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1

Foraging success of juvenile pike Esox lucius depends on visual conditions and prey pigmentation.  

PubMed

Young-of-the-year pike Esox lucius foraging on copepods experienced different foraging success depending on prey pigmentation in water visually degraded by brown colouration or algae. Both attack rate and prey consumption rate were higher for E. lucius foraging on transparent prey in brown water, whereas the opposite was true in algal turbid water. Pigments in copepod prey may have a cryptic function in brown water instead of a photo-protective function even if prey-size selectivity was stronger than selection based on pigmentation in juvenile E. lucius. PMID:21722125

Jönsson, M; Hylander, S; Ranåker, L; Nilsson, P A; Brönmark, C

2011-07-01

2

Större gädda (Esox lucius) konsumerar inte storspigg (Gasterosteus aculeatus).  

E-print Network

?? Övergödningen i Östersjön har varit ett problem de senaste årtionden vilket påverkar akvatiska organismer och minskar undervattenvegetationen som är viktig för fisklivet. Gädda (Esox lucius)… (more)

Nilsson, Klas

2010-01-01

3

Early life migration patterns of Baltic Sea pike Esox lucius.  

PubMed

This study investigated the movement patterns of Baltic Sea pike Esox lucius in Matsalu Bay, Estonia, using otolith microchemistry. Migration patterns of E. lucius were remarkably diverse, but distinct groups were evident. Of the E. lucius analysed (n = 28), 82% hatched in fresh water and 74% of them left this biotope during the first growth season. PMID:22471807

Rohtla, M; Vetemaa, M; Urtson, K; Soesoo, A

2012-04-01

4

Prey capture of pike Esox lucius larvae in turbid water.  

PubMed

Pike Esox lucius larvae captured fewer calanoid and cyclopoid copepods in turbid than in clear water, whereas no differences were detected in feeding rates on Daphnia longispina. Decreased capture of copepods may lead to lower growth and survival of E. lucius larvae in turbid areas, in particular, if cladocerans are scarce. PMID:20557612

Salonen, M; Engström-Ost, J

2010-06-01

5

Precocious induction of maturation and ovulation in northern pike (Esox lucius)  

E-print Network

Precocious induction of maturation and ovulation in northern pike (Esox lucius) G. DE MONTALEMBERT. Introduction. Hormonal control of ovulation is of particular interest in northern pike (Esox lucius) since

Paris-Sud XI, Université de

6

Behaviour and survival of pike, Esox lucius, with a retained lure in the lower jaw  

E-print Network

Behaviour and survival of pike, Esox lucius, with a retained lure in the lower jaw R . A R L I N G The behaviour and survival of pike, Esox lucius L., released with a retained lure in the mouth was studied Mitchell, and pike, Esox lucius L., are important targets for recreational anglers in the northern hemi

Cooke, Steven J.

7

MICROSATELLITE LETTERS EST-based microsatellites for northern pike (Esox lucius)  

E-print Network

MICROSATELLITE LETTERS EST-based microsatellites for northern pike (Esox lucius) and cross novel microsatellite markers in North American northern pike, Esox lucius, and tested cross out of 17 loci were successfully cross-amplified on all species. Keywords Esox lucius Á Northern pike

Bernatchez, Louis

8

L'organe pinal du Brochet (Esox lucius L.) III. Voies intrapinales de conduction  

E-print Network

L'organe pinéal du Brochet (Esox lucius L.) III. Voies intrapinéales de conduction des messages organ of the pike (Esox lucius, L.). II1. lntrapineal pathways for conduction of photosensory messages. In order to elucidate the sensory function of the pineal organ of the pike, Esox lucius

Paris-Sud XI, Université de

9

Cytological identification of cell types in the testis of Esox lucius and E. niger  

Microsoft Academic Search

Testes of Esox lucius and Esox niger were investigated histologically, cytochemically, and ultrastructurally in reproductive fish. Intralobular Sertoli cells possessed numerous lipid droplets in Esox lucius, but not in Esox niger. In both species, interlobular cell types included myoid cells and lipid-negative Leydig cells within the extravascular space. Evidence is presented for a contractile network of myoid cells within the

H. J. Grier; R. Hurk; R. Billard

1989-01-01

10

L'organe pinal du Brochet (Esox lucius, L.). I. Etude anatomique et cytologique  

E-print Network

L'organe pinéal du Brochet (Esox lucius, L.). I. Etude anatomique et cytologique J. FALCON Pineau, 86022 Poitiers Cedex, France. Summary. The pineal organ of the pike, Esox lucius L., I. A light ; Plecoglossus : Omura et al.,1969 ; Omura et Oguri, 1971 ; Esox : Owman et Rüdeberg, 1970; Anguilla et Lebistes

Boyer, Edmond

11

L'organe pinal du Brochet (Esox lucius, L.) V. Etude radioautographique de l'incorporation in vivo  

E-print Network

L'organe pinéal du Brochet (Esox lucius, L.) V. Etude radioautographique de l'incorporation in vivo Poitiers Cedex, France. Summary. The pineal organ of the pike (Esox lucius, L.). V. Radioautographic study

Paris-Sud XI, Université de

12

Northern pike (Esox lucius) are common sport fish in the northern United States and Canada. In  

E-print Network

6 Northern pike (Esox lucius) are common sport fish in the northern United States and Canada. In South Dakota, northern pike and muskellunge (Esox masquinongy) ranked second in total number of fishing days provided during 1991 (USDOI and USDOC 1993). In Minnesota, northern pike are the most widespread

13

Ovarian alterations in wild northern pike Esox lucius females.  

PubMed

The aim of the present study was to analyse the occurrence of macroscopically visible ovary alterations in 2 populations of northern pike Esox lucius L. originating from lakes in the Mazurian Lake District (NE Poland). The alterations were characterised by ovary tissue that was morphologically malformed, in part or in whole, and contained immature oocytes, i.e. trophoplastic or previtellogenic oocytes instead of vitellogenic oocytes. These alterations were found only in the ovaries, and no morphological alterations of the testes were noted. Macroscopic and histological analyses were carried out in order to classify the observed alterations in the ovaries. Three types of alterations were identified in which morphological malformations as well as histological investigation of the ovaries were considered. An analysis of the size and age of the fish in relation to the occurrence of alterations as well as of the macroscopic and histological nature of the alteration types was made. The data obtained revealed no lake or age dependency of the observed alterations. Based on the results obtained, we suggest that the presence of endocrine disruptors in the environment or/and genetic factors could be responsible for these kinds of gonad anomalies. However, our results did not allow us to determine the aetiology of the alterations. PMID:24062552

Zarski, Daniel; Rechulicz, Jacek; Krejszeff, S?awomir; Czarkowski, Tomasz K; Sta?czak, Katarzyna; Pali?ska, Katarzyna; Gryzi?ska, Magdalena; Targo?ska, Katarzyna; Koz?owski, Krzysztof; Mamcarz, Andrzej; Hliwa, Piotr

2013-09-24

14

Mercury elimination by a top predator, Esox lucius.  

PubMed

Top-level piscivores are highly sought after for consumption in freshwater fisheries, yet these species contain the highest levels of the neurotoxin monomethylmercury (MMHg) and therefore present the greatest concern for MMHg exposure to humans. The slow elimination of MMHg is one factor that contributes to high levels of this contaminant in fish; however, little quantitative information exists on elimination rates by top predators in nature. We determined rates of MMHg elimination in northern pike (Esox lucius) by transferring fish that had naturally accumulated isotope-enriched MMHg (spike MMHg) through a whole-lake Hg loading study to a different lake. Over a period of ~7 y, pike were periodically recaptured and a small amount of muscle tissue was extracted using a nonlethal biopsy. Spike total mercury (THg) persisted in muscle tissue throughout the entire study despite discontinuing exposure upon transfer to the new lake. Spike THg burdens increased for the first ~460 d, followed by a decline to 65% of original burden levels over the next 200 d, and subsequently reached a plateau near original burden levels for the remainder of the study. We estimated the half-life of muscle THg to be 3.3 y (1193 d), roughly 1.2- to 2.7-fold slower than predicted by current elimination models. We advocate for further long-term field studies that examine kinetics of MMHg in fish to better inform predictive models estimating the recovery of MMHg-contaminated fisheries. PMID:23566175

Van Walleghem, Jillian L A; Blanchfield, Paul J; Hrenchuk, Lee E; Hintelmann, Holger

2013-05-01

15

Analysis of sibling cannibalism among pike, Esox lucius , juveniles reared under semi-natural conditions  

Microsoft Academic Search

Synopsis Sibling cannibalism in pike, Esox lucius, larvae and juveniles living in outdoor rearing ponds was studied using stomach contents analysis. For the two initial densities tested (6 and 18 larvae m?2, equivalent to 12 and 36 larvae m?3), cannibalism was non-existent during the larval period (13 to 35 mm total length) and was observed only during the juvenile stages.

Christian Bry; Edgar Basset; Xavier Rognon; François Bonamy

1992-01-01

16

Individual specialization and trophic adaptability of northern pike (Esox lucius): an isotope and dietary analysis  

Microsoft Academic Search

Northern pike (Esox lucius) are often considered to be specialist piscivores, but under some circumstances will continue to eat invertebrates as adults. To examine effects of fish assemblage composition on the trophic ecology of pike, we combined stable isotope analysis (SIA) of carbon and nitrogen and stomach content analysis (SCA) on pike from five lakes in northern Alberta, three of

Catherine P. Beaudoin; William M. Tonn; Ellie E. Prepas; Leonard I. Wassenaar

1999-01-01

17

An experimental breakage of Reissner's fibre in the central canal of the pike ( Esox lucius )  

Microsoft Academic Search

Summary  The spinal cords of newly hatched pike (Esox lucius) fry were divided into two pieces by transverse cuts. After periods of different lengths, the appearances of the brokenReissner's fibres were investigated anatomically. The fibre normally terminates in the caudal end as a secretory accumulation, a caudal mass. After the operation this mass gradually disappears, apparently through the spinal cord wall

Ragnar Olsson

1957-01-01

18

Reduction of cannibalism in pike (Esox lucius) fry by isolation of full-sib families  

E-print Network

Reduction of cannibalism in pike (Esox lucius) fry by isolation of full-sib families C. BRY, C of other species ; 3) cannibalism. In extensive or semi-intensive conditions, work has mainly been focused) and of perch fry (Chauderon, 1969 ; Arrignon, 1972), Cannibalism is common in pike, especially in the fry which

Paris-Sud XI, Université de

19

Chemical labeling of northern pike ( Esox lucius ) by the alarm pheromone of fathead minnows ( Pimephales promelas )  

Microsoft Academic Search

In previous experiments, chemical stimuli from northern pike (Esox lucius) elicited fright responses from pike-naive fathead minnows (Pimephales promelas) only if the pike had recently eaten conspecific minnows. We used a behavioral assay to determine if the fright response is the result of the incorporation of the minnow alarm pheromone into the chemical signature of the pike. Because the alarm

Alicia Mathis; R. Jan F. Smith

1993-01-01

20

L'organe pinal du Brochet (Esox lucius, L.). IV. Srotonine endogne et activit monoamine oxydasique ;  

E-print Network

.). IV. Endogenous serotonin and monoamine oxidase activity : An histochemical, ultracytochemical-cored vesicles which were observed previously with electron microscopy (Falcon, 1979a). Monoamine oxidase (MAOL'organe pinéal du Brochet (Esox lucius, L.). IV. Sérotonine endogène et activité monoamine

Paris-Sud XI, Université de

21

General morphology and axonal ultrastructure of the olfactory nerve of the pike, Esox lucius  

Microsoft Academic Search

The olfactory nerve of the European pike (Esox lucius) contains 5.1 × 106 axons with an average diameter of 0.20 ± 0,04 µm and a length of 5.5 cm in 1 meter long pike. Each axon contains an average of 4 microtubules as well as neurofilaments, smooth endoplasmic reticulum and about 500 mitochondria per centimeter. The number of neurofilaments ranges

Georg W. Kreutzberg; Guenter W. Gross

1977-01-01

22

Mercury concentrations in northern pike, Esox lucius L., in small lakes of Evo area, southern Finland  

Microsoft Academic Search

We measured Hg concentrations in northern pike (Esox lucius) from 17 small lakes in Evo forest area, Lammi, southern Finland. The mean Hg concentration in muscle tissue of a 1 kg pike\\u000a ranged from 0.15 to 1.36 ?g g?1 (ww) in the lakes. There was a trend towards higher concentrations in acidic and humic lakes than in circumneutral and clear-water

M. Rask; T.-R. Metsälä

1991-01-01

23

THE MECHANICAL POWER OUTPUT AND HYDROMECHANICAL EFFICIENCY OF NORTHERN PIKE (ESOX LUCIUS) FAST-STARTS  

Microsoft Academic Search

The mechanical power output and hydrodynamic efficiency of northern pike, Esox lucius, during acceleration from rest (fast-start) are calculated from hydrodynamic theory for two kinematic patterns, C-starts (used in escape) and S-starts (used in prey capture). The Weihs model is employed and modified to calculate the mechanical power produced by a fish during a fast-start. A term is included for

H. RUSS FRITH; ROBERT W. BLAKE

24

New series of fatty acids in Northern Pike ( Esox lucius )  

Microsoft Academic Search

The presence in Northern Pike (Esox locius) liver and testes lipids of a group of eight homologous fatty acids of as yet unknown structure is reported. They occur esterified\\u000a to cholesterol and to glycerol as triglycerides but are absent from the phospholipids. They contain three oxygens and are\\u000a characterized further by being more resistant to hydrogenation than normal unsaturated fatty

R. L. Glass; Thomas P. Krick; Allen E. Eckhardt

1974-01-01

25

Genetic characterization of 18 novel microsatellite loci in northern pike (Esox lucius L.).  

PubMed

The northern pike (Esox lucius L.), an important predatory freshwater species, is undergoing significant population decline. In this study, 18 novel polymorphic microsatellite loci were isolated and used for assessing genetic variation in the Chinese Ulungur and Hungarian Balaton populations of the species. The number of alleles ranged from 2 to 13, observed heterozygosity from 0.154 to 0.920 and expected heterozygosity from 0.145 to 0.921, thereby indicating the specific usefulness of these suites of markers for investigating genetic variability. PMID:21637562

Wang, Jun; Wang, Chenghui; Qian, Long; Ma, Yuqing; Yang, Xinxin; Jeney, Zsigmond; Li, Sifa

2011-01-01

26

Rhipidocotyle fennica (Digenea: Bucephalidae) from Anodonta anatina and pike Esox lucius in Lithuania.  

PubMed

Ribosomal DNA sequences of Rhipidocotyle sp. adults from Esox lucius were shown to be identical to sequences of larval Rhipidocotyle fennica, occurring in Anodonta anatina in Lake Vilkokšnis, Lithuania. Morphological features and host specificity of this adult worm correspond with that, determinate in the first description of R. fennica in Finland. These data give the first evidence that a viable population of R. fennica exists in east central Europe. Bucephalus polymorphus which was reported in unionids in all previous publications is probably R. fennica. PMID:25190013

Stunž?nas, Virmantas; Petkevi?i?t?, Romualda; Stanevi?i?t?, Gražina; Binkien?, Rasa

2014-10-01

27

Genetic characterization of 18 novel microsatellite loci in northern pike (Esox lucius L.)  

PubMed Central

The northern pike (Esox lucius L.), an important predatory freshwater species, is undergoing significant population decline. In this study, 18 novel polymorphic microsatellite loci were isolated and used for assessing genetic variation in the Chinese Ulungur and Hungarian Balaton populations of the species. The number of alleles ranged from 2 to 13, observed heterozygosity from 0.154 to 0.920 and expected heterozygosity from 0.145 to 0.921, thereby indicating the specific usefulness of these suites of markers for investigating genetic variability. PMID:21637562

Wang, Jun; Wang, Chenghui; Qian, Long; Ma, Yuqing; Yang, Xinxin; Jeney, Zsigmond; Li, Sifa

2011-01-01

28

Dietary uptake in pike (Esox lucius) of some polychlorinated biphenyls, polychlorinated naphthalenes and polybrominated diphenyl ethers administered in natural diet  

Microsoft Academic Search

The dietary uptake of 12 halogenated diaromatic compounds was studied using northern pike (Esox lucius L.) fed with rainbow trout (Oncorhynchus mykiss (Walbaum)). Before the trout were fed to the pike, they had been injected with a cocktail of five polychlorinated biphenyls, four polychlorinated naphthalenes, and three polybrominated diphenyl ethers, dissolved in rainbow trout lipid. The reported uptake efficiencies (E)

Sven Burreau; Johan Axelman; Dag Broman; Eva Jakobsson

1997-01-01

29

Adrenergic neurons in the spinal cord of the pike ( Esox lucius ) and their relation to the caudal neurosecretory system  

Microsoft Academic Search

The lower spinal cord including the caudal neurosecretory system of the pike (Esox lucius) was investigated by means of light and electron microscopy and also with the fluorescence histochemical method of Falck and Hillarp for the visualization of monoamines. A system of perikarya displaying a specific green fluorescence of remarkably high intensity is disclosed in the basal part of the

H. G. Baumgarten; B. Falck; H. Wartenberg

1970-01-01

30

The population dynamics of pike, Esox lucius , and perch, Perca fluviatilis , in a simple predator-prey system  

Microsoft Academic Search

The population dynamics and predator-prey relationship of pike, Esox lucius, and perch, Perca fluviatilis, were examined in simple fish communities in two adjacent shallow lakes, Lochs Kinord and Davan, Deeside, Scotland. Few perch survive to age 3 but Z is low for fish > 3 years and perch live up to 17 years. Population fecundity remained relatively high and constant

James W. Treasurer; Roger Owen; Eric Bowers

1992-01-01

31

The photosensory function of the pineal organ of the pike ( Esox lucius L.) Correlation between structure and function  

Microsoft Academic Search

Electrical recordings from the exposed pineal organ of the pike (Esox lucius L.) were performed in order to localize the photoreceptive structures. Extracellular recordings showed a maintained activity of nerve fibers from the pineal tract and of single neurons from the distal region of the pineal organ. At increasing levels of steady exposure to white light, the impulse frequency decreased.

Jacky Falcón; Hilmar Meissl

1981-01-01

32

A quantitative comparison between diet and body fatty acid composition in wild northern pike ( Esox lucius L.)  

Microsoft Academic Search

The fatty acid compositions of wild female northern pike (Esox lucius L.) and their principle prey species were compared to assess the extent to which pike modify the relative abundance of dietary fatty acids during assimilation and to indicate the optimum dietary content of essential fatty acids (EFAs) for pike. Only minor differences existed between the estimated whole body fatty

Karl Schwalmel

1992-01-01

33

The inf luence of the invasive black bullhead Ameiurus melas on the predatory efficiency of pike Esox lucius L  

Microsoft Academic Search

The influence of the invasive black bullhead Ameiurus melas on the predatory efficiency of the pike Esox lucius was investigated using an additive experimental design. Pike predatory success on 0þ years roach Rutilus rutilus was significantly reduced in the presence of black bullhead. Among the different hypotheses that may explain such a pattern, the hypothesis of direct competition between pike

K. KREUTZENBERGER; F. L EPRIEUR; S. BROSSE

2008-01-01

34

ENDOCRINE (SEXUAL) DISRUPTION IS NOT A PROMINENT FEATURE IN THE PIKE (ESOX LUCIUS), A TOP PREDATOR, LIVING IN ENGLISH WATERS  

Microsoft Academic Search

The high incidence of intersex roach ( Rutilus rutilus) in some United Kingdom rivers that has been associated with exposure to sewage treatment works (STWs) effluent led us to hypothesize that top predator fish also may be affected by estrogenic chemicals, because they are likely to bioaccumulate lipophilic compounds through a predator-prey relationship. To investigate this possibility, pike (Esox lucius)

Emma Vine; Jan Shears; Ronny van Aerle; Charles R. Tyler; John P. Sumpter

2005-01-01

35

'Soft' harness for external attachment of large radio transmitters to northern pike (Esox lucius)  

USGS Publications Warehouse

We developed a 'soft' harness for dorsally attaching large, external radio transmitters to northern pike (Esox lucius). The key harness component was a soft, flexible, thick-walled tubing that prevented tissue abrasion by the attachment lines which passed through the tubing. Six field-tagged fish (1.5-7.5 kg) were monitored for 45-115 days before tracking was terminated. Tracking patterns of fish indicated no apparent effect of these large, external transmitters on movement behavior; further, the transmitters did not appear to entangle the fish in vegetation. One fish with its transmitter still secure was recaptured after 54 days, and there was minimal tissue erosion under the transmitter. With minor improvements for the attachment lines and the transmitter saddle, the method is suitable for externally attaching large telemetry transmitters to fish.

Herke, S.W.; Moring, J.R.

1999-01-01

36

Altered energetics and parasitism in juvenile northern pike (Esox lucius) inhabiting metal-mining contaminated lakes.  

PubMed

The objective of this study was to evaluate possible factors that could be contributing to altered bioenergetics of juvenile northern pike (Esox lucius) living in lakes receiving effluent from the Key Lake uranium mill in northern Saskatchewan, Canada. Although glycogen and triglycerides stores in liver and muscle were significantly greater in pike from exposure lakes compared to the reference, triglycerides stores of aquatic insects and spottail shiners that are prey items of juvenile pike showed no overall differences among lakes. Measures of parasitism, on the other hand, were negatively correlated with pike bioenergetics thereby reflecting a possible energetic cost of parasitism on reference lake fishes. The degree of infection, as measured by the abundance and biomass of intestinal parasites and the abundance of monogeneans on pike gills, was greatest in reference fishes and intermediate in low-exposure pike, whereas high-exposure fishes harbored no parasites. PMID:18329711

Kelly, Jocelyn M; Janz, David M

2008-07-01

37

Biogenic amines formation in high-pressure processed pike flesh (Esox lucius) during storage.  

PubMed

The effects of vacuum packaging followed by high pressure processing on the shelf-life of fillets of pike (Esox lucius) were examined. Samples were pressure-treated at 300 and 500 MPa and stored at 3.5 and 12 °C for up to 70 days. The content of eight biogenic amines (putrescine, cadaverine, spermidine, spermine, histamine, tyramine, tryptamine and phenylethylamine) were determined. Putrescine showed very good correspondence with the level of applied pressure and organoleptic properties. Polyamines spermidine and spermine did not show statistically significant changes with the level of applied pressure and the time of storage. Increased cadaverine and tyramine contents were found in samples with good sensory signs, stored for longer time and/or kept at 12 °C, thus indicating the loss of freshness. Tryptamine and phenylethylamine were not detected in pressure-treated samples kept at 3.5 °C. Histamine was not detected in samples of good quality. PMID:24423558

K?ížek, Martin; Mat?jková, Kate?ina; Vácha, František; Dadáková, Eva

2014-05-15

38

Mercury elimination rates for adult northern pike Esox lucius: evidence for a sex effect  

USGS Publications Warehouse

We examined the effect of sex on mercury elimination in fish by monitoring isotope-enriched mercury concentrations in the muscle tissue of three adult female and three adult male northern pike Esox lucius, which had accumulated the isotope-enriched mercury via a whole-lake manipulation and were subsequently moved to a clean lake. Mercury elimination rates for female and male northern pike were estimated to be 0.00034 and 0.00073 day?1, respectively. Thus, males were capable of eliminating mercury at more than double the rate than that of females. To the best of our knowledge, our study represents the first documentation of mercury elimination rates varying between the sexes of fish. This sex difference in elimination rates should be taken into account when comparing mercury accumulation between the sexes of fish from the same population. Further, our findings should eventually lead to an improved understanding of mechanisms responsible for mercury elimination in vertebrates.

Madenjian, Charles P.; Blanchfield, Paul J.; Hrenchuk, Lee E.; Van Walleghem, Jillian L. A.

2014-01-01

39

Mechanical suppression of northern pike (Esox lucius) populations in small Arizona reservoirs  

USGS Publications Warehouse

Introduced populations of northern pike Esox lucius have provided angling opportunities in the western United States (McMahon and Bennett 1996). However, the northern pike is a voracious piscivore and its large size, high fecundity, and broad physiological tolerance make it capable of drastically altering ecosystems it invades (Marchetti et al. 2004). Indeed, predation by northern pike has been shown to significantly alter fish community structure and put native fishes at a higher extinction risk (He and Kitchell 1990, Findlay et al. 2000). Predation by northern pike is viewed as a significant threat to native stocks of salmonids in Washington, British Columbia, and California (McMahon and Bennett 1996, California Department of Fish and Game [CDFG] 2003).

Kuzmenko, Yuliya; Spesiviy, Timofy; Bonar, Scott A.

2010-01-01

40

The desaturation and elongation of 14 C-labelled polyunsaturated fatty acids by pike ( Esox lucius L.) in vivo  

Microsoft Academic Search

To examine the ability of pike (Esox lucius L.) to modify exogenous PUFA by desaturation and elongation, 14C-labelled 18:2(n-6), 18:3(n-3), 20:4(n-6) and 20:5(n-3) were injected intraperitoneally and the distribution of radioactivity in tissue lipid classes and liver PUFA measured. In all tissues examined, radioactivity from all 14C-PUFA was recovered in many classes of acyl lipids and the level of recovery

R. James Henderson; Moira T. Park; John R. Sargent

1995-01-01

41

Temporal change estimation of mercury concentrations in northern pike (Esox lucius L.) in Swedish lakes.  

PubMed

Adequate temporal trend analysis of mercury (Hg) in freshwater ecosystems is critical to evaluate if actions from the human society have affected Hg concentrations ([Hg]) in fresh water biota. This study examined temporal change in [Hg] in Northern pike (Esox lucius L.) in Swedish freshwater lakes between 1994 and 2006. To achieve this were lake-specific, multiple-linear-regression models used to estimate pike [Hg], including indicator variables representing time and fish weight and their interactions. This approach permitted estimation of the direction and magnitude of temporal changes in 25 lakes selected from the Swedish national database on Hg in freshwater biota. A significant increase was found in 36% of the studied lakes with an average increase in pike [Hg] of 3.7±6.7% per year that was found to be positively correlated with total organic carbon. For lakes with a significant temporal change the dataset was based on a mean of 30 fish, while for lakes with no temporal change it was based on a mean of 13 fish. PMID:22014468

Åkerblom, Staffan; Nilsson, Mats; Yu, Jun; Ranneby, Bo; Johansson, Kjell

2012-02-01

42

Susceptibility of pike Esox lucius to a panel of Ranavirus isolates.  

PubMed

In order to study the pathogenicity of ranaviruses to a wild European freshwater fish species, pike Esox lucius fry were challenged with the following Ranavirus isolates: epizootic haematopoietic necrosis virus (EHNV), European sheatfish virus (ESV), European catfish virus (ECV), pike-perch iridovirus (PPIV), New Zealand eel virus (NZeelV) and frog virus 3 (FV3). The fry were infected using bath challenge at 12 and 22 degrees C. Significant mortalities were observed at 12 degrees C for EHNV, ESV, PPIV and NZeelV. Background mortality was too high in the experiments performed at 22 degrees C for any conclusions about viral pathogenicity at this temperature to be drawn. Viruses could be re-isolated from samples from all challenged groups, and their presence in infected tissue was demonstrated using immunohistochemistry. The findings suggest that pike fry are susceptible to EHNV, ESV, PPIV and NZeelV and can be a vector for ECV and FV3. Statistical analysis of the factors associated with positive virus re-isolation showed that the number of fish in the sample influenced the outcome of virus re-isolation. Moreover, the likelihood of positive virus re-isolation significantly differed among the 6 viral isolates. The temperature from where the sample was taken and the number of days after infection were not associated with the probability of a positive virus re-isolation. PMID:19402450

Jensen, Britt Bang; Ersbøll, Annette Kjaer; Ariel, Ellen

2009-02-25

43

Selective exploitation of large pike Esox lucius--effects on mercury concentrations in fish populations.  

PubMed

The present study outlines two main trends of mercury transfer patterns through the fish community: 1) the Hg concentrations increase with increase in the trophic level, with top predators having the highest concentrations, and 2) a fast growth rate may dilute the concentrations of Hg in fish muscle tissue (growth biodilution). In 2004, an extensive reduction in number of large pike (Esox lucius L.), was initiated by selective gillnet fishing in Lake Arungen, Norway, in order to increase the pike recruitment due to an expected reduction in cannibalism. In this connection, total mercury (THg) concentrations in the fish community were studied both before (2003) and after (2005) the removal of large pike. The delta(15)N signatures and stomach content analyses indicated that pike and perch (Perca fluviatilis L.) occupied the highest trophic position, while roach (Rutilus rutilus (L.)) was at the lower level, and rudd (Scardinius erythrophthalmus L.) at the lowest. The piscivores, pike and perch, had the highest concentrations of THg. The biomagnification rate of THg through the food web in the fish community was 0.163 (per thousand delta(15)N), with the highest uptake rate (0.232) in perch. A significant decrease in THg concentrations was found in all fish species in 2005 compared to 2003. Removal of the top predators in an Hg contaminated lake might thus be an important management tool for reducing Hg levels in fish, thereby reducing health risk to humans. PMID:18485450

Sharma, Chhatra Mani; Borgstrøm, Reidar; Huitfeldt, Jørgen Sinkaberg; Rosseland, Bjørn Olav

2008-07-25

44

Visibility conditions and diel period affect small-scale spatio-temporal behaviour of pike Esox lucius in the absence of prey and conspecifics.  

PubMed

Pike Esox lucius in the absence of prey and conspecifics were shown to have the highest habitat-change activity during dusk and to decrease preference for complex habitats in turbid water. As the behaviours indicate routine responses in the absence of behavioural interactions, E. lucius spatio-temporal distributions should be directly affected and thereby more easily assessed and avoided by prey, with potential consequences for encounter rates. PMID:22551189

Nilsson, P A; Baktoft, H; Boel, M; Meier, K; Jacobsen, L; Rokkjaer, E M; Clausen, T; Skov, C

2012-05-01

45

Mercury toxicity in livers of northern pike (Esox lucius) from Isle Royale, USA.  

PubMed

Many laboratory studies have documented that mercury can be toxic to fish, but it is largely unknown if mercury is toxic to fish in their natural environments. The objective of our study was to investigate the toxic effects of mercury on northern pike (Esox lucius) at Isle Royale, Michigan. In 124 northern pike from eight inland lakes, concentrations of total mercury in skin-on fillets ranged from 0.069 to 0.622 microg/g wet mass (wet wt). Concentrations of total mercury in livers increased exponentially compared with concentrations in fillets, to a maximum of 3.1 microg/g wet wt. Methylmercury constituted a majority of the mercury in livers with total mercury concentrations <0.5 microg/g wet wt, but declined to 28-51% of the mercury in livers with total mercury concentrations >0.5 microg/g wet wt. Liver color (absorbance at 400 nm) varied among northern pike and was positively related to liver total mercury concentration. The pigment causing variation in liver color was identified as lipofuscin, which results from lipid peroxidation of membranous organelles. An analysis of covariance revealed lipofuscin accumulation was primarily associated with mercury exposure, and this association obscured any normal accumulation from aging. We also documented decreased lipid reserves in livers and poor condition factors of northern pike with high liver total mercury concentrations. Our results suggest (i) northern pike at Isle Royale are experiencing toxicity at concentrations of total mercury common for northern pike and other piscivorous fish elsewhere in North America and (ii) liver color may be useful for indicating mercury exposure and effects in northern pike at Isle Royale and possibly other aquatic ecosystems and other fish species. PMID:18262851

Drevnick, Paul E; Roberts, Aaron P; Otter, Ryan R; Hammerschmidt, Chad R; Klaper, Rebecca; Oris, James T

2008-04-01

46

Genetic structure of pike (Esox lucius) reveals a complex and previously unrecognized colonization history of Ireland  

PubMed Central

Aim We investigated genetic variation of Irish pike populations and their relationship with European outgroups, in order to elucidate the origin of this species to the island, which is largely assumed to have occurred as a human-mediated introduction over the past few hundred years. We aimed thereby to provide new insights into population structure to improve fisheries and biodiversity management in Irish freshwaters. Location Ireland, Britain and continental Europe. Methods A total of 752 pike (Esox lucius) were sampled from 15 locations around Ireland, and 9 continental European sites, and genotyped at six polymorphic microsatellite loci. Patterns and mechanisms of population genetic structure were assessed through a diverse array of methods, including Bayesian clustering, hierarchical analysis of molecular variance, and approximate Bayesian computation. Results Varying levels of genetic diversity and a high degree of population genetic differentiation were detected. Clear substructure within Ireland was identified, with two main groups being evident. One of the Irish populations showed high similarity with British populations. The other, more widespread, Irish strain did not group with any European population examined. Approximate Bayesian computation suggested that this widespread Irish strain is older, and may have colonized Ireland independently of humans. Main conclusions Population genetic substructure in Irish pike is high and comparable to the levels observed elsewhere in Europe. A comparison of evolutionary scenarios upholds the possibility that pike may have colonized Ireland in two ‘waves’, the first of which, being independent of human colonization, would represent the first evidence for natural colonization of a non-anadromous freshwater fish to the island of Ireland. Although further investigations using comprehensive genomic techniques will be necessary to confirm this, the present results warrant a reappraisal of current management strategies for this species.

Pedreschi, Debbi; Kelly-Quinn, Mary; Caffrey, Joe; O’Grady, Martin; Mariani, Stefano; Phillimore, Albert

2014-01-01

47

Light, fluorescence, and electron microscopic studies on the pineal organ of the pike, Esox lucius L., with special regard to 5-hydroxytryptamine  

Microsoft Academic Search

The pineal organ of adult pikes, Esox lucius L., maintained under normal diurnal conditions, was studied with a combination of light microscopy, fluorescence histochemistry of certain arylethylamines, and electron microscopy.1.The pineal parenchyma consists of sensory cells, supporting cells, and a third cell type which may be identical with previously described ganglion cells. The nerve fibres constituting the pineal tract were

Christer Owman; Claes Rüdeberg

1970-01-01

48

Bioenergetics and growth of young-of the-year northern pike ( Esox lucius) and burbot ( Lota lota) exposed to metal mining effluent  

Microsoft Academic Search

We hypothesized that exposure to metal mining effluent would reduce the ability of young-of-the-year fishes to accumulate energy reserves to survive the overwinter period (known as “winter stress syndrome”) in a Canadian boreal forest watershed. Northern pike (Esox lucius) and burbot (Lota lota) were collected immediately before and after winter from a reference lake and two lakes receiving effluent. Unexpectedly,

Pamela M. Bennett; David M. Janz

2007-01-01

49

Biomarkers of contaminant exposure in northern pike (Esox lucius) from the Yukon River Basin, Alaska  

USGS Publications Warehouse

As part of a larger investigation, northern pike (n = 158; Esox lucius) were collected from ten sites in the Yukon River Basin (YRB), Alaska, to document biomarkers and their correlations with organochlorine pesticide (total p,p'-DDT, total chlordane, dieldrin, and toxaphene), total polychlorinated biphenyls (PCBs), and elemental contaminant (arsenic, cadmium, copper, lead, total mercury, selenium, and zinc) concentrations. A suite of biomarkers including somatic indices, hepatic 7-ethoxyresorufin O-deethylase (EROD) activity, vitellogenin concentrations, steroid hormone (17B- ustradiol and 16-kebtestosteront) concentrations, splenic macrophage aggregates (MAs), oocyte atresia, and other microscopic anomalies in various tissues were documented in YRB pike. Mean condition factor (0.50 to 0.68), hepatosomatic index (1.00% to 3.56%), and splenosomatic index (0.09% to 0.18%) were not anomalous at any site nor correlated with any contaminant concentration. Mean EROD activity (0.71 to 17.51 pmol/min/mg protein) was similar to basal activity levels previously measured in pike and was positively correlated with selenium concentrations (r = 0.88, P 0.01 mg/mL in male pike from multiple sites indicated exposure to estrogenic compounds. Mean steroid hormone concentrations and percent oocyte atresia were not anomalous in pike from any YRB site. Few site differences were significant for mean MA density (1.86 to 6.42 MA/mm2), size (812 to 1481 ??m2), and tissue occupied (MA-%; 0.24% to 0.75%). A linear regression between MA-% and total PCBs was significant, although PCB concentrations were generally low in YRB pike (???63 ng/g), and MA-% values in female pike (0.24% to 0.54%) were lower than in male pike (0.32% to 0.75%) at similar PCB concentrations. Greater numbers of MAs were found as zinc concentrations increased in YRB female pike, but it is unlikely that this is a causative relationship. Histological abnormalities observed in gill, liver, spleen, and kidney tissues were not likely a result of contaminant exposure but provide information on the general health of YRB pike. The most common histologic anomalies were parasitic infestations in various organs and developing nephrons and nephrocalcinosis in posterior kidney tissues. Overall, few biomarker responses in YRB pike were correlated with chemical contaminant concentrations, and YRB pike generally appeared to be healthy with no site having multiple anomalous biomarker responses. ?? 2007 Springer Science+Business Media, LLC.

Hinck, J. E.; Blazer, V. S.; Denslow, N. D.; Myers, M. S.; Gross, T. S.; Tillitt, D. E.

2007-01-01

50

Side-aspect target strength of Atlantic salmon ( Salmo salar ), brown trout ( Salmo trutta ), whitefish ( Coregonus lavaretus ), and pike ( Esox lucius )  

Microsoft Academic Search

The side-aspect acoustic target strengths (TS) of 19 Atlantic salmons (Salmo salar), 16 brown trouts (Salmo trutta), 10 whitefish (Coregonus lavaretus) and 9 pikes (Esox lucius) were measured using a 200 kHz split-beam echosounder, in order to study the relationship between TS and fish size indices (length, weight and side area). The effect of side aspect angle on TS was also

Juha Lilja; Timo J Marjomäki; Raimo Riikonen; Juha Jurvelius

2000-01-01

51

Changes in mercury levels in lake whitefish ( Coregonus clupeaformis ) and northern pike ( Esox lucius ) in the LG2 reservoir since flooding  

Microsoft Academic Search

After flooding of the LG-2 reservoir in 1978–1979, it was noticed that Hg levels in fish rose dramatically. In this study the Hg data have been examined on the basis of fish age for lake whitefish (Coregonus clupeaformis) and northern pike (Esox lucius), representing two different trophic levels. Data were fit to Von Bertalanffy functions using non-linear regression analyses. Reductions

K. A. Morrison; N. Thérien

1995-01-01

52

The mast cell nature of granule cells in the digestive tract of the pike, Esox lucius : similarity to mammalian mucosal mast cells and globule leucocytes  

Microsoft Academic Search

Observations were made on sections of intestinal tissue from the pike,Esox lucius, fixed in a solution containing 4% formaldehyde and 5% acetic acid in methanol. Four staining procedures, using May-Grünwald Giemsa combi-nation dye, hematoxylin and eosin, toluidine blue, and alcian blue in sequence with safranin, were applied. Numerous granule cells were found in the area of stratum compactum and in

OLA B. REITE

1996-01-01

53

[Taxonomic characteristics and physiological properties of microorganisms from the gut of pike (Esox lucius)].  

PubMed

The taxonomic composition and distribution of microorganisms differing in the degree of association with the intestinal mucosa of the pike (Lucius lucius) has been studied. Microorgansism of the families Enterobacteriaceae, Aeromonadaceae, and Vibrionaceae dominate in the gut microflora. Numerically prevailing bacterial species are characterized by high proteolytic and amylolytic enzyme activities as well as by high persistence accounted for by antilysozyme and antihistone activities. The results of this study show that Hafnia alvei, Yersinia ruckeri, Vibrio vulnificus, V. furnissii, Aeromonas salmonicida, and Shewanella putrefaciens may be regarded as normal components of the pike gut microflora. PMID:19198074

Izveskova, G I; Nemtseva, N V; Plotnikov, A O

2008-01-01

54

Induction of gene responses in St. Lawrence River northern pike (Esox lucius) environmentally exposed to perfluorinated compounds.  

PubMed

Municipal waste water effluents (MWWEs) are important sources of chemical contamination for aquatic environments. This study investigated the presence and effects of perfluorinated compounds (PFCs) in environmentally exposed northern pike (Esox lucius) collected upstream and downstream a major municipal waste water treatment plant (WWTP) in the St. Lawrence River, Canada. Twelve PFCs, including the newly detected perfluoroethylcyclohexane sulfonate (PFECHS), were quantified in fish muscle, liver, and plasma. Additionally, the expression of eight genes and the activity of three biomarkers were analyzed in fish tissues at both sites. Mean ?PFC concentration in fish plasma collected upstream the WWTP was 185ng/g w.w. compared to 545ng/g w.w. downstream the point of release. PFECHS was quantified for the first time in St. Lawrence River fish (mean plasma concentration in MWWE fish: 5.07±4.72ng/g w.w.). Results of transcriptomic responses were tissue-specific and indicated significant up-regulation for metallothionein (MT) in blood and MT, glutathion-S-transferase (GST), superoxide dismutase (SOD), and cytochromes P450 1A1 (CYP1A1) in gill tissue of fish collected in the MWWE suggesting greater stress responses for organisms at this location. Significant relationships were found between vitellogenin (Vtg) gene expression in liver, Vtg activity in plasma and perfluorotridecanoic acid (PFTrA), perfluorotetradecanoic acid (PFTeA), and perfluorodecane sulfonate (PFDS) plasma concentrations. The possible endocrine effects of these PFCs should be further investigated. PMID:23453599

Houde, Magali; Douville, Mélanie; Despatie, Simon-Pierre; De Silva, Amila O; Spencer, Christine

2013-08-01

55

Fish Community Responses to the Establishment of a Piscivore, Northern Pike (Esox lucius), in a Nebraska Sandhill Lake  

USGS Publications Warehouse

Northern pike (Esox lucius) was first documented in West Long Lake, Nebraska, in 1998 when two pike <380 mm were collected. In 2002, a Peterson mark-recapture population estimate on northern pike revealed density and standing stock (i.e., biomass) estimates of 35.8 fish/ha (95% CI= ?? 8.8) and 22.0 kg/ha (95% CI= ?? 5.4), respectively. Consequently, West Long Lake was sampled in 2002 to compare relative abundance, size structure, and growth of bluegill (Lepomis macrochirus), largemouth bass (Micropterus salmoides), and yellow perch (Perca flavescens) prior to and after the establishment of a high-density northern pike population. Bluegill, largemouth bass, and yellow perch relative abundances were significantly lower in 2002 than 1998. Similarly, size structures of all three species were significantly different between years. Size structure declined for both bluegill and yellow perch, and increased for largemouth bass. Growth was significantly higher for bluegill, largemouth bass, and yellow perch in 2002 than 1998. While the fish community changes were expected with the establishment of northern pike, they occurred in a relatively short time period (i.e., four years).

DeBates, T.J.; Paukert, C.P.; Willis, D.W.

2003-01-01

56

Between-population similarity in intestinal parasite community structure of pike (Esox lucius)--effects of distance and historical connections.  

