.V.; Carpenter, S.

2014-01-01

130

Are bogs reservoirs for emerging disease vectors? Evaluation of culicoides populations in the Hautes Fagnes Nature Reserve (Belgium).  

PubMed

Several species of Culicoides (Diptera: Ceratopogonidae) biting midges serve as biological vectors for the bluetongue virus (BTV) and the recently described Schmallenberg virus (SBV) in northern Europe. Since their recent emergence in this part of the continent, these diseases have caused considerable economic losses to the sheep and cattle industries. Much data is now available that describe the distribution, population dynamics, and feeding habits of these insects. However, little is known regarding the presence of Culicoides in unusual habitats such as peaty marshes, nor their potential vector capacity. This study evaluated Culicoides biting midges present in the bogs of a Belgian nature reserve compared to those residing at a nearby cattle farm. Culicoides were trapped in 2011 at four different sites (broadleaved and coniferous forested areas, open environments, and at a scientific station) located in the Hautes Fagnes Nature Reserve (Belgium). An additional light trap was operated on a nearby cattle farm. Very high numbers of biting midges were captured in the marshy area and most of them (70 to 95%) were Culicoides impunctatus, a potential vector of BTV and other pathogens. In addition, fewer numbers of C. obsoletus/C. scoticus species, C. chiopterus, and C. dewulfi were observed in the bogs compared to the farm. The wet environment and oligotrophic nature of the soil were probably responsible for these changes in the respective populations. A total of 297,808 Culicoides midges belonging to 27 species were identified during this study and 3 of these species (C. sphagnumensis, C. clintoni and C. comosioculatus) were described in Belgium for the first time. PMID:23799137

Zimmer, Jean-Yves; Smeets, François; Simonon, Grégory; Fagot, Jean; Haubruge, Eric; Francis, Frédéric; Losson, Bertrand

2013-01-01

131

Are Bogs Reservoirs for Emerging Disease Vectors? Evaluation of Culicoides Populations in the Hautes Fagnes Nature Reserve (Belgium)  

PubMed Central

Several species of Culicoides (Diptera: Ceratopogonidae) biting midges serve as biological vectors for the bluetongue virus (BTV) and the recently described Schmallenberg virus (SBV) in northern Europe. Since their recent emergence in this part of the continent, these diseases have caused considerable economic losses to the sheep and cattle industries. Much data is now available that describe the distribution, population dynamics, and feeding habits of these insects. However, little is known regarding the presence of Culicoides in unusual habitats such as peaty marshes, nor their potential vector capacity. This study evaluated Culicoides biting midges present in the bogs of a Belgian nature reserve compared to those residing at a nearby cattle farm. Culicoides were trapped in 2011 at four different sites (broadleaved and coniferous forested areas, open environments, and at a scientific station) located in the Hautes Fagnes Nature Reserve (Belgium). An additional light trap was operated on a nearby cattle farm. Very high numbers of biting midges were captured in the marshy area and most of them (70 to 95%) were Culicoides impunctatus, a potential vector of BTV and other pathogens. In addition, fewer numbers of C. obsoletus/C. scoticus species, C. chiopterus, and C. dewulfi were observed in the bogs compared to the farm. The wet environment and oligotrophic nature of the soil were probably responsible for these changes in the respective populations. A total of 297,808 Culicoides midges belonging to 27 species were identified during this study and 3 of these species (C. sphagnumensis, C. clintoni and C. comosioculatus) were described in Belgium for the first time.

Zimmer, Jean-Yves; Smeets, Francois; Simonon, Gregory; Fagot, Jean; Haubruge, Eric; Francis, Frederic; Losson, Bertrand

2013-01-01

132

Reproductive performance of pubertal red deer (Cervus elaphus) hinds: effects of genetic introgression of wapiti subspecies on pregnancy rates at 18 months of age.  

PubMed

Low reproductive productivity of young red deer (Cervus elaphus) hinds on New Zealand deer farms appears to reflect high incidences of puberty failure at 16 months of age. This is despite the general attainment of average liveweights 15-25 kg in excess of the accepted minimum threshold for puberty in subspecies of western European origin (scoticus, elaphus and hippelaphus) that form the basis of the national herd. The present study tests the hypotheses that introgression of the larger North American wapiti subspecies (nelsoni, manitobensis and roosevelti) into breeding herds (1) can be assessed from morphological features of individuals, (2) that there is a relationship between the level of wapiti parentage and non-pregnancy rate at 18 months of age (a proxy for puberty failure) and (3) that minimum liveweight thresholds for puberty increase with increasing levels of wapiti parentage. A total of 4329 18-month-old hinds across four "red" deer farms in southern New Zealand were scanned for pregnancy status. Each hind was assigned a wapiti score (WS) as a subjective assessment of the obviousness of wapiti features. Various body measurements were additionally recorded for each hind. A hair sample was collected for DNA analysis (14 markers) to objectively assign subspecies pedigree (i.e. "Elkmeter") on a subset of 1258 individuals. A total of 506 (11.7%) hinds were not pregnant at 18 months of age with rates varying between 4.1 and 37.3% between farms and years. Mean WS differed significantly between farms and reflected the genetic management policy of each farm. WS was positively correlated to Elkmeter for each farm/year (<0.05) although regression slopes varied significantly. WS was able to be adjusted for these differences to assign a corrected WS (CWS) for all 4329 individuals that estimated the proportion wapiti parentage. Discriminant analysis of morphological variables relative to Elkmeter supported the first hypothesis and showed that shoulder height and body length were good indicators of the degree of wapiti parentage within individuals. This enabled the development of an objective estimate of wapiti parentage (EWP). The actual level of such parentage within herds ranged from <5 to >55%. There was a significant negative association between wapiti parentage and pregnancy, which was strongly influenced by liveweight, supporting the second and third hypotheses. This was manifest as marked displacement of pregnancy probability curves in relation to liveweight between genotype groups, particularly for those groups with >20% wapiti parentage. For example, predicted threshold liveweights required to achieve a 90% pregnancy rate for EWP values that represent 0, 10, 20, 30, 40 and 50% wapiti parentage were 81, 81, 85, 106, 127 and approximately 137 kg, respectively. Within the study herds, the majority of hinds of 0-20% wapiti parentage exceeded the predicted 90% threshold liveweights for their genotype cohort. However, hinds with higher levels of wapiti parentage generally fell below the predicted threshold for their genotype group. The data strongly suggest that under liveweight performance levels measured for red deer, hinds with >20% wapiti parentage are at high risk of puberty failure. PMID:16298276

Asher, G W; Archer, J A; Scott, I C; O'Neill, K T; Ward, J; Littlejohn, R P

2005-12-01