PubMed

The effect of geographical distance on similarity in parasite communities of freshwater fish has received considerable attention in recent years, and it has become evident that these apparently simple relationships are influenced by, among other things, colonization ability of parasites and degree of connectivity between the populations. In the present paper, we explored qualitative and quantitative similarity in the intestinal parasite communities of pike (Esox lucius) in a particular system where previously interconnected groups of lakes became isolated ca. 8,400 yr ago. Contrary to our expectations, we did not find differences in similarity between the lake groups or a negative effect of distance among the populations. This supports the role of common ancestral colonization events and shows that no significant loss of species has occurred during the past 8,000 yr. However, the communities were dominated by a single parasite species, the cestode Triaenophorus nodulosus. The exclusion of this species from the data had a significant negative impact on the community similarities and also revealed a negative relationship between distance and quantitative similarity. This suggests that patterns of community organization may be obscured by a single dominant species. We also highlight the need for further studies in different systems and host species, as well as detailed reanalysis of existing data sets, to unravel the controversy in the relationship between distance and similarity in parasite communities. PMID:18925789

Karvonen, Anssi; Valtonen, E Tellervo

2009-06-01

57

Dietary uptake in pike (Esox lucius) of some polychlorinated biphenyls, polychlorinated naphthalenes and polybrominated diphenyl ethers administered in natural diet  

SciTech Connect

The dietary uptake of 12 halogenated diaromatic compounds was studied using northern pike (Esox lucius L.) fed with rainbow trout (Oncorhynchus mykiss (Walbaum)). Before the trout were fed to the pike, they had been injected with a cocktail of five polychlorinated biphenyls, four polychlorinated naphthalenes, and three polybrominated diphenyl ethers, dissolved in rainbow trout lipid. The reported uptake efficiencies (E) were in the range 35 to 90% and differ in some respect from earlier studies. The E-values for those substances with effective cross sections (ECS) >9.5 {angstrom} were considerably higher than expected if the membrane permeation at dietary uptake was restricted as proposed previously in the literature. There was no hydrophobicity dependency of the total dietary uptake efficiency as suggested by an earlier proposed empirical model. The difference between the results presented here and earlier studies is likely to depend on cotransport with lipids and/or proteins through a mediated, possibly active uptake of hydrophobic organic compounds (HOC) in the gastrointestinal tract enabled by the actual exposure method. For the proposed mediated/active uptake of HOCs, the uptake efficiency varied with molecular weight and was greatest for a molecular weight of approximately 450.

Burreau, S.; Axelman, J.; Broman, D.; Jakobsson, E. [Stockholm Univ. (Sweden)

1997-12-01

58

{sup 32}P-postlabeling analysis of DNA adducts in wild perch (Perca fluviatilis) and northern pike (Esox lucius)  

SciTech Connect

Several previous studies have demonstrated a correlation between high concentrations of sediment-associated contaminants and elevated levels of aromatic/hydrophobic DNA adduct levels in the liver of benthic fish species. In the present study DNA adducts was analyzed in coastal populations of perch (Perca fluviatilis) and northern pike (Esox lucius). Fish were sampled from four different sites in a gradient from a heavily industrialized area at the Swedish Baltic coast. For comparison, fish were also caught in a reference area with no main industries and comparatively low levels of contaminants of anthropogenic origin. DNA was extracted from liver and several extrahepatic tissues and DNA adducts were analyzed by the nuclease PI version of the {sup 32}P-postlabeling assay. The autoradiograms derived from DNA of fish from the contaminated sites showed several adduct spots not visible on the autoradiograms derived from fish from the reference area. Total adduct levels were significantly elevated in several tissues in fish from contaminated sites compared to the reference area. Species and tissue-specific differences in adduct levels and the use of {sup 32}P-postlabeling analysis of DNA adducts as a biomarker to monitor the presence and effects of genotoxic chemicals in the aquatic environment are discussed.

Ericson, G.; Liewenborg, B.; Balk, L. [Stockholm Univ., Nykoeping (Sweden)

1995-12-31

59

Quantifying selection differentials caused by recreational fishing: development of modeling framework and application to reproductive investment in pike (Esox lucius)  

PubMed Central

Methods for quantifying selection pressures on adaptive traits affected by size-selective fishing are still scarce, and none have as yet been developed for recreational fishing. We present an ecologically realistic age-structured model specifically tailored to recreational fishing that allows estimating selection differentials on adaptive life-history traits. The model accounts for multiple ecological feedbacks, which result in density-dependent and frequency-dependent selection. We study selection differentials on annual reproductive investment under size-selective exploitation in a highly demanded freshwater recreational fish species, northern pike (Esox lucius L.). We find that recreational angling mortality exerts positive selection differentials on annual reproductive investment, in agreement with predictions from life-history theory. The strength of selection increases with the intensity of harvesting. We also find that selection on reproductive investment can be reduced by implementing simple harvest regulations such as minimum-size limits. The general, yet computationally simple, methods introduced here allow evaluating and comparing selection pressures on adaptive traits in other fish populations and species, and thus have the potential to become a tool for evolutionary impact assessment of harvesting.

Arlinghaus, Robert; Matsumura, Shuichi; Dieckmann, Ulf

2009-01-01

60

Determination of polychlorinated biphenyls and total mercury in two fish species (Esox lucius and Carassius auratus) in Anzali Wetland, Iran.  

PubMed

The Anzali Wetland is one of the most important ecosystems in the north of Iran, and parts of it were registered as a Ramsar site in 1975. However, even though, due to many problems, including eutrophication produced by inflow of excess nutrients and organic materials, the wetland was also listed on the Montreux Record indicating the need to take urgent remedial action. This study was conducted to study the levels of polychlorinated biphenyls (PCBs) and total mercury (THg) in two fish species (Esox lucius and Carassius auratus) as bio-indicators of the ecosystem condition in eastern part of Anzali Wetland. The sampling was carried out in six different periods between years 2009 and 2010. The results showed that the amounts of PCBs in the muscle of northern pike were below the detection limit of gas chromatography, whereas the average concentration in goldfish was 0.449 mg/kg wet weight. Some possible reasons for the higher levels of PCBs in goldfish in comparison with pike have been discussed. No significant (p?

Sakizadeh, Mohammad; Esmaeili Sari, Abas; Abdoli, Asghar; Bahramifar, Nader; Hashemi, Seyed Hossein

2012-05-01

61

Assessment of oxidative stress and histopathology in juvenile northern pike (Esox lucius) inhabiting lakes downstream of a uranium mill.  

PubMed

Lakes receiving effluent from the Key Lake uranium mill in northern Saskatchewan contain elevated trace metals, some of which are associated with increased reactive oxygen species (ROS) in cells and tissues causing oxidative stress. The potential for oxidative stress was assessed in juvenile (age 1+) northern pike (Esox lucius) collected from two exposure (high and low) and one reference lake near the Key Lake operation. The concentrations of total, reduced and oxidized glutathione and the ratio of oxidized to reduced glutathione in liver and kidney did not differ significantly among pike collected from exposure and reference lakes, with the exception of low exposure pike kidney that had significantly greater oxidized glutathione and ratio of oxidized to reduced glutathione. The concentrations of by-products of lipid peroxidation (malondialdehyde and 4-hydroxyalkenal) were significantly greater in kidney of pike collected from the reference lake compared to both exposure lakes. The activity of the antioxidant enzyme glutathione peroxidase in liver was greater in pike collected from the high exposure lake compared to the reference lake. Histopathological evaluations revealed greater pathology in reference lake pike as indicated by a greater number of pyknotic and fragmented nuclei and dilated tubules as well as a thickening of Bowman's capsule in kidney, and as a thickening of the primary filament epithelial padding in gills. In liver, hepatocyte morphology, including transsectional area and degree of vacuolation, differed among lakes without any clear signs of pathology. Trace metal analyses of muscle showed that eight elements (arsenic, cobalt, copper, iron, molybdenum, selenium, thallium, and uranium) were significantly elevated in pike collected from both exposure lakes compared to reference. These results provide only limited evidence of oxidative stress in exposure pike tissues and no evidence of histopathology despite indications that trace metals, most notably arsenic and selenium, were bioaccumulating in tissue. PMID:19304330

Kelly, Jocelyn M; Janz, David M

2009-05-17

62

Effects of osmolality on sperm morphology, motility and flagellar wave parameters in Northern pike (Esox lucius L.).  

PubMed

Northern pike (Esox lucius L.) spermatozoa are uniflagellated cells differentiated into a head without acrosome, a midpiece and a flagellar tail region flanked by a fin structure. Total, flagellar, head and midpiece lengths of spermatozoa were measured and show mean values of 34.5, 32.0, 1.32, 1.17 microm, respectively, with anterior and posterior widths of the midpiece measuring 0.8 and 0.6 microm, respectively. The osmolality of seminal plasma ranged from 228 to 350 mOsmol kg(-1) (average: 283.88+/-33.05). After triggering of sperm motility in very low osmolality medium (distilled water), blebs appeared along the flagellum. At later periods in the motility phase, the tip of the flagellum became curled into a loop shape which resulted in a shortening of the flagellum and a restriction of wave development to the proximal part (close to head). Spermatozoa velocity and percentage of motile spermatozoa decreased rapidly as a function of time postactivation and depended on the osmolality of activation media (P<0.05). In general, the greatest percentage of motile spermatozoa and highest spermatozoa velocity were observed between 125 and 235 mOsmol kg(-1). Osmolality above 375 mOsmol kg(-1) inhibited the motility of spermatozoa. After triggering of sperm motility in activation media, beating waves propagated along the full length of flagella, while waves appeared dampened during later periods in the motility phase, and were absent at the end of the motility phase. By increasing osmolality, the velocity of spermatozoa reached the highest value while wave length, amplitude, number of waves and curvatures also were at their highest values. This study showed that sperm morphology can be used for fish classification. Sperm morphology, in particular, the flagellar part showed several changes during activation in distilled water. Sperm motility of pike is inhibited due to high osmolality in the seminal plasma. Osmolality of activation medium affects the percentage of motile sperm and spermatozoa velocity due to changes in flagellar wave parameters. PMID:19269024

Alavi, S M Hadi; Rodina, Marek; Viveiros, Ana T M; Cosson, Jacky; Gela, David; Boryshpolets, Sergei; Linhart, Otomar

2009-07-01

63

Investigation of first year biotic and abiotic influences on the recruitment of pike Esox lucius over 48 years in Windermere, UK.  

PubMed

Estimated pike Esox lucius recruitment varied by a factor of 16 for females from 1944 to 1991 and by a factor of 27 for males from 1943 to 1990 in Windermere, a temperate, mesotrophic U.K. lake. No significant stock-recruitment relationships were found, but analysis with general additive models (GAMs) revealed that early autumnal water temperature, strength and direction of the North Atlantic Oscillation displacement (corresponding to different climatic conditions in winter) and zooplankton abundance but above all, late summer water temperature were important explanatory variables over the entire time series. Female recruitment was also influenced by young-of-the-year winter temperature. There was no evidence that perch Perca fluviatilis year-class strength, lake level or the summer position of the Gulf Stream influenced recruitment. The fitted models explained up to c. 65% of the overall observed variation between years. PMID:20735553

Paxton, C G M; Winfield, I J; Fletcher, J M; George, D G; Hewitt, D P

2009-07-01

64

Environmental factors regulate the effects of roach Rutilus rutilus and pike Esox lucius on perch Perca fluviatilis populations in small boreal forest lakes.  

PubMed

In this study of 18 small boreal forest lakes, the effects of abiotic and biotic factors (roach Rutilus rutilus and pike Esox lucius) on various population variables of perch Perca fluviatilis were examined. As a single variable, the gillnet catch per unit effort (CPUE) of R. rutilus was negatively related to the mean mass of small (< 200 mm) and the growth rate of young (1-2 years) P. fluviatilis. The mean mass of large (> or = 200 mm) P. fluviatilis was the highest at intermediate CPUE of R. rutilus. Redundancy analysis including environmental factors and P. fluviatilis population variables suggested that 'predation-productivity-humus' gradient affected P. fluviatilis populations by decreasing the CPUE and mean mass of small individuals but increasing these variables of large individuals. The CPUE of R. rutilus and lake area had a negative effect on small and a positive effect on large P. fluviatilis growth rate. In small boreal forest lakes, P. fluviatilis populations are affected by the partially opposite forces of competition by R. rutilus and predation by E. lucius, and the intensity of these interactions is regulated by several environmental factors. PMID:20537014

Olin, M; Vinni, M; Lehtonen, H; Rask, M; Ruuhijärvi, J; Saulamo, K; Ala-Opas, P

2010-04-01

65

Uptake and distribution of (/sup 3/H)benzo(a)pyrene in the Northern pike (Esox lucius). Examination by whole-body autoradiography and scintillation counting  

SciTech Connect

The uptake and distribution of the polyaromatic hydrocarbon benzo(a)pyrene in Northern pike (Esox lucius) were investigated by whole body autoradiography and scintillation counting. (/sup 3/H)Benzo(a)pyrene was administered either in the diet or in the water. The uptake and distribution of this compound and its metabolites were followed from 10 hr to 21 days after the initial exposure. The autoradiography patterns observed here with both routes of administration suggest, as expected, that benzo(a)pyrene is taken up through the gastrointestinal system and the gills, metabolized in the liver, and excreted in the urine and bile. Other findings indicate that the gills may not be a major route of excretion for benzo(a)pyrene and its metabolites in the Northern pike; that benzo(a)pyrene may be taken up from the water directly into the skin of this fish; that benzo(a)pyrene and its metabolites are heterogeneously distributed in the kidney of the Northern pike; and that very little radioactivity accumulates in the adipose tissue. With scintillation counting, uptake of radioactivity from the water was found to occur rapidly in all organs, reaching a plateau in most cases after about 0.8 days. The concentrations of radioactivity in different organs ranged between 50 (many organs) and 80,000 (gallbladder + bile) times that found in the surrounding water.

Balk, L.; Meijer, J.; DePierre, J.W.; Appelgren, L.E.

1984-07-01

66

Bioenergetics and growth of young-of the-year northern pike (Esox lucius) and burbot (Lota lota) exposed to metal mining effluent.  

PubMed

We hypothesized that exposure to metal mining effluent would reduce the ability of young-of-the-year fishes to accumulate energy reserves to survive the overwinter period (known as "winter stress syndrome") in a Canadian boreal forest watershed. Northern pike (Esox lucius) and burbot (Lota lota) were collected immediately before and after winter from a reference lake and two lakes receiving effluent. Unexpectedly, total body lipid and triglyceride, and liver triglyceride levels were greater in effluent-exposed pike and burbot in both fall and spring. However, there were no lake or season differences in growth indices of length, weight, muscle RNA/DNA ratio, or muscle protein levels in pike. In addition, total lipids and triglycerides in burbot were greater in spring compared to fall, while no seasonal differences were observed in pike, suggesting that burbot continued to feed during winter. Findings do not support the winter stress syndrome hypothesis and suggest possible direct and indirect effects of metal mining effluent on lipid dynamics of juvenile fishes. PMID:17368537

Bennett, Pamela M; Janz, David M

2007-09-01

67

Assessment of larval deformities and selenium accumulation in northern pike (Esox lucius) and white sucker (Catostomus commersoni) exposed to metal mining effluent.  

PubMed

Uranium mining and milling operations in northern Saskatchewan (Canada) release effluents with elevated levels of certain trace metals and metalloids, including selenium. The goal of the present study was to evaluate the presence of selenium-induced deformities in northern pike (Esox lucius) and white sucker (Catostomus commersoni) larvae originating from adults collected downstream of a uranium mine. Eggs were fertilized in the field and incubated in the laboratory following a two-way (crossover) analysis-of-variance experimental design to discriminate effects from maternal transfer versus those from exposure to site water in the developing embryos. Selenium concentrations in northern pike and white sucker eggs (8.02 and 4.89 microg/g dry wt, respectively; mean +/- standard error throughout) from the exposure site were approximately two- to threefold higher than reference (2.35 +/- 0.20 and 1.94 +/- 0.25 microg/g dry wt, respectively). Among all evaluated deformities (skeletal curvatures, craniofacial deformities, fin deformities, and edema), only edema in white sucker fry from the exposure site was slightly elevated ( approximately 3%) compared to reference. The occurrence of edema, however, can be associated with factors other than selenium (e.g., other metals and organic compounds). Both fish species displayed strong linear relationships between the selenium concentrations in eggs and other tissues (muscle, liver, kidney, and bone), suggesting that selenium concentrations in eggs could be predicted from selenium concentrations in adult tissues. The lack of a clear, toxic response in the present study is in agreement with selenium thresholds for early life-stage deformities reported in other studies, with egg selenium concentrations in northern pike and white sucker collected at the exposure site being less than the 10 microg/g (dry wt) threshold associated with the presence of deformities. PMID:18939891

Muscatello, Jorgelina R; Janz, David M

2009-03-01

68

Metabolic enzymes activity and histomorphology in the liver of whitefish (Coregonus lavaretus L.) and pike (Esox lucius L.) inhabiting a mineral contaminated lake.  

PubMed

The effects of wastewater from a mining and ore-dressing mill on fish in Lake Kostomukshskoe, which is used as a cesspool of circulating water and for storage of industrial wastes produced by the Kostomuksha mining and ore-dressing mill in northwest Russia, were studied. The lake is characterized by heavy mineralization, high pH, elevated levels of K(+), Li(+), SO4 (2-), NO(2-), Cl(-), Li, Mn, and Ni, and the presence of a fine-dispersed mechanical suspension. To assess the impact of contamination on fish and determine the mechanisms of their adaptation, we investigated the biochemical indices and histology of the liver of whitefish (Coregonus lavaretus L.) and pike (Esox lucius L.) inhabiting Lake Kostomukshskoe, downstream Lake Koyvas (64° 47' 30° 59'), and Lake Kamennoe, which is located in a nature preserve and has not been affected by anthropogenic activity (64° 28' 30° 13'). Changes were detected in the activity of metabolic enzymes (cytochrome c oxidase (COX), lactate dehydrogenase, and glucose-6-phosphate dehydrogenase) in the liver. Specifically, the COX activity in the liver of both fish species from the contaminated lake decreased, indicating a low level of aerobic metabolism. Lipid infiltration was the most visible and widespread change observed in the liver of both fish species; therefore, it can be considered a marker of such long-term contamination. Lesions in pike liver demonstrated a wider range of severity than in those of whitefish. In summary, metabolic enzyme activity and histomorphology of the liver of whitefish and pike differed among lakes in a species-specific manner. The changes in enzyme activity and histomorphological alterations in fish that were observed can be applied for evaluation of freshwater systems that may be subjected to mineral pollution. PMID:24865502

Churova, Maria V; Murzina, Svetlana A; Meshcheryakova, Olga V; Nemova, Nina N

2014-12-01

69

2008. Transactions of the Nebraska Academy of Sciences 31: 43-49 NORTHERN PIKE (ESDX LUCIUS) POPULATION CHARACTERISTICS AND RELATIONS TO  

E-print Network

Knowledge of the population structure of northern pike (Esox lucius), an important recreational and top t t t The northern pike (Esox lucius) is an important recreational fish in North America, including the Nebraska2008. Transactions of the Nebraska Academy of Sciences 31: 43-49 NORTHERN PIKE (ESDX LUCIUS

70

Diplostomatid Eye Flukes in Young-of-the-Year and Forage Fishes in the St. Lawrence River, Quebec  

Microsoft Academic Search

Sixteen species of young-of-the year and forage fishes (alewife Alosa pseudoharengus, northern pike Esox lucius, common carp Cyprinus carpio, emerald shiner Notropis atherinoides, rosyface shiner Notropis rubellus, white sucker Catostomus commersoni, silver redhorse Moxostoma anisurum, brown bullhead Ameirurus nebulosus, trout-perch Percopsis omiscomaycus, rock bass Ambloplitis rupestris, pumpkinseed Lepomis gibbosus, smallmouth bass Micropterus dolomieu, largemouth bass Micropterus salmoides, black crappie Pomoxis

David J. Marcogliese; Sacha Compagna

1999-01-01

71

Development of new microsatellite loci and multiplex reactions for muskellunge (Esox masquinongy).  

PubMed

The muskellunge (Esox masquinongy) is a valued fisheries species throughout its native range. Numerous studies have documented performance and phenotypic differences among muskellunge populations, but genetic markers for assessment have been lacking. We characterized 14 microsatellite loci and developed five multiplex polymerase chain reactions. Successful amplification of northern pike (Esox lucius) was observed for seven loci. These microsatellites will be useful for analysing population structure, performance characteristics of propagated strains, and helping to develop and monitor hatchery management guidelines for muskellunge. PMID:21585899

Sloss, Brian L; Franckowiak, Ryan P; Murphy, Edward L

2008-07-01

72

Development of new microsatellite loci and multiplex reactions for muskellunge (Esox masquinongy)  

USGS Publications Warehouse

The muskellunge (Esox masquinongy) is a valued fisheries species throughout its native range. Numerous studies have documented performance and phenotypic differences among muskellunge populations, but genetic markers for assessment have been lacking. We characterized 14 microsatellite loci and developed five multiplex polymerase chain reactions. Successful amplification of northern pike (Esox lucius) was observed for seven loci. These microsatellites will be useful for analysing population structure, performance characteristics of propagated strains, and helping to develop and monitor hatchery management guidelines for muskellunge. ?? 2008 Blackwell Publishing Ltd.

Sloss, B.L.; Franckowiak, R.P.; Murphy, E.L.

2008-01-01

73

Lucius Quintus Cincinnatus Lamar  

Microsoft Academic Search

1825-1893 U.S. Senator 1856-60, 1872 Associate Justice, U.S. Supreme Court 1888-92 Artist: Maurice Siegler Donor: Law Classes of 1925 and 1926 Lucius Quintius Cincinnatus Lamar was born in Putnam County, Georgia, September 17, 1825. He received his early education in Oxford, Mississippi and was graduated from Emory College in 1845. Later he read law in Macon and was admitted to

Lucius Q. C. Lamar

2009-01-01

74

Development of the head skeleton and pectoral girdle in Esox.  

PubMed

A consideration of head development in two species of Esox, lucius and americanus (ssp. vermiculatus) representing the two subgenera Esox and Kenozoa respectively, focused on the significance of the variations of the latero-sensory canal system, its associated bones, and other skeletal elements. In living forms only aspects of "regression" or specialization can be studied. Canals tend to be reduced to pit lines first at their termini but can be broken in their course. Pit lines range from nearly canals to surface structures, or even fail to develop. The number of neuromasts varies. Canal bones develop from two centers: neuromast related and deeper membranous centers which may have no relationship to neuromasts. Tooth-bearing and non-canal-related dermal bones have only membranous (original) centers. The number of neuromasts associated with a bone usually does not affect its development or form. In the case of the circumorbital bones, the extrascapulars, and the nasal, a one to one relationship has developed by regression--towards the development of the latero-sensory component only. The idea that reductions in bone number are commonly traceable to fusion is rejected although examples of fusion are know. Most bones that disappear are simply lost (no blastema or other evidence of their presence seen in development). The relationship between dermal bone and chondral bone is examined and there is evidence of the former giving rise to the latter. The ontogenic order of appearances shows a feeding (functional) correlation. PMID:1159792

Jollie, M

1975-09-01

75

Temporal changes in mercury bioaccumulation by predatory fishes of boreal lakes following the invasion of an exotic forage fish.  

PubMed

We evaluated the prediction that mercury concentrations of predatory fishes in boreal lakes would rise following the invasion of an exotic forage fish species (rainbow smelt, Osmerus mordax) that was believed to feed at a higher trophic position than native forage fishes. We compared temporal trends (postinvasion minus preinvasion values) in fish mercury bioaccumulation between lakes experiencing recent smelt invasions and reference lakes of central Canada. Piscivore mercury concentrations in this region have remained stable or declined during approximately the last 20 years. These trends were not strongly influenced by the smelt invasion, despite the fact that smelt were a major prey item for all piscivore species examined. The effect of smelt invasion on mercury bioaccumulation in the predator species reflected the importance of smelt in their respective diets (lake trout, Salvelinus namaycush > walleye, Stizostedion vitreum > northern pike, Esox lucius). However, these effects were not statistically significant for any piscivore species. The impact of rainbow smelt invasion on mercury bioaccumulation in native piscivores of this region has been much less than previous food-web studies have predicted. PMID:12959531

Johnston, Thomas A; Leggett, William C; Bodaly, Richard A; Swanson, Heidi K

2003-09-01

76

Molecular and phenotypic evidence of a new species of genus Esox (Esocidae, Esociformes, Actinopterygii): the southern pike, Esox flaviae.  

PubMed

We address the taxonomic position of the southern European individuals of pike, performing a series of tests and comparisons from morphology, DNA taxonomy and population genetics parameters, in order to support the hypothesis that two species of pike, and not only one, exist in Europe. A strong relationship emerged between a northern genotype supported by COI, Cytb, AFLP and specific fragments, and a phenotype with round spot skin colour pattern and a large number of scales in the lateral line, clearly separated from a southern genotype with other skin colour pattern and a low number of scales in the lateral line. DNA taxonomy, based on a coalescent approach (GMYC) from phylogenetic reconstructions on COI and Cytb together with AFLP admixture analysis, supported the existence of two independently evolving entities. Such differences are not simply due to geographic distances, as northern European samples are more similar to Canadian and Chinese samples than the southern Europe ones. Thus, given that the differences between the two groups of European pike are significant at the phenotypic, genotypic and geographical levels, we propose the identification of two pike species: the already known northern pike (Esox lucius) and the southern pike (E. flaviae n.sp.). The correct identification of these two lineages as independent species should give rise to a ban on the introduction of northern pikes in southern Europe for recreational fishing, due to potential problems of hybridisation. PMID:22164201

Lucentini, Livia; Puletti, Maria Elena; Ricciolini, Claudia; Gigliarelli, Lilia; Fontaneto, Diego; Lanfaloni, Luisa; Bilò, Fabiana; Natali, Mauro; Panara, Fausto

2011-01-01

77

Turbidity decreases anti-predator behaviour in pike larvae, Esox lucius  

Microsoft Academic Search

Synopsis  We tested how algal turbidity and light conditions influence anti-predator behaviour of first-feeding pike. Results showed that pike larvae were able to detect the predator by both chemical and visual signals in turbid water. However, the anti-predator behaviour was reduced in turbid water compared with clear water. Larvae hid in the vegetation in the presence of predator cues more in

Maiju Lehtiniemi; Jonna Engström-Öst; Markku Viitasalo

2005-01-01

78

Effects of environmental mercury on gonadal function in Lake Champlain northern pike (Esox lucius)  

SciTech Connect

Levels of mercury in the environment have increased steadily over the past two centuries, primarily because of human activity. Common point sources of this heavy metal include industrial waste discharge from chloralkali and paper pulp plants. More diffuse emissions, which become widely distributed by global wind currents, result from the combustion of fossil fuels and incineration of municipal wastes. Stricter laws in the United States have decreased the amount of pollution from point sources. In contrast, mercury from diffuse atmospheric origins has been increasing, causing a rise in rainwater concentrations and aquatic environments frequently distant from the source of pollution. Once in aquatic systems, mercury is readily converted to the more toxic methylated form and is the only heavy metal that indisputably biomagnifies through the food web. Acid rain compounds the environmental impact of anthropogenic mercury because aquatic organisms concentrate more mercury when living in waters with lower alkalinity. The persistence of this heavy metal in teleosts is illustrated by the finding that mercury, unlike cadmium, arsenic, and lead, did not decrease in North American freshwater fish between 1976 and 1984.

Friedmann, A.S.; Leiter, J.C. [Dartmouth Medical School, Lebanon, NH (United States)] [Dartmouth Medical School, Lebanon, NH (United States); Watzin, M.C. [Univ. of Vermont, Burlington, VT (United States)] [and others] [Univ. of Vermont, Burlington, VT (United States); and others

1996-03-01

79

Fine-scale oscillatory banding in otoliths from arctic charr (Salveninus alpinus) and pike (Esox lucius)  

SciTech Connect

Transmission electron microscopy of otoliths from the inner ear of arctic charr and pike has revealed the presence of fine banding on the scale of several nanometers. The thickness of the bands was observed to vary in different portions of the sample, and some areas were not banded. EDS analysis could not detect chemical differences within the bands, but electron diffraction showed that the crystallographic orientation of the bands is related by a lattice mismatch. Previously, banding on the scale of 50 to 100 microns was observed by SEM in otoliths from arctic charr and was attributed to seasonal variations in growth. The fine-scale banding observed in this study, however, is unlikely to represent a daily variation. Electron diffraction from the pike samples shows that the material is composed of CaCO{sub 3} having the both the vaterite and aragonite structure, and hydrous CaCO{sub 3} was also observed. The large-scale banding previously identified by SEM was not observed in the TEM despite attempts to intersect the boundaries of the micron-sized layers. The interaction of the electron beam with the sample material was investigated by conducting several electron-irradiation experiments. The electron beam was observed to interact strongly with the sample and caused the precipitation of cubic CaO from the calcium carbonate matrix. Bright-field imaging showed the development of fine grained ({approximately} 5 nm) randomly oriented crystallites which accumulated with increasing electron dose. These initial results suggest that the precipitation of CaO is not driven by electron-beam beating. Previously, a similar phase-change phenomenon has been observed in hydroxyapatite from dental enamel. Other Ca-bearing biominerals may therefore also be expected to be sensitive to electron irradiation.

Meldrum, A. [Oak Ridge National Lab., TN (United States); Halden, N.M. [Univ. of Manitoba, Winnipeg (Canada). Dept. of Geological Sciences

1997-12-31

80

Food of Young Pike, Esox Lucius L., and Associated Fishes in Peterson's Ditches, Houghton Lake, Michigan  

Microsoft Academic Search

Stomach contents of 551 young pike (11–152 millimeters in length), 345 small yellow perch, and 431 other fish representing 18 species were examined. All specimens were collected from an area widely used by spawning pike from Houghton Lake, Michigan. Organisms utilized for food by young pike included Entomostraca, insects (chiefly Chironomidae), tadpoles, minnows, darters, and other pike. As pike increased

Burton P. Hunt; William F. Carbine

1951-01-01

81

Esox lucius k = (y2 -y1) / (x2 -x1)  

E-print Network

was later made into a college. 1813The Royal Swedish Academy of Agriculture was founded at the incentive.renren.com/601498210 youtube.com/SLUutbildning Follow us on facebook! 2 #12;Table of contents 02 SLU in brief 05 Swedish University of Agricultural Sciences was formed, combining the three existing separate colleges

82

Temporal stability in size distributions and growth rates of three Esox lucius L. populations.  

E-print Network

. A result of cannibalism? L. PERSSON*, A. BERTOLO* AND A. M. DE ROOS§ *Department of Ecology-history characteristics such as minimum and maximum victim:cannibal size ratios and (2) the cannibal-driven population: cannibalism; growth rates; pike; population length structure; predation window. INTRODUCTION The ability

Roos, André M. de

83

Length-weight relationship of northern pike, Esox lucius, from East Harbor, Ohio  

USGS Publications Warehouse

The northern pike is one of Ohio's largest game fish but is well known to comparatively few anglers. Large numbers of the big fish spawn in the Ohio marshes adjacent to Lake Erie. Movements related to spawning reach a peak in late March or early April. Later the spawning population disperses and is seldom represented in catches by experimental gear or by anglers. The short period of availability was used to obtain life history information in March of 1951 through 1953. No comprehensive length-weight data for this species have previously been published from this area. East Harbor is a sandspit pond separated from Lake Erie by a large sand bar. Waters and fish populations of the harbor and lake can mix freely through a permanent connecting channel. The larger part of the 850 surface acres of the harbor is normally less than 8 feet deep. The male northern pike averaged 20.5 inches in length and ranged from 13.5 to 28.5 inches. The conspicuously larger females averaged 26.0 inches and ranged from 15.5 to 37.5 inches.

Brown, Edward H., Jr.; Clark, Clarence F.

1965-01-01

84

J. N. Am. Benthol. Soc., 2005, 24(4):904918 2005 by The North American Benthological Society  

E-print Network

Invertivory by northern pike (Esox lucius) structures communities of littoral macroinvertebrates in small and subsequent recovery even when such fluctuations involve the normally piscivorous northern pike (Esox lucius

Venturelli, Paul

85

Pikes (Esox lucius L. ) shown to be affected by low pH values during first weeks after hatching  

Microsoft Academic Search

Due to the increasing amount of sulfurous fuels combusted, more and more sulfur is being emitted into the air. The sulfur is primarily converted to SOâ during combustion but will form HâSOâ in the air (Brosset, 1973). This has led to a decreased pH of rainwater, and thus to a decreased pH in lakes and rivers (Oden and Ahl, 1970).

N. Johansson; J. E. Kihlstroem

1973-01-01

86

Pike (Esox lucius L.) stocking as a biomanipulation tool 2. Effects on lower trophic levels in Lake Lyng, Denmark  

Microsoft Academic Search

In order to study how pike stocking affects trophic structurepikefingerlings (0–3600 ha-1) were stocked during six yearsineutrophic Lake Lyng (lake area 10 ha), Denmark. Subsequently,marked changes were recorded in the abundance ofzooplanktivorousfish, catch per unit effort of roach, which was the dominantfishspecies, thus varied from 17 to 272. Simultaneously, markedchangeswere recorded in the abundance and relative composition ofzooplankton. Daphnia abundance

Martin Søndergaard; Erik Jeppesen; Søren Berg

1997-01-01

87

UV-B exposure causes DNA damage and changes in protein expression in northern pike (Esox lucius) posthatched embryos.  

PubMed

The ongoing anthropogenically caused ozone depletion and climate change has increased the amount of biologically harmful UV-B radiation, which is detrimental to fish in embryonal stages. The effects of UV-B radiation on the levels and locations of DNA damage manifested as cyclobutane pyrimidine dimers (CPDs), heat shock protein 70 (HSP70) and p53 protein in newly hatched embryos of pike were examined. Pike larvae were exposed in the laboratory to current and enhanced doses of UV-B radiation. UV-B exposure caused the formation of CPDs in a fluence rate-dependent manner, and the CPDs were found deeper in the tissues with increasing fluence rates. UV-B radiation induced HSP70 in epidermis, and caused plausible p53 activation in the brain and epidermis of some individuals. Also at a fluence rate occurring in nature, the DNA damage in the brain and eyes of pike and changes in protein expression were followed by severe behavioral disorders, suggesting that neural molecular changes were associated with functional consequences. PMID:22145705

Vehniäinen, Eeva-Riikka; Vähäkangas, Kirsi; Oikari, Aimo

2012-01-01

88

The influence of angling-induced exercise on the carbohydrate metabolism of northern pike ( Esox lucius L.)  

Microsoft Academic Search

Summary  Capture by angling was used to induce burst exercise in northern pike. By 3 h after exercise blood lactate had risen to levels\\u000a of 15.2 mmol l?1 (Fig. 2), which greatly exceeded the maximum post-exercise levels (4.0 mmol l?1) previously reported for muskellunge, a close relative of pike. White muscle lactate level was high, 41.8 mmol kg?1, immediately after capture

K. Schwalme; W. C. Mackay

1985-01-01

89

Four decades of opposing natural and human-induced artificial selection acting on Windermere pike (Esox lucius)  

Microsoft Academic Search

The ability of natural selection to drive local adaptation has been appreciated ever since Darwin. Whether human impacts can impede the adaptive process has received less attention. We tested this hypothesis by quantifying natural selection and harvest selection acting on a freshwater fish (pike) over four decades. Across the time series, directional natural selection tended to favour large individuals whereas

Stephanie M. Carlson; Eric Edeline; L. Asbjørn Vøllestad; Thrond. O. Haugen; Ian J. Winfield; Janice M. Fletcher; J. Ben James; Nils Chr. Stenseth

2007-01-01

90

Ultrastructure of atrial and ventricular myocardium in the pike Esox lucius L. and mackerel Scomber scombrus L. (Pisces)  

Microsoft Academic Search

Atrial and ventricular muscle in the pike and mackerel hearts consists of narrow, branching cells. The atrial cells in the two species are similar whereas the ventricular cells differ. The sarcolemma is attached to the Z and M lines of the sarcomere. Intercalated discs are common, and the transverse parts display desmosomes and intermediate junctions. Nexuses are uncommon and only

Bjørn Midttun

1980-01-01

91

Pineal-retinal relationships: rhythmic biosynthesis and immunocytochemical localization of melatonin in the retina of the pike ( Esox lucius )  

Microsoft Academic Search

The levels of melatonin and the activities of two enzymes of the melatonin biosynthetic pathway, serotonin N-acetyltransferase (NAT) and hydroxyindole-O-methyltransferase (HIOMT), were measured throughout the light-dark cycle in the retina of a teleost fish, the pike. HIOMT activity did not display significant variations, whereas NAT activity and melatonin content showed a daily rhythm, high levels occurring during the night. The

Jacky Falcón; Jean-Pierre Collin

1991-01-01

92

The conservation and fishery benefits of protecting large pike (Esox lucius L.) by harvest regulations in recreational fishing  

E-print Network

a Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries regulatory approach of man- agement by small minimum-length limits (so that culling of large fish

Dieckmann, Ulf

93

Spatial behaviour of young-of-the-year northern pike (Esox lucius L.) in a temporarily flooded  

E-print Network

freshwater environments (Cassel- man 1996), and seasonally flooded and vegetated areas are essential spawning of Freshwater Fish 2009: 18: 314­322 Printed in Malaysia � All rights reserved � 2009 John Wiley & Sons A/S ECOLOGY OF FRESHWATER FISH Cucherousset J, Paillisson J-M, Cuzol A, Roussel J-M. Spatial behaviour

Cucherousset, Julien

94

Northern pike ( Esox lucius L.) and aquatic vegetation, tools in the management of fisheries and water quality in shallow waters  

Microsoft Academic Search

Species and size composition of fish communities in shallow stagnant waters appear to be associated with the type, abundance and pattern of the vegetation. Man-induced impacts as eutrophication, and suppression of vegetation for reasons of water quantity management or angling pleasure may induce irreversible changes in the aquatic ecosystem. Water quality management should aim at restoring former pike habitat. Submerged

M. P. Grimm

1989-01-01

95

Changes in lipid class and fatty acid composition during development in pike (Esox lucius L) eggs and larvae  

Microsoft Academic Search

To establish the changes which occur during embryogenesis and early larval development, eggs, yolk sac larvae and swim-up\\u000a larvae of pike were examined for lipid class and fatty acid composition. At a water temperature of 15.5°C, the embryonic phase\\u000a was short (6 days) and characterized by a 41.3% decline in the lipid content of eggs, accompanied by large reductions in

C. Desvilettes; G. Bourdier; J. C. Breton

1997-01-01

96

Historical Analysis of Genetic Variation Reveals Low Effective Population Size in a Northern Pike (Esox Lucius) Population  

PubMed Central

Effective population size (N(e)) of a natural fish population was estimated from temporal changes in allele frequencies at seven microsatellite loci. Use of a historical collection of fish scales made it possible to increase the precision of estimates by increasing the time interval between samples and to use an equation developed for discrete generations without correcting for demographic parameters. Estimates of N(e) for the time intervals 1961-1977 and 1977-1993 were 35 and 72, respectively. For the entire interval, 1961-1993, the estimate of N(e) was 48 when based on a weighted mean derived from the above two estimates or 125 when calculated from 1961 and 1993 samples only. Corresponding ratios of effective size to adult census size ranged from 0.03 to 0.14. An N(e) of 48 over a 32-year period would imply that this population lost as much as 8% of its heterozygosity in that time. Results suggest the potential for using genetic methods based on microsatellite loci data to compare historical trends in N(e) with population dynamic parameters. Such comparisons will help to evaluate the relationship between genetic diversity and long-term persistence of natural populations. PMID:9383067

Miller, L. M.; Kapuscinski, A. R.

1997-01-01

97

OCCURRENCE OF 'ESOX NIGER' IN SANTA ROSA SOUND, FLORIDA  

EPA Science Inventory

This is the first report of Esox niger collected from the normally saline portion of the lower Pensacola estuary. A 109 mm standard length chain pickerel was seined on 7 August 1975 from Santa Rosa Sound, in Santa Rosa County, Florida, from Thalassia beds about 300 m W. of the N....

98

PILOT EVALUATION OF ENHANCED E-SOX PROCESS  

EPA Science Inventory

The paper discusses pilot-plant tests with a 28 cu m/min (1000 cfm)electrostatic precipitator (ESP) to evaluate techniques that havea potential for enhancing the S02 removal of the E-SOx process forretrofit application. he techniques investigated includedmass-transfer additives, ...

99

Transactions of the American Fisheries Society 129:186193, 2000 Copyright by the American Fisheries Society 2000  

E-print Network

fit between predicted and observed food consumption for northern pike Esox lucius. Similarly, poor, 1999 kellunge Esox masquinongy and tiger muskellunge Esox masquinongy E. lucius (Wahl and Stein 1991

100

Early Life History of the Northern Pike, Esox lucius L., with Special Reference to the Factors Influencing the Numerical Strength of Year Classes  

Microsoft Academic Search

The early life history of northern pike was studied to determine the relationship of adult pike abundance to the strength of resulting year classes and the existence and chronology of critical survival periods, along with the nature and origin of the mortality mechanisms involved. Adult abundance and the strength of the resulting year classes were not directly related. Two critical

Donald R. Franklin; Lloyd L. Smith Jr

1963-01-01

101

The genome and linkage map of the northern pike (Esox lucius): conserved synteny revealed between the salmonid sister group and the Neoteleostei.  

PubMed

The northern pike is the most frequently studied member of the Esociformes, the closest order to the diverse and economically important Salmoniformes. The ancestor of all salmonids purportedly experienced a whole-genome duplication (WGD) event, making salmonid species ideal for studying the early impacts of genome duplication while complicating their use in wider analyses of teleost evolution. Studies suggest that the Esociformes diverged from the salmonid lineage prior to the WGD, supporting the use of northern pike as a pre-duplication outgroup. Here we present the first genome assembly, reference transcriptome and linkage map for northern pike, and evaluate the suitability of this species to provide a representative pre-duplication genome for future studies of salmonid and teleost evolution. The northern pike genome sequence is composed of 94,267 contigs (N50 = 16,909 bp) contained in 5,688 scaffolds (N50 = 700,535 bp); the total scaffolded genome size is 878 million bases. Multiple lines of evidence suggest that over 96% of the protein-coding genome is present in the genome assembly. The reference transcriptome was constructed from 13 tissues and contains 38,696 transcripts, which are accompanied by normalized expression data in all tissues. Gene-prediction analysis produced a total of 19,601 northern pike-specific gene models. The first-generation linkage map identifies 25 linkage groups, in agreement with northern pike's diploid karyotype of 2N = 50, and facilitates the placement of 46% of assembled bases onto linkage groups. Analyses reveal a high degree of conserved synteny between northern pike and other model teleost genomes. While conservation of gene order is limited to smaller syntenic blocks, the wider conservation of genome organization implies the northern pike exhibits a suitable approximation of a non-duplicated Protacanthopterygiian genome. This dataset will facilitate future studies of esocid biology and empower ongoing examinations of the Atlantic salmon and rainbow trout genomes by facilitating their comparison with other major teleost groups. PMID:25069045

Rondeau, Eric B; Minkley, David R; Leong, Jong S; Messmer, Amber M; Jantzen, Johanna R; von Schalburg, Kristian R; Lemon, Craig; Bird, Nathan H; Koop, Ben F

2014-01-01

102

The contribution of ventricular apicobasal and transmural repolarization patterns to the development of the T wave body surface potentials in frogs (Rana temporaria) and pike (Esox lucius).  

PubMed

The study aimed at the simultaneous determination of the transmural and apicobasal differences in the repolarization timing and the comparison of the contributions of these two repolarization gradients to the development of the body surface T wave potentials in animals with the single heart ventricle (fishes and amphibians). Unipolar potentials were measured on the body surface, epicardium and in the intramural (subepicardial, Epi; midmyocardial; and subendocardial, Endo) ventricular layers of 9 pike and 8 frogs. Activation times, repolarization times and activation-recovery intervals were determined. A transmural gradient in repolarization durations in frogs (Endo>Epi, P<0.024) corresponds to the gradient in repolarization times. No significant transmural difference in repolarization duration is observed in pike that produces a repolarization sequence from Endo to Epi (Endo

Vaykshnorayte, Marina A; Azarov, Jan E; Tsvetkova, Alena S; Vityazev, Vladimir A; Ovechkin, Alexey O; Shmakov, Dmitry N

2011-05-01

103

A survey of the spawning of perch (Perca fluviatilis), pike (Esox lucius), and roach (Rutilus rutilus), using artificial spawning substrates in lakes  

Microsoft Academic Search

The development of spawning in perch, pike and roach in Lake Geneva has been studied by means of artificial spawning substrates, laid at different depths, from 1984 to 1993. In Lake Geneva, perch spawned in May. A rise of surface water temperature up to 14 °C stimulated spawning activity while bad weather (surface temperature at 10 °C) induced a spread

C. Gillet; J. P. Dubois

1995-01-01

104

Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on early life stages of the pike (Esox lucius L.)  

Microsoft Academic Search

Freshly fertilized pike eggs were exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) at concentrations of 0.1, 1.0 and 10 ppt (ng\\/liter) for 96 hours. At all concentrations examined egg development was retarded by 23%, and the growth of fry was also significantly retarded for a long period after exposure. A dose-related mortality was observed. Highest mortality rates occurred during resorption of the yolk

T. Helder

1980-01-01

105

Reproductive status and lipid content as factors in PCB, DDT and HCH contamination of a population of pike (Esox lucius L. )  

SciTech Connect

Levels of persistent pollutants, including PCBs, [Sigma]DDT, and [gamma]-hexachlorocyclohexane, were examined in a pike population inhabiting a eutrophic lake in southern Scandinavia. For females, levels of persistent pollutants decreased linearly with age, weight, or length. This decline was ascribed to the seasonal elimination of the lipophilic pollutants in roe, which contained up to 10 times higher fat levels compared to muscle and over 10 times the amounts of pollutants. Male pike contained higher levels of pollutants than females, probably due to the lower elimination via gonadal products, as germinal tissue constitutes only 2% of the male total body weight and has a lower fat content than ovaries. Female germinal tissue can account for as much as 15% of the body weight. No major fat deposits other than those in germinal tissue were found in pike, which also had a low muscle fat content, suggesting that the importance of roe elimination in removing pollutants may be greater in pike than in salmonids. Uptake of persistent pollutants can vary greatly within a species, owing to differences in sex, age, and so forth, as well as between species, owing to differences in fat deposition strategies.

Larsson, P.; Okla, L.; Collvin, L. (Dept. of Ecology, Lund (Sweden))

1993-05-01

106

Production, consumption and prey availability of northern pike ( Esox lucius ), pikeperch ( Stizostedion lucioperca ) and European catfish ( Silurus glanis ): a bioenergetics approach  

Microsoft Academic Search

Bioenergetics models were applied for the assessment of food consumption of northern pike, pikeperch and European catfish\\u000a in drainable ponds of 0.4 ha. The ponds were stocked with known numbers of the 0+ predators. The prey fish consisted of naturally recruited 0+ cyprinids (rudd, roach and bream). The study shows that the impact of the three 0+ piscivores on the

Alexander J. P. Raat

1990-01-01

107

Reproductive status and lipid content as factors in PCB, DDT and HCH contamination of a population of pike (Esox lucius L. )  

Microsoft Academic Search

Levels of persistent pollutants, including PCBs, [Sigma]DDT, and [gamma]-hexachlorocyclohexane, were examined in a pike population inhabiting a eutrophic lake in southern Scandinavia. For females, levels of persistent pollutants decreased linearly with age, weight, or length. This decline was ascribed to the seasonal elimination of the lipophilic pollutants in roe, which contained up to 10 times higher fat levels compared to

Per Larsson; Lennart Okla; Lars Collvin

1993-01-01

108

The effects of season on fatty acid composition and ?3/?6 ratios of northern pike (Esox lucius L., 1758) muscle lipids  

NASA Astrophysics Data System (ADS)

In the present study, the effects of season on fatty acid composition, total lipids, and ?3/?6 ratios of northern pike muscle lipids in K?z?l?rmak River (K?r?kkale, Turkey) were investigated. A total of 35 different fatty acids were determined in gas chromatography. Among these, palmitic, oleic, and palmitoleic acids had the highest proportion. The main polyunsaturated fatty acids (PUFAs) were found to be docosahexaenoic acid, eicosapentaenoic acid, and arachidonic acid. There were more PUFAs than monounsaturated fatty acids (MUFA) in all seasons. Similarly, the percentages of ?3 fatty acids were higher than those of total ?6 fatty acids in the fatty acid composition. ?3/?6 ratios were calculated as 1.53, 1.32, 1.97, and 1.71 in spring, summer, autumn and winter, respectively. Overall, we found that the fatty acid composition and ?3/?6 fatty acid ratio in the muscle of northern pike were significantly influenced by season.

Mert, Ramazan; Bulut, Sait; Konuk, Muhsin

2014-10-01

109

The Genome and Linkage Map of the Northern Pike (Esox lucius): Conserved Synteny Revealed between the Salmonid Sister Group and the Neoteleostei  

PubMed Central

The northern pike is the most frequently studied member of the Esociformes, the closest order to the diverse and economically important Salmoniformes. The ancestor of all salmonids purportedly experienced a whole-genome duplication (WGD) event, making salmonid species ideal for studying the early impacts of genome duplication while complicating their use in wider analyses of teleost evolution. Studies suggest that the Esociformes diverged from the salmonid lineage prior to the WGD, supporting the use of northern pike as a pre-duplication outgroup. Here we present the first genome assembly, reference transcriptome and linkage map for northern pike, and evaluate the suitability of this species to provide a representative pre-duplication genome for future studies of salmonid and teleost evolution. The northern pike genome sequence is composed of 94,267 contigs (N50?=?16,909 bp) contained in 5,688 scaffolds (N50?=?700,535 bp); the total scaffolded genome size is 878 million bases. Multiple lines of evidence suggest that over 96% of the protein-coding genome is present in the genome assembly. The reference transcriptome was constructed from 13 tissues and contains 38,696 transcripts, which are accompanied by normalized expression data in all tissues. Gene-prediction analysis produced a total of 19,601 northern pike-specific gene models. The first-generation linkage map identifies 25 linkage groups, in agreement with northern pike's diploid karyotype of 2N?=?50, and facilitates the placement of 46% of assembled bases onto linkage groups. Analyses reveal a high degree of conserved synteny between northern pike and other model teleost genomes. While conservation of gene order is limited to smaller syntenic blocks, the wider conservation of genome organization implies the northern pike exhibits a suitable approximation of a non-duplicated Protacanthopterygiian genome. This dataset will facilitate future studies of esocid biology and empower ongoing examinations of the Atlantic salmon and rainbow trout genomes by facilitating their comparison with other major teleost groups. PMID:25069045

Rondeau, Eric B.; Minkley, David R.; Leong, Jong S.; Messmer, Amber M.; Jantzen, Johanna R.; von Schalburg, Kristian R.; Lemon, Craig; Bird, Nathan H.; Koop, Ben F.

2014-01-01

110

Nearshore fish assemblages associated with introduced predatory fishes in lakes  

E-print Network

Micropterus salmoides, pike Esox lucius, rock bass Ambloplites rupestris, smallmouth bass Micropterus dolomieu lucius, rock bass Ambloplites rupestris, smallmouth bass Micropterus dolomieu, and walleye Sander vitreus

Ricciardi, Anthony

111

ORIGINAL ARTICLE Quantifying selection differentials caused by recreational  

E-print Network

of modeling framework and application to reproductive investment in pike (Esox lucius) Robert Arlinghaus,1-selective exploitation in a highly demanded freshwater recreational fish species, northern pike (Esox lucius L.). We find

Dieckmann, Ulf

112

Retention of Floy FD-94 Anchor Tags and Effect on Growth and Condition of Northern Pike and Largemouth Bass  

E-print Network

and October 1995.315 largemouth bass (Micropterus salmoides) and 170 northern pike (Esox lucius) were captured 1973. Tranquilli and Childers 1982) and northern pike (Esox lucius; Gengerke 1977, Scheirer and Coble

113

Fisheries Research 97 (2009) 223233 Contents lists available at ScienceDirect  

E-print Network

-and-release angling on northern pike (Esox lucius L.) Robert Arlinghausa,b, , Thomas Klefotha , Steven J. Cookec stressors using a combined laboratory and field study in northern pike (Esox lucius L.). A labora- tory

Suski, Cory David

114

Trait changes in a harvested population are driven by a dynamic tug-of-war between  

E-print Network

-based data on Windermere pike (Esox lucius), we show that trait changes tracked the adaptive peak, which populations. We performed this task in pike (Esox lucius) from Windermere, U.K. This system is particu- larly

Carlson, Stephanie

115

ORIGINAL PAPER Assessing evolutionary consequences of size-selective  

E-print Network

on multiple life-history traits, with an application to northern pike (Esox lucius) Shuichi Matsumura · Robert- selective exploitation of northern pike (Esox lucius L.) with recreational-fishing gear. An age

Dieckmann, Ulf

116

Journal of Aquatic Ecosystem Stress and Recovery 9: 137147, 2002. 2002 Kluwer Academic Publishers. Printed in the Netherlands.  

E-print Network

salmoides) and northern pike (Esox lucius). We compared simulations using field data to hypothetical taken. For instance, northern pike (Esox lucius) are more strict piscivores compared to largemouth bass

117

Diet and Growth of Northern Pike in the Absence of Prey Fishes: Initial Consequences for Persisting in Disturbance-Prone Lakes  

E-print Network

of Alberta, Edmonton, Alberta T6G 2E9, Canada Abstract.--The northern pike Esox lucius is a renowned to stunting. The northern pike Esox lucius is considered to be piscivorous throughout most of its circumpolar

Venturelli, Paul

118

This article was originally published in a journal published by Elsevier, and the attached copy is provided by Elsevier for the  

E-print Network

-tagged hatchery-reared young-of-the-year northern pike Esox lucius (mean fork length FL 51.0 mm ± 5.3 S: Passive integrated transponder; Portable detector; Esox lucius; Survival; Stocking program 1. Introduction Northern pike (Esox lucius) is a predatory keystone species that tolerates a broad range of environmental

Cucherousset, Julien

119

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research  

E-print Network

pike (Esox lucius L.) S.M. Hadi Alavi a,*, Marek Rodina a , Ana T.M. Viveiros b , Jacky Cosson c; received in revised form 23 January 2009; accepted 25 January 2009 Abstract Northern pike (Esox lucius L reserved. Keywords: Esox lucius; Sperm; SEM; Flagella; Osmolality 1. Introduction

Villefranche sur mer

120

EVALUATION OF THE E-SOX PROCESS ON THE EPA PILOT ELECTROSTATIC PRECIPITATOR  

EPA Science Inventory

The report gives results of a small pilot-scale evaluation of the E-SOx process, undertaken to obtain information needed to conduct a planned 5 MWe field pilot demonstration. he process uses an electrostatic precipitator (ESP) for combined sulfur dioxide (SO2) removal and particu...

121

Trianchoratus longianchoratus sp. n. (Monogenea: Ancyrocephalidae: Heteronchocleidinae) from Channa lucius (Osteichthyes: Channidae) in Peninsular Malaysia.  

PubMed

One new and three previously described species of Trianchoratus Price et Berry, 1966 were collected from the gills of Channa lucius (Cuvier) and Channa striata (Bloch) from the Bukit Merah Reservoir, Perak and Endau-Rompin, Pahang, Peninsular Malaysia. They are Trianchoratus longianchoratus sp.n., T. malayensis Lim, 1986 and T. pahangensis Lim, 1986 from C. lucius, and T. ophicephali Lim, 1986 from C. striata. The new species differs from the Trianchoratus species hitherto described from channids and anabantoids in having two ventral anchors with a long curved inner root and one dorsal anchor with a curved inner root and lacking an outer root. A table summarizing the known species of heteronchocleidins (Trianchoratus, Eutrianchoratus and Heteronchocleidus) and Sundanonchus reported from fish hosts of different families (Channidae, Helostomatidae, Anabantidae and Osphronemidae) is provided. PMID:19827361

Tan, W B; Lim, L H S

2009-09-01

122

United States Department of the Interior, Fred A. Seaton, Secretary  

E-print Network

) . In North America the~e are five specie s: Esox masquinongy (muskellunge) , Esox lucius (northern #12;pike confused as pike and pickerel. The true pikes a ll belong to one fam- ily (Esocidae) and to one genus (Esox, pike, pickerel, jack), Esox niger (chain or eastern picker el) ) Esox vermiculatus (grass, mud

123

United States Department of the Interior, Douglas McKay, Secretary Fish and Wildlife Service, John L. Farley, Director  

E-print Network

). In North America there are five species: Esox masquinongy (muskellunge), Esox lucius (north- ern pike, pike confused as pike and pickerel. The true pikes all belong to one family (Esocidae) and to one genus (Esox, pickerel, jack), Esox nig)r (chain-or-eastern pickerel), Esox vermiculatus (mUd or little pickerel

124

Information Foraging Peter Pirolli  

E-print Network

Information Foraging Peter Pirolli and Stuart K. Card UIR Technical Report Funded in part of Naval Research, under contract N00014-96-C-0097. #12;Information Foraging 2 ABSTRACT Information Foraging Theory is an approach to understanding how strategies and technologies for information seeking

125

Behavior of fish predators and their prey: habitat choice between open water and dense vegetation  

Microsoft Academic Search

Synopsis  Behavior of largemouth bass, Micropterus salmoides, and northern pike, Esox lucius, foraging on fathead minnows, Pimephales promelas, or bluegills, Lepomis macrochirus, was quantified in pools with 50% cover (half the pool had artificial stems at a density of 1000 stems m?2). Both predators spent most of their time in the vegetation. Largemouth bass searched for bluegills and ambushed minnows,\\u000a whereas

Jacqueline F. Savino; Roy A. Stein

1989-01-01

126

Forage Quality Photo Guide  

E-print Network

Livestock Specialist, and Professor - Department of Rangeland Ecology and Management, The Texas A&M University System. R i s k M a n ag ement E d u c a t i o n ? Forage Quality Photo Guide 7-00 E-541 Photo Guide to Forage Quality This dropping indicates a... Livestock Specialist, and Professor - Department of Rangeland Ecology and Management, The Texas A&M University System. R i s k M a n ag ement E d u c a t i o n ? Forage Quality Photo Guide 7-00 E-541 Photo Guide to Forage Quality This dropping indicates a...

Lyons, Robert K.; Machen, Richard V.; Stuth, Jerry W.

2000-08-18

127

Interactions of multiple predators with different foraging modes in an aquatic food web.  

PubMed

Top predators can have different foraging modes that may alter their interactions and effects on food webs. Interactions between predators may be non-additive resulting from facilitation or interference, whereas their combined effects on a shared prey may result in emergent effects that are risk enhanced or risk reduced. To test the importance of multiple predators with different foraging modes, we examined the interaction between a cruising predator (largemouth bass, Micropterus salmoides) and an ambush predator (muskellunge, Esox masquinongy) foraging on a shared prey (bluegill sunfish, Lepomis macrochirus) with strong anti-predator defense behaviors. Additive and substitution designs were used to compare individual to combined predator treatments in experimental ponds. The multiple predator interaction facilitated growth of the cruising predator in the combined predator treatments, whereas predator species had substitutable effects on the growth of the ambush predator. The combined predator treatments created an emergent effect on the prey; however, the direction was dependent on the experimental design. The additive design found a risk-reducing effect, whereas the substitution design found a risk-enhancing effect for prey fish. Indirect effects from the predators weakly extended to lower trophic levels (i.e., zooplankton community). Our results highlight the need to consider differences in foraging mode of top predators, interactions between predators, and emergent effects on prey to understand food webs. PMID:19777265

Carey, Michael P; Wahl, David H

2010-02-01

128

Forages for Beef Cattle  

E-print Network

Pasture forages for beef cattle are of five types--warm-season perennials, warm-season annuals, cool-season annuals, cool-season perennials and legumes. This publication discusses the five types and proposes a year-round forage management system...

Bade, David H.; Dorsett, Donald J.

2002-09-05

129

NORTHEAST FLORIDA BEEF & FORAGE GROUP  

E-print Network

Page | 1 2008 NORTHEAST FLORIDA BEEF & FORAGE GROUP FARM & FORAGE RESOURCE GUIDE #12 Beef & Forage Group, Alachua County Extension, Baker County Extension, Bradford County Extension, Clay Beef and Forage Group We are a group of Extension Agents providing regional programming for livestock

Watson, Craig A.

130

Time trends of chlordane, DDT, and PCB concentrations in pike ( Esox lucius ) and Baltic herring ( Clupea harengus ) in the Turku archipelago, northern Baltic sea for the period 1971–1982  

Microsoft Academic Search

The concentrations of PCB- and DDT-compounds in Baltic wildlife have been extensively studied during the last decade. Since the use of DDT was banned in the early 70's in many countries, including those in Baltic area, the level of DDT-compounds has decreased in the Baltic environment by PAASIVIRTA and LINKO (198o)o The use of PCBcompounds is now banned in Sweden

Raija Moilanen; Heikki Pyysalo; Kim Wickström; Reino Linko

1982-01-01

131

2004 by the American Society of Ichthyologists and Herpetologists Copeia, 2004(4), pp. 743757  

E-print Network

Amur Pike) is restricted to the Amur River basin of northeastern Asia. Esox lucius is the type species lucius (the Amur and Northern Pike, respectively). Incongru- ent results between the morphological

Laten, Howard M.

132

Trophic ecology of largemouth bass and northern pike in allopatric and sympatric assemblages in  

E-print Network

(Mieropferus salmoides) and northern pike (Esox lucius) are top predators in the food chain in most aquatic overlap. Resume: L'Achigan it grande bouche (Mieropferus salmoides) et Ie Brochet du Nord (Esox lucills

133

North American Journal of Fisheries Management 9:488-492, 1989 Copyright by the American Fisheries Society 1989  

E-print Network

) is an index used to quantify length-frequency data. The PSD of populations ofnorthern pike Esox lucius- son and Weithman (1978) suggested that walleyes Stizostedion vitreum and northern pike Esox lu- cius

134

This is an author-deposited version published in: http://oatao.univ-toulouse.fr/ Eprints ID: 6158  

E-print Network

roach (Rutilus rutilus L.), perch (Perca fluviatilis L.), and pike (Esox lucius L.). The two methods vegetation. It is likely microhabitat; scuba diving; lake; Rutilus rutilus; Perca fluviatilis; Esox

Paris-Sud XI, Université de

135

Asymptotic growth, egg production and trivariate allometry in Esox masquinongy Mitchill.  

PubMed

Multivariate growth models based on the Lotka-Volterra equations seem more complicated than necessary for a fruitful analysis of relative growth data. A simpler and more practical approach combines multivariate allometry with parabolic or asymptotic growth with respect to time. A modified von Bertalanffy curve, X = A [1-exp (-t/D)]C, is compatible with allometry and yields a satisfactory description of somatic growth and egg production in the female muskellunge (Esox masquinongy). A multiplicative variation model appears adequate and partial linearization can be used. While the muskellunge reaches a large size, the present analysis suggests that its growth pattern is limited (asymptotic, determinate). The allometry exponents inferred from the multivariate asymptotic growth model differ slightly from those obtained from principal component analysis or from a trivariate linear structural relationship, but the latter may reflect physiological age rather than physical time. PMID:3792904

Lebeau, B; Jolicoeur, P; Pageau, G; Crossman, E J

1986-01-01

136

Hauen kasvu ja ravinto Tornionjoen alajuoksulla.  

E-print Network

??Tässä opinnäytetyössä selvitetään hauen (Esox lucius) kasvunopeutta ja ravinnonkäyttöä Tornionjoen alajuoksulla sekä, onko hauen ravinnonkäyttö muuttunut lohen (Salmo salar) vaelluspoikasten kasvaneen määrän johdosta. Osaa tuloksista… (more)

Peltola, Mikko

2010-01-01

137

Foraging Experiences with Children  

ERIC Educational Resources Information Center

Provided are foraging experiences and wild foods information for utilization in the urban school curriculum. Food uses are detailed for roses, dandelions, wild onions, acorns, cattails, violets and mints. (BT)

Russell, Helen Ross

1976-01-01

138

Understanding Forage Quality Analysis  

E-print Network

are two methods used to analyze forage samples in a laboratory. These include the tra- ditional wet chemistry analysis and the newer, near-infrared reflectance spectroscopy (NIRS) analy- sis. Wet chemistry analysis, based upon well-estab- lished chemical... are two methods used to analyze forage samples in a laboratory. These include the tra- ditional wet chemistry analysis and the newer, near-infrared reflectance spectroscopy (NIRS) analy- sis. Wet chemistry analysis, based upon well-estab- lished chemical...

Stokes, Sandra R.; Prostko, Eric P.

1998-03-23

139

Foraging search: Prototypical intelligence  

NASA Astrophysics Data System (ADS)

We think because we eat. Or as Descartes might have said, on a little more reflection, "I need to eat, therefore I think." Animals that forage for a living repeatedly face the problem of searching for a sparsely distributed resource in a vast space. Furthermore, the resource may occur sporadically and episodically under conditions of true uncertainty (nonstationary, complex and non-linear dynamics). I assert that this problem is the canonical problem solved by intelligence. It's solution is the basis for the evolution of more advanced intelligence in which the space of search includes that of concepts (objects and relations) encoded in cortical structures. In humans the conscious experience of searching through concept space we call thinking. The foraging search model is based upon a higher-order autopoeitic system (the forager) employing anticipatory processing to enhance its success at finding food while avoiding becoming food or having accidents in a hostile world. I present a semi-formal description of the general foraging search problem and an approach to its solution. The latter is a brain-like structure employing dynamically adaptive neurons. A physical robot, MAVRIC, embodies some principles of foraging. It learns cues that lead to improvements in finding targets in a dynamic and nonstationary environment. This capability is based on a unique learning mechanism that encodes causal relations in the neural-like processing element. An argument is advanced that searching for resources in the physical world, as per the foraging model, is a prototype for generalized search for conceptual resources as when we think. A problem represents a conceptual disturbance in a homeostatic sense. The finding of a solution restores the homeostatic balance. The establishment of links between conceptual cues and solutions (resources) and the later use of those cues to think through to solutions of quasi-isomorphic problems is, essentially, foraging for ideas. It is a quite natural extension of the fundamental foraging model.

Mobus, George

2000-05-01

140

Do You Have Enough Forage?  

E-print Network

To limit the impact of a forage crisis, a rancher must be able to recognize forage shortfalls and make timely decisions for the good of the livestock and the enterprise. This publication discusses strategies that help ranchers determine exactly how...

White, Larry D.

1999-02-12

141

Irrigation Systems for Forage Crops.  

E-print Network

&M University System ? College Station, Texas (Blank Pa,ge -In. O-riIIJIal BuIIetinl . 1?? .. , * ): . Irrigation Systems for Forage Crops Joseph C. Henggeler* Several types of irrigation systems can be chosen for irrigating forage crops for grazing...&M University System ? College Station, Texas (Blank Pa,ge -In. O-riIIJIal BuIIetinl . 1?? .. , * ): . Irrigation Systems for Forage Crops Joseph C. Henggeler* Several types of irrigation systems can be chosen for irrigating forage crops for grazing...

Henggeler, Joseph C.

1988-01-01

142

The Physics of Foraging  

NASA Astrophysics Data System (ADS)

Part I. Introduction: Movement: 1. Empirical motivation for studying movement; 2. Statistical physics of biological motion; 3. Random walks and Lévy flights; 4. Wandering albatrosses; Part II. Experimental Findings: 5. Early studies; 6. Evidence of anomalous diffusion; 7. Human dispersal; 8. How strong is the evidence?; Part III. Theory of Foraging: 9. Optimizing encounter rates; 10. Lévy flight foraging; 11. Other search models; Part IV. Finale: A Broader Context: 12. Superdiffusive random searches; 13. Adaptational versus emergent superdiffusion; 14. Perspectives and open problems; Appendices; References; Index.

Viswanathan, Gandhimohan. M.; da Luz, Marcos G. E.; Raposo, Ernesto P.; Stanley, H. Eugene

2011-06-01

143

Foraging Robots Alan FT Winfield  

E-print Network

and vice-versa, then if the sensors are light sensitive the robot will automatically steer towards a lightForaging Robots Alan FT Winfield University of the West of England, Bristol, UK Article Outline Glossary 1. Definition 2. Introduction 3. An Abstract model of Robot Foraging 4. Single Robot Foraging 5

Winfield, Alan FT

144

Collective foraging in heterogeneous landscapes.  

PubMed

Animals foraging alone are hypothesized to optimize the encounter rates with resources through Lévy walks. However, the issue of how the interactions between multiple foragers influence their search efficiency is still not completely understood. To address this, we consider a model to study the optimal strategy for a group of foragers searching for targets distributed heterogeneously. In our model, foragers move on a square lattice containing immobile but regenerative targets. At any instant, a forager is able to detect only those targets that happen to be in the same site. However, we allow the foragers to have information about the state of other foragers. A forager who has not detected any target walks towards the nearest location, where another forager has detected a target, with a probability exp(-?d), where d is the distance between the foragers and ? is a parameter characterizing the propensity of the foragers to aggregate. The model reveals that neither overcrowding (? ? 0) nor independent searching (? ? ?) is beneficial for the foragers. For a patchy distribution of targets, the efficiency is maximum for intermediate values of ?. In addition, in the limit ? ? 0, the length of the walks can become scale-free. PMID:25165596

Bhattacharya, Kunal; Vicsek, Tamás

2014-11-01

145

Learning Ant Foraging Behaviors  

Microsoft Academic Search

Insects are good at cooperatively solving many complex tasks. For example, foraging for food far away from a nest can be solved through relatively simple behaviors in combi- nation with pheromones. As task complexity increases, how- ever, it may become difficult to find individual agent rules which yield a desired emergent cooperative behavior, or to know if any such rules

Liviu A. Panait; Sean Luke

2004-01-01

146

Foraging & Optimality ... economic decisions  

E-print Network

&physiologicalecol ogy 1 Cost-benefit Model · Most often applied to foraging decisions · This type of analysis could 12 #12;· What size should be taken? · Crabs (Carcinus maenas) eating mussels · Profitability (energy profitability · Very large mussels - long h · Very small mussels - low E Prey choice Elner & Hughes. 1978. J

Blouin-Demers, Gabriel

147

Foraging bats avoid noise  

Microsoft Academic Search

SUMMARY Ambient noise influences the availability and use of acoustic information in animals in many ways. While much research has focused on the effects of noise on acoustic communication, here, we present the first study concerned with anthropogenic noise and foraging behaviour. We chose the greater mouse-eared bat (Myotis myotis) as a model species because it represents the especially vulnerable

Andrea Schaub; Joachim Ostwald; Björn M. Siemers

2008-01-01

148

Wide home ranges for widely foraging lizards  

Microsoft Academic Search

Space usage by animals may be influenced by a range of factors. In this study we investigate whether foraging behaviour affects the home range size of lizards. Two distinct tactics of foraging have been recognized in predators: sit-and-wait foraging (SW) and active foraging (AF). Foraging activity level of a data set of lizard species, mainly compiled from literature, is compared

Dave Verwaijen; Raoul Van Damme

2008-01-01

149

Defining Forage Quality  

E-print Network

that is essentially indigestible, accumulates mostly at maturity and acts as a barrier to fiber degradation by rumen microbes. The microbial population in the rumen leads to de- grading of the forage fiber, thereby making it un- available for the animal... analyses (wet chem- istry or near infrared test) include measurement of moisture, protein and fiber (Table 2). #24; ? those associated with cell contents (soluble car- bohydrates, highly digestible, easily broken down by the rumen microbes) ? those more...

Muir, James; Lambert, Barry; Newman, Yoana

2007-01-18

150

North American Journal of Fisheries Management 15 :838-844, 1995 Copyright by the American Fisheries Society 1995  

E-print Network

of northern pike Esox lucius (Fisheries Techniques Standardization Committee 1992) . Seasonal variations Fisheries Society 1995 Seasonal Variation in Gill-Net Sample Indexes for Northern Pike Collected from pike Esox lucius in 416 gill-net sets on 17 monthly oc- casions from July 1991 to June 1993 to examine

151

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research  

E-print Network

of catch-and-release angling on northern pike (Esox lucius L.) Robert Arlinghausa,b, , Thomas Klefotha, catch-and-release related stressors using a combined laboratory and field study in northern pike (Esox lucius L.). A labora- tory experiment was conducted to investigate the recovery dynamics of physiological

Cooke, Steven J.

152

C. R. Biologies 332 (2009) 741746 Ecology / cologie  

E-print Network

± SE = 4.2 ± 0.1) compared to other predatory fish such as the native pike (Esox lucius, TP = 3.7 ± 0 brochet (Esox lucius, TP = 3,7 ± 0,1) ou le silure (Silurus glanis, TP = 3,8 ± 0,1). La plupart des études

Cucherousset, Julien

153

Muskie lunacy: does the lunar cycle influence angler catch of muskellunge (Esox masquinongy)?  

USGS Publications Warehouse

We analyzed angling catch records for 341,959 muskellunge (Esox masquinongy) from North America to test for a cyclic lunar influence on the catch. Using periodic regression, we showed that the number caught was strongly related to the 29-day lunar cycle, and the effect was consistent across most fisheries. More muskellunge were caught around the full and new moon than at other times. At night, more muskellunge were caught around the full moon than the new moon. The predicted maximum relative effect was ?5% overall. Anglers fishing exclusively on the peak lunar day would, on average, catch 5% more muskellunge than anglers fishing on random days. On some lakes and at night, the maximum relative effect was higher. We obtained angler effort data for Wisconsin, Mille Lacs (MN), and Lake Vermilion (MN). For Lake Vermilion there was a significant effect of the lunar cycle on angler effort. We could therefore not conclude that the lunar effect on catch was due to an effect on fish behavior alone. Several factors affected the amount of variation explained by the lunar cycle. The lunar effect was stronger for larger muskellunge (>102 cm) than for smaller fish, stronger in midsummer than in June or October, and stronger for fish caught at high latitudes (>48°N) than for fish caught further south. There was no difference in the lunar effect between expert and novice muskellunge anglers. We argue that this variation is evidence that the effect of the lunar cycle on catch is mediated by biological factors and is not due solely to angler effort and reflects lunar synchronization in feeding. This effect has been attributed to variation among moon phases in lunar illumination, but our results do not support that hypothesis for angler-caught muskellunge.

Vinson, Mark R.; Angradi, Ted R.

2014-01-01

154

Androgenesis and homozygous gynogenesis in muskellunge (Esox masquinongy): evaluation using flow cytometry.  

PubMed

The purpose of this work was to study the effects of ultraviolet (UV) irradiation on denucleation of eggs and investigate the heat-shock conditions for diploidization for induction of androgenesis in muskellunge, Esox masquinongy. Several egg incubation media, including saline, Ringer's solution, and Ringer's solution supplemented with bovine serum albumin (BSA), were found suitable to maintain the egg fertility as high as in muskellunge ovarian fluid. The optimal doses of UV radiation were 660-1320 J/m2, at which 100% haploid larvae were produced at a hatching rate of 22.5 +/- 2.8%. UV irradiation at low doses (165-330 J/m2) generated abnormal larvae, which were morphologically identical to haploids. Using a flow cytometry method, it was found that cellular DNA content of these larvae was close to that of diploids but significantly lower in value and had a wider distribution (expressed as coefficient of variation) than that of control fish. This suggested that a low dose of UV irradiation might cause gene mutations, alteration of chromosomal conformation and fragmentation, but did not prevent maternal DNA from participating in mitotic division. Interference of maternal DNA residues could be another reason for the poor viability of androgenetic fish. A high dose of UV radiation (1980 J/m2) caused development of severely deformed embryos, indicating that UV radiation also damaged molecules in the eggs other than the denucleation. Our results suggest that classic color and allozyme markers might not be sufficient to prove a complete androgenesis. In order to optimize time and duration of shock for induced diploidization, we investigated the heat-shock conditions for inhibiting the first mitotic cleavage through induction of homozygous gynogenesis. We found that heat-shock treatment at 31 degrees C for 9 min starting at 1.4 tau 0 (a dimensionless factor describing progress in embryo development) after fertilization produced the highest percentage of diploids at hatching. PMID:9406191

Lin, F; Dabrowski, K

1998-01-01

155

Shedding of viral hemorrhagic septicemia virus (Genotype IVb) by experimentally infected muskellunge (Esox masquinongy).  

PubMed

Previous experimental infection demonstrated that juvenile muskellunge (Esox masquinongy) can survive experimental infection of viral hemorrhagic septicemia virus, Genotype IVb (VHSV IVb) at a low concentration of exposure. Herein we report that survivors of experimental infection with VHSV IVb shed the virus into the surrounding environment for an extended period of time. When muskellunge were exposed to VHSV IVb by immersion at a concentration of 1,400 plaque forming units (PFU)/ml, VHSV IVb was detected in the water of surviving fish for up to 15 weeks postexposure (p.e.) with the highest levels of shedding occurring between weeks 1 and 5 p.e. We estimated that each juvenile muskellunge can shed upwards of 1.36×10(5) PFU/fish/h after initial exposure signifying the uptake and amplification of VHSV to several orders of magnitude above the original exposure concentration. Muskellunge surviving low concentration exposure were re-infected with VHSV IVb by immersion at week 22 p.e. at concentrations ranging from 0 to 10(6) PFU/ml. Viral shedding was detected in all re-exposed fish, including mock rechallenged controls up to 15 consecutive weeks. Rates of viral shedding were substantially higher following rechallenge in the first 5 weeks. The highest rate of viral shedding was approximately 4.6×10(6) PFU/fish/h and shedding did not necessarily correspond to the re-exposure VHSV concentration. The results of this study shed new light into the dynamics of VHSV IVb shedding in a highly susceptible host and provide useful insights to fishery managers to design effective control strategies to this deadly virus. PMID:22538657

Kim, Robert K; Faisal, Mohamed

2012-04-01

156

S- and C-start escape responses of the muskellunge (Esox masquinongy) require alternative neuromotor mechanisms.  

PubMed

The startle response is a model system for examining the neural basis of behavior because of its relatively simple neural circuit organization and kinematic pattern. In fishes, the two primary types of startle behavior differ in their initial movements. In the C-start type of startle, the fish bends into a C shape, while the S-start involves an S-shaped body bend. Although considerable research has focused on determining how the C-start is generated neurally, S-start neurobiology has not been examined. I quantify the kinematics and electromyographic patterns of the initial movements of the C-start and S-start behaviors of the muskellunge (Esox masquinongy) to test three hypotheses for how the S-start is generated. (i) The S-start is generated by the same motor neural circuit as the C-start, but passive bending of the tail causes the body to take on an S shape. (ii) The S-start is generated by the same motor neural circuit as undulatory swimming. (iii) The S-start is generated by an independent neural mechanism from that used either in the C-start or in undulatory swimming. Results from kinematics and muscle activity patterns support the third hypothesis. In the muskellunge, the S-start is a high-performance startle behavior with peak angular velocity and peak angular acceleration of its initial bending comparable with those of the C-start and higher than would be expected for undulatory swimming. The S-start motor pattern, however, is distinct from the C-start motor pattern in having simultaneous muscle activity anteriorly on one side of the body and posteriorly on the opposite side. In contrast, the C-start is characterized by simultaneous unilateral muscle activity along the full length of the body. Alternative models are proposed for S-start neural circuit organization involving reticulospinal and local control of muscle activity. PMID:12089206

Hale, Melina E

2002-07-01

157

The Dynamics of Foraging Ants  

NASA Astrophysics Data System (ADS)

We experimentally study the foraging of small black ants, Formicinae lasius flavus, in order to describe their foraging behavior mathematically. Individual ants are allowed to forage on a two-dimensional surface in the absence of any food sources. The position of the ant as a function of time is determined using a high-resolution digital camera. Analysis of the average square displacements of many ants suggests that the foraging strategy is a non-reversing random walk. Moreover, the ants do not retrace their steps to return home but instead continue the random walk until it brings them back near their starting point.

Baxter, G. William

2009-03-01

158

Isolation of viral haemorrhagic septicaemia virus from muskellunge, Esox masquinongy (Mitchill), in Lake St Clair, Michigan, USA reveals a new sublineage of the North American genotype  

Microsoft Academic Search

Viral haemorrhagic septicaemia virus (VHSV) was isolated from muskellunge, Esox masquinongy (Mitchill), caught from the NW portion of Lake St Clair, Michigan, USA in 2003. Affected fish exhibited congestion of internal organs; the inner wall of the swim bladder was thickened and con- tained numerous budding, fluid-filled vesicles. A virus was isolated using fish cell lines inoculated with a homogenate

E Elsayed; M Faisal; M Thomas; G Whelan; W Batts; J Winton

2006-01-01

159

What do foraging hummingbirds maximize?  

Microsoft Academic Search

Hainsworth and Wolf (1976) reported that under certain conditions hummingbirds made food choices which did not maximize their net rate of energy intake while foraging. They concluded that the birds were not foraging optimally. We show here that their birds probably maximized a different utility function, the net energy per unit volume consumed (NEVC), which appears to be an optimal

Robert D. Montgomerie; John Mc A. Eadie; Lawrence D. Harder

1984-01-01

160

RED-COCKADED WOODPECKER FORAGING BEHAVIOR  

Microsoft Academic Search

We studied Red-cockaded Woodpeckers (Picoides borealis) to examine the effect of status and gender on foraging behavior. Foraging behavior of breeding pairs extended beyond separation by foraging height to include zones (bole, trunk in crown, primary limb, secondary limb) of the tree used and foraging methods (scaling, probing, excavating). Helper males and juvenile females maintained partial spatial separation from breeding

D. CRAIG RUDOLPH; RICHARD N. CONNER; RICHARD R. SCHAEFER; NANCY E. KOERTH

2007-01-01

161

Root nutrient foraging.  

PubMed

During a plant's lifecycle, the availability of nutrients in the soil is mostly heterogeneous in space and time. Plants are able to adapt to nutrient shortage or localized nutrient availability by altering their root system architecture to efficiently explore soil zones containing the limited nutrient. It has been shown that the deficiency of different nutrients induces root architectural and morphological changes that are, at least to some extent, nutrient specific. Here, we highlight what is known about the importance of individual root system components for nutrient acquisition and how developmental and physiological responses can be coupled to increase nutrient foraging by roots. In addition, we review prominent molecular mechanisms involved in altering the root system in response to local nutrient availability or to the plant's nutritional status. PMID:25082891

Giehl, Ricardo F H; von Wirén, Nicolaus

2014-10-01

162

Irrigation of Forage Crops  

E-print Network

divisions and irrigated areas. Source: Durwood, 1960. Texas Water Board of Engineers. Table 1. Water requirements for selected forage crops. Alfalfa and pastures Sorghum Corn Location Seasonal Daily Seasonal Daily Seasonal Daily (in.) (GPM/ac.) (in.) (GPM.../ac.) (in.) (GPM/ac.) 1. High Plains 58-66 6.6 21-26 6.2 27-31 6.7 2. Trans-Pecos 65-67 6.7 27 6.6 31 8.5 3. Edwards Plateau ? Central Basin 59-67 6.7 23-26 6.1 27-31 8.8 4. Rio Grande Plain 50-67 6.8 17-23 5.6 20-27 7.7 5. Coastal Prairie 47-49 4.7 18 4...

Enciso, Juan; Porter, Dana; Fipps, Guy; Colaizzi, Paul

2004-06-10

163

Root foraging influences plant growth responses to earthworm foraging.  

PubMed

Interactions among the foraging behaviours of co-occurring animal species can impact population and community dynamics; the consequences of interactions between plant and animal foraging behaviours have received less attention. In North American forests, invasions by European earthworms have led to substantial changes in plant community composition. Changes in leaf litter have been identified as a critical indirect mechanism driving earthworm impacts on plants. However, there has been limited examination of the direct effects of earthworm burrowing on plant growth. Here we show a novel second pathway exists, whereby earthworms (Lumbricus terrestris L.) impact plant root foraging. In a mini-rhizotron experiment, roots occurred more frequently in burrows and soil cracks than in the soil matrix. The roots of Achillea millefolium L. preferentially occupied earthworm burrows, where nutrient availability was presumably higher than in cracks due to earthworm excreta. In contrast, the roots of Campanula rotundifolia L. were less likely to occur in burrows. This shift in root behaviour was associated with a 30% decline in the overall biomass of C. rotundifolia when earthworms were present. Our results indicate earthworm impacts on plant foraging can occur indirectly via physical and chemical changes to the soil and directly via root consumption or abrasion and thus may be one factor influencing plant growth and community change following earthworm invasion. More generally, this work demonstrates the potential for interactions to occur between the foraging behaviours of plants and soil animals and emphasizes the importance of integrating behavioural understanding in foraging studies involving plants. PMID:25268503

Cameron, Erin K; Cahill, James F; Bayne, Erin M

2014-01-01

164

Root Foraging Influences Plant Growth Responses to Earthworm Foraging  

PubMed Central

Interactions among the foraging behaviours of co-occurring animal species can impact population and community dynamics; the consequences of interactions between plant and animal foraging behaviours have received less attention. In North American forests, invasions by European earthworms have led to substantial changes in plant community composition. Changes in leaf litter have been identified as a critical indirect mechanism driving earthworm impacts on plants. However, there has been limited examination of the direct effects of earthworm burrowing on plant growth. Here we show a novel second pathway exists, whereby earthworms (Lumbricus terrestris L.) impact plant root foraging. In a mini-rhizotron experiment, roots occurred more frequently in burrows and soil cracks than in the soil matrix. The roots of Achillea millefolium L. preferentially occupied earthworm burrows, where nutrient availability was presumably higher than in cracks due to earthworm excreta. In contrast, the roots of Campanula rotundifolia L. were less likely to occur in burrows. This shift in root behaviour was associated with a 30% decline in the overall biomass of C. rotundifolia when earthworms were present. Our results indicate earthworm impacts on plant foraging can occur indirectly via physical and chemical changes to the soil and directly via root consumption or abrasion and thus may be one factor influencing plant growth and community change following earthworm invasion. More generally, this work demonstrates the potential for interactions to occur between the foraging behaviours of plants and soil animals and emphasizes the importance of integrating behavioural understanding in foraging studies involving plants. PMID:25268503

Cameron, Erin K.; Cahill, James F.; Bayne, Erin M.

2014-01-01

165

CROP & SOIL SCIENCES Forage Breeding  

E-print Network

CROP & SOIL SCIENCES Forage Breeding Committee Membership Dr. Joseph Bouton - committee chair Dr. Brian Schwartz Department of Crop & Soil Sciences Department of Crop & Soil Sciences University & Soil Sciences Department of Crop & Soil Sciences University of Georgia University of Georgia Center

Arnold, Jonathan

166

Morphological and molecular evidence of three species of pikes Esox spp. (Actinopterygii, Esocidae) in France, including the description of a new species.  

PubMed

This integrative taxonomy study of French pikes compares morphological characters and molecular sequence data (mitochondrial COI and nuclear Plagl2 genes). In addition to the expected E. lucius, DNA sequences and morphology both support a new species in France, E. aquitanicus sp. nov. from the Charente to the Adour drainages. It is characterized by a color pattern of sides with narrow 1-1.5-scale-wide oblique vertical bands, conferring it a marbled coat, a snout only 0.9 times larger than the postorbital length, an anal fin basis 1.1-1.2 times larger than the caudal peduncle length, 101 to 121 lateral scales, 53 to 57 vertebrae, as well as 24 diagnostic sites in the COI gene and 3 in the Plagl2 gene. Partial COI sequences (131 bp) from modern and historical specimens indicate also the presence of E. cisalpinus and E. lucius during the 19th century in Lake Geneva. Morphological and molecular data points to a possible hybridization between E. lucius with both other local pike species, representing a risk for them. Their endangerment status should be evaluated rapidly in order to take conservation measures. PMID:25242691

Denys, Gaël Pierre Julien; Dettai, Agnès; Persat, Henri; Hautecœur, Mélyne; Keith, Philippe

2014-09-01

167

The locust foraging gene.  

PubMed

Our knowledge of how genes act on the nervous system in response to the environment to generate behavioral plasticity is limited. A number of recent advancements in this area concern food-related behaviors and a specific gene family called foraging (for), which encodes a cGMP-dependent protein kinase (PKG). The desert locust (Schistocerca gregaria) is notorious for its destructive feeding and long-term migratory behavior. Locust phase polyphenism is an extreme example of environmentally induced behavioral plasticity. In response to changes in population density, locusts dramatically alter their behavior, from solitary and relatively sedentary behavior to active aggregation and swarming. Very little is known about the molecular and genetic basis of this striking behavioral phenomenon. Here we initiated studies into the locust for gene by identifying, cloning, and studying expression of the gene in the locust brain. We determined the phylogenetic relationships between the locust PKG and other known PKG proteins in insects. FOR expression was found to be confined to neurons of the anterior midline of the brain, the pars intercerebralis. Our results suggest that differences in PKG enzyme activity are correlated to well-established phase-related behavioral differences. These results lay the groundwork for functional studies of the locust for gene and its possible relations to locust phase polyphenism. PMID:20422718

Lucas, C; Kornfein, R; Chakaborty-Chatterjee, M; Schonfeld, J; Geva, N; Sokolowski, M B; Ayali, A

2010-05-01

168

Octopamine influences honey bee foraging preference  

PubMed Central

Colony condition and differences in individual preferences influence forage type collected by bees. Physiological bases for the changing preferences of individual foragers are just beginning to be examined. Recently, for honey bees octopamine is shown to influence age at onset of foraging and probability of dance for rewards. However, octopamine has not been causally linked with foraging preference in the field. We tested the hypothesis that changes in octopamine may alter forage type (preference hypothesis). We treated identified foragers orally with octopamine or its immediate precursor, tyramine, or sucrose syrup (control). Octopamine treated foragers switched type of material collected, control bees did not. Tyramine group results were not different from the control group. In addition, sugar concentrations of nectar collected by foragers after octopamine treatment were lower than before treatment, indicating change in preference. In contrast, before and after nectar concentrations for bees in the control group were similar. These results, taken together, support the preference hypothesis. PMID:17574568

Giray, Tugrul; Galindo, Alberto; Oskay, Devrim

2010-01-01

169

Fish predation selects for reduced foraging activity  

Microsoft Academic Search

Despite the importance of foraging activity for the growth\\/predation risk trade-off, studies that demonstrated predator-induced\\u000a survival selection on foraging activity under semi-natural conditions are relatively rare. Here, we tested for fish-induced\\u000a selection for reduced foraging activity in two larval Enallagma damselflies using a field enclosure experiment. Fish imposed considerable mortality in both damselfly species and survival\\u000a selection on foraging activity

Francis Strobbe; Mark A. McPeek; Marjan De Block; Robby Stoks

2011-01-01

170

Understanding Forage Intake in Range Animals  

E-print Network

as important as forage quality, especially when quality is marginal. Forage intake in a rangeland environment is influenced by a num- ber of important factors, including: ? Herbivore species and size. ? Foraging behavior. ? Physiological status. ? Animal... intake associated with declining leaf material. Bite size also has a great influence on forage intake. While bite size declines as leaf material becomes less available, animals temporarily com- pensate by increasing bite rate and grazing time. However...

Lyons, Robert K.; Machen, Richard V.; Forbes, T. D. A.

1999-02-08

171

Nutritive characteristics of forage chemical components  

E-print Network

the nutritive characteristics of forage chemical components as related to their digesti- bility and level of intake Each forage was fed to two sheep at 0. 50 of estimated voluntary intake (EVI), 0. 75 EVI and at voluntary intake (VI). Samples of each forage... and resultant sheep feces, at a specified level of intake, were collected and identified for subsequent chemical analysis. Forage and fecal samples were extracted with a neutral detergent solution yielding a residue (NDF) and an extract which was determined...

Buentello, Jose Luis

2012-06-07

172

Nocturnal foraging in the American White Pelican  

Microsoft Academic Search

Nocturnal foraging was examined in American White Pelicans (Pelecanus erythrorhynchos) at the Dauphin River, about 50 km from a breeding colony on Lake Winnipeg, Manitoba, Canada. From two to three times as many pelicans foraged at night as in the daytime, with foraging flocks being larger at night. In contrast, more pelicans were present at adjacent loafing sites during the

BLAIR F. MCMAHON; ROGER M. EVANS

1992-01-01

173

Prey availability and selective foraging in shorebirds  

Microsoft Academic Search

Accurate measurements of prey availability are vital to our understanding of foraging behaviour, particularly prey selectivity. In the present study, observations of shorebirds foraging for fiddler crabs on intertidal mudflats demonstrate that prey availability depends both on the temporal variation in crab activity and on the crabs’ responses to the presence of foraging shorebirds. Our results suggest that measurements of

PATRICIA R. Y. BACKWELL; PATRICK D O’HARA; JOHN H. CHRISTY

1998-01-01

174

7 CFR 1437.401 - Forage.  

...un-harvested for the purposes of determining a payment factor. (e) Small grain forage is the specific acreage of wheat, barley, oats, triticale, or rye intended for use as forage. Small grain forage shall be considered separate crops and distinct from...

2014-01-01

175

Forage shrubs in North Island hill country 1. Forage production  

Microsoft Academic Search

A range of shrubs was evaluated as potential sources of forage for grazing animals. Shrubs were established in rows in hill pastures near Wood ville. Nine “true” shrubs and two erect grasses, pampas grass (Cortaderia selloana) and toetoe (C. fulvida), were evaluated. The true shrubs were: Chamaecytisus palmensis, tagasaste; Medicago arborea, tree medic; Ulex europaeus, gorse (two variants: wild gorse

M. G. Lambert; G. A. Jung; D. A. Costall

1989-01-01

176

Forage shrubs in North Island hill country 3. Forage digestibility  

Microsoft Academic Search

A range of shrubs was evaluated as potential sources of forage for grazing animals. Shrubs were established in rows in hill pastures near Wood ville. Nine “true” shrubs, and two erect grasses, pampas grass (Cortaderia selloana), and toetoe (C. fulvida) were evaluated. The true shrubs were: Chamaecytisus palmensis, tagasaste; Medicago arborea, tree medic; Ulex europaeus, gorse (two variants: wild gorse

M. G. Lambert; G. A. Jung; H. W. Harpster; P. J. Budding; G. S. Wewala

1989-01-01

177

Development of neutralizing antibody responses in muskellunge, Esox masquinongy (Mitchill), experimentally exposed to viral haemorrhagic septicaemia virus (genotype IVb).  

PubMed

A complement-dependent 50% plaque neutralization test was used to assess the neutralizing antibody response in sera of muskellunge, Esox masquinongy, experimentally infected with viral haemorrhagic septicaemia virus (VHSV, genotype IVb) by immersion. Groups of muskellunge were challenged with varying concentrations of VHSV: Group 1 with 10(2) plaque-forming units (pfu)?mL(-1) , Group 2 with 4?×?10(3) ?pfu?mL(-1) , Group 3 with 10(5) ?pfu?mL(-1) and Group 4 with 0?pfu?mL(-1) . The fish were held at a temperature of 11?±?1?°C and were sampled over a 20-week period. Neutralizing antibodies were not detected in sera of any of the negative control fish throughout the study. Low neutralizing titres were detected in Groups 1-3 by 6?days post-infection (p.i.). Neutralizing titres of ?80 [corrected]. were not detected again until 3, 4 and 7?weeks p.i. for Groups 2, 3 and 1, respectively, with peak titres for those groups occurring 16, 11 and 17?weeks p.i., respectively. VHSV was detected in serum for up to 11?weeks p.i. Results of this study show that survivors can be detected by a serological technique, despite being virus negative. This may benefit the investigation of VHSV IVb distribution in the Great Lakes and the study of host immune responses to this emerging sublineage. PMID:22091537

Millard, E V; Faisal, M

2012-01-01

178

Detection of viral hemorrhagic septicemia virus-IVb antibodies in sera of muskellunge Esox masquinongy using competitive ELISA.  

PubMed

A competitive enzyme-linked immunosorbent assay (cELISA) was developed for the detection of antibodies to viral hemorrhagic septicemia virus genotype IVb (VHSV-IVb) in fish sera. Assay conditions were standardized using known negative and positive muskellunge Esox masquinongy. A positive-negative threshold of 14.6% inhibition was established based on analysis of sera of 60 muskellunge with no previous exposure to VHSV-IVb. The cELISA was then used to investigate immune responses of wild muskellunge sampled from 5 water bodies in Michigan and Wisconsin, USA, between 2005 and 2012. Antibodies were detected in fish from Lake St. Clair, Michigan, and Lower Fox River/Green Bay, Wisconsin. Both water systems were considered enzootic for VHSV-IVb. Additionally, antibodies were detected in muskellunge from Thornapple Lake, a Michigan inland lake previously considered negative for VHSV-IVb based on virus isolation methods. Muskellunge populations from Lake Hudson, Michigan, and Butternut Lake, Wisconsin, lacked evidence of an immune response to VHSV-IVb. When results of the cELISA were compared to the 50% plaque neutralization test for several groups of fish, there was 78.4% agreement between the tests for antibody presence. The cELISA is a rapid and efficient test for the detection of binding antibodies to VHSV-IVb and will be a useful non-lethal tool for monitoring the spread of this serious pathogen. PMID:24695232

Millard, Elena V; Brenden, Travis O; LaPatra, Scott E; Marcquenski, Susan; Faisal, Mohamed

2014-04-01

179

Alternative options in forage fertilization  

E-print Network

Alternative options in forage fertilization Tom Obreza #12;Topics Fertilizer prices Biosolids construction. #12;#12;#12;0 200 400 600 800 1000 1200Dollarsperton Date Amm Nit Potash DAP #12;Biosolids #12;Rule changes on the horizon "Domestic wastewater residuals" replaced by "biosolids." Biosolids site

Watson, Craig A.

180

Drying of Grains and Forages  

Microsoft Academic Search

Recent published literature (1990–1995) on the subject of grain drying and drying of forages is reviewed. Research priorities regarding crop drying tends to be regionalized. responding at times to differences in socio-economic conditions, at times to the status of energy research and environmental policy. Because grains have recently become much more important feedstocks for various food and industrial products, drying

S. Sokhansanj; G. S. V. Aaghavan

1996-01-01

181

Squirrel Foraging Preferences: Gone Nuts?  

ERIC Educational Resources Information Center

This field exercise examines the feeding preferences of Gray Squirrels ("Sciurus carolinensis"). Students present squirrels with a variety of food types in a cafeteria-style arrangement in order to test hypotheses about foraging preferences. This exercise, which is appropriate for introductory biology, ecology, and animal behavior classes, is…

Darling, Randi A.

2007-01-01

182

Forage Crops in Northwest Texas.  

E-print Network

......................................... 'reparation of the Land 14 ieeding ......................................................... 15 ............................................ Jutting and Curing -15 ......................................... 'reatment of the Field 15 rield.... On account of the remarkable drought resistance of most varieties, it safeguards against absolute failure and produces as well heavy yields of cured forage per acre. The fact that ln doubtful crop seasons, many farmers resort to the growth of this crop...

Conner, A. B. (Arthur Benjamin)

1908-01-01

183

Foraging currencies, metabolism and behavioural routines.  

PubMed

A fundamental issue in foraging theory is whether it is possible to find a simple currency that characterizes foraging behaviour. If such a currency exists, then it is tempting to argue that the selective forces that have shaped the evolution of foraging behaviour have been understood. We review previous work on currencies for the foraging behaviour of an animal that maximizes total energy gained. In many circumstances, it is optimal to maximize a suitably modified form of efficiency. We show how energy gain, predation and damage can be combined in a single currency based on reproductive value. We draw attention to the idea that hard work may have an adverse effect on an animal's condition. We develop a model of optimal foraging over a day when a forager's state consists of its energy reserves and its condition. Optimal foraging behaviour in our model depends on energy reserves, condition and time of day. The pattern of optimal behaviour depends strongly on assumptions about the probability that the forager is killed by a predator. If condition is important, no simple currency characterizes foraging behaviour, but behaviour can be understood in terms of the maximization of reproductive value. It may be optimal to adopt a foraging option that results in a rate of energy expenditure that is less than the rate associated with maximizing efficiency. PMID:23730810

Houston, Alasdair I; McNamara, John M

2014-01-01

184

Potential of Forages to Diversify Northern Great Plains Cropping Systems  

Microsoft Academic Search

Cultivated forage crops are grown on almost 12 million hectares on the Northern Great Plains. This paper reviews the benefits of diversifying annual crop rotations with forage crops, and highlights innovations in forage systems. Agronomic benefits of rotating forage crops with annual grain crops include higher grain crop yields following forages (up to 13 years in one study); shifts in

M. H. Entz; V. S. Baron; P. M. Carr; D. W. Meyer; S. R. Smith; W. P. McCaughey

185

Hazardous duty pay and the foraging cost of predation  

Microsoft Academic Search

We review the concepts and research associated with measuring fear and its consequences for foraging. When foraging, animals should and do demand hazardous duty pay. They assess a foraging cost of predation to compensate for the risk of predation or the risk of catastrophic injury. Similarly, in weighing foraging options, animals tradeoff food and safety. The foraging cost of predation

Joel S. Brown; Burt P. Kotler

2004-01-01

186

Strike feeding behavior in the muskellunge, Esox masquinongy: contributions of the lateral line and visual sensory systems.  

PubMed

The muskellunge, Esox masquinongy, is a predatory esocid fish with well-developed visual and lateral line systems. The purpose of this study was to determine the relative roles of these two sensory modalities in organizing the strike behavior of the animal. Subadult muskellunge were videotaped in a test arena while feeding on fathead minnows (Pimephales promelas). Animals were tested under five conditions: (i) control animals in which the visual and lateral line systems were intact; (ii) animals with lateral line afference suppressed by immersion for 12-24 h in 0.1 mmol l(-1) CoCl2; (iii) animals blinded by bilateral optic nerve transection; (iv) animals that had been unilaterally blinded; and (v) animals in which the lateral line system had been unilaterally denervated. The feeding behavior of the muskellunge consists of two phases: a slow stalk of the prey with minimal body movement followed by an explosive C- or S-start lunge at the prey. Quantitative comparisons of animals in the five test groups indicate that, although vision is used in the initial acquisition of the prey, both vision and the lateral line system play important roles in determining the initiation of the rapid strike. The lateral line system may play a critical role in the final capture of the prey at the end of the strike. In addition, lateral-line-suppressed muskellunge strongly alter their approaches to more distant prey. Bilaterally blinded muskellunge do not stalk their prey, but will lunge only at prey that are at close range. Unilaterally blinded or denervated muskellunge also alter their detection of and approach to prey, attending to a wider region of the intact sensory hemisphere. Our data suggest not only that the visual and lateral line systems play complementary roles in the feeding behavior sequence but also that each system plays a more or less dominant role during consecutive phases of the behavior. PMID:11222136

New, J G; Alborg Fewkes, L; Khan, A N

2001-03-01

187

Geographic profiling and animal foraging.  

PubMed

Geographic profiling was originally developed as a statistical tool for use in criminal cases, particularly those involving serial killers and rapists. It is designed to help police forces prioritize lists of suspects by using the location of crime scenes to identify the areas in which the criminal is most likely to live. Two important concepts are the buffer zone (criminals are less likely to commit crimes in the immediate vicinity of their home) and distance decay (criminals commit fewer crimes as the distance from their home increases). In this study, we show how the techniques of geographic profiling may be applied to animal data, using as an example foraging patterns in two sympatric colonies of pipistrelle bats, Pipistrellus pipistrellus and P. pygmaeus, in the northeast of Scotland. We show that if model variables are fitted to known roost locations, these variables may be used as numerical descriptors of foraging patterns. We go on to show that these variables can be used to differentiate patterns of foraging in these two species. PMID:16263134

Le Comber, Steven C; Nicholls, Barry; Rossmo, D Kim; Racey, Paul A

2006-05-21

188

Foraging habitats of bats in southern Finland  

Microsoft Academic Search

We determined the foraging habitats of the northern batEptesicus nilssonii (Keyserling et Blasius, 1839), Brandt’s batMyotis brandtii (Eversmann, 1845), whiskered batMyotis mystacinus (Kuhl, 1819), Daubenton’s batMyotis daubentonii (Kuhl, 1819) and brown long-eared batPlecotus auritus (Linnaeus, 1758) in southern Finland. Among these species, we compared the diversities of foraging habitats, linear feature\\u000a preference and the bats’ tendencies to forage simultaneously.Eptesicus nilssonii

Terhi Wermundsen; Yrjö Siivonen

2008-01-01

189

7 Social Information Use in Foraging Insects  

E-print Network

. 192). How surprising it is that modern science, with its scorn for anthropomorphism and overinter...................................................................................138 Deciding When to Follow Dances"..................................................................................................................... 140 Social Transmission of Foraging Techniques

Chittka, Lars

190

Boa constrictor (Boa constrictor): foraging behavior  

USGS Publications Warehouse

Boa constrictor is often referred to as a sit-and-wait or ambush forager that chooses locations to maximize the likelihood of prey encounters (Greene 1983. In Janzen [ed.], Costa Rica Natural History, pp. 380-382. Univ. Chicago Press, Illinois). However, as more is learned about the natural history of snakes in general, the dichotomy between active versus ambush foraging is becoming blurred. Herein, we describe an instance of diurnal active foraging by a B. constrictor, illustrating that this species exhibits a range of foraging behaviors.

Sorrell, G. G.; Boback, M. S.; Reed, R. N.; Green, S.; Montgomery, C. E.; DeSouza, L. S.; Chiaraviglio, M.

2011-01-01

191

Genetic determination of nectar foraging, pollen foraging, and nest-site scouting in honey bee colonies  

Microsoft Academic Search

Allozyme analyses of honey bee workers revealed significant differences in the intracolonial subfamily composition of groups of nectar foragers, pollen foragers, and nest-site scouts. These differences demonstrate that colony genetic structure influences the division of labor among older foraging-age bees just as it does for younger workers. The maintenance of genetic variability for the behavior of individual workers and its

Gene E. Robinson; Robert E. Page

1989-01-01

192

This article was downloaded by: [University of Wisconsin -Madison] On: 28 May 2013, At: 05:28  

E-print Network

Wisconsin. Muskellunge Esox masquinongy, black bass (i.e., Smallmouth Bass Micropterus dolomieu and Largemouth Bass M. salmoides), Northern Pike E. lucius, Walleye Sander vitreus, and panfish were released

193

fisheriesresearch Introduction  

E-print Network

in fishery research. Zooplankton abundance and size structure have been related to yellow perch (Perca-den- sity populations of yellow perch, black bullhead (Ameiurus melas), and north- ern pike (Esox lucius

194

Structural and functional impairment of the hypothalamo-pituitary-interrenal axis in fish  

E-print Network

pike, Esox lucius, and the yellow perch, Perca flavescens, sampled upstream and downstream from a pulp cortisol following a standardized capture and handling stress were lower in pike and perch from sites

Rasmussen, Joseph

195

Journal of Chemical Ecology, Vol. 23, No. 4, 1997 REACTIONS OF Gammarus lacustris TO CHEMICAL  

E-print Network

pheromone decreases the capture efficiency of predatory larvaldragonflies (Aeshna umbrosa) (Hews, 1988 and to chemical stimuli from two types of natural predators: dragonfly larvae (Aeshna eremita) and northern pike, alarm pheromone, kairomone, predator avoidance, antipredator behavior, Esox lucius, Aeshna eremita

Wisenden, Brian D.

196

Selective Predation by Three Esocids: The Role of Prey Behavior and Morphology  

Microsoft Academic Search

We documented differential vulnerability of fathead minnows Pimephales promelas, gizzard shad Dorosoma cepedianum. and bluegills Lepomis macrochirus to predation by muskel- lunge Esox masquinongy. northern pike E. lucius. and tiger muskellunge £\\

DAVID H. WAHL; ROY A. STEIN

1988-01-01

197

COOK, A. F., N. E. STACEY, AND R. E. PETER. 1980. Periovulatory changes in serum cortisol levels in  

E-print Network

in the goldfish, Carassius auratus. Gen. Compo Endocri- no\\. 40:507-510. HIROSE, K. 1976. Endocrine control pike(Esox lucius), and goldfish (Carassius auratus). J. Fish. Res. Board Can. 33:974-988. KAYA, C. M

198

I. Fish..........................................................................................................................................2 A) Fish native to both Europe and North America (not analyzed) ........................................2  

E-print Network

autumnalis 2. Esox lucius 3. Gasterosteus aculeatus 4. Lampetra richardsoni 5. Lethenteron japonicum 6. Lota lota 7. Petromyzon marinus 8. Pungitius pungitius 9. Salmo salar 10. Salvelinus alpinus 11. Stenodus

Jeschke, Jonathan

199

DISSOLVED OXYGEN, TEMPERATURE, SURVIVAL OF YOUNG AT FISH SPAWNING SITES  

EPA Science Inventory

Fluctuations of dissolved oxygen concentrations and water temperatures in their natural spawning sites were measured during embryo through larva stages of northern pike (Esox lucius), and during embryo and sac larva stages of bluegills (Lepomis macrochirus) and pumpkinseeds (Lepo...

200

Visual perception and social foraging in birds  

Microsoft Academic Search

Birds gather information about their environment mainly through vision by scanning their surroundings. Many prevalent models of social foraging assume that foraging and scanning are mutually exclusive. Although this assumption is valid for birds with narrow visual fields, these models have also been applied to species with wide fields. In fact, available models do not make precise predictions for birds

Esteban Fernández-Juricic; Jonathan T. Erichsen; Alex Kacelnik

2004-01-01

201

DEMONSTRATION BULLETIN: FORAGER? SPONGE TECHNOLOGY - DYNAPHORE, INC.  

EPA Science Inventory

The Forager? Sponge is an open-celled cellulose sponge incorporating an amine-containing chelating polymer that has selective affinity for dissolved heavy metals in both cationic and anionic states. The Forager? Sponge technology can be utilized to remove and concentrate heavy me...

202

ORIGINAL PAPER Evolutionary Foraging Models in Zooarchaeological  

E-print Network

economics. Keywords Zooarchaeology Á Foraging models Á Behavioral ecology Introduction The last three of foraging economics in zooarchaeology has generated a number of very sophisticated models to explain viewed as a catalyst for declining health and fertility, increased interpersonal violence, and major

Kohler, Tim A.

203

Prey Processing in Central Place Foragers  

Microsoft Academic Search

The importance of prey processing as an integral part of foraging behaviour has long been acknowledged, but little theoretical consideration has been given to the optimization of the processing behaviour itself. Processing renders food down to ingestible, palatable portions, and also removes non-essential mass thus reducing transport costs. Here, several models of processing are developed for a central place forager.

SEAN A. RANDS; ALASDAIR I. HOUSTON; CATHERINE E. GASSON

2000-01-01

204

Perennial Forages as Second Generation Bioenergy Crops  

PubMed Central

The lignocellulose in forage crops represents a second generation of biomass feedstock for conversion into energy-related end products. Some of the most extensively studied species for cellulosic feedstock production include forages such as switchgrass (Panicum virgatum L.), reed canarygrass (Phalaris arundinacea L.), and alfalfa (Medicago sativa L.). An advantage of using forages as bioenergy crops is that farmers are familiar with their management and already have the capacity to grow, harvest, store, and transport them. Forage crops offer additional flexibility in management because they can be used for biomass or forage and the land can be returned to other uses or put into crop rotation. Estimates indicate about 22.3 million ha of cropland, idle cropland, and cropland pasture will be needed for biomass production in 2030. Converting these lands to large scale cellulosic energy farming could push the traditional forage-livestock industry to ever more marginal lands. Furthermore, encouraging bioenergy production from marginal lands could directly compete with forage-livestock production. PMID:19325783

Sanderson, Matt A.; Adler, Paul R.

2008-01-01

205

Beef/Forage Day Friday, September 21, 2012  

E-print Network

Beef/Forage Day Friday, September 21, 2012 NorthCentralResearch&OutreachCenter UniversityofMinnesota BeefandForageResearchFarm Events: Public Engagement and Education: "Learn about NCROC, beef cattle and learn our mission in agriculture and learn basics of forage, beef and meat production Beef and Forage

Minnesota, University of

206

Differential effects of structural complexity on predator foraging behavior  

Microsoft Academic Search

The choice of predator foraging mode has important consequences for ecological communities. Foraging mode designations are often made on the basis of predator activity, yet activity can be affected by various environmental stimuli independent of changes in foraging mode. Structural complexity can reduce predator activity by either interfering with predator vision and mobility or as part of a foraging mode

Matt J. Michel; Melinda M. Adams

2009-01-01

207

Gregarious foraging in barn swallows after the breeding season  

Microsoft Academic Search

Aerial vertebrate foragers, e.g. insectivorous bats, martins and swallows, often show gregarious behavior such as colonial breeding, communal roosting and aggregating behavior during foraging. Studies of gregariousness in aerial foragers have mostly focused on colonial breeding or communal roosting, and only a few intensive studies have dealt with gregariousness during foraging. Here, we report on large and stable aggregations of

Go Fujita; Hiroyoshi Higuchi

2005-01-01

208

Ungulate foraging strategies: energy maximizing or time minimizing?  

Microsoft Academic Search

Summary 1. Many classical models of ungulate foraging are premised on energy maximization, yet limited empirical evidence and untested currency assumptions make the choice of currency a non-trivial issue. The primary constraints on forage intake of ungulates are forage quality and availability. Using a model that incorporates these two constraints, we predicted the optimal biomass of forage patches for ungulate

Carita M. Bergman; John M. Fryxell; C. Cormack Gates; Daniel Fortin

2001-01-01

209

The impact of weather on kingbird foraging behavior  

Microsoft Academic Search

Foraging data on Eastern Kingbirds (Tyrannus tyrannus) were collected during the early breeding season in eastern Kansas to test the hypothesis that foraging rate and other aspects of foraging behavior vary with weather. Foraging characteristics of five additional kingbird species were also examined to assess Fitzpatrick's 1980 generalization that kingbirds (Tyrannus spp.) are aerial hawking specialists. In Eastern Kingbirds, total

1987-01-01

210

Worker honey bee pheromone regulation of foraging ontogeny  

NASA Astrophysics Data System (ADS)

The evolution of sociality has configured communication chemicals, called primer pheromones, which play key roles in regulating the organization of social life. Primer pheromones exert relatively slow effects that fundamentally alter developmental, physiological, and neural systems. Here, I demonstrate how substances extracted from the surface of foraging and young pre-foraging worker bees regulated age at onset of foraging, a developmental process. Hexane-extractable compounds washed from foraging workers increased foraging age compared with controls, whereas extracts of young pre-foraging workers decreased foraging age. This represents the first known direct demonstration of primer pheromone activity derived from adult worker bees.

Pankiw, Tanya

211

Seasonal range selection in bighorn sheep: conflicts between forage quality, forage quantity, and predator avoidance  

Microsoft Academic Search

Summary  The migratory and foraging behavior of individually marked bighorn ewes (Ovis canadensis) was studied to test the hypothesis that forage quality determined seasonal range selection. Forage quality was monitored\\u000a through analysis of fecal crude protein. Ewes in the study population utilized two distinct ranges differing in elevation\\u000a and possibly predation risk. Pregnant ewes migrated in May from the low-elevation winter

M. Festa-Bianchet

1988-01-01

212

Rangeland Risk Management for Texans: Forage Quality and Quantity  

E-print Network

and Correcting Forage Quality Problems Producers understand forage quality, especially crude protein content, in relation to livestock performance. Hay shows emphasize the importance of forage testing to determine quality, and demonstrate how forage quality can..., The Texas A&M University System Rangeland Risk Management for Texans E-118 10-00 scarce. If you see animals grazing in the heat of the day in the middle of summer, forage is probably scarce. You can use the body condition scores of your animals...

Lyons, Robert K.

2000-11-01

213

Aggressive and Foraging Behavioral Interactions Among Ruffe  

Microsoft Academic Search

The ruffe, Gymnocephalus cernuus, is a nonindigenous percid in the Great Lakes. Ruffe are aggressive benthivores and forage over soft substrates. Laboratory studies in pools (100?cm diameter, 15?cm water depth) were conducted to determine whether fish density (low=2, medium=4, high=6 ruffe per pool) changed foraging and aggressive behaviors with a limited food supply of chironomid larvae. All fish densities demonstrated

Jacqueline F. Savino; Melissa J. Kostich

2000-01-01

214

Forage Bermudagrass: Selection, Establishment and Management  

E-print Network

E-179 4-03 Forage Bermudagrass: Selection, Establishment and Management Charles Stichler and David Bade, Extension Agronomists The Texas A&M University System Introduction In April of 1943, with the introduction of Coastal bermudagrass (an F 1... David Bade, Gerald Evers, S. Simecek and M. Hussey. Establishment Establishment is a critical step. Considering the time, effort and expense involved in establishing any forage, attention to details is important to success. The ideal seed bed...

Stichler, Charles; Bade, David H.

2003-04-04

215

How Much Forage Do You Have?  

E-print Network

*Extension Range Specialists, The Texas A&M University System. B-1646 06/06 quantitative information will improve stocking rate decisions and help avoid overuse or underuse of forage resources. Overuse can damage range resources and lead to a...*Extension Range Specialists, The Texas A&M University System. B-1646 06/06 quantitative information will improve stocking rate decisions and help avoid overuse or underuse of forage resources. Overuse can damage range resources and lead to a...

Hanselka, C. Wayne; McGinty, Allan

2006-06-21

216

Aggressive and foraging behavioral interactions among ruffe  

USGS Publications Warehouse

The ruffe, Gymnocephalus cernuus, is a nonindigenous percid in the Great Lakes. Ruffe are aggressive benthivores and forage over soft substrates. Laboratory studies in pools (100 cm in diameter, 15 cm water depth) were conducted to determine whether fish density (low = 2, medium = 4, high = 6 ruffe per pool) changed foraging and aggressive behaviors with a limited food supply of chironomid larvae. All fish densities demonstrated a hierarchy based on aggressive interactions, but ruffe were most aggressive at low and high fish densities. Time spent in foraging was lowest at the low fish density. The best forager at the low fish density was the most aggressive individual, but the second most aggressive fish at the medium and high fish density was the best forager and also the one chased most frequently. A medium fish density offered the best energetic benefits to ruffe by providing the lowest ratio of time spent in aggression to that spent foraging. Based on our results, ruffe should grow best at an intermediate density. With high ruffe densities, we would also expect disparity in size as the more aggressive fish are able to garner a disproportionate amount of the resources. Alternatively, as the Great Lakes are a fairly open system, ruffe could migrate out of one area to colonize another as populations exceed optimal densities.

Savino, Jacqueline F.; Kostich, Melissa J.

2000-01-01

217

Social foragers adopt a riskier foraging mode in the centre of their groups.  

PubMed

Foraging in groups provides many benefits that are not necessarily experienced the same way by all individuals. I explore the possibility that foraging mode, the way individuals exploit resources, varies as a function of spatial position in the group, reflecting commonly occurring spatial differences in predation risk. I show that semipalmated sandpipers (Calidris pusilla), a social foraging avian species, tended to adopt a riskier foraging mode in the central, more protected areas of their groups. Central birds effectively used the more peripheral group members as sentinels, allowing them to exploit a wider range of resources within the same group at the same time. This finding provides a novel benefit of living in groups, which may have a broad relevance given that social foraging species often exploit a large array of resources. PMID:24108674

Beauchamp, Guy

2013-01-01

218

Macronutrient modifications of optimal foraging theory: an approach using indifference curves applied to some modern foragers  

SciTech Connect

The use of energy (calories) as the currency to be maximized per unit time in Optimal Foraging Models is considered in light of data on several foraging groups. Observations on the Ache, Cuiva, and Yora foragers suggest men do not attempt to maximize energetic return rates, but instead often concentration on acquiring meat resources which provide lower energetic returns. The possibility that this preference is due to the macronutrient composition of hunted and gathered foods is explored. Indifference curves are introduced as a means of modeling the tradeoff between two desirable commodities, meat (protein-lipid) and carbohydrate, and a specific indifference curve is derived using observed choices in five foraging situations. This curve is used to predict the amount of meat that Mbuti foragers will trade for carbohydrate, in an attempt to test the utility of the approach.

Hill, K.

1988-06-01

219

Female degus ( Octodon degus ) monitor their environment while foraging socially  

Microsoft Academic Search

Vigilance or scanning involves interruptions in foraging behavior when individuals lift their heads and conduct visual monitoring\\u000a of the environment. Theoretical considerations assume that foraging with the “head down”, and scanning (“head up”) are mutually\\u000a exclusive activities, such that foraging precludes vigilance. We tested this generalization in a socially foraging, small\\u000a mammal model, the diurnal Chilean degu (Octodon degus). We

Verónica Quirici; Rodrigo A. Castro; Javiera Oyarzún; Luis A. Ebensperger

2008-01-01

220

Foraging behavior of individual workers and foraging dynamics of colonies of three Sumatran stingless bees  

Microsoft Academic Search

Summary  The foraging behavior of three stingless bees,Trigona (Tetragonula) minangkabau, T. (Trigonella) moorei andT. (Heterotrigona) itama, was studied to describe patterns of resource harvest in disturbed forest areas in Sumatra, Indonesia.\\u000a \\u000a \\u000a 1. \\u000a \\u000a Average daily total number of foraging flights per colony was 1200 inT. minangkabau, 2400 inT. moorei and 7000 inT. itama and it was proportional to colony population size. Foragers

Tamiji Inoue; Siti Salmah; Idrus Abbas; Erniwati Yusuf

1985-01-01

221

Metabolomics of forage plants: a review  

PubMed Central

Background Forage plant breeding is under increasing pressure to deliver new cultivars with improved yield, quality and persistence to the pastoral industry. New innovations in DNA sequencing technologies mean that quantitative trait loci analysis and marker-assisted selection approaches are becoming faster and cheaper, and are increasingly used in the breeding process with the aim to speed it up and improve its precision. High-throughput phenotyping is currently a major bottle neck and emerging technologies such as metabolomics are being developed to bridge the gap between genotype and phenotype; metabolomics studies on forages are reviewed in this article. Scope Major challenges for pasture production arise from the reduced availability of resources, mainly water, nitrogen and phosphorus, and metabolomics studies on metabolic responses to these abiotic stresses in Lolium perenne and Lotus species will be discussed here. Many forage plants can be associated with symbiotic microorganisms such as legumes with nitrogen fixing rhizobia, grasses and legumes with phosphorus-solubilizing arbuscular mycorrhizal fungi, and cool temperate grasses with fungal anti-herbivorous alkaloid-producing Neotyphodium endophytes and metabolomics studies have shown that these associations can significantly affect the metabolic composition of forage plants. The combination of genetics and metabolomics, also known as genetical metabolomics can be a powerful tool to identify genetic regions related to specific metabolites or metabolic profiles, but this approach has not been widely adopted for forages yet, and we argue here that more studies are needed to improve our chances of success in forage breeding. Conclusions Metabolomics combined with other ‘-omics’ technologies and genome sequencing can be invaluable tools for large-scale geno- and phenotyping of breeding populations, although the implementation of these approaches in forage breeding programmes still lags behind. The majority of studies using metabolomics approaches have been performed with model species or cereals and findings from these studies are not easily translated to forage species. To be most effective these approaches should be accompanied by whole-plant physiology and proof of concept (modelling) studies. Wider considerations of possible consequences of novel traits on the fitness of new cultivars and symbiotic associations need also to be taken into account. PMID:22351485

Rasmussen, Susanne; Parsons, Anthony J.; Jones, Christopher S.

2012-01-01

222

Kinetics of digestion f forage fiber components  

E-print Network

& to 150 q were fabricated into 3. 5 cm by 15 cm open-end. bags, sutured with nylon thread and seams sealed with epoxy glue. Bags were attached to free-floating 13 cm polyethylene spools by O-rings. Ashed? acid-washed asbestos and fO/80 mesh chromosorb... contained ei+her e 2 forage sample or 1 g sample of acid washed, ashed, neu- tral detergent washed asbestos to simulate inert bulk in- cspa'ole of digestion. The forag~ sample gave an indica- tion of digestibility, while the bag containing asbestos gave...

Van Hellen, Russell William

2012-06-07

223

CCIEA PHASE II REPORT 2012: ECOSYSTEM COMPONENTS, FISHERIES COASTAL PELAGICS AND FORAGE COASTAL PELAGICS AND FORAGE FISHES  

E-print Network

C - 374 CCIEA PHASE II REPORT 2012: ECOSYSTEM COMPONENTS, FISHERIES ­ COASTAL PELAGICS AND FORAGE COASTAL PELAGICS AND FORAGE FISHES Sam McClatchie1, Richard D. Brodeur2, John C. Field1, Ed Weber1, Andrew.......................................................................................................................................394 Risk

224

' SNAG CONDITION AND WOODPECKER FORAGING ECOLOGY IN A BOTTOMLAND  

Microsoft Academic Search

we studied woodpecker foraging behavior, snag quality, and surrounding habitat in a bottomland hardwood forest in the Stephen F. Austin Experimental Forest from December 1984 through November 1986. The amount and location of woodpecker foraging excavations indicated that woodpeckers excavated mainly at the well-decayed tops and bases of snags. Woodpeckers preferred to forage on oaks (Quercus spp.) (snags and live

Stephen F. Austin

225

Long-term foraging optimization in northern shovelers  

Microsoft Academic Search

In this paper I attempt to explain the seasonal foraging strategy employed by male northern shovelers (Anas clypeata). Through the use of dynamic-optimization modeling I demonstrate that male shovelers are optimizing total foraging time over the entire summer by foraging heavily when resources (cladocerans) are abundant and utilizing endogenous reserves during times when resources are in short supply. Additionally, I

Paul J. DuBowy

1997-01-01

226

Piping Plover Foraging-Site Selection on the Missouri River  

Microsoft Academic Search

Selection of a foraging site entails costs and benefits which are reflected in survival and reproductive success. We studied Piping Plover ( Charadrius melodus ) foraging-site selection during the breeding season (2001- 2003) on the Missouri River and examined the relationship between site selection and invertebrate abundance in- dices within habitats. Foraging adult plovers selected protected shoreline (inter-sandbar channels, inlets,

D ANIELLE L E F ER; J AMES D. F RASER; ASEY D. K RUSE

227

Soil, Water and Forage Testing Laboratory Nitrogen recommendations applicable for  

E-print Network

Soil, Water and Forage Testing Laboratory Nitrogen recommendations applicable for methods used by laboratory. Nitrogen Soil Fertility Recommendations for Forage Crops 0 2 4 6 8 10 12 14 16 18 20 updated on 3 (ESTABLISHMENT) 40 35 30 25 20 20 15 10 5 0 #12;Soil, Water and Forage Testing Laboratory Nitrogen

228

Sulfur fertilization of wheat and triticale for forage production  

Microsoft Academic Search

Throughout the Great Plains, wheat (Triticurn aestivum L.) is utilized for grain and forage production. Triticale (Triticum aestivum L. x Secale cereale L.) is known for its ability to produce large quantities of high quality forage. With recent improvement in winter hardiness, interest in and acreage of triticale is spreading north in the central Great Plains. The forage production potential

R. L. Feyh; R. E. Lamond; D. A. Whitney; R. G. Sears

1993-01-01

229

Biomimicry of Foraging for Optimization, Control, and Automation  

E-print Network

UNIVERSITY Outline · Philosophy, foraging theory · Chemotactic behavior (foraging strategy) of E. coli (Foraging) Behavior of E. coli · E. coli: Diameter: 1µm, Length: 2µm Figure 4: E. coli bacterium (from [2]). · Can reproduce (split) in 20 min. #12;9 OHIO STATE T . H . E UNIVERSITY 5 E. coli in action... (from C

230

The mechanisms of interference competition: two experiments on foraging waders  

Microsoft Academic Search

Models of population dynamics that include interference competition have often been applied to foraging waders and less so to other foragers, even though these models are, in principle, generally applicable. At present, however, it is still unclear whether interference competition is of importance for foraging waders. To support this idea experimental evidence and knowledge of the mechanisms underlying interference effects

Wouter K. Vahl; Jaap van der Meer; Franz J. Weissing; Diederik van Dullemen; Theunis Piersma

2005-01-01

231

Foraging relationships within a guild of bumble bees  

Microsoft Academic Search

Three species of bumble bees (Bombus spp.) that forage on goldenrod (Solidago spp.) inflorescences were run in pairwise experiments designed to test the effect of one species on another species' foraging. When paired with increasing numbers of a larger species, the smaller species of a pair usually foraged progressively more peripherally in the inflorescences. Larger species did not significantly change

Douglass H. Morse

1982-01-01

232

Foraging for Trust: Exploring Rationality and the Stag Hunt Game  

E-print Network

Foraging for Trust: Exploring Rationality and the Stag Hunt Game Steven O. Kimbrough 565 JMHH "Foraging for Trust: Foraging Rationality and the Stag Hunt Game," PDF at http.) · On the strategy of modeling (in this context) · What are the games? · KISS: Prisoner's Dilemma and Stag Hunt

Kimbrough, Steven Orla

233

Predator foraging behaviour drives food-web topological structure  

Microsoft Academic Search

Summary 1. The structure and dynamics of prey populations are shaped by the foraging behaviours of their predators. Yet, there is still little documentation on how distinct predator foraging types control biodiversity, food-web architecture and ecosystem functioning. 2. We experimentally compared the effects of model fish species of two major foraging types of lake planktivores: a size-selective visual feeder (bluegill),

Xavier Lazzaro; Gérard Lacroix; Benoît Gauzens; Jacques Gignoux; Stéphane Legendre

2009-01-01

234

Overnight memory retention of foraging skills by bumblebees is imperfect  

Microsoft Academic Search

Abstract. Newly emerged bees learn to forage more efficiently as they gain experience. To test the hypothesis that foraging efficiency would increase as bees gain experience during the day, but would decrease after a night, owing to loss of memory, naiveBombus terrestrisbumblebees were allowed to forage on two clusters of artificial flowers of unequal profitabilities during 3 consecutive days. Nectar

TAMAR KEASAR; UZI MOTRO; YOAV SHUR; AVI SHMIDA

1996-01-01

235

Information flow and organization of stingless bee foraging  

Microsoft Academic Search

Stingless bees (Hymenoptera, Apidae, Meliponini) live in populous permanent colonies and face the same problem as other foraging social insects: how to coordinate the worker's actions and respond to the spatio-temporal uncertainties of food availability in their habitat. Here we review the (social) information used by individual foragers and how organized collective foraging emerges from the individual actions. We also

Jacobus C. Biesmeijer; E. Judith Slaa

2004-01-01

236

Loggerhead Shrike (Lanius ludovicianus L) Foraging Patch and Perch Selection  

Microsoft Academic Search

Loggerhead shrikes have disappeared across much of their former range, most likely due to habitat loss. I studied the habitat shrikes prefer for foraging. Shrikes forage from a perch on prey that they see in the surrounding vegetation. When I mowed the vegetation on one side of selected perches, shrikes strongly preferred to forage on the mowed side even though

Miles Becker

2006-01-01

237

Interactions between shoal size and conformity in guppy social foraging  

Microsoft Academic Search

Previous experimental studies have established that shoaling fish forage more effectively in large than small groups. We investigated how shoal size affects the foraging efficiency of laboratory populations of the guppy, Poecilia reticulata, exposed to different foraging tasks. Experiment 1 confirmed the prediction that in open water the first fish and focal fish of larger shoals locate food faster than

Rachel L. Day; Tom MacDonald; Culum Brown; Kevin N. Laland; Simon M. Reader

2001-01-01

238

Density-dependent foraging effort of Deer Mice (Peromyscus maniculatus)  

Microsoft Academic Search

Summary 1. Little is known about how population density affects the foraging behaviour of individuals. Simple models are developed to predict the net effect of density on the quitting-harvest rates of optimal foragers. The theory was tested with experiments that measured the foraging behaviour of free-ranging Deer Mice under control and reduced densities. 2. An increased density of conspecifics may

D. L. Davidson; D. W. Morris

2001-01-01

239

Original article The foraging behaviour of honey bees  

E-print Network

Original article The foraging behaviour of honey bees (Apis mellifera L) and bumble bees (Bombus — The behaviour of honey bees and bumble bees while foraging on cultivated cranberry in southeastern Massachusetts was studied. Bumble bees were much more consistent foragers than are honey bees

Paris-Sud XI, Université de

240

Do cattle egrets gain information from conspecifics when foraging?  

Microsoft Academic Search

We examined whether individual cattle egrets (Bubulcus ibis) base their decisions of where to forage, and how long to stay in a patch, on the behavior of other flock members. Cattle egrets commonly forage in flocks associated with cattle and capture prey at higher rates when they do not share a cow with another egret. Foraging egrets provide cues of

Karen J. Metz; Kent A. Prior; Mark L. Mallory

1991-01-01

241

Seasonal foraging ecology in a forest avifauna of northern Kenya  

Microsoft Academic Search

We studied the avian foraging ecology in a single montane forest of northern Kenya, analysing the pattern of seasonal variation (wet vs. dry period) and its relationship with habitat structure. The foraging behaviour of 28 species was described in terms of four major dimensions (i.e. foraging technique, food substrate, perching site and perching height). Seasonal rainfall produced an increase in

Luca Borghesio; Paola Laiolo

2004-01-01

242

Foraging behavior of browsing ruminants in a heterogeneous landscape  

Microsoft Academic Search

Movement patterns of white-tailed deer (Odocoileus virginianus) and Spanish goats (Carpa hircus) were mapped and analyzed to test the hypothesis that foraging movements and behaviors within an Acacia shrub community are significantly related to environmental heterogeneity. Animal response to plant community heterogeneity was characterized using foraging velocity and the animals' foraging path fractal dimension (Dd). Environmental heterogeneity was characterized using

Matthew J. Etzenhouser; M. Keith Owens; Donald E. Spalinger; S. Blake Murden

1998-01-01

243

Behavioural interaction between fish predators and their prey: effects of plant density  

USGS Publications Warehouse

Prey-specific anti-predatory behaviour under different degrees of structural complexity determines foraging success of predators. The behaviour of piscivorous fish (largemouth bass, Micropterus salmoides and northern pike, Esox lucius) and their prey (bluegills, Lepomis macrochirus, and fathead minnows, Pimephales promelas) were quantified in 60-min experiments in laboratory pools (2 multiplied by 4 m in diameter, 0 multiplied by 5 m deep) with artificial vegetation at densities of 0, 50, 250, and 1000 stems/m2. Largemouth bass switched predatory tactics from searching to ambushing as plant density increased whereas northern pike always used ambushing. At high plant density, both predators captured minnows, but not bluegills. Bluegills modified their behaviour more than minnows in response to predators, thereby avoiding predation at high plant densities. Structural complexity alone did not always provide refuge for prey; prey must use the structure to avoid predators. Predators may seek vegetated areas if appropriate, vulnerable prey are present.

Savino, Jacqueline F.; Stein, Roy A.

1989-01-01

244

Isolation of viral haemorrhagic septicaemia virus from muskellunge, Esox masquinongy (Mitchill), in Lake St Clair, Michigan, USA reveals a new sublineage of the North American genotype.  

PubMed

Viral haemorrhagic septicaemia virus (VHSV) was isolated from muskellunge, Esox masquinongy (Mitchill), caught from the NW portion of Lake St Clair, Michigan, USA in 2003. Affected fish exhibited congestion of internal organs; the inner wall of the swim bladder was thickened and contained numerous budding, fluid-filled vesicles. A virus was isolated using fish cell lines inoculated with a homogenate of kidney and spleen tissues from affected fish. Focal areas of cell rounding and granulation appeared as early as 24 h post-inoculation and expanded rapidly to destroy the entire cell sheet by 96 h. Electron microscopy revealed virions that were 170-180 nm in length by 60-70 nm in width having a bullet-shaped morphology typical of rhabdoviruses. The virus was confirmed as VHSV by reverse transcriptase-polymerase chain reaction. Sequence analysis of the entire nucleoprotein and glycoprotein genes revealed the virus was a member of the North American genotype of VHSV; however, the isolate was sufficiently distinct to be considered a separate sublineage, suggesting its origin may have been from marine species inhabiting the eastern coastal areas of the USA or Canada. PMID:17026670

Elsayed, E; Faisal, M; Thomas, M; Whelan, G; Batts, W; Winton, J

2006-10-01

245

Colony foraging in different species of stingless bees (Apidae, Meliponinae) and the regulation of individual nectar foraging  

Microsoft Academic Search

Summary: For Melipona fasciata, M. beecheii, M. favosa and Tetragonisca angustula we found distinct intergeneric differences in foraging activity patterns. The Melipona species had a longer daily foraging activity period than T. angustula. Pollen foraging patterns of the Melipona species were different from that of T. angustula: Melipona collect pollen earlier in the day. In an experimental habitat without competitors,

L. L. M. de Bruijn; M. J. Sommeijer

1997-01-01

246

Transformation of forage legumes using Agrobacterium tumefaciens  

Microsoft Academic Search

Galls were induced in six species of forage legumes following inoculation with wild-type strains of A. tumefaciens. The plant species was more influential than the bacterial strain in determining the type of tumour produced. Inoculation of Medicago sativa resulted in small, disorganised tumours. The three Trifolium species, T. repens, T. hybridum and T. pratense, formed galls which tended to produce

K. J. Webb

1986-01-01

247

Social organization and foraging in emballonurid bats  

Microsoft Academic Search

1.Five species of emballonurid bats (Rhynchonycteris naso, Saccopteryx leptura, Balantiopteryx plicata, Saccopteryx bilineata, and Peropteryx kappleri), were studied in Costa Rica and Trinidad. Stomach contents suggest that prey size generally increases for bat body size, but within these species there is considerable overlap. R. naso, S. leptura, and P. kappleri each appear to be specialized for foraging in a particular

J. W. Bradbury; S. L. Vehrencamp

1976-01-01

248

Name ___________________________________________ Soil, Water and Forage Testing Laboratory  

E-print Network

Name ___________________________________________ Soil, Water and Forage Testing Laboratory + Micronutrients (Micro) $17 per sample (in addition to Suite 1, DTPA Zn, Fe, Cu, and Mn) 3. R + Micro + Hot Water limestone test) 7. R + Micro + B + Lime + Organic Matter + Sal $74 per sample (in addition to Suite 3, adds

249

Name ___________________________________________ Soil, Water and Forage Testing Laboratory  

E-print Network

Name ___________________________________________ Soil, Water and Forage Testing Laboratory + Micronutrients (Micro) $17 per sample (In addition to suite 1, DTPA Zn, Fe, Cu, and Mn) 3. R + Micro + Hot Water acidity titration test) 7. R + Micro + B + Lime + Organic Matter + Sal $74 per sample (In addition

250

Foraging behaviour in fishes: perspectives on variance  

Microsoft Academic Search

Synopsis The positive relationship between size of prey and frequency of ingestion by predators has been a focal point of investigations in foraging ecology. Field studies compare the frequency distribution of prey sizes in the predator's gut with that in the environment. Laboratory and field (enclosure) studies are based upon comparison of the frequency distributions of prey sizes in controlled

Brian M. Marcotte; Howard I. Browman

1986-01-01

251

Prey processing in central place foragers.  

PubMed

The importance of prey processing as an integral part of foraging behaviour has long been acknowledged, but little theoretical consideration has been given to the optimization of the processing behaviour itself. Processing renders food down to ingestible, palatable portions, and also removes non-essential mass thus reducing transport costs. Here, several models of processing are developed for a central place forager. When the forager has to make a simple choice between processing the prey and not, a critical distance from the central place can be calculated, beyond which it is optimal to process prey. If the forager also decides on how much of the prey to remove, the optimal amount to be removed can also be calculated. Imposing a ceiling on overall metabolic expenditure is shown to reduce the distances at which processing becomes the optimal strategy. The models are tested using parameters derived for a provisioning merlin, Falco columbarius, and alternative explanations as to why observed behaviours should differ from the optimal behaviour predicted are discussed. PMID:10640435

Rands, S A; Houston, A I; Gasson, C E

2000-01-21

252

ADAPTIVENESS OF CATTLE EGRET'S (BUBULCUS IBIS) FORAGING  

Microsoft Academic Search

Cattle Egrets (Bubulcus ibis) feeding in close association with cattle catch insect prey at a significantly higher rate and expend less energy than do those foraging alone. Cattle Egrets once had a strong association with grazing cattle, but have now shifted themselves behind tractors specially in inundated agricultural fields. Captures per minute were 2.06 for the egrets feeding near the

Aeshita Mukherjee

2000-01-01

253

Nitrates and Prussic Acid in Forages  

E-print Network

When nitrates and prussic acid accumulate in forage, the feed may not be safe for livestock consumption. Learn the symptoms of nitrate and prussic acid poisoning and which plants are most likely to pose a risk to livestock. Also learn sampling...

Provin, Tony; Pitt, John L.

2003-01-06

254

BLUE WHALE-SIZED MOUTHFULS MAKE FORAGING  

E-print Network

Inside JEB i BLUE WHALE-SIZED MOUTHFULS MAKE FORAGING SUPER EFFICIENT When a blue whale dives from the University of British Columbia, Canada, explains that blue whales may be able to dive, measuring the energetics of blue whale lunges at depth seemed almost impossible until Shadwick and his

Martin, Paul R.

255

Field and Forage Crop Pests. MEP 310.  

ERIC Educational Resources Information Center

As part of a cooperative extension service series by the University of Maryland, this publication introduces the identification and control of common agricultural pests that can be found in field and forage crops. The first of the five sections defines "pest" and "weed" and generally introduces different kinds of pests in the categories of…

Morgan, Omar, D.; And Others

256

The Dynamics of Infant Visual Foraging  

ERIC Educational Resources Information Center

Human infants actively forage for visual information from the moment of birth onward. Although we know a great deal about how stimulus characteristics influence looking behavior in the first few postnatal weeks, we know much less about the intrinsic dynamics of the behavior. Here we show that a simple stochastic dynamical system acts…

Robertson, Steven S.; Guckenheimer, John; Masnick, Amy M.; Bacher, Leigh F.

2004-01-01

257

What Makes a Competent Adult Forager?  

E-print Network

in humans and see the large human brain and the long juvenile pe- riod as a response to the great amount- and experience- based embodied capital on the development of foraging competency in this community and broader implications for theoretical development and fu- ture research. MODELS OF THE EVOLUTION OF CHILDHOOD

Bock, John

258

The hidden cost of information in collective foraging  

PubMed Central

Many animals nest or roost colonially. At the start of a potential foraging period, they may set out independently or await information from returning foragers. When should such individuals act independently and when should they wait for information? In a social insect colony, for example, information transfer may greatly increase a recruit's probability of finding food, and it is commonly assumed that this will always increase the colony's net energy gain. We test this assumption with a mathematical model. Energy gain by a colony is a function both of the probability of finding food sources and of the duration of their availability. A key factor is the ratio of pro-active foragers to re-active foragers. When leaving the nest, pro-active foragers search for food independently, whereas re-active foragers rely on information from successful foragers to find food. Under certain conditions, the optimum strategy is totally independent (pro-active) foraging because potentially valuable information that re-active foragers may gain from successful foragers is not worth waiting for. This counter-intuitive outcome is remarkably robust over a wide range of parameters. It occurs because food sources are only available for a limited period. Our study emphasizes the importance of time constraints and the analysis of dynamics, not just steady states, to understand social insect foraging. PMID:16087424

Dechaume-Moncharmont, François-Xavier; Dornhaus, Anna; Houston, Alasdair I; McNamara, John M; Collins, Edmund J; Franks, Nigel R

2005-01-01

259

Foraging strategy and predator avoidance behaviour: an intraspecific approach  

NASA Astrophysics Data System (ADS)

Relationships between predator avoidance behaviour (scanning and flocking) and foraging were studied in Calidris alpina, to test predictions regarding the effect of foraging techniques on such behaviours. The scanning hypothesis predicts that individuals with a tactile hunting technique and individuals with a visual hunting technique (both continuous searchers) do not differ in any variable related to scanning behaviour. The flocking hypothesis predicts that visually hunting individuals witl tend to form smaller flocks than tactile-foraging individuals. The two continuous feeding strategies did not differ among individuals in vigilance rate, nor in vigilance time or mean scan duration. However, with respect to flocking behaviour, visual foragers differed from tactile foragers in foraging flock size. The relationships between flocking behaviour and foraging strategy are discussed. The pattern found at the intraspecific level are the same as those found at interspecific level.

Barbosa, Andrés

1997-11-01

260

A Perspective on Forage Production in Canada  

PubMed Central

Over the past decade, the cattle industry has experienced practically a full circle. With the promising beef prices in the early 1970s, with the glut of grain and a generous assist from government incentive programs, the forage acreage and cattle population have increased at a record rate. By 1974, the tide began to turn — grain prices went up sharply and beef prices became sluggish — and by 1976 a major crisis faced the producers. The cattle industry which had been developing on a cheap grain economy was now obliged to rely more on forage for its survival. Unfortunately, the forage was not existent and the only salvation of the industry was the gift of Providence — weather patterns that provided ample moisture conditions and above normal forage crops, the utilization of cereals and the intervention of government cow-calf support programs. Over the past year, the cycle was completed and record beef prices again prevail. The barley bins are full again and the cattlemen are gearing up for a few fat years. Demands for forage seed are brisk and the seeding down of forage acreage is bound to increase substantially over the next few years. And with this increase, cattle population expansion is bound to follow: how much expansion can the economy support? The production cost factors will determine the extent, but one can almost be certain that any expansion will either be modest or of short duration. At least, it should be. If the cattle industry is to establish solid foundations, it cannot be dependent upon the instability of a grain surplus-shortage position. With the present resources and the potential for developing it in direct competition with other crops, one can only expect a small and steady expansion over a long time span. One must agree with the range researchers and specialists of the Canada Research Stations at Lethbridge and Swift Current that pasture and range will continue to be the limiting factors of cattle expansion as they have been for the past 50 years. It is interesting to note that in the Prairie Provinces at least, the number of livestock raised each year has not changed since 1930 although cattle have largely replaced the horses. It is easy to speculate on paper that Canada can double in the next 20 years its forage and cattle production on its large expanses of land on the fringes of the agriculturally settled areas. It is true that these lands, while marginal for cash crops, could produce excellent forage. But at what cost? And what kind of pasture could we grow on them? It is easy to speculate that our livestock geneticists can breed a ruminant-type animal that will feed on poplar saplings and poplar leaves, or develop a new breed of cattle with buffalo vigor that will thrive in the extreme north. But looking at the musk-ox experience in the Northwest Territories and the history of the Wood Buffalo National Park leaves little room for optimism. The present generation is not likely to see in its lifetime the cattle population go beyond the 20 million mark. We can look, however, with good assurance on the present cattle numbers remaining stable and can look forward to gradual increase brought about by normal improvement in both forage and cattle management. Hopefully, both the cattle producer and the veterinarian will be able to reap the benefits of this most important segment of Canada's agricultural industry. PMID:7363269

Gareau, L.

1980-01-01

261

Habitat-specific foraging of prothonotary warblers: Deducing habitat quality  

USGS Publications Warehouse

Foraging behavior often reflects food availability in predictable ways. For example, in habitats where food availability is high, predators should attack prey more often and move more slowly than in habitats where food availability is low. To assess relative food availability and habitat quality, I studied the foraging behavior of breeding Prothonotary Warblers (Protonotaria citrea) in two forest habitat types, cypress-gum swamp forest and coastal-plain levee forest. I quantified foraging behavior with focal animal sampling and continuous recording during foraging bouts. I measured two aspects of foraging behavior: 1) prey attack rate (attacks per minute), using four attack maneuvers (glean, sally, hover, strike), and 2) foraging speed (movements per minute), using three types of movement (hop, short flight [???1 m], long flight [>1 m]). Warblers attacked prey more often in cypress-gum swamp forest than in coastal-plain levee forest. Foraging speed, however, was not different between habitats. I also measured foraging effort (% time spent foraging) and relative frequency of attack maneuvers employed in each habitat; neither of these variables was influenced by forest type. I conclude that Prothonotary Warblers encounter more prey when foraging in cypress-gum swamps than in coastal-plain levee forest, and that greater food availability results in higher density and greater reproductive success for birds breeding in cypress-gum swamp.

Lyons, J.E.

2005-01-01

262

Female degus (Octodon degus) monitor their environment while foraging socially.  

PubMed

Vigilance or scanning involves interruptions in foraging behavior when individuals lift their heads and conduct visual monitoring of the environment. Theoretical considerations assume that foraging with the "head down", and scanning ("head up") are mutually exclusive activities, such that foraging precludes vigilance. We tested this generalization in a socially foraging, small mammal model, the diurnal Chilean degu (Octodon degus). We studied spontaneous bouts of scanning of captive degus when foraging in pairs of female sibs and non-sibs. We examined the extent to which foraging (head down postures) and scanning (head up postures) were mutually exclusive in subjects exposed to none, partial, and complete lateral visual obstruction of their partners. In addition, we monitored the orientation of their bodies to examine the target of attention while foraging and scanning. Lastly, we examined the temporal occurrence of scanning events to assess the extent of scanning coordination, and whether this coordination is kin-biased. Visual obstruction had a significant influence on degu vigilance. Focal degus increased their quadrupedal and semi-erect scanning when foraging under a partially obstructed view of their partners. Degus oriented their bodies toward partners when foraging and scanning. Despite this, degus did not coordinate scanning bouts; instead, they scanned independently from one another. Relatedness among cage mates did not influence any aspect of degu behavior. Contrary to theoretical expectations, these results indicate that foraging and vigilance are not mutually exclusive, and that kinship per se does not influence scanning behavior and coordination. PMID:18214556

Quirici, Verónica; Castro, Rodrigo A; Oyarzún, Javiera; Ebensperger, Luis A

2008-07-01

263

Anterior cingulate cortical lesion attenuates food foraging in rats.  

PubMed

We have developed a novel laboratory rodent model to detect competitive, non-competitive and no-hurdle foraging behaviors as seen in natural environment. However, it is not clear which brain region is important for the food foraging activity. In the present study, we evaluated the effect of lesions in the bilateral anterior cingulate cortex (ACC) on the rat food foraging behavior with the established model. In contrast to the sham lesion group (saline microinjection into the ACC), bilateral complete ACC chemical lesions (kainic acid microinjection into the ACC) significantly decreased the amount of foraged food in the competitive food foraging tests, non-competitive or no-hurdle foraging test. Moreover, the deficit of the food foraging activity was more prominent in the competitive food foraging test than in the non-competitive food and no-hurdle foraging test after ACC lesions. No alterations after ACC lesions were found in other behaviors including elevated plus-maze test (EPM), forced swimming test (FST), open field test (OFT), sucrose preference test and exploratory behavior. These findings suggest that the ACC mediate the food foraging-related behaviors. PMID:22683801

Li, Fang; Li, Mingbo; Cao, Wenyu; Xu, Yang; Luo, Yanwei; Zhong, Xiaolin; Zhang, Jianyi; Dai, Ruping; Zhou, Xin-Fu; Li, Zhiyuan; Li, Changqi

2012-09-01

264

Foraging behaviour in Drosophila larvae: mushroom body ablation.  

PubMed

Drosophila larvae and adults exhibit a naturally occurring genetically based behavioural polymorphism in locomotor activity while foraging. Larvae of the rover morph exhibit longer foraging trails than sitters and forage between food patches, while sitters have shorter foraging trails and forage within patches. This behaviour is influenced by levels of cGMP-dependent protein kinase (PGK) encoded by the foraging (for) gene. Rover larvae have higher expression levels and higher PGK activities than do sitters. Here we discuss the importance of the for gene for studies of the mechanistic and evolutionary significance of individual differences in behaviour. We also show how structure-function analysis can be used to investigate a role for mushroom bodies in larval behaviour both in the presence and in the absence of food. Hydroxyurea fed to newly hatched larvae prevents the development of all post-embryonically derived mushroom body (MB) neuropil. This method was used to ablate MBs in rover and sitter genetic variants of foraging to test whether these structures mediate expression of the foraging behavioural polymorphism. We found that locomotor activity levels during foraging of both the rover and sitter larval morphs were not significantly influenced by MB ablation. Alternative hypotheses that may explain how variation in foraging behaviour is generated are discussed. PMID:11238255

Osborne, K A; de Belle, J S; Sokolowski, M B

2001-02-01

265

The Laurentian Great Lakes strain (MI03) of the viral haemorrhagic septicaemia virus is highly pathogenic for juvenile muskellunge, Esox masquinongy (Mitchill).  

PubMed

The Great Lakes strain of viral haemorrhagic septicaemia virus (VHSV) isolated from adult subclinical muskellunge, Esox masquinongy (Mitchill), in Lake St. Clair, MI, USA was shown to be highly pathogenic in juvenile muskellunge through intraperitoneal (i.p.) injection and waterborne challenge. Mortality began as early as 3 days after exposure in waterborne challenged fish, whereas fish infected by the i.p. route experienced the first mortality by 5 days post-infection (p.i.). The median lethal intraperitoneal injection dose (IP-LD(50)) was approximately 2.21 plaque forming units (PFU) as opposed to the median lethal immersion challenge dose (IM-LD(50)) of 1.7 x 10(4) PFU mL(-1). A high, medium and low dose of infection caused acute, subacute and chronic progression of the disease, respectively, as was evident by the cumulative mortality data. Clinical signs of disease observed in dead and moribund fish were very pale gills, dermal petechial haemorrhages along the flanks, severe nuchal haemorrhages, intramuscular haemorrhages at the fin-muscle junction and focal haemorrhaging on the caudal peduncle. Internal lesions included livers that were pale, discoloured and friable, and kidneys that were either congested or degenerative in appearance, and petechial to ecchymotic haemorrhages on the swim bladder wall. Histopathologic examination demonstrated massive haemorrhages in the swimbladder wall and muscle, severe vacuolation and multifocal necrosis of the liver, multifocal necrosis of the gills and depletion of lymphoid tissues within the spleen. Kidney tissues also exhibited a mixed pattern of degeneration that included tubular necrosis, interstitial oedema and congestion. Virus was recovered from kidney and spleen tissues through tissue culture and reverse transcriptase-polymerase chain reaction (RT-PCR). PMID:20367742

Kim, R K; Faisal, M

2010-06-01

266

Uptake and depletion of plasma 17alpha-methyltestosterone during induction of masculinization in muskellunge, Esox masquinongy: effect on plasma steroids and sex reversal.  

PubMed

Oral administration of 17alpha-methyltestosterone (MT) was used to induce masculinization of sexually undifferentiated muskellunge, Esox masquinongy. Three groups of muskellunge (mean weight, 2.5 +/- 0.6 g) were submitted to MT treatment (15 mg of MT/kg) for 60 days. An additional one group was used as a control (hormone-free diet). Food was distributed over a 10-h period by using automatic belt feeders. Blood was sampled in both control and treated fish at different intervals during and after feeding: before (0 h), at 3 h, 6 h, and cessation of feeding (10 h), and after a fast of 22 h (32 h). MT had no significant effect on growth and survival in muskellunge 6 months after the treatment. Concentrations of plasma MT increased during the feeding period and reached their maximum levels 6 or 10 h after starting feeding. This rapid increase of MT indicated a rapid absorption of this steroid. Plasma MT levels then declined and reached a radir by 22 h after cessation of feeding, suggesting that MT is rapidly metabolized and excreted. The profiles of plasma testosterone during the MT treatment did not differ significantly between control and MT-treated groups. During and after the MT treatment, the concentration of plasma testosterone did not differ significantly between control and MT-treated groups. Moreover, no sexual dimorphism of testosterone levels was observed. Six months after treatment, the sex ratio in MT-treated groups (33% males, 62% females, and 5% intersex) was opposite to control (70% and 30%, respectively) and differed significantly. This suggests that at 15 mg of MT/kg over 60 days, a paradoxical feminization took place. PMID:10493596

Rinchard, J; Dabrowski, K; Garcia-Abiado, M A; Ottobre, J

1999-08-01

267

SEASONAL VARIATION IN THE FORAGING BEHAVIOR OF SOME MIGRATORY WESTERN WOOD WARBLERS  

Microsoft Academic Search

I observed the foraging behavior of four warbler species (Dendroica petechia, Oporornis tolmiei, Geothlypis trichas, and Wilsonia pusilla) in the summer in Wyoming and in the winter in Nayarit, Mxico. Of six variables (absolute foraging height, relative foraging height, vegetation density, horizontal foraging position, feeding method, and foraging substrate) believed to be potentially important in distinguishing the warbler species ecologically,

RICHARD L. HUTTO

268

Explaining variability in Early Paleoindian foraging  

Microsoft Academic Search

We have argued elsewhere [Cannon, M.D., Meltzer, D.J., 2004. Early Paleoindian foraging: examining the faunal evidence for large mammal specialization and regional variability in prey choice. Quaternary Science Reviews 23, 1955–1987] that the North American archaeofaunal record provides little support for the notion that Early Paleoindians across the continent practiced a uniform subsistence strategy focused on the specialized hunting of

Michael D. Cannon; David J. Meltzer

2008-01-01

269

Common Attentional Constraints in Visual Foraging  

PubMed Central

Predators are known to select food of the same type in non-random sequences or “runs” that are longer than would be expected by chance. If prey are conspicuous, predators will switch between available sources, interleaving runs of different prey types. However, when prey are cryptic, predators tend to focus on one food type at a time, effectively ignoring equally available sources. This latter finding is regarded as a key indicator that animal foraging is strongly constrained by attention. It is unknown whether human foraging is equally constrained. Here, using a novel iPad task, we demonstrate for the first time that it is. Participants were required to locate and touch 40 targets from 2 different categories embedded within a dense field of distractors. When individual target items “popped-out” search was organized into multiple runs, with frequent switching between target categories. In contrast, as soon as focused attention was required to identify individual targets, participants typically exhausted one entire category before beginning to search for the other. This commonality in animal and human foraging is compelling given the additional cognitive tools available to humans, and suggests that attention constrains search behavior in a similar way across a broad range of species. PMID:24964082

Kristjansson, Arni; Johannesson, Omar I.; Thornton, Ian M.

2014-01-01

270

Visually Guided Decision Making in Foraging Honeybees  

PubMed Central

Honeybees can easily be trained to perform different types of discrimination tasks under controlled laboratory conditions. This review describes a range of experiments carried out with free-flying forager honeybees under such conditions. The research done over the past 30 or so years suggests that cognitive abilities (learning and perception) in insects are more intricate and flexible than was originally imagined. It has become apparent that honeybees are capable of a variety of visually guided tasks, involving decision making under challenging situations: this includes simultaneously making use of different sensory modalities, such as vision and olfaction, and learning to use abstract concepts such as “sameness” and “difference.” Many studies have shown that decision making in foraging honeybees is highly flexible. The trained animals learn how to solve a task, and do so with a high accuracy, but when they are presented with a new variation of the task, they apply the learnt rules from the earlier setup to the new situation, and solve the new task as well. Honeybees therefore not only feature a rich behavioral repertoire to choose from, but also make decisions most apt to the current situation. The experiments in this review give an insight into the environmental cues and cognitive resources that are probably highly significant for a forager bee that must continually make decisions regarding patches of resources to be exploited. PMID:22719721

Zhang, Shaowu; Si, Aung; Pahl, Mario

2012-01-01

271

Elk winter foraging at fine scale in Yellowstone National Park  

Microsoft Academic Search

The link between landscape properties and foraging decisions by herbivores remains unclear, but such knowledge is central\\u000a to the understanding of plant–herbivore dynamics. Our goal was to determine whether fine-scale foraging paths of free-ranging\\u000a elk (Cervus canadensis) respond to spatial structure of habitats in Yellowstone National Park. During winter 2002 we gathered elk-foraging information\\u000a by following snow tracks in open

Daniel Fortin; Juan M. Morales; Mark S. Boyce

2005-01-01

272

Sex differences in giraffe foraging behavior at two spatial scales  

Microsoft Academic Search

We test predictions about differences in the foraging behaviors of male and female giraffes (Giraffa camelopardalis tippelskirchi Matchie) that derive from a hypothesis linking sexual size dimorphism to foraging behavior. This body-size hypothesis predicts\\u000a that males will exhibit specific behaviors that increase their dry-matter intake rate relative to females. Foraging behavior\\u000a was examined at two hierarchical levels corresponding to two

Tim F. Ginnett; Montague W. Demment

1997-01-01

273

Assessing Habitat for Avian Species in Assessing Habitat for Avian Species in an Integrated Forage/Biofuels an Integrated Forage/Biofuels  

E-print Network

in an Integrated Forage/Biofuels an Integrated Forage/Biofuels Management System Management System in the Midin NWSG mixes beneficial to forage, biofuels production, and wildlife habitatp , 3. identify wildlife habitat benefits associated with varying forage and biofuels management strategies 4. identify optimum

Gray, Matthew

274

Intelligent decisions from the hive mind: Foragers and nectar receivers of Apis mellifera collaborate to optimise active forager numbers.  

PubMed

We present a differential equation-based mathematical model of nectar foraging by the honey bee Apis mellifera. The model focuses on two behavioural classes; nectar foragers and nectar receivers. Results generated from the model are used to demonstrate how different classes within a collective can collaborate to combine information and produce finely tuned decisions through simple interactions. In particular we show the importance of the 'search time' - the time a returning forager takes to find an available nectar receiver - in restricting the forager population to a level consistent with colony-wide needs. PMID:21126525

Edwards, James R; Myerscough, Mary R

2011-02-21

275

The impact of weather on kingbird foraging behavior  

SciTech Connect

Foraging data on Eastern Kingbirds (Tyrannus tyrannus) were collected during the early breeding season in eastern Kansas to test the hypothesis that foraging rate and other aspects of foraging behavior vary with weather. Foraging characteristics of five additional kingbird species were also examined to assess Fitzpatrick's 1980 generalization that kingbirds (Tyrannus spp.) are aerial hawking specialists. In Eastern Kingbirds, total foraging rate was independent of air temperature, cloud cover, wind speed, and time of day, but the rate of aerial hawking varied directly with air temperature and inversely with cloud cover (both P < 0.05). Effects of the two variables were additive. The percentage of foraging movements that were aerial hawks also increased with temperature and declined with cloud cover, and hover-gleaning and perch-to-ground sallying were observed mainly during cloudy weather. Sally (i.e., foraging flight) distance correlated directly with perch height and air temperature, and large insects were captured almost exclusively in long upward or horizontal flights. I interpret these data to indicate that foraging behavior and the capture of large, flying insects depends on weather because of how it affects the activity of insect prey. Foraging data on kingbirds support Fitzpatrick's generalization, but the relative use of aerial hawking varies considerably among species. Resident Tropical Kingbirds (T. melancholicus) are the most specialized foragers, whereas the migrant and widely distributed Eastern Kingbird appears to be the most generalized. Certain habitats also appear to favor the use of particular foraging methods (e.g., outward striking in grasslands, and perch-to-ground sallying in drier, open habitats).

Murphy, M.T. (Museum of Natural History, The University of Kansas, Lawrence, KS 66045)

1987-01-01

276

Behavioural syndrome in a solitary predator is independent of body size and growth rate.  

PubMed

Models explaining behavioural syndromes often focus on state-dependency, linking behavioural variation to individual differences in other phenotypic features. Empirical studies are, however, rare. Here, we tested for a size and growth-dependent stable behavioural syndrome in the juvenile-stages of a solitary apex predator (pike, Esox lucius), shown as repeatable foraging behaviour across risk. Pike swimming activity, latency to prey attack, number of successful and unsuccessful prey attacks was measured during the presence/absence of visual contact with a competitor or predator. Foraging behaviour across risks was considered an appropriate indicator of boldness in this solitary predator where a trade-off between foraging behaviour and threat avoidance has been reported. Support was found for a behavioural syndrome, where the rank order differences in the foraging behaviour between individuals were maintained across time and risk situation. However, individual behaviour was independent of body size and growth in conditions of high food availability, showing no evidence to support the state-dependent personality hypothesis. The importance of a combination of spatial and temporal environmental variation for generating growth differences is highlighted. PMID:22363687

Nyqvist, Marina J; Gozlan, Rodolphe E; Cucherousset, Julien; Britton, J Robert

2012-01-01

277

Downy woodpecker foraging behavior: foraging by expectation and energy intake rate  

Microsoft Academic Search

I describe an artificial patch system that was used to study the foraging behavior of free-roaming downy woodpeckers (Picoides pubescens) in a woodlot in southeastern Michigan. The artificial “patches” used were thin logs into which were drilled small holes to hold food items (bits of sunflower seed kernels). Downy woodpeckers would systematically search the holes of a patch for food

Steven L. Lima

1983-01-01

278

Eye size, foraging methods and the timing of foraging in shorebirds  

Microsoft Academic Search

Summary 1. Birds with large eyes can achieve a greater pupil diameter and\\/or focal length, and hence, all other things being equal, greater visual sensitivity and resolution than birds with small eyes. Thus eye size is predicted to reflect adaptations to ecology. 2. We tested three predictions about the relationships between eye size, foraging method (from wholly visual to tactile

R. J. THOMAS; T. SZEKELY; R. F. POWELL; I. C. CUTHILL

2006-01-01

279

Social foraging in honey bees: how nectar foragers assess their colony's nutritional status  

Microsoft Academic Search

A honey bee colony operates as a tightly integrated unit of behavioral action. One manifestation of this in the context of foraging is a colony's ability to adjust its selectivity among nectar sources in relation to its nutritional status. When a colony's food situation is good, it exploits only highly profitable patches of flowers, but when its situation is poor,

Thomas D. Seeley

1989-01-01

280

Complex scaling behavior in animal foraging patterns  

NASA Astrophysics Data System (ADS)

This dissertation attempts to answer questions from two different areas of biology, ecology and neuroscience, using physics-based techniques. In Section 2, suitability of three competing random walk models is tested to describe the emergent movement patterns of two species of primates. The truncated power law (power law with exponential cut off) is the most suitable random walk model that characterizes the emergent movement patterns of these primates. In Section 3, an agent-based model is used to simulate search behavior in different environments (landscapes) to investigate the impact of the resource landscape on the optimal foraging movement patterns of deterministic foragers. It should be noted that this model goes beyond previous work in that it includes parameters such as spatial memory and satiation, which have received little consideration to date in the field of movement ecology. When the food availability is scarce in a tropical forest-like environment with feeding trees distributed in a clumped fashion and the size of those trees are distributed according to a lognormal distribution, the optimal foraging pattern of a generalist who can consume various and abundant food types indeed reaches the Levy range, and hence, show evidence for Levy-flight-like (power law distribution with exponent between 1 and 3) behavior. Section 4 of the dissertation presents an investigation of phase transition behavior in a network of locally coupled self-sustained oscillators as the system passes through various bursting states. The results suggest that a phase transition does not occur for this locally coupled neuronal network. The data analysis in the dissertation adopts a model selection approach and relies on methods based on information theory and maximum likelihood.

Premachandra, Prabhavi Kaushalya

281

Nutrient-Specific Foraging in Invertebrate Predators  

NASA Astrophysics Data System (ADS)

Many herbivores and omnivores adjust their food selection behavior to regulate the intake of multiple nutrients. Carnivores, however, are generally assumed to optimize the rate of prey capture rather than select prey according to nutrient composition. We showed experimentally that invertebrate predators can forage selectively for protein and lipids to redress specific nutritional imbalances. This selection can take place at different stages of prey handling: The predator may select among foods of different nutritional composition, eat more of a prey if it is rich in nutrients that the predator is deficient in, or extract specific nutrients from a single prey item.

Mayntz, David; Raubenheimer, David; Salomon, Mor; Toft, Søren; Simpson, Stephen J.

2005-01-01

282

Stable Isotopes Confirm Community Patterns in Foraging Among Hawaiian Procellariiformes  

E-print Network

, Ontario, K7L 3N6, Canada *Corresponding author; E-mail: mgreg@sun.ac.za Abstract.--Stable-isotope analysis was to compare community foraging patterns as determined by stable-isotope analysis with tradi- tional studies50 Stable Isotopes Confirm Community Patterns in Foraging Among Hawaiian Procellariiformes

Jones, Ian L.

283

Original article Lignin-carbohydrate complexes in forages  

E-print Network

Original article Lignin-carbohydrate complexes in forages: structure and consequences in the ruminal degradation of cell-wall carbohydrates A Cornu JM Besle P Mosoni, E Grenet INRA-Theix, Unité) Summary ― Lignin-carbohydrate complexes (LCCS) are recognised as key structures in forage

Boyer, Edmond

284

Green Crab (Carcinus maenas) Foraging Efficiency Reduced by Fast Flows  

Microsoft Academic Search

Predators can strongly influence prey populations and the structure and function of ecosystems, but these effects can be modified by environmental stress. For example, fluid velocity and turbulence can alter the impact of predators by limiting their environmental range and altering their foraging ability. We investigated how hydrodynamics affected the foraging behavior of the green crab (Carcinus maenas), which is

Elizabeth M. Robinson; Delbert L. Smee; Geoffrey C. Trussell

2011-01-01

285

Soil, Water and Forage Testing Laboratory Nitrogen recommendations applicable for  

E-print Network

Soil, Water and Forage Testing Laboratory Nitrogen recommendations applicable for methods used by laboratory. Nitrogen Soil Fertility Recommendations for Texas Fiber Crop 0 2 4 6 8 10 12 14 16 18 20 updated 140 130 120 110 100 #12;Soil, Water and Forage Testing Laboratory Nitrogen recommendations applicable

286

Soil, Water and Forage Testing Laboratory Nitrogen recommendations applicable for  

E-print Network

Soil, Water and Forage Testing Laboratory Nitrogen recommendations applicable for methods used by laboratory. Nitrogen Soil Fertility Recommendations for Texas Grain and Row Crops 0 2 4 6 8 10 12 14 16 18 20/A) 295 295 290 285 280 275 275 270 265 260 255 #12;Soil, Water and Forage Testing Laboratory Nitrogen

287

Soil, Water and Forage Testing Laboratory Nitrogen recommendations applicable for  

E-print Network

Soil, Water and Forage Testing Laboratory Nitrogen recommendations applicable for methods used by laboratory. Nitrogen Soil Fertility Recommendations for Texas Vegetable, Nut and Fruit Production 0 2 4 6 8 110 105 100 100 95 90 85 80 80 #12;Soil, Water and Forage Testing Laboratory Nitrogen recommendations

288

Coordinating Beef Cattle Management with the Range Forage Resource  

Microsoft Academic Search

Highlight: Seasonal changes in forage production and quality occur due to climatic factors, principally precipitation. Increased eficiency of livestock production could occur if livestock management were coordinated to the changes that occur in forage quality. Traditionally, calves are born in the spring in much of the western United States. Weaning then occurs sometime in late fall. Manage- ment practices of

MARTIN VAVRA; ROBERT J. RALEIGH

289

Competition in foraging flocks of migrating semipalmated sandpipers  

Microsoft Academic Search

I examined the effect of competitor density on foraging success in staging semipalmated sandpipers (Calidris pusilla) foraging on a burrowing amphipod (Corophium volutator) in each of two study years. Little is known about the effect of competitor density when predation attempts disturb prey,\\u000a causing a temporary decrease in food availability. Controlling for Corophium density and other potentially confounding factors such

Guy Beauchamp

2007-01-01

290

Group size and foraging efficiency in yellow baboons  

Microsoft Academic Search

I studied the foraging behaviour of adults in three different-sized groups of yellow baboons (Papio cynocephalus) at Amboseli National Park in Kenya to assess the relationship between group size and foraging efficiency in this species. Study groups ranged in size from 8 to 44 members; within each group, I collected feeding data for the dominant adult male, the highest ranking

Peter B. Stacey

1986-01-01

291

Using Multilevel Models to Estimate Variation in Foraging Returns  

E-print Network

2014 # Springer Science+Business Media New York 2014 Abstract Distributions of human foraging success returns is complicated by (1) the zero-inflated nature of hunting returns, as many if not most trips fail modeling . Life history Foraging returns vary for many reasons. Prey vary in value and cost. Individual

McElreath, Richard

292

Group foraging by a stream minnow: shoals or aggregations?  

USGS Publications Warehouse

The importance of social attraction in the formation of foraging groups was examined for a stream-dwelling cyprinid, the rosyside dace, Clinostomus funduloides. Dace arrivals and departures at natural foraging sites were monitored and tested for (1) tendency of dace to travel in groups, and (2) dependency of arrival and departure rates on group size. Dace usually entered and departed foraging sites independently of each other. Group size usually affected neither arrival rate nor departure probability. Thus, attraction among dace appeared weak; foraging groups most often resulted from dace aggregating in preferred foraging sites. The strongest evidence of social attraction was during autumn, when dace departure probability often decreased with increasing group size, possibly in response to increased threat of predation by a seasonally occurring predator. Dace also rarely avoided conspecifics, except when an aggressive individual defended a foraging site. Otherwise, there was little evidence of exploitative competition among dace for drifting prey or of foraging benefits in groups, because group size usually did not affect individual feeding rates. These results suggest that the benefits of group foraging demonstrated under laboratory conditions in other studies may not always apply to field conditions.

Freeman, M.C.; Grossman, G.D.

1992-01-01

293

Ant foraging behavior: ambient temperature influences prey selection  

Microsoft Academic Search

When prey of two sizes (6 and 32 mg) were offered in a choice situation to foragers of the ant Formica schaufussi at different ambient temperatures, significantly more workers rejected the smaller prey at low temperatures, whereas at high temperatures workers accepted the less profitable smaller item. Foragers scavenge for arthropod prey over a temperature range of 15–40°C, and increasing

James F. A. Traniello; Marty S. Fujita; Rhys V. Bowen

1984-01-01

294

Testing Optimal Foraging Theory Using Bird Predation on Goldenrod Galls  

ERIC Educational Resources Information Center

All animals must make choices regarding what foods to eat, where to eat, and how much time to spend feeding. Optimal foraging theory explains these behaviors in terms of costs and benefits. This laboratory exercise focuses on optimal foraging theory by investigating the winter feeding behavior of birds on the goldenrod gall fly by comparing…

Yahnke, Christopher J.

2006-01-01

295

Individual variation in winter foraging of black-capped chickadees  

Microsoft Academic Search

Wintering black-capped chickadees (Paridae: Parus atricapillus) in northwestern Massachusetts showed a high degree of individual variation in foraging behavior. After accounting for the effects of different habitats and weather conditions, individual differences comprised 6–17% of the total observed variation in four measures of foraging location and rate of feeding. Differences between age and sex groups were not significant and explained

J. Van Buskirk; D. C. Smith

1989-01-01

296

Factors Affecting Fatty Acid Composition in Forage and Milk  

E-print Network

Factors Affecting Fatty Acid Composition in Forage and Milk Katarina Arvidsson Faculty of Natural in Forage and Milk Abstract The aims of the studies underlying this thesis were to evaluate variations on the FA contents of the milk. Initially, samples of timothy (Phleum pratense L.) were subjected

297

SHORT COMMUNICATION Do inexperienced bumblebee foragers use scent marks  

E-print Network

SHORT COMMUNICATION Do inexperienced bumblebee foragers use scent marks as social information / Published online: 4 June 2011 Ã? Springer-Verlag 2011 Abstract Bumblebees (Bombus spp.) foraging in the field learning shapes the development of this process, in both bumblebees and other bee species. This raises

Chittka, Lars

298

Declines in forage availability for bumblebees at a national scale  

Microsoft Academic Search

We assessed national scale changes in the forage plants of bumblebees in Britain, as a means of providing quantitative evidence for the likely principal cause of declines in bumblebee species. We quantified the relative value of native and long-established plant species as forage (nectar and pollen) resources for bumblebees by collating visitation data from 14 field sites across Britain. Twentieth

Claire Carvell; David B. Roy; Simon M. Smart; Richard F. Pywell; Chris D. Preston; Dave Goulson

2006-01-01

299

Do bumblebees (Hymenoptera: Apidae) really forage close to their nests?  

Microsoft Academic Search

This paper questions whether bumblebees really forage as close to their nests as has commonly been assumed in the bumblebee literature. Three experiments are described that involved marking and reobservation bumblebees. None of these experiments showed any tendency for bumblebees to concentrate their foraging close to (e.g., within 50 m from) the nest. Rather, the results suggested that bumblebees may

W. E. Dramstad

1996-01-01

300

Optimal foraging: Random movement by pollen collecting bumblebees  

Microsoft Academic Search

Two bumblebee species, Bombus bifarius and B. flavifrons, forage randomly with respect to direction when gathering pollen on Potentilla gracilis. Bees avoid revisiting flowers by being able to differentiate recently visited from unvisited flowers. This recognition occurs while bees are flying over open flowers and appears to be a response to the amount of available pollen within flowers. Random foraging

Michael Zimmerman

1982-01-01

301

Comparative Sucrose Responsiveness in Apis mellifera and A. cerana Foragers  

PubMed Central

In the European honey bee, Apis mellifera, pollen foragers have a higher sucrose responsiveness than nectar foragers when tested using a proboscis extension response (PER) assay. In addition, Africanized honey bees have a higher sucrose responsiveness than European honey bees. Based on the biology of the Eastern honey bee, A. cerana, we hypothesized that A. cerana should also have a higher responsiveness to sucrose than A. mellifera. To test this hypothesis, we compared the sucrose thresholds of pollen foragers and nectar foragers in both A. cerana and A. mellifera in Fujian Province, China. Pollen foragers were more responsive to sucrose than nectar foragers in both species, consistent with previous studies. However, contrary to our hypothesis, A. mellifera was more responsive than A. cerana. We also demonstrated that this higher sucrose responsiveness in A. mellifera was not due to differences in the colony environment by co-fostering two species of bees in the same mixed-species colonies. Because A. mellifera foragers were more responsive to sucrose, we predicted that their nectar foragers should bring in less concentrated nectar compared to that of A. cerana. However, we found no differences between the two species. We conclude that A. cerana shows a different pattern in sucrose responsiveness from that of Africanized bees. There may be other mechanisms that enable A. cerana to perform well in areas with sparse nectar resources. PMID:24194958

Yang, Wenchao; Kuang, Haiou; Wang, Shanshan; Wang, Jie; Liu, Wei; Wu, Zhenhong; Tian, Yuanyuan; Huang, Zachary Y.; Miao, Xiaoqing

2013-01-01

302

Food Recruitment Information can Spatially Redirect Employed Stingless Bee Foragers  

E-print Network

Food Recruitment Information can Spatially Redirect Employed Stingless Bee Foragers Daniel Sa a rewarding food patch with high quality food (Seeley et al. 1991). Stingless bees behave similarly. Employed in the stingless bee Scapto- trigona mexicana. Thus, we trained three groups of foragers to three feeders

Nieh, James

303

ORIGINAL PAPER The effect of ambient temperature on forager sound  

E-print Network

temperature in the stingless bee, Melipona panamica Felipe A. L. Contrera & James C. Nieh Received: 6 April # Springer-Verlag 2006 Abstract Foragers of the stingless bees genus Melipona may produce intranidal sounds Thoracic temperature . Stingless bees . Sound production . Foraging . Flight warm-up Introduction

Nieh, James

304

Original article Nectar foraging by stingless bees in Costa Rica  

E-print Network

Original article Nectar foraging by stingless bees in Costa Rica: botanical and climatological; accepted 23 October 1998) Abstract - Nectar foraging by two species of stingless bees, Melipona beecheii are the stingless bees, subfamily Meliponini [8, 9]. Because stingless bees are eusocial and live in large permanent

Paris-Sud XI, Université de

305

Original article Relation between size and foraging range  

E-print Network

Original article Relation between size and foraging range in stingless bees (Apidae, Meliponinae— We estimated the maximum foraging distances of four species of neotropical stingless bees using two indicated by these two methods. Apidae / Meliponinae / stingless bee / flight distance / body size

Boyer, Edmond

306

Meat Production from Forages in the Northeast1  

Microsoft Academic Search

The purposes of this paper were to determine the animal-forage management practices used in the Northeast and to review practices which may increase efficiency of utilization. University agron- omy and animal science specialists and producers in 12 Northeastern states were surveyed by mail questionnaire. Pertinent results are presented and are related to animal-forage management practices which have been developed and

L. L. Wilson; W. C. Stringer

1981-01-01

307

Protein quality of cottontail rabbit forages following range- land disturbance  

Microsoft Academic Search

Seasonal changes in the botanical composition of diets and pro- tein quality of forages consumed by cottontail rabbits (Sylvilagus floridanus) were monitored on disturbed and undisturbed upland hardwood forest-tallgrass prairies in central Oklahoma Our pri- mary objective was to evaluate the seasonal dynamics of levels of selected amino acid nutrients in forages required for mainte- nance, growth, or reproduction, and

D. G. PEITZ; R. L. LOCHMILLER; D. M. LESLIE; D. M. ENGLE

1997-01-01

308

ORIGINAL PAPER Time stress, predation risk and diurnalnocturnal foraging  

E-print Network

time stress. Here we test if size-dependent risk and time constraints on feeding affect the foraging stress. Keywords Predation risk . Growth rate . Life history theory. Body size . Seasonal constraintsORIGINAL PAPER Time stress, predation risk and diurnal­nocturnal foraging trade-offs in larval prey

Gotthard, Karl

309

Use of Active Acoustics to Study Fish and its Forage  

E-print Network

Use of Active Acoustics to Study Fish and its Forage Pacific Islands Fisheries Science Center Acoustics · Fisheries Independent ­ Unbiased by fishing location gear type catchability · Predetermined · Schooling patterns and aggregative behavior · Simultaneous data on fish and its forage #12;Active Acoustics

Hawai'i at Manoa, University of

310

FORAGING SUCCESS AND TREE SPECIES USE IN THE LEAST FLYCATCHER  

Microsoft Academic Search

.,BSTRACT.--I examined the effect of tree species morphology on foraging behavior in a hover-gleaning bird species, the Least Flycatcher (Empidonax minimus). Birds in four breeding territories in northern Wisconsin displayed nonsignificant differences in an index of forag- ing success (S) among four tree species of divergent morphology. However, significant vari- ation in S occurred among the three tree species common

CHRISTOPHER M. ROGERS

311

Ache at the settlement: Contrasts between farming and foraging  

Microsoft Academic Search

The Northern Ache comprise a small continuously interacting population with a shared community history. Full-time hunter-gatherers until recently, they now divide their time between mobile foraging and settled farming. Here we describe adult time allocation at the settlement and contrast it with our previous descriptions of time allocation during foraging periods. We report that at the settlement men and women

Kristen Hawkes; Hillard Kaplan; Kim Hill; Ana Magdalena Hurtado

1987-01-01

312

Sampling Hay Bales and Pastures for Forage Analysis  

E-print Network

Forage analysis helps you know the nutritive value of forage and plan for any supplements that might be needed. To get an accurate analysis, hay and pastures must be sampled properly. In this publication you will learn how to sample both round...

Provin, Tony; Pitt, John L.

2002-05-03

313

Forages for Grazing Animal Health AGRICULTURE IN 2008  

E-print Network

; and isoflavones to mimic estrogenic activity. Genetic transformation of forage plants to express novel bio-active proteins also has potential to impact animal health issues. One exciting possibility is the genetic transformation of a forage crop (grass or legume) to ex- press a novel Bacillus thuringiensis (Bt) crystal

314

FLIGHT STRATEGIES OF MIGRATING OSPREY: FASTING VS. FORAGING  

Microsoft Academic Search

We developed energetics models to predict migration times and fat consumption rates of osprey (Pandion haliaetus) migrating south from their breeding grounds in the Intermountain West of North America. In these models we simulated three migration strategies: fasting, foraging at several mid-migration stopovers (jump strategy) and frequent foraging at stopovers (hop strategy). Because these piscivores appear to migrate predominantly over

GRADY L. CANDLERAND; PATRICIA L. KENNEDY

315

AMMONIATION OR CANE MOLASSES SUPPLEMENTATION OF LOW QUALITY FORAGES 1  

Microsoft Academic Search

Three digestion and two cattle growth studies evaluated ammoniation level or the nutritional value of ammoniated forage relative to nontreated forage plus a molasses-urea supplement. In trial 1, mature limpograss (Hemarthria altissima) was treated with anhydrous ammonia at 0, 2, 3 or 4% of the dry matter (DM), and fed to steers (217 kg) in a digestion trial. Increases (P<.01)

W. F. Brown; J. D. Phillips; D. B. Jones

316

Foraging swarms as Nash equilibria of dynamic games.  

PubMed

The question of whether foraging swarms can form as a result of a noncooperative game played by individuals is shown here to have an affirmative answer. A dynamic game played by N agents in 1-D motion is introduced and models, for instance, a foraging ant colony. Each agent controls its velocity to minimize its total work done in a finite time interval. The game is shown to have a unique Nash equilibrium under two different foraging location specifications, and both equilibria display many features of a foraging swarm behavior observed in biological swarms. Explicit expressions are derived for pairwise distances between individuals of the swarm, swarm size, and swarm center location during foraging. PMID:24122615

Özgüler, Arif Bülent; Yildiz, Aykut

2014-06-01

317

Linking foraging decisions to residential yard bird composition.  

PubMed

Urban bird communities have higher densities but lower diversity compared with wildlands. However, recent studies show that residential urban yards with native plantings have higher native bird diversity compared with yards with exotic vegetation. Here we tested whether landscape designs also affect bird foraging behavior. We estimated foraging decisions by measuring the giving-up densities (GUD; amount of food resources remaining when the final forager quits foraging on an artificial food patch, i.e seed trays) in residential yards in Phoenix, AZ, USA. We assessed how two yard designs (mesic: lush, exotic vegetation; xeric: drought-tolerant and native vegetation) differed in foraging costs. Further, we developed a statistical model to calculate GUDs for every species visiting the seed tray. Birds foraging in mesic yards depleted seed trays to a lower level (i.e. had lower GUDs) compared to birds foraging in xeric yards. After accounting for bird densities, the lower GUDs in mesic yards appeared largely driven by invasive and synanthropic species. Furthermore, behavioral responses of individual species were affected by yard design. Species visiting trays in both yard designs had lower GUDs in mesic yards. Differences in resource abundance (i.e., alternative resources more abundant and of higher quality in xeric yards) contributed to our results, while predation costs associated with foraging did not. By enhancing the GUD, a common method for assessing the costs associated with foraging, our statistical model provided insights into how individual species and bird densities influenced the GUD. These differences we found in foraging behavior were indicative of differences in habitat quality, and thus our study lends additional support for native landscapes to help reverse the loss of urban bird diversity. PMID:22927974

Lerman, Susannah B; Warren, Paige S; Gan, Hilary; Shochat, Eyal

2012-01-01

318

Wood bison population recovery and forage availability in northwestern Canada.  

PubMed

Forage availability was assessed to determine sustainable stocking rates for eight broadly defined vegetation types (Treed Uplands, Treed Lowlands, Mixed Tall Shrub/Sedge, Closed-canopied Willow, and Open-canopied Willow, Meadow, Wetland Grass, Wetland Sedge) for use by wood bison (Bison bison athabascae), a threatened subspecies, in the Canadian boreal forest of northern Alberta. Clip plots (n=108) were used to sample peak availability of herbs and current annual growth of Salix spp. in late summer. Graminoid wetlands dominated by Carex atherodes, Carex aquatilis, Carex utriculata, Scolochloa festucacea, or Calamagrostis stricta produced 1975-4575 kg ha(-1) of fair to good quality forage, whereas treed stands produced < 250 kg ha(-1) of forb-dominated forage (>85% content), which was below a published 25% foraging efficiency threshold of 263 kg ha(-1) for bison. Upland forests that dominate the region produced < or = 1 animal unit day (AUD) of forage per hectare in summer. Most forest understory plants were of poor forage value, suggesting the potential sustainable stocking rate of such areas was actually < or = 0.3 AUD ha(-1), with even lower rates during winter due to snow cover. Herbaceous wetlands contained approximately 78 AUD ha(-1) of forage, but were considered largely unavailable in summer because of flooding and soft organic soils that make access difficult. Conversion of prime foraging habitat to agricultural land, forest expansion due to fire control, and a warmer and wetter climatic regime after the mid-1900s likely contributed to a regional reduction in carrying capacity. It is hypothesized that substantial recovery of the wood bison population toward historical levels will be constrained in northern Alberta by the availability of summer forage, and the limited extent of graminoid wetlands that provide winter foraging habitat. PMID:18191321

Strong, Wayne L; Gates, C Cormack

2009-01-01

319

Linking Foraging Decisions to Residential Yard Bird Composition  

PubMed Central

Urban bird communities have higher densities but lower diversity compared with wildlands. However, recent studies show that residential urban yards with native plantings have higher native bird diversity compared with yards with exotic vegetation. Here we tested whether landscape designs also affect bird foraging behavior. We estimated foraging decisions by measuring the giving-up densities (GUD; amount of food resources remaining when the final forager quits foraging on an artificial food patch, i.e seed trays) in residential yards in Phoenix, AZ, USA. We assessed how two yard designs (mesic: lush, exotic vegetation; xeric: drought-tolerant and native vegetation) differed in foraging costs. Further, we developed a statistical model to calculate GUDs for every species visiting the seed tray. Birds foraging in mesic yards depleted seed trays to a lower level (i.e. had lower GUDs) compared to birds foraging in xeric yards. After accounting for bird densities, the lower GUDs in mesic yards appeared largely driven by invasive and synanthropic species. Furthermore, behavioral responses of individual species were affected by yard design. Species visiting trays in both yard designs had lower GUDs in mesic yards. Differences in resource abundance (i.e., alternative resources more abundant and of higher quality in xeric yards) contributed to our results, while predation costs associated with foraging did not. By enhancing the GUD, a common method for assessing the costs associated with foraging, our statistical model provided insights into how individual species and bird densities influenced the GUD. These differences we found in foraging behavior were indicative of differences in habitat quality, and thus our study lends additional support for native landscapes to help reverse the loss of urban bird diversity. PMID:22927974

Lerman, Susannah B.; Warren, Paige S.; Gan, Hilary; Shochat, Eyal

2012-01-01

320

A flexible model of foraging by a honey bee colony: the effects of individual behaviour on foraging success.  

PubMed

This paper develops and explores a model of foraging in honey bee colonies. The model may be applied to forage sources with various properties, and to colonies with different foraging-related parameters. In particular, we examine the effect of five foraging-related parameters on the foraging response and consequent nectar intake of a homogeneous colony. The parameters investigated affect different quantities critical to the foraging cycle--visit rate (affected by g), probability of dancing (mpd and bpd), duration of dancing (mcirc), or probability of abandonment (A). We show that one parameter, A, affects nectar intake in a nonlinear way. Further, we show that colonies with a midrange value of any foraging parameter perform better than the average of colonies with high- and low-range values, when profitable sources are available. Together these observations suggest that a heterogeneous colony, in which a range of parameter values are present, may perform better than a homogeneous colony. We modify the model to represent heterogeneous colonies and use it to show that the most important effect of heterogeneous foraging behaviour within the colony is to reduce the variance in the average quantity of nectar collected by heterogeneous colonies. PMID:12814601

Cox, Melissa D; Myerscough, Mary R

2003-07-21

321

SYMPOSIUM: IMPROVING FORAGES FOR DAIRY CATTLE The Role of Plant Breeding in Improving the Nutritive Value of Forages 1  

Microsoft Academic Search

In recent years many public forage breeders have added breeding for higher forage quality to their programs. Genetic studies have revealed that improvement of quality traits may be slow because most quality traits have intermediate to low heritability. A reasonable selection scheme under these circumstances would be to progeny test large populations of parental clones over locations, harvests, and generations.

JOHN S. SHENK

322

Foraging Patch Selection and Departure by Non-Omniscient Foragers: A Field Example in White-Fronted Geese  

Microsoft Academic Search

Animals often face great uncertainty as to the quality of foraging pat- ches. There have been a number of theoretical studies investigating how non-omniscient predators, i.e. predators that are unable to assess for- aging patch quality prior to patch exploitation, should forage in a het- erogeneous environment, but empirical studies, especially in the field, are scarce. This paper describes the

Tatsuya Amano; Katsumi Ushiyama; Go Fujita; Hiroyoshi Higuchi

2006-01-01

323

Personality, Foraging and Fitness Consequences in a Long Lived Seabird  

PubMed Central

While personality differences in animals are defined as consistent behavioural variation between individuals, the widely studied field of foraging specialisation in marine vertebrates has rarely been addressed within this framework. However there is much overlap between the two fields, both aiming to measure the causes and consequences of consistent individual behaviour. Here for the first time we use both a classic measure of personality, the response to a novel object, and an estimate of foraging strategy, derived from GPS data, to examine individual personality differences in black browed albatross and their consequences for fitness. First, we examine the repeatability of personality scores and link these to variation in foraging habitat. Bolder individuals forage nearer the colony, in shallower regions, whereas shyer birds travel further from the colony, and fed in deeper oceanic waters. Interestingly, neither personality score predicted a bird’s overlap with fisheries. Second, we show that both personality scores are correlated with fitness consequences, dependent on sex and year quality. Our data suggest that shyer males and bolder females have higher fitness, but the strength of this relationship depends on year quality. Females who forage further from the colony have higher breeding success in poor quality years, whereas males foraging close to the colony always have higher fitness. Together these results highlight the potential importance of personality variation in seabirds and that the fitness consequences of boldness and foraging strategy may be highly sex dependent. PMID:24504180

Patrick, Samantha C.; Weimerskirch, Henri

2014-01-01

324

Crop scents affect the occurrence of trophallaxis among forager honeybees.  

PubMed

Previous evidence indicates that the recognition of the nectar delivered by forager honeybees within the colony may have been a primitive method of communication on food resources. Thus, the association between scent and reward that nectar foragers establish while they collect on a given flower species should be retrieved during trophallaxis, i.e., the transfer of liquid food by mouth, and, accordingly, foraging experience could affect the occurrence of these interactions inside the nest. We used experimental arenas to analyze how crop scents carried by donor bees affect trophallaxis among foragers, i.e., donors and receivers, which differ in their foraging experience. Results showed that whenever the foragers had collected unscented sugar solution from a feeder the presence of scents in the solution carried by donors did not affect the occurrence of trophallaxis nor its dynamics. In contrast, whenever the foragers had previous olfactory information, new scents present in the crop of the donors negatively affected the occurrence, but not the dynamics of trophallaxis. Thus, the association learned at the food source seems to be retrieved during trophallaxis, and it is possible that known scents present in the mouthparts of nest-mates may operate as a triggering stimulus to elicit trophallactic behavior within the hive. PMID:12720034

Gil, M; Farina, W M

2003-05-01

325

Foraging behaviour of Nuthatches (Sitta europaea) in relation to the presence of mates and mixed flocks  

Microsoft Academic Search

Summary Nuthatches (Sitta europaea) usually forage in pairs outside the breeding season. I investigated whether foraging site selection in winter (tree species, height, substrate size) differed between sexes and whether this difference was related to the presence of mixed-species flocks. Foraging sites of pair members foraging together were highly correlated. In the rare cases when each used different tree species,

Erik Matthysen

1999-01-01

326

Group size, foraging, and antipredator ploys: An analysis of bighorn sheep decisions  

Microsoft Academic Search

1.Several aspects of the foraging behavior of California bighorn sheep (Ovis canadensis californiana) were studied in homogeneous habitats in the interior of British Columbia, Canada. The manner in which an individual sheep foraged was based upon the size of group within which it was found.2.In small groups (five or less individuals) sheep foraging efficiency was poor and interruptions of foraging

Joel Berger

1978-01-01

327

Foraging methods can affect patch choice: an experimental study in Mallard ( Anas platyrhynchos)  

Microsoft Academic Search

Animals can adapt to changes in feeding conditions by switching between foraging methods. Dabbling ducks use different foraging methods, including dabbling in deep water with the head and neck submerged, and grubbing in the mud (or shallow water) where the eyes are above the surface, so the bird can visually monitor its environment while foraging. Deep foraging is considered to

Matthieu Guillemain; Hervé Fritz; Sandra Blais

2000-01-01

328

The effect of reproductive condition on the foraging behavior of female hoary bats, Lasiurus cinereus  

Microsoft Academic Search

Female mammals experience larg changes in time and energy budgets associated with reproduction and these may influence the foraging strategies of individuals. I studied the changes in foraging behavior associated with reproduction in female hoary bats, Lasiurus cinereus. As lactation progressed, individuals departed to forage earlier in the evening and spent more time foraging per night and less time roosting

R. M. R. Barclay

1989-01-01

329

Winter foraging behavior of elk in the shrub-steppe of Washington  

SciTech Connect

Numerous models of ungulate foraging behavior have been published, but data on foraging behavior for wild North American ungulates relevant to model testing are scarce. I studied the detailed foraging behavior of elk from autumn through early spring in Washington's shrub-steppe using focal animal sampling and collected corollary data on elk diets, forage quality, and home ranges. I tested the hypotheses that foraging effort is proportional to energetic payoffs determined by the quality and abundance of various forages, and elk home-range size reflects relative foraging movements (i.e., macro and micro movements are related). Elk were mobile foragers during autumn and spring and were relatively sedentary during mid-winter. High mobility was associated with low diet diversity and generally with reduced forage harvesting rates. This mobile foraging occurred during periods of higher quality forage availability. Thus, mobile foraging appeared to reflect increased effort when energetic payoffs of selective foraging were enhanced. Degree of dietary specialization was limited by the relative abundance of preferred forages, being greater when grass quality was high, and less when forb quality was high. Indices of elk movement while foraging were also positively related to home-range size and distance between relocations of radio-collared elk. These data are generally consistent with ungulate foraging model predictions. 34 refs., 4 figs., 2 tabs.

McCorquodale, S.M. (Pacific Northwest Lab., Richland, WA (United States))

1993-01-01

330

FOOD AND PREDATION RISK AS FACTORS RELATED TO FORAGING LOCATIONS OF NORTHERN FLICKERS  

Microsoft Academic Search

Foraging site selection by birds may be related to foraging efficiency, food availability and abundance, and predation risk. We identified selectively used foraging habitat within home ranges of 29 adult radio-tagged Northern Flickers (Colaptes auratus) in British Columbia during the nestling period. We compared habitat characteristics of flicker foraging locations to randomly selected locations in their home range using discriminant

CANDACE L. ELCHUK; KAREN L. WIEBE

2002-01-01

331

Individual Foraging Strategies Reveal Niche Overlap between Endangered Galapagos Pinnipeds  

PubMed Central

Most competition studies between species are conducted from a population-level approach. Few studies have examined inter-specific competition in conjunction with intra-specific competition, with an individual-based approach. To our knowledge, none has been conducted on marine top predators. Sympatric Galapagos fur seals (Arctocephalus galapagoensis) and sea lions (Zalophus wollebaeki) share similar geographic habitats and potentially compete. We studied their foraging niche overlap at Cabo Douglas, Fernandina Island from simultaneously collected dive and movement data to examine spatial and temporal inter- and intra-specific competition. Sea lions exhibited 3 foraging strategies (shallow, intermediate and deep) indicating intra-specific competition. Fur seals exhibited one foraging strategy, diving predominantly at night, between 0–80 m depth and mostly at 19–22 h. Most sea lion dives also occurred at night (63%), between 0–40 m, within fur seals' diving depth range. 34% of sea lions night dives occurred at 19–22 h, when fur seals dived the most, but most of them occurred at dawn and dusk, when fur seals exhibited the least amount of dives. Fur seals and sea lions foraging behavior overlapped at 19 and 21 h between 0–30 m depths. Sea lions from the deep diving strategy exhibited the greatest foraging overlap with fur seals, in time (19 h), depth during overlapping time (21–24 m), and foraging range (37.7%). Fur seals foraging range was larger. Cabo Douglas northwest coastal area, region of highest diving density, is a foraging “hot spot” for both species. Fur seals and sea lions foraging niche overlap occurred, but segregation also occurred; fur seals primarily dived at night, while sea lions exhibited night and day diving. Both species exploited depths and areas exclusive to their species. Niche breadth generally increases with environmental uncertainty and decreased productivity. Potential competition between these species could be greater during warmer periods when prey availability is reduced. PMID:23967096

Villegas-Amtmann, Stella; Jeglinski, Jana W. E.; Costa, Daniel P.; Robinson, Patrick W.; Trillmich, Fritz

2013-01-01

332

Foraging activity is reduced in a mouse model of depression.  

PubMed

Depression interferes with the human ability to make decisions. Multiple criteria have been adopted for the diagnosis of depression in humans, but no clear indicators are available in animal models to reflect the depressive mood, involving higher cognitive functions. The act of foraging is a species-specific behaviour which is believed to involve the decision-making and higher cognitive functions. We previously established a method to detect the foraging behaviour of rodents, in which our results demonstrated that NMDA and dopamine receptors were involved. Conversely, increased NMDA receptors and reduced dopamine have been reported in depression model rodents. However, we hypothesise that foraging activities may also be impaired in depression. To test the theory, we successfully established a mouse model of depression using the chronic unpredictable mild stress (CUMS) paradigm. Most interestingly, the food foraging activity of mice after CUMS was significantly reduced. In addition, the treatment of anti-depressant fluoxetine reversed most depressive symptoms and reduced glial fibrillary associated protein (GFAP) expression in the hippocampus, but was less effective in the reduction of foraging activities. However, clozapine reversed all symptoms of CUMS-exposed mice including reduction of GFAP expression in the hippocampus and impaired foraging activity. Our findings of GFAP expression as a marker to validate the CUMS protocol provide further validation of our hypothesis, that the reduced food foraging is probably a new behavioural finding of depression in which the serotoninergic system could not be singly involved. Our study suggests that NMDA receptors, serotoninergic and dopaminergic systems are differentially involved in these food foraging behaviours. Our data suggest that the foraging test in rodents can be a useful tool to assess the ability of decision-making in depression. PMID:23873577

Yang, C R; Zhang, Z G; Bai, Y Y; Zhou, H Fiona; Zhou, L; Ruan, C S; Li, F; Li, C Q; Zheng, H Y; Shen, L J; Zhou, X F

2014-04-01

333

Transformation of forage legumes using Agrobacterium tumefaciens.  

PubMed

Galls were induced in six species of forage legumes following inoculation with wild-type strains of A. tumefaciens. The plant species was more influential than the bacterial strain in determining the type of tumour produced. Inoculation of Medicago sativa resulted in small, disorganised tumours. The three Trifolium species, T. repens, T. hybridum and T. pratense, formed galls which tended to produce roots and both Onobrychis viciifolia and Lotus corniculatus produced teratomatous galls. The shoots elongated in the latter species only. In L. corniculatus, tissues that were infected by five bacterial strains were capable of shoot regeneration when cultured on a hormone-free medium. The transformed nature of these shoots was confirmed by their failure to root, the production of callus from leaves cultured on hormone-free medium and the presence of opines. PMID:24247771

Webb, K J

1986-04-01

334

Space use by foragers consuming renewable resources  

NASA Astrophysics Data System (ADS)

We study a simple model of a forager as a walk that modifies a relaxing substrate. Within it simplicity, this provides an insight on a number of relevant and non-intuitive facts. Even without memory of the good places to feed and no explicit cost of moving, we observe the emergence of a finite home range. We characterize the walks and the use of resources in several statistical ways, involving the behavior of the average used fraction of the system, the length of the cycles followed by the walkers, and the frequency of visits to plants. Preliminary results on population effects are explored by means of a system of two non directly interacting animals. Properties of the overlap of home ranges show the existence of a set of parameters that provides the best utilization of the shared resource.

Abramson, Guillermo; Kuperman, Marcelo N.; Morales, Juan M.; Miller, Joel C.

2014-05-01

335

Seabird and Forage Fish Research in Alaska  

NSDL National Science Digital Library

The US Geological Survey (USGS)'s Alaska Biological Science Center (ABSC) conducts research in a number of areas, including this research on seabirds and forage fish in Alaska. Organized by topic, the site includes general information on marine animals and ecosystems in Alaska, specific information on ABSC seabird and fish projects (including some methods and results), and several informal 'sketches' of participating scientists. Although of particular interest to the research community, the site simultaneously serves as an excellent example of how scientists study complex ecosystems. By clicking on each "What we learned" icon, viewers may access results of specific projects and explanations of how those results tie into "the bigger picture." Further information on the Alaska Biological Science Center is provided at the ABSC homepage.

336

The Organization of Foraging in the Fire Ant, Solenopsis invicta  

PubMed Central

Although natural selection in ants acts most strongly at the colony, or superorganismal level, foraging patterns have rarely been studied at that level, focusing instead on the behavior of individual foragers or groups of foragers. The experiments and observations in this paper reveal in broad strokes how colonies of the fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), allocate their available labor to foraging, how they disperse that force within their territory, and how this force changes with colony size, season and worker age. Territory area is positively related to colony size and the number of foragers, more so during the spring than fall. Changes of colony size and territory area are driven by seasonal variation of sexual and worker production, which in turn drive seasonal variation of worker age-distribution. During spring sexual production, colonies shrink because worker production falls below replacement. This loss is proportional to colony size, causing forager density in the spring to be negatively related to colony and territory size. In the fall, colonies emphasize worker production, bringing colony size back up. However, because smaller colonies curtailed spring worker production less than larger ones, their fall forager populations are proportionally greater, causing them to gain territory at the expense of large colonies. Much variation of territory area remains unexplained and can probably be attributed to pressure from neighboring colonies. Boundaries between territories are characterized by “no ants' zones” mostly devoid of fire ants. The forager population can be divided into a younger group of recruitable workers that wait for scouts to activate them to help retrieve large food finds. About one-third of the recruits wait near openings in the foraging tunnels that underlie the entire territory, while two-thirds wait in the nest. Recruitment to food is initially very rapid and local from the foraging tunnels, while sustained recruitment gradually involves the recruits waiting in the nest. As recruits age, they become scouts searching for food on the surface, and die about two weeks later. Foraging tunnels decrease in cross-sectional area with distance from the nest, in keeping with the gradual bleeding off of workers to the surface with distance. Foragers lack route-faithfulness, and having been marked and released at one point within the territory, they can be recaptured at any other point a day later. The size of the territory actually occupied may be limited during dry weather, resulting in very large no-ants' zones. PMID:21529150

Tschinkel, Walter R.

2011-01-01

337

Forage production of intraspecific small grain varietal mixtures  

E-print Network

of entries in oat mixture test "A" grown at Temple, Texas, in 1972-73 . 29 Forage yields from four dates of harvest of entries in oat mixture test "A" sown at two seeding rates at Temple, Texas, in 1972-73. Forage yields from four dates of harvest... of entries in oat mixture test "8" grown at Temp 1 e, Te xa s, i n 1972- 73 . 32 Forage yields from four dates of harvest of entries in oat mixture test "8" sown at two seeding rates at Temple, Texas, in 1972-73. 33 LIST OF TABLES (Continued) TABLE PAGE...

Morgan, Thomas Edward

2012-06-07

338

Stature in Holocene foragers of North India.  

PubMed

The Ganga Plain of North India provides an archaeological and skeletal record of semi-nomadic Holocene foragers in association with an aceramic Mesolithic culture. Prior estimates of stature for Mesolithic Lake Cultures (MLC) used inappropriate equations from an American White reference group and need revision. Attention is given to intralimb body proportions and geo-climatic provenance of MLC series in considering the most suitable reference population. Regression equations from ancient Egyptians are used in reconstructing stature for MLC skeletal series from Damdama (DDM), Mahadaha (MDH), and Sarai Nahar Rai (SNR). Mean stature is estimated at between 174 (MDH) and 178 cm (DDM and SNR) for males, and between 163 cm (MDH) and 179 cm (SNR) for females. Stature estimates based on ancient Egyptian equations are significantly shorter (from 3.5 to 7.1 cm shorter in males; from 3.2 to 7.5 cm shorter in females) than estimates using the American White reference group. Revised stature estimates from tibia length and from femur?+?tibia more accurately estimate MLC stature for two reasons: a) these elements are highly correlated with stature and have lower standard estimates of error, and b) uncertainty regarding methods of measuring tibia length is avoided. When compared with Holocene samples of native Americans and Mesolithic Europeans, MLC series from North India are tall. This aspect of their biological variation confirms earlier assessments and results from the synergistic influence of balanced nutrition from broad-spectrum foraging, body-proportions adapted to a seasonally hot and arid climate, and the functional demands of a mobile, semi-nomadic life-style. PMID:24374782

Lukacs, John R; Pal, J N; Nelson, Greg C

2014-03-01

339

Forage Quality and Quantity in Texas: Managing Nutrition in Range Beef Cattle  

E-print Network

&M University System Forage Quality and Quantity in Texas ? Managing Nutrition in Range Beef Cattle Robert K. Lyons, Richard V. Machen and Jerry W. Stuth* Regional Cattle Forage Diet Quality Trends Regional monthly average crude protein and digestibil- ity... used a nutritional analysis system to estimate forage intake, an indicator of forage availability. This system includes 1) NIRS fecal analysis to estimate forage diet quality, 2) the Nutritional Balance Analyzer (NUTBAL PRO) computer software...

Lyons, Robert K.; Machen, Richard V.; Stuth, Jerry W.

2002-09-23

340

Spatial and temporal patterns of resource heterogeneity and foraging behavior  

E-print Network

Movement patterns reflect how an animal responds to aphics. variations in resource distribution, with important implications for management and conservation concerns. Foraging paths and food items provide a unique opportunity to relate movement...

Baum, Kristen Anne

2012-06-07

341

Managing Insect and Mite Pests of Texas Forage Crops  

E-print Network

This publication describes and illustrates common pests of forage crops in Texas. It discusses treatment options and pesticide application techniques as well as specific insecticides labeled to treat specific pests....

Muegge, Mark A.; Robinson, James V.

2002-10-09

342

DYNAPHORE, INC., FORAGER SPONGE TECHNOLOGY - INNOVATIVE TECHNOLOGY EVALUATION REPORT  

EPA Science Inventory

The Forager Sponge is a volume reduction technology in which heavy metal contaminants from an aqueous medium are selectively concentrated into a smaller volume for facilitated disposal. he technology treats contaminated groundwater, surface voters and porous waters by absorbing d...

343

Prescribed Fire Effects on Wintering, Bark-Foraging Birds  

Microsoft Academic Search

We examined effects of prescribed fire on 3 wintering, bark-foraging birds, hairy woodpeckers (Picoides villosus), pygmy nuthatches (Sitta pygmaea), and white-breasted nuthatches (S. carolinensis), in ponderosa pine (Pinus ponderosa) forests of northern Arizona, USA. During winters of 2004-2006, we compared bird density, foraging behavior, and bark beetle activity among burned treatment and unburned control units. Hairy woodpecker density was 5

THERESA L. POPE; WILLIAM M. BLOCK; PAUL BEIER

344

Do naive juvenile seabirds forage differently from adults?  

PubMed

Foraging skills of young individuals are assumed to be inferior to those of adults. The reduced efficiency of naive individuals may be the primary cause of the high juvenile mortality and explain the deferment of maturity in long-lived species. However, the study of juvenile and immature foraging behaviour has been limited so far. We used satellite telemetry to compare the foraging movements of juveniles, immatures and breeding adult wandering albatrosses Diomedea exulans, a species where foraging success is positively influenced by the distance covered daily. We showed that juveniles are able to use favourable winds as soon as the first month of independence, but cover shorter distances daily and spend more time sitting on water than adults during the first two months after fledging. These reduced movement capacities do not seem to be the cause of higher juvenile mortality. Moreover, juveniles almost never restrict their movement to specific areas, as adults and immatures frequently do over shelf edges or oceanic zones, which suggest that the location of appropriate areas is learned through experience. Immatures and adults have equivalent movement capacities, but when they are central place foragers, i.e. when adults breed or immatures come to the colony to display and pair, immatures make shorter trips than adults. The long duration of immaturity in this species seems to be related to a long period of learning to integrate the foraging constraints associated with reproduction and central place foraging. Our results indicate that foraging behaviour of young albatrosses is partly innate and partly learned progressively over immaturity. The first months of learning appear critical in terms of survival, whereas the long period of immaturity is necessary for young birds to attain the skills necessary for efficient breeding without fitness costs. PMID:23926153

Riotte-Lambert, Louise; Weimerskirch, Henri

2013-10-01

345

The forager oral tradition and the evolution of prolonged juvenility.  

PubMed

The foraging niche is characterized by the exploitation of nutrient-rich resources using complex extraction techniques that take a long time to acquire. This costly period of development is supported by intensive parental investment. Although human life history theory tends to characterize this investment in terms of food and care, ethnographic research on foraging skill transmission suggests that the flow of resources from old-to-young also includes knowledge. Given the adaptive value of information, parents may have been under selection pressure to invest knowledge - e.g., warnings, advice - in children: proactive provisioning of reliable information would have increased offspring survival rates and, hence, parental fitness. One way that foragers acquire subsistence knowledge is through symbolic communication, including narrative. Tellingly, oral traditions are characterized by an old-to-young transmission pattern, which suggests that, in forager groups, storytelling might be an important means by which adults transfer knowledge to juveniles. In particular, by providing juveniles with vicarious experience, storytelling may expand episodic memory, which is believed to be integral to the generation of possible future scenarios (i.e., planning). In support of this hypothesis, this essay reviews evidence that: mastery of foraging knowledge and skill sets takes a long time to acquire; foraging knowledge is transmitted from parent to child; the human mind contains adaptations specific to social learning; full assembly of learning mechanisms is not complete in early childhood; and forager oral traditions contain a wide range of information integral to occupation of the foraging niche. It concludes with suggestions for tests of the proposed hypothesis. PMID:21897825

Scalise Sugiyama, Michelle

2011-01-01

346

Small Grains Forage Management and Evaluation in Central Texas  

E-print Network

SMALL GRAINS FORAGE MANAGEMENT AND EVALUATION IN CENTRAL TEXAS A Thesis by AARON MICHAEL FRANKS Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... Aaron Michael Franks ii ABSTRACT Hard Red Winter (HRW) and Soft Red Winter (HRW) wheat classes (Triticum aestivum L.) and oat (Avena sativa L.) are commonly established as a source of winter and spring forage for cattle grazing in many regions...

Franks, Aaron Michael

2013-04-25

347

Do naive juvenile seabirds forage differently from adults?  

PubMed Central

Foraging skills of young individuals are assumed to be inferior to those of adults. The reduced efficiency of naive individuals may be the primary cause of the high juvenile mortality and explain the deferment of maturity in long-lived species. However, the study of juvenile and immature foraging behaviour has been limited so far. We used satellite telemetry to compare the foraging movements of juveniles, immatures and breeding adult wandering albatrosses Diomedea exulans, a species where foraging success is positively influenced by the distance covered daily. We showed that juveniles are able to use favourable winds as soon as the first month of independence, but cover shorter distances daily and spend more time sitting on water than adults during the first two months after fledging. These reduced movement capacities do not seem to be the cause of higher juvenile mortality. Moreover, juveniles almost never restrict their movement to specific areas, as adults and immatures frequently do over shelf edges or oceanic zones, which suggest that the location of appropriate areas is learned through experience. Immatures and adults have equivalent movement capacities, but when they are central place foragers, i.e. when adults breed or immatures come to the colony to display and pair, immatures make shorter trips than adults. The long duration of immaturity in this species seems to be related to a long period of learning to integrate the foraging constraints associated with reproduction and central place foraging. Our results indicate that foraging behaviour of young albatrosses is partly innate and partly learned progressively over immaturity. The first months of learning appear critical in terms of survival, whereas the long period of immaturity is necessary for young birds to attain the skills necessary for efficient breeding without fitness costs. PMID:23926153

Riotte-Lambert, Louise; Weimerskirch, Henri

2013-01-01

348

Socially learned foraging behaviour in wild black bears, Ursus americanus  

Microsoft Academic Search

To date, research on social learning has been limited mainly to only a few taxa in captive or seminatural settings. We undertook a quantitative study of social learning in free-ranging black bears at Sequoia and Yosemite National Parks, U.S.A. from 1995 to 2006. We tested the hypothesis that food-conditioned forag- ing behaviour (foraging on human food in developed areas) by

Rachel Mazur; Victoria Seher

2008-01-01

349

Foraging tactics of two guilds of web-spinning spiders  

Microsoft Academic Search

The foraging behavior of orbweaving and sheetweb weaving guilds of spiders was investigated. Orbweavers move among web-sites frequently, but sheetweb weavers do not. A simple model that examines the adaptive advantages of active foraging and sit-and-wait strategies leads to three predictions: 1) Orbweavers should have a simple decision rule for leaving web-sites, 2) Orbweavers' web-sites should have more variable payoffs

Anthony C. Janetos

1982-01-01

350

Potential digestibilities and digestion kinetics of forage cell wall components  

E-print Network

, 12, 18, 24, 48 and 72 hrs. with common source innocula. Forage and in sitz'o residue composition was analyzed for neutral detergent fiber (NDF); easily hydrolyzable hemicellulose (EHH); difficultly hydrolyzable hemicellulose (DHH); cellulose (C...); and lignin (L) . Between species comparison of forage composition indicated a higher percent neutral detergent extract (cell solubles) and cellulose for Sorghums. The coefficients of digestibility for all fractions were higher for the Sorghums...

Tauskey, William Henry

2012-06-07

351

Foragers of the harvester ant, Pogonomyrmex owyheei : a disposable caste?  

Microsoft Academic Search

1.Exterior workers of the harvester ant, Pogonomyrmex owyheei, were subdivided into forager, defender and refuse worker behavior roles (Fig. 2). Exterior workers comprised approximately 16% of the total colony population with interior workers comprising the remainder.2.An average of less than 10% of the total worker population foraged (Table 1). Studies of role changes comfirmed a general one-way progression from interior

Sanford D. Porter; Clive D. Jorgensen

1981-01-01

352

Waggle Dance Distances as Integrative Indicators of Seasonal Foraging Challenges  

PubMed Central

Even as demand for their services increases, honey bees (Apis mellifera) and other pollinating insects continue to decline in Europe and North America. Honey bees face many challenges, including an issue generally affecting wildlife: landscape changes have reduced flower-rich areas. One way to help is therefore to supplement with flowers, but when would this be most beneficial? We use the waggle dance, a unique behaviour in which a successful forager communicates to nestmates the location of visited flowers, to make a 2-year survey of food availability. We “eavesdropped” on 5097 dances to track seasonal changes in foraging, as indicated by the distance to which the bees as economic foragers will recruit, over a representative rural-urban landscape. In year 3, we determined nectar sugar concentration. We found that mean foraging distance/area significantly increase from springs (493 m, 0.8 km2) to summers (2156 m, 15.2 km2), even though nectar is not better quality, before decreasing in autumns (1275 m, 5.1 km2). As bees will not forage at long distances unnecessarily, this suggests summer is the most challenging season, with bees utilizing an area 22 and 6 times greater than spring or autumn. Our study demonstrates that dancing bees as indicators can provide information relevant to helping them, and, in particular, can show the months when additional forage would be most valuable. PMID:24695678

Couvillon, Margaret J.; Schurch, Roger; Ratnieks, Francis L. W.

2014-01-01

353

Chaos-order transition in foraging behavior of ants.  

PubMed

The study of the foraging behavior of group animals (especially ants) is of practical ecological importance, but it also contributes to the development of widely applicable optimization problem-solving techniques. Biologists have discovered that single ants exhibit low-dimensional deterministic-chaotic activities. However, the influences of the nest, ants' physical abilities, and ants' knowledge (or experience) on foraging behavior have received relatively little attention in studies of the collective behavior of ants. This paper provides new insights into basic mechanisms of effective foraging for social insects or group animals that have a home. We propose that the whole foraging process of ants is controlled by three successive strategies: hunting, homing, and path building. A mathematical model is developed to study this complex scheme. We show that the transition from chaotic to periodic regimes observed in our model results from an optimization scheme for group animals with a home. According to our investigation, the behavior of such insects is not represented by random but rather deterministic walks (as generated by deterministic dynamical systems, e.g., by maps) in a random environment: the animals use their intelligence and experience to guide them. The more knowledge an ant has, the higher its foraging efficiency is. When young insects join the collective to forage with old and middle-aged ants, it benefits the whole colony in the long run. The resulting strategy can even be optimal. PMID:24912159

Li, Lixiang; Peng, Haipeng; Kurths, Jürgen; Yang, Yixian; Schellnhuber, Hans Joachim

2014-06-10

354

Social calls predict foraging success in big brown bats.  

PubMed

Animals foraging in the dark are engaged simultaneously in prey pursuit, collision avoidance, and interactions with conspecifics, making efficient nonvisual communication essential. A variety of birds and mammals emit food-associated calls that inform, attract, or repel conspecifics (e.g.,). Big brown bats (Eptesicus fuscus) are insectivorous aerial hawkers that may forage near conspecifics and are known to emit social calls (e.g.,). Calls recorded in a foraging setting might attract (e.g.,) or repel conspecifics and could denote territoriality or food claiming. Here, we provide evidence that the "frequency-modulated bout" (FMB), a social call emitted only by male bats (exclusively in a foraging context), is used to claim food and is individually distinct. Bats were studied individually and in pairs in a flight room equipped with synchronized high-speed stereo video and audio recording equipment while sex and experience with a foraging task were experimentally manipulated. Male bats emitting the FMB showed greater success in capturing prey. Following FMB emission, interbat distance, diverging flight, and the other bat's distance to the prey each increased. These findings highlight the importance and utility of vocal communication for a nocturnal animal mediating interactions with conspecifics in a fast-paced foraging setting. PMID:24684936

Wright, Genevieve Spanjer; Chiu, Chen; Xian, Wei; Wilkinson, Gerald S; Moss, Cynthia F

2014-04-14

355

Information Foraging in Nuclear Power Plant Control Rooms  

SciTech Connect

nformation foraging theory articulates the role of the human as an 'informavore' that seeks information and follows optimal foraging strategies (i.e., the 'information scent') to find meaningful information. This paper briefly reviews the findings from information foraging theory outside the nuclear domain and then discusses the types of information foraging strategies operators employ for normal and off-normal operations in the control room. For example, operators may employ a predatory 'wolf' strategy of hunting for information in the face of a plant upset. However, during routine operations, the operators may employ a trapping 'spider' strategy of waiting for relevant indicators to appear. This delineation corresponds to information pull and push strategies, respectively. No studies have been conducted to determine explicitly the characteristics of a control room interface that is optimized for both push and pull information foraging strategies, nor has there been empirical work to validate operator performance when transitioning between push and pull strategies. This paper explores examples of control room operators as wolves vs. spiders and con- cludes by proposing a set of research questions to investigate information foraging in control room settings.

R.L. Boring

2011-09-01

356

Sex-specific foraging behaviour in a monomorphic seabird.  

PubMed Central

Sexual differences in the foraging behaviour of parents have been observed in a number of sexually sizedimorphic birds, particularly seabirds, and the usual inference has been that these sex-specific differences are mediated primarily by differences in body size. To test this explanation, we compared the foraging behaviour of parents in a monomorphic seabird species, the northern gannet Morus bassanus. Using specially designed instruments and radio telemetry we found that individuals of both sexes were consistent in the directions and durations of their foraging trips. However, there were significant differences in the foraging behaviour of males and females. Female gannets were not only more selective than males in the areas where they foraged, but they also made longer, deeper dives and spent more time on the sea surface than males. As the sexes are morphologically similar in this species, then these differences are unlikely to have been mediated by body size. Our work highlights the need to investigate sexual differences in the foraging behaviour of seabirds and other species more closely, in order to test alternative theories that do not rely on differences in body size. PMID:12204129

Lewis, S; Benvenuti, S; Dall'Antonia, L; Griffiths, R; Money, L; Sherratt, T N; Wanless, S; Hamer, K C

2002-01-01

357

Waggle dance distances as integrative indicators of seasonal foraging challenges.  

PubMed

Even as demand for their services increases, honey bees (Apis mellifera) and other pollinating insects continue to decline in Europe and North America. Honey bees face many challenges, including an issue generally affecting wildlife: landscape changes have reduced flower-rich areas. One way to help is therefore to supplement with flowers, but when would this be most beneficial? We use the waggle dance, a unique behaviour in which a successful forager communicates to nestmates the location of visited flowers, to make a 2-year survey of food availability. We "eavesdropped" on 5097 dances to track seasonal changes in foraging, as indicated by the distance to which the bees as economic foragers will recruit, over a representative rural-urban landscape. In year 3, we determined nectar sugar concentration. We found that mean foraging distance/area significantly increase from springs (493 m, 0.8 km2) to summers (2156 m, 15.2 km2), even though nectar is not better quality, before decreasing in autumns (1275 m, 5.1 km2). As bees will not forage at long distances unnecessarily, this suggests summer is the most challenging season, with bees utilizing an area 22 and 6 times greater than spring or autumn. Our study demonstrates that dancing bees as indicators can provide information relevant to helping them, and, in particular, can show the months when additional forage would be most valuable. PMID:24695678

Couvillon, Margaret J; Schürch, Roger; Ratnieks, Francis L W

2014-01-01

358

RELATIONSHIPS BETWEEN NUTRITIVE QUALITY AND FIBER COMPONENTS OF COOL SEASON AND WARM SEASON FORAGES:A RETROSPECTIVE STUDY 1  

Microsoft Academic Search

Feeding trials were conducted with 428 forages in three forage classes (C a grasses, legumes, C 4 grasses) fed ad libitum to sheep and with 170 forages fed to cattle over a 20-yr period. Of this total, 153 forages were fed concurrently to sheep and cattle. Where the same forages were fed, mean dry matter digestibility (DMD) and dry matter

R. L. Reid; G. A. Jung; W. V. Thayne

359

Central place foraging by beavers ( Castor canadensis ): a test of foraging predictions and the impact of selective feeding on the growth form of cottonwoods ( Populus fremontii )  

Microsoft Academic Search

Several predictions of central place foraging theory were tested. As predicted, beavers foraged more selectively at increasing distance from the central place. With increasing distance from the river's edge, beavers cut fewer branches and deleted small branches from their diet. Large branches were favored at all distances, which differs from patterns observed in previous studies of beaver foraging. This difference,

Mark A. McGinley; Thomas G. Whitham

1985-01-01

360

Performance and economic analyses of year-round forage systems for forage-fed beef production in the Gulf Coast.  

PubMed

On a global scale, most beef is produced from grazing pastures or rangelands. Certain limitations exist, however, such as not having adequate animal rates of gain for marbling and availability of adequate forage nutritional value and quantity for constant animal weight gains. In the last 20 yr, there has been an increased interest in forage-fed beef for multiple reasons (health related, environmental concerns, and welfare issues). Starting on June 5, 13, 14, and 8 in 4 consecutive yr, 54 steers (initial BW = 259 ± 5.6 kg; average of 9 mo of age) were randomly allotted to 3 yr-round forage systems. Each system occupied 6 ha/replicate and had the same stocking rate. System 1 had annual ryegrass (Lolium multiflorum) for winter grazing and bermudagrass (Cynodon dactylon) for summer grazing; while Systems 2 and 3 added rye and a clover mix to the ryegrass and diversified the use of pastures in the fall (dallisgrass [Paspalum dilatatum] and clovers [Trifolium spp.]). System 3 added the use of annual summer forages. During their respective growing season for each forage or forage mix, mass and height did not limit animal performance; however, there was a sampling date effect (P < 0.05) for nutritive value variables since it decreased as forages became mature. The ADG observed (0.44 kg) for all systems (P = 0.78) during summer was lower than expected and might have been limited by the observed temperature as well as forage nutritive value. Systems 1 and 2 had more grazing days (P = 0.03) during summer (155 and 146 d, respectively) compared to System 3 (132 d) due to the greater pasture area of bermudagrass in those systems. Steers in System 3 were fed more hay for a longer period of time (P < 0.05) than on the other 2 systems. System 1 and 2 produced more hay per hectare than System 3 (P < 0.05). No differences (P > 0.05) were detected between systems in ADG year round, during the winter season, or carcass characteristics. Return over total direct costs and total specified expenses were greater for Systems 1 and 2, while System 3 was the lowest. Hay making and bale sales played a major role in explaining the economic results of this study. Where possible, year-round forage systems are a viable alternative for forage-fed beef production; however, the low gains during summer and forage availability during the transition period when hay is necessary deserve further research to find alternatives to improve productivity during those times of the year. PMID:25367513

Scaglia, G; Rodriguez, J; Gillespie, J; Bhandari, B; Wang, J J; McMillin, K W

2014-12-01

361

Persistence of forage fish ‘hot spots’ and its association with foraging Steller sea lions (Eumetopias jubatus) in southeast Alaska  

NASA Astrophysics Data System (ADS)

Whereas primary and secondary productivity at oceanic 'hotspots' may be a function of upwelling and temperature fronts, the aggregation of higher-order vertebrates is a function of their ability to search for and locate these areas. Thus, understanding how predators aggregate at these productive foraging areas is germane to the study of oceanic hot spots. We examined the spatial distribution of forage fish in southeast Alaska for three years to better understand Steller sea lion ( Eumetopias jubatus) aggregations and foraging behavior. Energy densities (millions KJ/km 2) of forage fish were orders of magnitude greater during the winter months (November-February), due to the presence of schools of overwintering Pacific herring ( Clupea pallasi). Within the winter months, herring consistently aggregated at a few areas, and these areas persisted throughout the season and among years. Thus, our study area was characterized by seasonally variable, highly abundant but highly patchily distributed forage fish hot spots. More importantly, the persistence of these forage fish hot spots was an important characteristic in determining whether foraging sea lions utilized them. Over 40% of the variation in the distribution of sea lions on our surveys was explained by the persistence of forage fish hot spots. Using a simple spatial model, we demonstrate that when the density of these hot spots is low, effort necessary to locate these spots is minimized when those spots persist through time. In contrast, under similar prey densities but lower persistence, effort increases dramatically. Thus an important characteristic of pelagic hot spots is their persistence, allowing predators to predict their locations and concentrate search efforts accordingly.

Gende, Scott M.; Sigler, Michael F.

2006-02-01

362

Comparative digestibility by cattle versus sheep: effect of forage quality.  

PubMed

The objective was to determine the effect of forage quality on apparent total tract digestibility and ruminal fermentation in cattle versus sheep. Five yearling English crossbred (Hereford × Angus) steers (440.4 ± 35.6 kg of initial BW) and 5 yearling whiteface (Rambouillet × Columbia × Debouillet) wethers (44.4 ± 4.6 kg of initial BW), each fitted with a ruminal cannula, were randomly assigned to 1 of 3 forage sources within ruminant specie, and the study was conducted over 3 periods. For forage source, both animal and period served as the blocking factor with all forage sources represented once within each animal and all forage sources represented at least once within each period. The treatment structure was arranged in a 2 × 3 factorial with ruminant species (2) and forage source (3) as the factors. Forage sources were 1) alfalfa hay (Medicago sativa; 17.5% CP and 34.1% NDF, DM basis), 2) warm-season grass hay mix (Bothriochloa ischaemum and Cynodon dactylon; 7.3% CP and 74.7% NDF, DM basis), and 3) lovegrass hay (Eragrostis curvula; 2.5% CP and 81.9% NDF, DM basis). As a percent of BW, steers and wethers consumed similar (P ? 0.06) amounts of forage, and intake was more influenced by forage quality (P < 0.001) than ruminant species (P = 0.35). When expressed per unit of metabolic BW, cattle consumed more (P < 0.001) DM, NDF, and N than sheep. Apparent total tract digestibility was similar among steers and wethers when alfalfa or grass hay was fed, but decreased to a greater extent in wethers when low-quality lovegrass hay was fed (ruminant species × diet interaction, P ? 0.01). Rate (%/h) of ruminal NDF disappearance was greater (P = 0.02) for alfalfa and grass hay than lovegrass, but was not influenced (P = 0.12) by ruminant species. In addition, ruminal DM fill was influenced more (P < 0.01) by forage than by ruminant species (P = 0.07). Steers and wethers had greater (P < 0.01) DM fill from grass hay and lovegrass hay than alfalfa before and 5 h after feeding. Ruminal VFA were generally not influenced (P ? 0.06) by ruminant specie. Results suggest that apparent total tract digestibilities are more similar among ruminant species when moderate- to high-quality forages are evaluated. However, sheep are not an adequate model for cattle when low-quality forages are compared because cattle digest low-quality forages to a greater extent than sheep. Expressing digestibility as digestible intake per unit of BW allows for a wider range of forage qualities to be compared when substituting sheep for cattle. PMID:24663196

Soto-Navarro, S A; Lopez, R; Sankey, C; Capitan, B M; Holland, B P; Balstad, L A; Krehbiel, C R

2014-04-01

363

Specialist Osmia bees forage indiscriminately among hybridizing Balsamorhiza floral hosts.  

PubMed

Pollinators, even floral generalists (=polyleges), typically specialize during individual foraging bouts, infrequently switching between floral hosts. Such transient floral constancy restricts pollen flow, and thereby gene flow, to conspecific flowers in mixed plant communities. Where incipient flowering species meet, however, weak cross-fertility and often similar floral traits can yield mixed reproductive outcomes among pollinator-dependent species. In these cases, floral constancy by polyleges sometimes serves as an ethological mating barrier. More often, their foraging infidelities instead facilitate host introgression and hybridization. Many other bee species are oligolectic (taxonomic specialists for pollen). Oligoleges could be more discriminating connoisseurs than polyleges when foraging among their limited set of related floral hosts. If true, greater foraging constancy might ensue, contributing to positive assortative mating and disruptive selection, thereby facilitating speciation among their interfertile floral hosts. To test this Connoisseur Hypothesis, nesting females of two species of oligolectic Osmia bees were presented with randomized mixed arrays of flowers of two sympatric species of their pollen host, Balsamorhiza, a genus known for hybridization. In a closely spaced grid, the females of both species preferred the larger flowered B. macrophylla, evidence for discrimination. However, both species' females showed no floral constancy whatsoever during their individual foraging bouts, switching randomly between species proportional to their floral preference. In a wider spaced array in which the bouquets reflected natural plant spacing, foraging oligolectic bees often transferred pollen surrogates (fluorescent powders) both between conspecific flowers (geitonogamy and xenogamy) and between the two Balsamorhiza species. The Connoisseur Hypothesis was therefore rejected. Foraging infidelity by these oligolectic Osmia bees will contribute to introgression and hybridization where interfertile species of Balsamorhiza meet and flower together. A literature review reveals that other plant genera whose species hybridize also attract numerous oligolectic bees, providing independent opportunities to test the generality of this conclusion. PMID:21468665

Cane, James H

2011-09-01

364

Effect of forage: concentrate on kinetics of forage fiber digestion in vivo.  

PubMed

With five rumen-fistulated Holstein steers in a Latin square design, we determined the effect of dietary concentrate (0, 20, 40, 60, or 80% cracked corn) on kinetic characteristics influencing forage fiber digestion in vivo. Rate and potential extent of neutral detergent fiber degradation were determined for fescue hay in situ by nylon bag technique. Rate of fiber passage from the rumen was measured by fecal excretion of chromium-mordanted fescue cell walls. Apparent extent of forage fiber digestion was predicted by a model in which fiber disappearance from the rumen is conceptualized as the sum of two competing first-order processes, digestion and passage, modified further by a discrete lag time during which fiber passes from the rumen before digestion commences. Stepwise multiple regression analysis revealed that potential extent of fiber degradation in situ was the primary determinant of depression of fiber digestibility as dietary concentrate increased. Rate of digestion, rate of passage, and lag effects collectively accounted for a small portion of the depression of fiber digestibility. PMID:2984271

Miller, B G; Muntifering, R B

1985-01-01

365

Modelling foraging movements of diving predators: a theoretical study exploring the effect of heterogeneous landscapes on foraging efficiency  

PubMed Central

Foraging in the marine environment presents particular challenges for air-breathing predators. Information about prey capture rates, the strategies that diving predators use to maximise prey encounter rates and foraging success are still largely unknown and difficult to observe. As well, with the growing awareness of potential climate change impacts and the increasing interest in the development of renewable sources it is unknown how the foraging activity of diving predators such as seabirds will respond to both the presence of underwater structures and the potential corresponding changes in prey distributions. Motivated by this issue we developed a theoretical model to gain general understanding of how the foraging efficiency of diving predators may vary according to landscape structure and foraging strategy. Our theoretical model highlights that animal movements, intervals between prey capture and foraging efficiency are likely to critically depend on the distribution of the prey resource and the size and distribution of introduced underwater structures. For multiple prey loaders, changes in prey distribution affected the searching time necessary to catch a set amount of prey which in turn affected the foraging efficiency. The spatial aggregation of prey around small devices (? 9 × 9 m) created a valuable habitat for a successful foraging activity resulting in shorter intervals between prey captures and higher foraging efficiency. The presence of large devices (? 24 × 24 m) however represented an obstacle for predator movement, thus increasing the intervals between prey captures. In contrast, for single prey loaders the introduction of spatial aggregation of the resources did not represent an advantage suggesting that their foraging efficiency is more strongly affected by other factors such as the timing to find the first prey item which was found to occur faster in the presence of large devices. The development of this theoretical model represents a useful starting point to understand the energetic reasons for a range of potential predator responses to spatial heterogeneity and environmental uncertainties in terms of search behaviour and predator–prey interactions. We highlight future directions that integrated empirical and modelling studies should take to improve our ability to predict how diving predators will be impacted by the deployment of manmade structures in the marine environment.

Barton, Kamil A.; Scott, Beth E.; Travis, Justin M.J.

2014-01-01

366

Foraging area fidelity for Kemp's ridleys in the Gulf of Mexico  

PubMed Central

For many marine species, locations of key foraging areas are not well defined. We used satellite telemetry and switching state-space modeling (SSM) to identify distinct foraging areas used by Kemp's ridley turtles (Lepidochelys kempii) tagged after nesting during 1998–2011 at Padre Island National Seashore, Texas, USA (PAIS; N = 22), and Rancho Nuevo, Tamaulipas, Mexico (RN; N = 9). Overall, turtles traveled a mean distance of 793.1 km (±347.8 SD) to foraging sites, where 24 of 31 turtles showed foraging area fidelity (FAF) over time (N = 22 in USA, N = 2 in Mexico). Multiple turtles foraged along their migratory route, prior to arrival at their “final” foraging sites. We identified new foraging “hotspots” where adult female Kemp's ridley turtles spent 44% of their time during tracking (i.e., 2641/6009 tracking days in foraging mode). Nearshore Gulf of Mexico waters served as foraging habitat for all turtles tracked in this study; final foraging sites were located in water <68 m deep and a mean distance of 33.2 km (±25.3 SD) from the nearest mainland coast. Distance to release site, distance to mainland shore, annual mean sea surface temperature, bathymetry, and net primary production were significant predictors of sites where turtles spent large numbers of days in foraging mode. Spatial similarity of particular foraging sites selected by different turtles over the 13-year tracking period indicates that these areas represent critical foraging habitat, particularly in waters off Louisiana. Furthermore, the wide distribution of foraging sites indicates that a foraging corridor exists for Kemp's ridleys in the Gulf. Our results highlight the need for further study of environmental and bathymetric components of foraging sites and prey resources contained therein, as well as international cooperation to protect essential at-sea foraging habitats for this imperiled species. PMID:23919146

Shaver, Donna J; Hart, Kristen M; Fujisaki, Ikuko; Rubio, Cynthia; Sartain, Autumn R; Pena, Jaime; Burchfield, Patrick M; Gamez, Daniel Gomez; Ortiz, Jaime

2013-01-01

367

Foraging area fidelity for Kemp's ridleys in the Gulf of Mexico.  

PubMed

For many marine species, locations of key foraging areas are not well defined. We used satellite telemetry and switching state-space modeling (SSM) to identify distinct foraging areas used by Kemp's ridley turtles (Lepidochelys kempii) tagged after nesting during 1998-2011 at Padre Island National Seashore, Texas, USA (PAIS; N = 22), and Rancho Nuevo, Tamaulipas, Mexico (RN; N = 9). Overall, turtles traveled a mean distance of 793.1 km (±347.8 SD) to foraging sites, where 24 of 31 turtles showed foraging area fidelity (FAF) over time (N = 22 in USA, N = 2 in Mexico). Multiple turtles foraged along their migratory route, prior to arrival at their "final" foraging sites. We identified new foraging "hotspots" where adult female Kemp's ridley turtles spent 44% of their time during tracking (i.e., 2641/6009 tracking days in foraging mode). Nearshore Gulf of Mexico waters served as foraging habitat for all turtles tracked in this study; final foraging sites were located in water <68 m deep and a mean distance of 33.2 km (±25.3 SD) from the nearest mainland coast. Distance to release site, distance to mainland shore, annual mean sea surface temperature, bathymetry, and net primary production were significant predictors of sites where turtles spent large numbers of days in foraging mode. Spatial similarity of particular foraging sites selected by different turtles over the 13-year tracking period indicates that these areas represent critical foraging habitat, particularly in waters off Louisiana. Furthermore, the wide distribution of foraging sites indicates that a foraging corridor exists for Kemp's ridleys in the Gulf. Our results highlight the need for further study of environmental and bathymetric components of foraging sites and prey resources contained therein, as well as international cooperation to protect essential at-sea foraging habitats for this imperiled species. PMID:23919146

Shaver, Donna J; Hart, Kristen M; Fujisaki, Ikuko; Rubio, Cynthia; Sartain, Autumn R; Peña, Jaime; Burchfield, Patrick M; Gamez, Daniel Gomez; Ortiz, Jaime

2013-07-01

368

Foraging in corallivorous butterflyfish varies with wave exposure  

NASA Astrophysics Data System (ADS)

Understanding the foraging patterns of reef fishes is crucial for determining patterns of resource use and the sensitivity of species to environmental change. While changes in prey availability and interspecific competition have been linked to patterns of prey selection, body condition, and survival in coral reef fishes, rarely has the influence of abiotic environmental conditions on foraging been considered. We used underwater digital video to explore how prey availability and wave exposure influence the behavioural time budgets and prey selectivity of four species of obligate coral-feeding butterflyfishes. All four species displayed high selectivity towards live hard corals, both in terms of time invested and frequency of searching and feeding events. However, our novel analysis revealed that such selectivity was sensitive to wave exposure in some species, despite there being no significant differences in the availability of each prey category across exposures. In most cases, these obligate corallivores increased their selectivity towards their most favoured prey types at sites of high wave exposure. This suggests there are costs to foraging under different wave environments that can shape the foraging patterns of butterflyfishes in concert with other conditions such as prey availability, interspecific competition, and territoriality. Given that energy acquisition is crucial to the survival and fitness of fishes, we highlight how such environmental forcing of foraging behaviour may influence the ecological response of species to the ubiquitous and highly variable wave climates of shallow coral reefs.

Noble, Mae M.; Pratchett, Morgan S.; Coker, Darren J.; Cvitanovic, Christopher; Fulton, Christopher J.

2014-06-01

369

Introduced forage species herbage dry matter production and chemical composition at two  

E-print Network

Introduced forage species herbage dry matter production and chemical composition at two moist of introduced forage species whose seed were provided by ILCA's gene bank were evaluated for adaptation and dry

Paris-Sud XI, Université de

370

A mathematical model of foraging in a dynamic environment by trail-laying Argentine ants.  

PubMed

Ants live in dynamically changing environments, where food sources become depleted and alternative sources appear. Yet most mathematical models of ant foraging assume that the ants' foraging environment is static. Here we describe a mathematical model of ant foraging in a dynamic environment. Our model attempts to explain recent empirical data on dynamic foraging in the Argentine ant Linepithema humile (Mayr). The ants are able to find the shortest path in a Towers of Hanoi maze, a complex network containing 32,768 alternative paths, even when the maze is altered dynamically. We modify existing models developed to explain ant foraging in static environments, to elucidate what possible mechanisms allow the ants to quickly adapt to changes in their foraging environment. Our results suggest that navigation of individual ants based on a combination of one pheromone deposited during foraging and directional information enables the ants to adapt their foraging trails and recreates the experimental results. PMID:22575583

Ramsch, Kai; Reid, Chris R; Beekman, Madeleine; Middendorf, Martin

2012-08-01

371

Neuronal mechanism for acute mechanosensitivity in tactile-foraging waterfowl.  

PubMed

Relying almost exclusively on their acute sense of touch, tactile-foraging birds can feed in murky water, but the cellular mechanism is unknown. Mechanical stimuli activate specialized cutaneous end organs in the bill, innervated by trigeminal afferents. We report that trigeminal ganglia (TG) of domestic and wild tactile-foraging ducks exhibit numerical expansion of large-diameter mechanoreceptive neurons expressing the mechano-gated ion channel Piezo2. These features are not found in visually foraging birds. Moreover, in the duck, the expansion of mechanoreceptors occurs at the expense of thermosensors. Direct mechanical stimulation of duck TG neurons evokes high-amplitude depolarizing current with a low threshold of activation, high signal amplification gain, and slow kinetics of inactivation. Together, these factors contribute to efficient conversion of light mechanical stimuli into neuronal excitation. Our results reveal an evolutionary strategy to hone tactile perception in vertebrates at the level of primary afferents. PMID:25246547

Schneider, Eve R; Mastrotto, Marco; Laursen, Willem J; Schulz, Vincent P; Goodman, Jena B; Funk, Owen H; Gallagher, Patrick G; Gracheva, Elena O; Bagriantsev, Sviatoslav N

2014-10-14

372

The M?ller-Lyer Illusion in Ant Foraging  

PubMed Central

The Müller-Lyer illusion is a classical geometric illusion in which the apparent (perceived) length of a line depends on whether the line terminates in an arrow tail or arrowhead. This effect may be caused by economic compensation for the gap between the physical stimulus and visual fields. Here, we show that the Müller-Lyer illusion can also be produced by the foraging patterns of garden ants (Lasius niger) and that the pattern obtained can be explained by a simple, asynchronously updated foraging ant model. Our results suggest that the geometric illusion may be a byproduct of the foraging process, in which local interactions underlying efficient exploitation can also give rise to global exploration, and that visual information processing in human could implement similar modulation between local efficient processing and widespread computation. PMID:24349117

Sakiyama, Tomoko; Gunji, Yukio-Pegio

2013-01-01

373

Decision making in ant foragers ( Lasius niger ) facing conflicting private and social information  

Microsoft Academic Search

Foragers of many ant species use pheromone trails to guide nestmates to food sources. During foraging, individual workers\\u000a can also learn the route to a food source. Foragers of the mass-recruiting ant Lasius niger use both pheromone trails and memory to locate a food source. As a result, an experienced forager can have a conflict between\\u000a social information (trail pheromones)

Christoph Grüter; Tomer J. Czaczkes; Francis L. W. Ratnieks

2011-01-01

374

Spatio-temporal ranging behaviour and its relevance to foraging strategies in wide-ranging wolverines  

Microsoft Academic Search

Conservation of carnivores in an increasingly changing environment is greatly helped by understanding the decision-making processes underlying habitat patch choice. Foraging theory may give us insight into spatio-temporal search patterns and consequent foraging decisions that carnivores make in heterogeneous and fluctuating environments. Constraints placed on central-place foragers in particular are likely to influence both foraging decisions and related spatio-temporal movement

Roel May; Jiska van Dijk; Arild Landa; Roy Andersen; Reidar Andersen

2010-01-01

375

Does Foraging Behaviour Affect Female Mate Preferences and Pair Formation in Captive Zebra Finches?  

PubMed Central

Background Successful foraging is essential for survival and reproductive success. In many bird species, foraging is a learned behaviour. To cope with environmental change and survive periods in which regular foods are scarce, the ability to solve novel foraging problems by learning new foraging techniques can be crucial. Although females have been shown to prefer more efficient foragers, the effect of males' foraging techniques on female mate choice has never been studied. We tested whether females would prefer males showing the same learned foraging technique as they had been exposed to as juveniles, or whether females would prefer males that showed a complementary foraging technique. Methodology/Principal Findings We first trained juvenile male and female zebra finches (Taeniopygia guttata) to obtain a significant proportion of their food by one of two foraging techniques. We then tested whether females showed a preference for males with the same or the alternative technique. We found that neither a male's foraging technique nor his foraging performance affected the time females spent in his proximity in the mate-choice apparatus. We then released flocks of these finches into an aviary to investigate whether assortative pairing would be facilitated by birds taught the same technique exploiting the same habitat. Zebra finches trained as juveniles in a specific foraging technique maintained their foraging specialisation in the aviary as adults. However, pair formation and nest location were random with regard to foraging technique. Conclusions/Significance Our findings show that zebra finches can be successfully trained to be foraging specialists. However, the robust negative results of the conditions tested here suggest that learned foraging specializations do not affect mate choice or pair formation in our experimental context. PMID:21179514

Boogert, Neeltje J.; Bui, Cavina; Howarth, Krista; Giraldeau, Luc-Alain; Lefebvre, Louis

2010-01-01

376

Foraging site use and interspecific competition between bluegills and golden shiners  

Microsoft Academic Search

Laboratory experiments examined the foraging performances of a dietary generalist, bluegill,Lepomis macrochirus, and a dietary specialist, golden shiner,Notemigonus crysoleucas, as they fed from devices simulating four foraging sites (bottom substrate, water column, submerged macrophytes, and water surface). Fishes foraged in monospecific and mixed-species groups of two and four individuals. For monospecific groups, foraging rates of bluegills did not differ among

Cynthia A. Paszkowski

1986-01-01

377

Contrafreeloading in grizzly bears: implications for captive foraging enrichment.  

PubMed

Although traditional feeding regimens for captive animals were focused on meeting physiological needs to assure good health, more recently emphasis has also been placed on non-nutritive aspects of feeding. The provision of foraging materials to diversify feeding behavior is a common practice in zoos but selective consumption of foraging enrichment items over more balanced "chow" diets could lead to nutrient imbalance. One alternative is to provide balanced diets in a contrafreeloading paradigm. Contrafreeloading occurs when animals choose resources that require effort to exploit when identical resources are freely available. To investigate contrafreeloading and its potential as a theoretical foundation for foraging enrichment, we conducted two experiments with captive grizzly bears (Ursus arctos horribilis). In Experiment 1, bears were presented with five foraging choices simultaneously: apples, apples in ice, salmon, salmon in ice, and plain ice under two levels of food restriction. Two measures of contrafreeloading were considered: weight of earned food consumed and time spent working for earned food. More free than earned food was eaten, with only two bears consuming food extracted from ice, but all bears spent more time manipulating ice containing salmon or apples than plain ice regardless of level of food restriction. In Experiment 2, food-restricted bears were presented with three foraging choices simultaneously: apples, apples inside a box, and an empty box. Although they ate more free than earned food, five bears consumed food from boxes and all spent more time manipulating boxes containing apples than empty boxes. Our findings support the provision of contrafreeloading opportunities as a foraging enrichment strategy for captive wildlife. PMID:19816856

McGowan, Ragen T S; Robbins, Charles T; Alldredge, J Richard; Newberry, Ruth C

2010-01-01

378

Elk winter foraging at fine scale in Yellowstone National Park.  

PubMed

The link between landscape properties and foraging decisions by herbivores remains unclear, but such knowledge is central to the understanding of plant-herbivore dynamics. Our goal was to determine whether fine-scale foraging paths of free-ranging elk (Cervus canadensis) respond to spatial structure of habitats in Yellowstone National Park. During winter 2002 we gathered elk-foraging information by following snow tracks in open habitats located on hillsides and flat terrain. The 21 snow paths surveyed were comprised on average of 15 discrete snow craters connected to each other by relatively straight-line movements. Our analyses revealed two levels of selection: elk chose where to dig, and how much search effort to allocate at digging sites based on habitat characteristics. On hillsides, elk preferentially dug in areas of greater biomass of grasses and forbs, and simply walked through poorer sites without digging. Individuals also searched more intensively, creating larger craters, where food biomass was higher. On flat terrain, crater size decreased with snow depth and increased with snow density. Correlated random walk models usually were adequate to characterize elk movement on flat terrain, but not on hillsides. First, as the number of movements between local foraging areas increased, elk displacements on hillsides became shorter than expected from random patterns. This trend on hillsides was strongly influenced by interindividual variation in movement behavior. Second, elk tended to forage perpendicularly to aspect, resulting in horizontal displacements. Our study demonstrates that free-ranging elk adjust their foraging to fine-scale habitat structure. PMID:15965755

Fortin, Daniel; Morales, Juan M; Boyce, Mark S

2005-09-01

379

Determinants of habitat use in large roach  

Microsoft Academic Search

In this study gillnet catches of large roach Rutilus rutilus and their potential predators, large perch Perca fluviatilis, pikeperch Sander lucioperca and pike Esox lucius, in combination with data on food resources and abiotic variables were used to reveal the variables influencing the habitat use of large roach in Lake Großer Vatersee. The occurrence of large roach was negatively coupled

T. Schulze; H. Dörner; F. Hölker; T. Mehner

2006-01-01

380

The relationship between piscivory and growth of white sucker ( Catostomus commersoni ) and yellow perch ( Perca flavescens ) in headwater lakes of the Canadian Shield  

Microsoft Academic Search

We used data from a survey of 36 headwater lakes of the Canadian Shield to investigate the relationship between piscivory and growth, abundance, and longevity of white sucker (Catostomus commersoni) and yellow perch (Perca flavescens). The occurrence of northern pike (Esox lucius) and walleye (Sander vitreus) explained variations in the abundance of both white sucker and yellow perch, suggesting strong

Andrea Bertolo; Pierre Magnan

2005-01-01

381

Mercury evolution (1978–1988) in fishes of the La Grande hydroelectric complex, Quebec, Canada  

Microsoft Academic Search

From 1978 to 1988, the evolution of the Hg content of fish has been monitored in the areas affected by the La Grande hydroelectric\\u000a complex. Four fish species were considered: two non piscivorous, lake whitefish (Coregonus clupeaformis) and longnose sucker (Catostomus catostomus), and two piscivorous, northern pike (Esox lucius) and walleye (Stizostedion vitreum). The evolution of Hg concentrations in time

R. Verdon; D. Brouard; C. Demers; R. Lalumiere; M. Laperle; R. Schetagne

1991-01-01

382

Über die Muster ninhydrinpositiver Substanzen im Muskelgewebe von Knochenfischen  

Microsoft Academic Search

Summary The free ninhydrimeactive substances have been estimated by column chromatography in the white lateral body muscles of the following fishes: 6 mirror carps (Cyprinus carpio, L.), 3 tenches (Tinca vulgaris, Cuv.), 3 rainbowtrouts (Salmo gairdneri, R.), 3 pikes (Esox lucius, L), 4 eels (Anguilla anguilla, L.),14 cods (Gadus morrhua, L.), 3 haddocks (Gadus aeglefinus, L.), 3 coalfishes (Gadus virens,

W. Partmann; H. Schlaszus

1973-01-01

383

An Overview of Northern Pike Regulations in North America  

Microsoft Academic Search

Northern pike (Esox lucius) is a popular sport fish in the United States and Canada that is currently managed for multiple angler uses. However, there has been increased concern over lower quality (i.e., smaller fish) northern pike populations. In 1997, the Esocid Technical Committee (ETC) of the North Central Division of the American Fisheries Society surveyed natural resource agencies about

Craig P. Paukert; Joel A. Klammer; Rodney B. Pierce; Timothy D. Simonson

2001-01-01

384

Construct Mechanical Pike and Tow Tank Chengcheng Feng  

E-print Network

Construct Mechanical Pike and Tow Tank Chengcheng Feng Faculty Mentor: Professor Yahya Modarres-Sadeghi, Mechanical and Industrial Engineering Biomimicry offers valuable solutions to engineering problems through observing nature. The aim of this project is to examine the mechanisms of a northern pike, esox lucius fast

Mountziaris, T. J.

385

Relation between trophic position and mercury accumulation among fishes from the Tongue River Reservoir, Montana  

Microsoft Academic Search

Concentrations of total mercury were determined in muscle tissue from northern pike (Esox lucius), sauger (Stizostedion canadense), walleye (S. vitreum), black crappie (Pomoxis nigromaculatus), and white crappie (P. annularis) collected from the Tongue River Reservoir, Montana, prior to extensive surface coal-mine development in the region. Mercury concentrations in fish flesh increased with fish size and age; larger individuals of all

Glenn R. Phillips; Thomas E. Lenhart; Richard W. Gregory

1980-01-01

386

Fish Community Responses to the Introduction of Muskellunge in Minnesota Lakes  

Microsoft Academic Search

Abstract—We evaluated responses of seven ,fish species to muskellunge ,by comparing catch per unit effort (CPUE) before and after muskellunge ,were stocked in 41 Minnesota lakes composed of 12 lake classes. The species examined were: northern pike Esox lucius, walleye Sander vitreus, yellow perch Perca flavescens, bluegill Lepomis macrochirus, black crappie Pomoxis nigromaculatus, white sucker Catostomus commersoni, and tullibee Core-

Michael L. Knapp; Steven W. Mero; David J. Bohlander; David F. Staples; E. Hwy; Grand Rapids

387

Trends in Abundance and Mean Size of Fish Captured in Gill Nets from Minnesota Lakes, 1983–1997  

Microsoft Academic Search

We investigated seasonal and 15-year trends in catch per unit effort (CPUE) and mean weight of black crappies Pomoxis nigromaculatus, ciscoes Coregonus artedi, northern pike Esox lucius, walleyes Sander vitreus (formerly Stizostedion vitreum), white suckers Catostomus commersoni, and yellow perch Perca flavescens captured in gill nets from 433 Minnesota lakes between 1983 and 1997. Seasonal trends were modeled using least-squares

Gerold C. Grant; Yaniv Schwartz; Sanford Weisberg; Dennis H. Schupp

2004-01-01

388

Seasonal Variation in Catch Rate and Body Condition for Four Fish Species in a South Dakota Natural Lake  

Microsoft Academic Search

Seasonal variation in catch rate (catch per unit effort, CPUE) and body condition (relative weight, Wr) for northern pike Esox lucius, black crappie Pomoxis nigromaculatus, yellow perch Perca flavescens, and walleye Stizostedion vitreum sampled with trap (modified fyke) nets was evaluated in Lake Madison, a natural lake in eastern South Dakota, from March through October, 1990. Seasonal variation in CPUE

Christopher S. Guy; David W. Willis

1991-01-01

389

Some Factors Influencing Seasonal Changes in Angler Catch in a Minnesota Lake  

Microsoft Academic Search

An investigation was undertaken in a small Minnesota lake to determine the relationship between angler success for northern pike (Esox lucius), bluegill (Lepomis macrochirus), and crappie (Pomoxis nigromaculatus) and food availability and food selectivity by these species. Fishing success was determined by creel census and food selectivity by stomach analysis of angler-caught fish. Food availability was determined by bottom sampling

Fred E. Lux; Lloyd L. Smith Jr

1960-01-01

390

LES CELLULES DE SERTOLI DES POISSONS TLOSTENS  

E-print Network

Salvelinus fontinalis HENDERSON (1962) qualifie également les cellules de la paroi des lobules de « lobules'espace extralobulaire). Il s'agit de : Esox lucius, Salvelinus willughbü et Labeo (MARSH!,r, et LOFTS, ig56 ; LOFTS et

Paris-Sud XI, Université de

391

The role of olfaction in chemosensory-based predator recognition in the fathead minnow, Pimephales promelas  

Microsoft Academic Search

Solitary fathead minnows (Pimephales promelas) were rendered anosmic and exposed to chemical stimuli from a predatory northern pike (Esox lucius) to determine the role of olfaction in the minnow's ability to recognize predators on the basis of chemical stimuli. Anosmic fish did not respond to the pike stimuli with a typical fright reaction, while control fish, with intact olfactory receptors,

Douglas P. Chivers; R. Jan F. Smith

1993-01-01

392

Journal of Chemical Ecology, Vol. 23, No. 1, 1997 LEARNED RECOGNITION OF PREDATION RISK BY  

E-print Network

minnows (Pimephales promelas). The response to injured fathead minnows was not a general response). European minnows (Phoxinus phoxinus), fathead minnows (Pimephales promelas), and brook stick- leback promelas, northern pike, Esox lucius. *To whom correspondence should be addressed at Center for Ecology

Wisenden, Brian D.

393

Damselfly larvae learn to recognize predators from chemical cues in the predator's diet  

Microsoft Academic Search

Chemosensory recognition of predators by naive prey may be facilitated if the predator's diet chemically ‘labels’ the predator. In a laboratory experiment, behaviour patterns were quantified in individual damselfly larvae,Enallagmaspp., that had never been exposed to pike,Esox lucius, before and after exposing the damselflies to one of three chemical stimuli: water from a tank that held pike fed a diet

DOUGLAS P. CHIVERS; BRIAN D. WISENDEN; R. JAN F. SMITH

1996-01-01

394

Comparison of mercury and methylmercury in northern pike and Arctic grayling from western Alaska rivers  

Microsoft Academic Search

In western Alaska, mercury (Hg) could be a potential health risk to people whose diet is primarily fish-based. In 2000, total Hg (THg) and methylmercury (MeHg) were examined in northern pike (Esox lucius) and Arctic grayling (Thymallus arcticus) from two watersheds in western Alaska, the Yukon and Kuskokwim rivers. Whitefish (Coregonus sp.) were also examined from the Kuskokwim River. Pike

Stephen C. Jewett; Xiaoming Zhang; A. Sathy Naidu; John J. Kelley; Doug Dasher; Lawrence K. Duffy

2003-01-01

395

Comparison of dietary mercury exposure in two sympatric top predator fishes, largemouth bass and northern pike: a bioenergetics modeling approach  

Microsoft Academic Search

Physical and ecological factors, including lake temperature, fish physiology, and diet, influence methylmercury (MeHg) exposure in fish. We employed bioenergetics modeling to compare dietary MeHg exposure in sympatric top predators, largemouth bass (Micropterus salmoides) and northern pike (Esox lucius). We compared simulations using field data to hypothetical simulations with (1) ± 25% change in mean daily lake temperature for juvenile

Nicole K. MacRury; Brian D. S. Graeb; Brett M. Johnson; William H. Clements

2002-01-01

396

Ranking Predatory Threats by Nonnative Fishes in the Yampa River, Colorado, via Bioenergetics Modeling  

Microsoft Academic Search

Because of its relatively natural hydrograph, the Yampa River, Colorado, is considered the crown jewel of native fish habitat in the upper basin of the Colorado River and has supported a relatively intact native fish assemblage. Nonnative fishes are thought to pose the greatest threat to native fishes in this system. Removal programs for nonnative northern pike Esox lucius and

Brett M. Johnson; Patrick J. Martinez; John A. Hawkins; Kevin R. Bestgen

2008-01-01

397

Using Bioenergetics Modeling to Estimate Consumption of Native Juvenile Salmonids by Nonnative Northern Pike in the Upper Flathead River System, Montana  

Microsoft Academic Search

Introductions of nonnative northern pike Esox lucius have created recreational fisheries in many waters in the United States and Canada, yet many studies have shown that introduced northern pike may alter the composition and structure of fish communities through predation. We estimated the abundance of nonnative northern pike (2002–2003) and applied food habits data (1999–2003) to estimate their annual consumption

Clint C. Muhlfeld; David H. Bennett; R. Kirk Steinhorst; Brian Marotz; Matthew Boyer

2008-01-01

398

Biological Methylation of Mercury in Aquatic Organisms  

Microsoft Academic Search

FRESHWATER fish, especially pike (Esox lucius), from Sweden sometimes contain abnormally large amounts of mercury1. It was initially concluded to be either inorganic mercury or phenyl mercury, which are known to be released as industrial wastes, but later it was shown that the mercury was present almost entirely as methyl mercury (CH3Hg+)2. A possible explanation is that living organisms have

S. Jensen; A. JERNELÖV

1969-01-01

399

Genetic Divergence among Northern Pike from Spawning Locations in the Upper St. Lawrence River  

Microsoft Academic Search

To assess the ecological consequences associated with the degradation of riparian wetlands that historically provided spawning and rearing habitat for northern pike Esox lucius, annual spawning migrations and genetic structure were used to examine this species' dependence on four specific spawning areas in the Thousand Islands region of the Saint Lawrence River. Tagging and recapture over three consecutive spawning seasons

Aaron Bosworth; John M. Farrell

2006-01-01

400

Growth and Relative Size of Calcified Structures of Fish  

Microsoft Academic Search

The relationship between size of calcified structures and the body of fish has been used widely in fisheries science to estimate body size at a younger age by “back-calculation.” I labeled the calcified tissue of northern pike Esox lucius with tetracycline to examine the concurrent linear growth of calcified structures and the body. I also conducted comparisons of the sizes

John M. Casselman

1990-01-01

401

Masculinization of Northern Pike Fry Using the Steroid 11 ?-Hydroxyandrostenedione  

Microsoft Academic Search

Morphological and histological studies of gonads demonstrated that 11 ?-hydroxyandrostenedione (11 ?-HA) can be used to control the phenotypic sex in northern pike Esox lucius. Oral administration of 11 ?-HA (30 mg\\/kg pelleted food) to northern pike juveniles (average total length ± SD = 2.80 ± 0.18 cm) for 2 weeks resulted in sex reversal of most of the females

Krystyna Demska-Zakes; Jaroslaw Krol; Marek J. Luczynski; Konrad Dabrowski; Miroslaw Luczynski

2000-01-01

402

Electrofishing Catchability of Walleyes, Largemouth Bass, Smallmouth Bass, Northern Pike, and Muskellunge in Wisconsin Lakes  

Microsoft Academic Search

We sought to determine whether electrofishing catchability was density dependent and varied with physical and biological factors for walleyes Sander vitreus, largemouth bass Micropterus salmoides, smallmouth bass M. dolomieu, northern pike Esox lucius, and muskellunge E. masquinongy in Wisconsin lakes. Electrofishing catch rate (number of fish caught per shoreline mile) was linearly related to population density (number of fish per

Casey W. Schoenebeck; Michael J. Hansen

2005-01-01

403

Effects of exposure to predatory cues on territorial behaviour of male fathead minnows  

Microsoft Academic Search

We conducted a laboratory study to determine if male fathead minnows, Pimephales promelas, altered their territorial behaviour associated with reproduction in response to combinations of visual and chemical cues from northern pike, Esox lucius. We introduced the following stimuli to a territorial male: a brick (control), fathead minnow alarm pheromone, a pike fed brook stickleback, Culea inconstans, or a pike

Hilary M. Jones; Cynthia A. Paszkowski

1997-01-01

404

Qualitative indices of edible and inedible products obtained from fish in the lower Yenisei River basin  

Microsoft Academic Search

The results of biochemical investigations of samples of products obtained from burbot (Lota lota L.), perch (Perca fluviatilis L.), and pike (Esox lucius L.) inhabiting the lower reaches of the Yenisei River basin are given. Biologically active substances—macro- and microelements,\\u000a fatty acids, amino acids, and vitamins—are analyzed.

A. A. Gnedov; A. A. Kaizer

2010-01-01

405

Oviduct Insertion of Radio Transmitters as a Means of Locating Northern Pike Spawning Habitat  

Microsoft Academic Search

I inserted radio transmitters into the oviducts of northern pike Esox lucius in an attempt to find their spawning grounds. Oviduct insertion of miniature radio transmitters was quick and easy. I hoped that transmitters would be expelled with the eggs to aid in identifying critical habitat used for egg deposition. Ten transmitters were implanted in the egg masses of female

Rodney B. Pierce

2004-01-01

406

Response of the residential piscivorous fish community to introduction of a new predator type in a mesotrophic lake  

Microsoft Academic Search

Although the effects of introduced predators on prey populations in aquatic ecosystems have been studied frequently, less is known about the interactions between predators. We performed a whole-lake experiment by stocking a non-native top predator (pikeperch (Sander lucioperca)) to two residential piscivores (Eurasian perch (Perca fluviatilis) and northern pike (Esox lucius)). By analyzing spatial distribution, diet composition, growth, and consump-

Torsten Schulze; Ulrich Baade; Hendrik Dörner; Reiner Eckmann; Susanne S. Haertel-Borer; Franz Hölker; Thomas Mehner

2006-01-01

407

Walleye and Northern Pike: Boost or Bane to Northwest Fisheries?  

E-print Network

of these species in the northwestern United States and outline some approaches for evaluating risks and benefits popularity of nonnative walleye (Stizostedion vit- reum) and northern pike (Esox lucius) as sport fishes has, while state agencies have ini- tiated detailed environmental re- views to evaluate risks and benefits

McMahon, Thomas E.

408

Reactions of Gammarus lacustris to Chemical Stimuli from Natural Predators and Injured Conspecifics  

Microsoft Academic Search

We exposed the freshwater amphipod Gammarus lacustris, to chemical stimuli from injured conspecifics and to chemical stimuli from two types of natural predators: dragonfly larvae (Aeshna eremita) and northern pike (Esox lucius). Exposure to all three stimuli caused G. lacustris to reduce significantly its level of activity relative to activity recorded in response to a distilled water control. The similarity

Karen Wudkevich; Brian D. Wisenden; Douglas P. Chivers; R. Jan F. Smith

1997-01-01

409

Littoral Fish Community Response to Smallmouth Bass Removal from an Adirondack Lake  

E-print Network

littoral fish abundance, we removed 47,682 smallmouth bass Micropterus dolomieu from a 271-ha Adirondack 1999). Previous observational studies have shown that introductions of smallmouth bass Micropterus dolo- mieu, largemouth bass M. salmoides, and northern pike Esox lucius have been associated

Kraft, Clifford E.

410

Interactions between Walleyes and Four Fish Species with Implications for Walleye Stocking  

Microsoft Academic Search

We used a number of different data sets and four criteria to evaluate evidence of competition and predation between walleye Sander vitreus and northern pike Esox lucius, muskellunge E. masquinongy, smallmouth bass Micropterus dolomieu, and largemouth bass M. salmoides in northern Wisconsin lakes. The four criteria were as follows: (1) indices of population abundance were inversely related, (2) two species

Andrew H. Fayram; Michael J. Hansen; Timothy J. Ehlinger

2005-01-01

411

A BroadScale Approach to Management of Ontario's Recreational Fisheries  

Microsoft Academic Search

Sustainable exploitation of Ontario's aquatic resources calls for a new management approach. This vast resource includes more than 250,000 lakes and offers angling opportunities for many popular species (e.g., walleye Sander vitreus (formerly Stizostedion vitreum), lake trout Salvelinus namaycush, brook trout S. fontinalis, northern pike Esox lucius, smallmouth bass Micropterus dolomieu, largemouth bass M. salmoides, and muskellunge E. masquinongy). In

Nigel P. Lester; Terry R. Marshall; Kim Armstrong; Warren I. Dunlop; Bev Ritchie

2003-01-01

412

Auto-Clustering Using Particle Swarm Optimization and Bacterial Foraging  

NASA Astrophysics Data System (ADS)

This paper presents a hybrid approach for clustering based on particle swarm optimization (PSO) and bacteria foraging algorithms (BFA). The new method AutoCPB (Auto-Clustering based on particle bacterial foraging) makes use of autonomous agents whose primary objective is to cluster chunks of data by using simplistic collaboration. Inspired by the advances in clustering using particle swarm optimization, we suggest further improvements. Moreover, we gathered standard benchmark datasets and compared our new approach against the standard K-means algorithm, obtaining promising results. Our hybrid mechanism outperforms earlier PSO-based approaches by using simplistic communication between agents.

Olesen, Jakob R.; Cordero H., Jorge; Zeng, Yifeng

413

Factors determining grazed forage intake of Coastal bermudagrass  

E-print Network

were significantly correlated (r = . 91, P & . 001), with esophageal IVDOM for grazer means ranging from 66. 0 + 1, 5! to 40. 9 + 4, 1;!. The mean of ingested forage was 11. 3 percentage units more digestible than that of available forage, with A... to plot areas: 38. 5 + 2. 9, 17. 5 + . 9, 11. 7 + . 9, 10. 8 + 1. 6, and 4. 3 + . 5 kg DM/100 kg BW for the . 040 to . 005 ha plot-series, respectively, and showed standing crop to be similar for the five plot-series. Digestibility of Esophageal...

Davis, James Vollie

2012-06-07

414

Foraging behaviour and echolocation in the rufous horseshoe bat ( Rhinolophus rouxi ) of Sri Lanka  

Microsoft Academic Search

In October 1984 foraging areas and foraging behaviour of the rufous horseshoe bat, Rhinolophus rouxi, were studied around a nursery colony on the hill slopes of Sri Lanka. The bats only foraged in dense forest and were not found in open woodlands (Fig. 1). This strongly supports the hypothesis that detection of fluttering prey is by pure tone echolocation within

G. Neuweiler; W. Metzner; U. Heilmann; R. Riibsamen; M. Eckrich; H. H. Costa

1987-01-01

415

ASSESSING EFFECTS OF PREDATION RISK ON FORAGING BEHAVIOR OF MULE DEER  

Microsoft Academic Search

We applied optimal foraging theory to test effects of habitat and predation risk on foraging behavior of mule deer (Odocoileus hemionus) subject to predation by mountain lions (Puma concolor). We predicted that deer would spend less time foraging, have higher giving-up densities of food (GUDs), and have higher vigilance behavior when occupying patch edges than when in open and forest

Kelly B. Altendorf; John W. Laundré; Carlos A. López González; Joel S. Brown

2001-01-01

416

FORBEEF: A Forage-Livestock System Computer Model Used as a Teaching Aid for Decision Making.  

ERIC Educational Resources Information Center

Describes the development of a computer simulation model of forage-beef production systems, which is intended to incorporate soil, forage, and animal decisions into an enterprise scenario. Produces a summary of forage production and livestock needs. Cites positive assessment of the program's value by participants in inservice training workshops.…

Stringer, W. C.; And Others

1987-01-01

417

A test of simultaneous and successive negative contrast in fallow deer foraging behaviour  

E-print Network

A test of simultaneous and successive negative contrast in fallow deer foraging behaviour ULRIKA; MS. number: 8932R) The study of contrast investigates how rewards influence behaviour when animals, no direct experimental tests of contrast effects in foraging by mammalian herbivores exist. During foraging

Leimar, Olof

418

Rodent foraging is affected by indirect, but not by direct, cues of predation risk  

Microsoft Academic Search

We used foraging trays to determine whether oldfield mice, Peromyscus polionotus, altered foraging in response to direct cues of predation risk (urine of native and nonnative predators) and indirect cues of predation risk (foraging microhabitat, precipitation, and moon illumination). The proportion of seeds remaining in each tray (a measure of the giving-up density [GUD]) was used to measure risk perceived

John L. Orrock; Brent J. Danielson; R. Jory Brinkerhoffb; R. Brinkerhoff; Jory

2004-01-01

419

The influence of social interactions on the foraging path of Bewick's Swans Cygnus columbianus bewickii  

Microsoft Academic Search

The efficiency in which high-density food patches are found is determined by the way foragers move between patches. In this study we explore the effect of social interactions on the foraging path, in particular the distance moved between patches. We studied Bewick¿s Swans Cygnus columbianus bewickii that foraged on belowground tubers of Fennel Pondweed Potamogeton pectinatus. We accurately mapped the

R. H. G. Klaassen; B. A. Nolet; D. Bankert

2006-01-01

420

Wing wear affects wing use and choice of floral density in foraging bumble bees  

Microsoft Academic Search

Damage to structures that enable mobility can potentially influence foraging behavior. Bumble bees vary in extent of individual wing wear, a trait predicted to affect mechanical performance during foraging. This study asks 1) do bumble bees distribute themselves across different floral densities in accordance with their concurrent wing wear? and 2) does wing use in foraging bumble bees depend on

Danusha J. Foster; Ralph V. Cartar

2011-01-01

421

The influence of reproductive status on foraging by hoary marmots ( Marmota caligata )  

Microsoft Academic Search

Predictions were made and tested, comparing the foraging behavior of reproductive (rf) and nonreproductive (nrf) female hoary marmots, with the following findings: In June, no differences occur between rf's and nrf's, regarding daytime foraging. However, rf's forage more in the evening and during inclement weather, suggesting that greater nutritional needs and higher reproductive value select for the assumption of more

David P. Barash

1980-01-01

422

Foraging speed in staging flocks of semipalmated sandpipers: evidence for scramble competition.  

PubMed

Foraging speed is a key determinant of fitness affecting both foraging success and predator attack survival. In a scramble for food, for instance, evolutionary stable strategy models predict that speed should increase with competitor density and decrease when the risk of attack by predators increases. Foraging speed should also decrease in richer food patches where the level of competition is reduced. I tested these predictions in fall staging flocks of semipalmated sandpipers (Calidris pusilla) foraging for an evasive prey. Capture rate of these prey decreased with sandpiper density as the presence of competitors reduced the availability of resources for those behind. Foraging speed was evaluated indirectly by measuring the time needed to cross fixed boundaries on mudflats over 6 years. As predicted, foraging speed increased with sandpiper density and decreased with food density, but, unexpectedly, increased closer to obstructive cover where predation risk was deemed higher. When foraging closer to cover, from where predators launch surprise attacks, the increase in foraging speed may compensate for an increase in false alarms that interrupted foraging. While foraging in denser flocks decreases foraging success, joining such flocks may also increase safety against predators. In semipalmated sandpipers that occupy an intermediate position in the food chain, foraging behavior is influenced simultaneously by the evasive responses of their prey and by the risk of attack from their own predators. PMID:22302514

Beauchamp, Guy

2012-08-01

423

The use and misuse of public information by foraging red crossbills  

Microsoft Academic Search

Group foragers may assess patch quality more efficiently by paying attention to the sampling behavior of group members foraging in the same patch (i.e., using ''public information''). To determine whether red crossbills (Loxia curvirostra) use public infor- mation to aid their patch departure decisions, we conducted experiments that compared the sampling behavior of crossbills foraging on a two-patch system (one

Julie W. Smith; Craig W. Benkman; Kimberly Coffey

1999-01-01

424

Foraging time and dietary intake by breeding Ross's and Lesser Snow Geese  

Microsoft Academic Search

We compared foraging times of female Ross's (Chen rossii) and Lesser Snow Geese (Chen caerulescens caerulescens) breeding at Karrak Lake, NT, Canada and examined variation due to time of day and reproductive stage. We subsequently collected female geese that had foraged for known duration and we estimated mass of foods consumed during foraging bouts. Female Ross's Geese spent more time

Mark L. Gloutney; Ray T. Alisauskas; Alan D. Afton; Stuart M. Slattery

2001-01-01

425

Foraging by Male and Female Solitary Bees with Implications for Pollination  

Microsoft Academic Search

Both male and female solitary bees visit flowers for rewards. Sex related differences in foraging efficiency may also affect their probability to act as pollinators. In some major genera of solitary bees, males can be identified from a distance enabling a comparative foraging-behavior study. We have simultaneously examined nectar foraging of males and females of three bee species on five

Gidi Ne’eman; Ofrit Shavit; Liora Shaltiel; Avi Shmida

2006-01-01

426

Foraging games between gerbils and their predators: temporal dynamics of resource depletion and apprehension in gerbils  

Microsoft Academic Search

Predator-prey interactions constitute a foraging game when prey individuals manage risk from predators and predator individuals manage fear in their prey. As tools for managing risk, clever prey can use time allocation and apprehension (redirecting attention from foraging to predator detection). One such foraging game occurs between gerbils and their predators on the sand dunes of the Negev Desert. Here,

Burt P. Kotler; Joel S. Brown; Sasha R. X. Dall; Shaan Gresser; David Ganey; Amos Bouskila

2002-01-01

427

Consequences of Vegetation Density and Prey Species on Spotted Gar Foraging  

Microsoft Academic Search

Adult spotted gar Lepisosteus oculatus are potentially important components of food webs given their predatory habits and high relative abundance. However, few studies have examined their foraging behavior. Therefore, we examined the effects of vegetation density on the foraging success of adult spotted gars preying on bluegill Lepomis macrochirus and fathead minnow Pimephales promelas. Spotted gars use ambush foraging and

Kenneth G. Ostrand; Ben J. Braeutigam; David H. Wahl

2004-01-01

428

Winter Active Bumblebees (Bombus terrestris) Achieve High Foraging Rates in Urban Britain  

E-print Network

Winter Active Bumblebees (Bombus terrestris) Achieve High Foraging Rates in Urban Britain Ralph J and how much winter forage can they collect? Methodology/Principal Findings: To test if urban areas/Significance: B. terrestris in the UK are now able to utilise a rich winter foraging resource in urban parks

Chittka, Lars

429

Selective differences between naive and experienced cattle foraging among eight grasses  

Microsoft Academic Search

Cattle are often required to adapt to new forages when they are moved to new pasture. The objectives of this research were: (1) to determine how rapidly naive cattle express clearly defined preferences when they encounter a new array of forages, and (2) to compare their evolving forage preferences and grazing behavior with those of experienced cattle. Three naive and

David Ganskopp; Ruben Cruz

1999-01-01

430

Foraging behaviour of western sandpipers changes with sediment temperature: implications for their hemispheric distribution  

Microsoft Academic Search

Migratory shorebirds need to replenish their energy reserves by foraging at stop-over sites en route. Adjusting their foraging behaviour to accommodate variation in local prey availability would therefore be advantageous. We test whether western sandpipers (Calidris mauri), a sexually dimorphic shorebird, adjust their foraging behaviour in response to local changes in prey availability, as inferred by changes in diurnal time

Silke Nebel; Graham J. Thompson

2005-01-01

431

Milk from Forage as Affected by Carbohydrate Source and Degradability with Alfalfa Silage-Based Diets  

Microsoft Academic Search

Milk from forage (MF) is an estimation of the milk produced solely from forage intake. It is calculated by subtracting milk production theoretically allowed by concentrates from total milk production, assuming that maintenance requirements are covered by the forage portion of the diet. Eight multiparous Holstein cows in early lactation were used in a replicated 4 × 4 Latin square

E. Charbonneau; P. Y. Chouinard; G. Allard; H. Lapierre; D. Pellerin

2006-01-01

432

Effects of human activity on the foraging behavior of sanderlings Calidris alba  

Microsoft Academic Search

Urbanization and coastal development has dramatically reduced the beach habitat available for foraging shorebirds worldwide. This study tested the general hypothesis that recreational use of shorebird foraging areas adversely affects the foraging behavior of sanderlings Calidris alba. Observations conducted on two central California beaches from January through May and September through December of 1999 showed that number and activity of

Kate Thomas; Rikk G Kvitek; Carrie Bretz

2003-01-01

433

FORAGING STRATEGY OF WANDERING ALBATROSSES THROUGH THE BREEDING SEASON: A STUDY USING SATELLITE TELEMETRY  

Microsoft Academic Search

Satellite telemetry of Wandering Albatrosses (Diomedea exulans) breeding on the Crozet Islands, southwestern Indian Ocean, revealed two distinct foraging strategies during successive stages of the breeding season: systematic foraging over extensive distances; and use of specific areas close to the colony. During early incubation, Wandering Albatrosses foraged over pelagic waters at an average range of 1,284 kin. The length of

HENRI WEIMERSKIRCH; MARC SALAMOLARD; FRANCOIS SARRAZIN; PIERRE JOUVENTIN

1993-01-01

434

A distance-dependent estimation of foraging ranges of neighbouring bird colonies  

Microsoft Academic Search

A reliable estimation of foraging ranges is often an indispensable prerequisite of research in animal ecology and in species conservation. In colonial species, home ranges of members of one colony are frequently overlapping and for practical and theoretical reasons, it can be necessary to assess the foraging areas of whole colonies. Here, we show a method to calculate foraging areas

Erwin Nemeth; Peter Bossew; Christoph Plutzar

2005-01-01

435

Spatio-temporal foraging patterns of a giant zooplanktivore, the leatherback turtle Sabrina Fossette a,  

E-print Network

Spatio-temporal foraging patterns of a giant zooplanktivore, the leatherback turtle Sabrina Keywords: Leatherback turtle Migration strategy Foraging behavior Zooplankton distribution Diving pattern-temporal foraging patterns in 21 leatherback turtles during their pluri-annual migration in the Northern Atlantic

Hays, Graeme

436

Noise-Induced Adaptive Decision-Making in Ant-Foraging  

Microsoft Academic Search

Ant foraging is a paradigmatic example of self-organized be- havior. We give new experimental evidence for previously unobserved short-term adaptiveness in ant foraging and show that current mathe- matical foraging models cannot predict this behavior. As a true exten- sion, we develop Ito diusion models that explain the newly discovered behavior qualitatively and quantitatively. The theoretical analysis is sup- ported

Bernd Meyer; Madeleine Beekman; Audrey Dussutour

2008-01-01

437

POLLEN MAKES BEES HOT Forager bees like nothing more than a  

E-print Network

Inside JEB iii POLLEN MAKES BEES HOT Forager bees like nothing more than a sweet supply of nectar. But bees do not live by nectar alone. One of their main sources of protein is pollen. Knowing that bees% pollen protein samples and offered them to a bee colony in an isolated foraging arena. Measuring foraging

Nieh, James

438

Bumble bee pollen foraging regulation: role of pollen quality, storage levels, and odor  

E-print Network

ERRATUM Bumble bee pollen foraging regulation: role of pollen quality, storage levels, and odor T was made to the article title. The correct title should read: Bumble bee pollen foraging regulation: role for Behavioral Ecology and Sociobiology Bumble bee pollen foraging regulation: role of pollen quality, storage

Nieh, James

439

Foraging modes of stream benthic fishes in relation to their predation effects on local prey density  

Microsoft Academic Search

Habitat use and foraging behavior of two benthic insectivorous gobies, Rhinogobius sp. CO (cobalt type) and Rhinogobius sp. DA (dark type), were examined in relation to their predation effects on local prey density in a small coastal stream in southwestern Shikoku, Japan. Correlations among the foraging range, frequency of foraging attempts and current velocity indicated that individuals using fast-current habitats

Mikio Inoue; Masanobu Miyayoshi; Shin Sone

2005-01-01

440

Colony state and regulation of pollen foraging in the honey bee, Apis mellifera L  

Microsoft Academic Search

To place social insect foraging behavior within an evolutionary context, it is necessary to establish relationships between individual foraging decisions and parameters influencing colony fitness. To address this problem, we examined interactions between individual foraging behavior and pollen storage levels in the honey bee, Apis mellifera L. Colonies responded to low pollen storage conditions by increasing pollen intake rates 54%

Jennifer H. Fewell; Mark L. Winston

1992-01-01

441

Ecology of fear: Foraging games between predators and prey with pulsed resources  

Microsoft Academic Search

We model the foraging game between a prey and predator when the prey experiences a temporally pulsed resource (e.g., seed-eating gerbils). Animals have the options of foraging or remaining inactive. Prey harvest resources and incur a mortality risk only while foraging. ESS levels of prey and predator activity have three distinct phases over the time course of a resource pulse.

Joel S. Brown; Burt P. Kotler; Amos Bouskila

442

Fatty Acid Composition of Mixed-Rumen Bacteria: Effect of Concentration and Type of Forage  

Microsoft Academic Search

The effects of concentration and type of forage in the diet on lipid content and fatty acid (FA) composition of rumen bacteria were studied in 14 goats fitted with duodenal cannulas. The goats were fed a complete maintenance diet containing 40, 70, or 100% chopped forage (dry matter basis) in two equal meals. Forage was either corn stover or alfalfa

P. Bas; H. Archimède; A. Rouzeau; D. Sauvant

2003-01-01

443

Interactions with Combined Chemical Cues Inform Harvester Ant Foragers' Decisions to Leave the Nest in Search of Food  

PubMed Central

Social insect colonies operate without central control or any global assessment of what needs to be done by workers. Colony organization arises from the responses of individuals to local cues. Red harvester ants (Pogonomyrmex barbatus) regulate foraging using interactions between returning and outgoing foragers. The rate at which foragers return with seeds, a measure of food availability, sets the rate at which outgoing foragers leave the nest on foraging trips. We used mimics to test whether outgoing foragers inside the nest respond to the odor of food, oleic acid, the odor of the forager itself, cuticular hydrocarbons, or a combination of both with increased foraging activity. We compared foraging activity, the rate at which foragers passed a line on a trail, before and after the addition of mimics. The combination of both odors, those of food and of foragers, is required to stimulate foraging. The addition of blank mimics, mimics coated with food odor alone, or mimics coated with forager odor alone did not increase foraging activity. We compared the rates at which foragers inside the nest interacted with other ants, blank mimics, and mimics coated with a combination of food and forager odor. Foragers inside the nest interacted more with mimics coated with combined forager/seed odors than with blank mimics, and these interactions had the same effect as those with other foragers. Outgoing foragers inside the nest entrance are stimulated to leave the nest in search of food by interacting with foragers returning with seeds. By using the combined odors of forager cuticular hydrocarbons and of seeds, the colony captures precise information, on the timescale of seconds, about the current availability of food. PMID:23308106

Greene, Michael J.; Pinter-Wollman, Noa; Gordon, Deborah M.

2013-01-01

444

Foraging behaviour and diet selection in domestic herbivores  

E-print Network

! accepted 23 September 1998) Abstract— Foraging behaviour and diet selection determine both the nutrient intake by the ani- mals and their impact on the vegetation. They are therefore of importance the charac- teristics of the animal and the characteristics of food in the environment. We review some

Boyer, Edmond

445

How do cattle's preferences vary according to forage accessibility ?  

E-print Network

hay was first offered alone for 5 sessions to teach the animals the press number/food reward. The poor number/food reward, fasting and individual animals were considered in an analysis of variance the response of animals either fed or deprived of food to changes in good forage accessibility. Nine 1-year

Paris-Sud XI, Université de

446

Rational Analyses of Information Foraging on the Web  

ERIC Educational Resources Information Center

This article describes rational analyses and cognitive models of Web users developed within information foraging theory. This is done by following the rational analysis methodology of (a) characterizing the problems posed by the environment, (b) developing rational analyses of behavioral solutions to those problems, and (c) developing cognitive…

Pirolli, Peter

2005-01-01

447

The Self-Construction and -Repair of a Foraging  

E-print Network

The Self-Construction and -Repair of a Foraging Organism by Explicitly Specified Development from¨rich, Switzerland rjd@ini.phys.ethz.ch Keywords Self-construction, self-repair, behaving organism, stigmergy need for novel engineering methods that offer self-construction, adaptation to the environment

Siegelmann , Hava T

448

Testing optimal foraging models for air-breathing divers  

Microsoft Academic Search

Models of diving optimality qualitatively predict diving behaviours of aquatic birds and mammals. However, none of them has been empirically tested. We examined the quantitative predictions of optimal diving models by combining cumulative oxygen uptake curves with estimates of power costs during the dives of six tufted ducks, Aythya fuligula. The effects of differing foraging costs on dive duration and

Lewis Halsey; Anthony Woakes; Patrick Butler

2003-01-01

449

Nutritional Toxicology of Tannins and Related Polyphenols in Forage Legumes  

Microsoft Academic Search

Proanthocyanidins (PA) (condensed tannins) and hydrolyzable tannins (HT) are the two major classes of tannins. Proanthocyanidins are flavo- noid polymers. Hydrolyzable tannins are polymers of gallic or ellagic acid esterified to a core molecule, commonly glucose or a polyphenol such as catechin. Proanthocyanidins are the most common type of tannin found in forage legumes. Problems in the analysis of tannins

Jess D. Reed

2010-01-01

450

Soil, Water and Forage Testing Laboratory Nitrogen recommendations applicable for  

E-print Network

Soil, Water and Forage Testing Laboratory Nitrogen recommendations applicable for methods used by laboratory. Nitrogen Soil Fertility Recommendations for Lawn and Gardens 0 2 4 6 8 10 12 14 16 18 20 updated. Nitrogen Soil Fertility Recommendations for Lawn and Gardens 25 30 35 40 45 50 55 60 65 70 75 updated on 3

451

Soil, Water and Forage Testing Laboratory Nitrogen recommendations applicable for  

E-print Network

Soil, Water and Forage Testing Laboratory Nitrogen recommendations applicable for methods used by laboratory. Nitrogen Soil Fertility Recommendations for Texas Turf and Landscapes 0 2 4 6 8 10 12 14 16 18 20 Testing Laboratory Nitrogen recommendations applicable for methods used by laboratory. Nitrogen Soil

452

Soil, Water and Forage Testing Laboratory Nitrogen recommendations applicable for  

E-print Network

Soil, Water and Forage Testing Laboratory Nitrogen recommendations applicable for methods used by laboratory. Nitrogen Soil Fertility Recommendations for Oil Crops 0 2 4 6 8 10 12 14 16 18 20 updated on 3. Nitrogen Soil Fertility Recommendations for Oil Crops 0 2 4 6 8 10 12 14 16 18 20 updated on 3

453

DYNAPHORE, INC. FORAGER¿ SPONGE TECHNOLOGY - INNOVATIVE TECHNOLOGY EVALUATION REPORT  

EPA Science Inventory

The Forager¿ Sponge is an open-celled cellulose sponge incorporating an amine-containing chelating polymer that selectively absorbs dissolved heavy metals from aqueous waste streams. The Developer states that the technology can be utilized to remove and concentrate heavy metals f...

454

Competition in foraging flocks of migrating semipalmated sandpipers.  

PubMed

I examined the effect of competitor density on foraging success in staging semipalmated sandpipers (Calidris pusilla) foraging on a burrowing amphipod (Corophium volutator) in each of two study years. Little is known about the effect of competitor density when predation attempts disturb prey, causing a temporary decrease in food availability. Controlling for Corophium density and other potentially confounding factors such as temperature, pecking rate and capture rate increased linearly with sandpiper density. Success rate, the ratio of captures to pecks, was not influenced by sandpiper density. The effect of sandpiper density was similar in each of the two study years and was documented early and late in the low tide period. The increase in foraging rate is argued to be a response to increased competition for rapidly depleting prey at the temporal scale of exploitation by a flock. Potential fitness costs associated with higher foraging costs may include decreased ability to distinguish between the profitability of different prey and reduced vigilance against predators. PMID:17676344

Beauchamp, Guy

2007-11-01

455

Foraging under uniform risk from different types of predators  

PubMed Central

Background Many animals live in environments where different types of predators pose a permanent threat and call for predator specific strategies. When foraging, animals have to balance the competing needs of food and safety in order to survive. While animals sometimes can choose between microhabitats that differ in their risk of predation, many habitats are uniform in their risk distribution. So far, little is known about adaptive antipredator behavior under uniform risk. We simulated two predator types, avian and mammalian, each representing a spatially uniform risk in the artificial resource landscapes. Voles served as experimental foragers. Results Animals were exposed to factorial combinations of weasel odour and ground cover to simulate avian and/or mammalian predation. We measured short and long term responses with video analysis and giving-up densities. The results show that previously experienced conditions cause delayed effects. After these effects ceased, the risks of both types of predation caused a reduction in food intake. Avian predation induced a concentration on a smaller number of feeding patches. While higher avian risk caused a delay in activity, the weasel odour shortened the latency until the voles started to be active. Conclusion We show that the voles differed in risk types and adjusted their feeding strategies accordingly. Responses to avian and mammalian risk differed both in strength and time scales. Uniformity of risk resulted in a concentration of foraging investment and lower foraging efficiency. PMID:19068146

Liesenjohann, T; Eccard, JA

2008-01-01

456

Estimating Shrub Forage Yield and Utilization Using a Photographic Technique  

Microsoft Academic Search

We assessed a photographic technique to estimate shrub yield and utilization of common snowberry (Symphoricarpos albus (L.) Blake), snowbrush (Ceanothus velutinus Douglas ex Hook.), and firmleaf willow ( Salix rigida Muhl.) found in mixed-conifer rangelands. We determined the correlation between green leaf area size (LA) and forage yield (Y) and compared plant utilization estimated by photographic technique (ULA) to actual

Daalkhaijav Damiran; Timothy DelCurto; Douglas E. Johnson; Scott L. Findholt; Bruce K. Johnson

2006-01-01

457

FORAGE FISH ABUNDANCE AND DISTRIBUTION AT FORRESTER ISLAND, ALASKA  

E-print Network

1 FORAGE FISH ABUNDANCE AND DISTRIBUTION AT FORRESTER ISLAND, ALASKA Brenda L. Norcross Principal Investigator Institute of Marine Sciences School of Fisheries and Ocean Sciences University of Alaska Fairbanks Fairbanks, Alaska 99775-7220 Prepared by: Brenda A. Holladay Brenda L. Norcross Franz Mueter Final contract

458

Malate Content of Forage Varieties Commonly Fed to Cattle  

Microsoft Academic Search

The objective of this study was to determine the concentration of malate in forage varieties at different stages of maturity. Five alfalfa varieties (Alfagraze, Apollo Supreme, Cimarron, Crockett, and Magnum III) and three bermudagrass varieties (Coastal, Tifton-78, and Tifton-85) were collected at different stages of maturity. Samples were collected from repli- cate plots (n = 3 ) of each alfalfa

T. R. Callaway; S. A. Martin; J. L. Wampler; N. S. Hill; G. M. Hill

1997-01-01

459

Nutrient compensatory foraging in a free-living social insect  

NASA Astrophysics Data System (ADS)

The geometric framework model predicts that animal foraging decisions are influenced by their dietary history, with animals targeting a combination of essential nutrients through compensatory foraging. We provide experimental confirmation of nutrient-specific compensatory foraging in a natural, free-living population of social insects by supplementing their diet with sources of protein- or carbohydrate-rich food. Colonies of the ant Iridomyrmex suchieri were provided with feeders containing food rich in either carbohydrate or protein for 6 days, and were then provided with a feeder containing the same or different diet. The patterns of recruitment were consistent with the geometric framework: while feeders with a carbohydrate diet typically attracted more workers than did feeders with protein diet, the difference in recruitment between the two nutrients was smaller if the colonies had had prior access to carbohydrate than protein. Further, fewer ants visited feeders if the colony had had prior access to protein than to carbohydrates, suggesting that the larvae play a role in worker foraging behaviour.

Christensen, Keri L.; Gallacher, Anthony P.; Martin, Lizzie; Tong, Desmond; Elgar, Mark A.

2010-10-01

460

Allocating Great Lakes forage bases in response to multiple demand  

USGS Publications Warehouse

Forage base allocation, which has become an important issue because of major changes in the fish communities and fisheries of the Great Lakes since the 1950s is examined and documented in this chapter. Management initiatives that were used to address the issue, and supporting research and development that provided new or improved methods of field sampling and analysis are also highlighted.

Brown, Edward H., Jr.; Busiahn, Thomas R.; Jones, Michael L.; Argyle, Ray L.

1999-01-01

461

People's Study Time Allocation and its Relation to Animal Foraging  

PubMed Central

In this article we suggest a relation between people's metacognitively guided study time allocation strategies and animal foraging. These two domains are similar insofar as people use specific metacognitive cues to assist their study time allocation just as other species use cues, such as scent marking. People decline to study items that they know they already know, just as other species use a win-shift strategy – avoiding already visited and depleted patches – in foraging. People selectively study the easiest as-yet-unlearned items first, before turning to more difficult items just as other species take the ‘just right’ size and challenge of prey--the so-called Goldilocks principle. People use a stop rule by which they give up on one item and turn to another when the returns diminish just as others species use a stop rule that guides shifting from one patch to another. The value that each item is assigned on the criterion test, if known during study, influenced which items people choose to study and how long they study them just as knowledge of the nutritional or energy value of the food influences choices and perseverance in foraging. Finally, study time allocation strategies can differ in their effectiveness depending upon the expertise of the student just as some species forage close to optimally while others do not. PMID:20026197

Metcalfe, Janet; Jacobs, W. Jake

2010-01-01

462

Diet niches of major forage fish in Lake Michigan  

USGS Publications Warehouse

A large complex of coregonine species historically dominated the fish community of Lake Michigan. The current species complex is simplified with one remaining coregonine, bloater (Coregonus hoyi), deepwater sculpin (Myoxocephalus thompsoni), slimy sculpin (Cottus cognatus), and two dominant invaders, alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax). To better understand the diet relationships of the major offshore forage fishes now in Lake Michigan, diets of bloater, alewife, rainbow smelt, deepwater sculpin, and slimy sculpin were compared. The three sites, chosen to represent northern, central, and southern components of the lake, were sampled during spring, summer, and fall in 1994, and spring and fall in 1995. Forage fishes had diverse and variable diets, with niches differentiated by prey type or location. Diporeia hoyi, Mysis relicta, and zooplankton were the major diet items. The index of relative importance showed benthic (slimy and deepwater sculpins) and pelagic (alewife, rainbow smelt) feeding strategies with opportunistic bloaters incorporating both feeding strategies. Highest diet overlaps were between species of sculpin, and between large and small bloaters; both groups partitioned food by size. Though competition for food may be minimized by spatial segregation of potential competitors, the forage fish in Lake Michigan apparently partition food resources. Fishery management models incorporating food habits of pelagic forage fish would need to take into account diet variation associated with location and season. ?? 2007 E. Schweizerbart'sche Verlagsbuchhandlung.

Davis, B.M.; Savino, J.F.; Ogilvie, L.M.

2007-01-01

463

Foraging by bats in cleared, thinned and unharvested boreal forest  

Microsoft Academic Search

Summary 1. Modern silvicultural methods employ various styles of selective harvesting in addi- tion to traditional clear-cutting. This can create a mosaic of patches with different tree densities that may influence habitat use by foraging bats. Use of forest patches may also vary among bat species due to variation in their manoeuvrability. Apart from studies investigating use of clear-cuts, few

Krista J. Patriquin; Robert M. R. Barclay

2003-01-01

464

Green crab (Carcinus maenas) foraging efficiency reduced by fast flows.  

PubMed

Predators can strongly influence prey populations and the structure and function of ecosystems, but these effects can be modified by environmental stress. For example, fluid velocity and turbulence can alter the impact of predators by limiting their environmental range and altering their foraging ability. We investigated how hydrodynamics affected the foraging behavior of the green crab (Carcinus maenas), which is invading marine habitats throughout the world. High flow velocities are known to reduce green crab predation rates and our study sought to identify the mechanisms by which flow affects green crabs. We performed a series of experiments with green crabs to determine: 1) if their ability to find prey was altered by flow in the field, 2) how flow velocity influenced their foraging efficiency, and 3) how flow velocity affected their handling time of prey. In a field study, we caught significantly fewer crabs in baited traps at sites with fast versus slow flows even though crabs were more abundant in high flow areas. This finding suggests that higher velocity flows impair the ability of green crabs to locate prey. In laboratory flume assays, green crabs foraged less efficiently when flow velocity was increased. Moreover, green crabs required significantly more time to consume prey in high velocity flows. Our data indicate that flow can impose significant chemosensory and physical constraints on green crabs. Hence, hydrodynamics may strongly influence the role that green crabs and other predators play in rocky intertidal communities. PMID:21687742

Robinson, Elizabeth M; Smee, Delbert L; Trussell, Geoffrey C

2011-01-01

465

Learning, odour preference and flower foraging in moths  

Microsoft Academic Search

Floral volatiles play a major role in plant-insect communication. We examined the influence of two volatiles, phenylacetaldehyde and ?-pinene, on the innate and learnt foraging behaviour of the moth Helicoverpa armigera. In dual-choice wind tunnel tests, adult moths flew upwind towards both volatiles, with a preference for phenylacetaldehyde. When exposure to either of these volatiles was paired with a feeding

John Paul Cunningham; Chris J. Moore; Myron P. Zalucki; Stuart A. West

2004-01-01

466

SHORT COMMUNICATION Foraging scent marks of bumblebees: footprint cues rather  

E-print Network

SHORT COMMUNICATION Foraging scent marks of bumblebees: footprint cues rather than pheromone bumblebees refuse to land on and probe flowers that have been recently visited (and depleted) by themselves with specific scent marks). Bumblebees rejected both active and passive feeders more frequently than unvisited

Eltz, Thomas

467

IDENTITY AND FUNCTION OF SCENT MARKS DEPOSITED BY FORAGING BUMBLEBEES  

Microsoft Academic Search

Foraging bumblebees can detect scents left on flowers by previous bumblebee visitors and hence avoid flowers that have been depleted of nectar. Tarsal secretions are probably responsible for this repellent effect. The chemical components of the tarsal glands were analyzed by combined gas chromatography-mass spectrometry for three species of bumblebee, Bombus terrestris, B. lapidarius, and B. pascuorum. The hydrocarbons identified

DAVE GOULSON; JANE C. STOUT; JOHN LANGLEY

2000-01-01

468

Providing foraging resources for bumblebees in intensively farmed landscapes  

Microsoft Academic Search

Habitat loss and the intensification of farming practices have caused severe declines in the range and abundance of many bumblebee species in the UK. This study examines the long-term effectiveness of four different management strategies to enhance and restore bumblebee foraging habitat on arable field margins in two regions with markedly contrasting landscape structure, farming systems and amount of semi-natural

R. F. Pywell; E. A. Warman; C. Carvell; T. H. Sparks; L. V. Dicks; D. Bennett; A. Wright; C. N. R. Critchley; A. Sherwood

2005-01-01

469

Sampling requirements for forage quality characterization of rectangular hay bales  

SciTech Connect

Commercial lots of alfalfa (Medicago sativa L.) hay are often bought and sold on the basis of forage quality. Proper sampling is essential to obtain accurate forage quality results for pricing of alfalfa hay, but information about sampling is limited to small, 20- to 40-kg rectangular bales. Their objectives were to determine the within-bale variation in 400-kg rectangular bales and to determine the number and distribution of core samples required to represent the crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), and dry matter (DM) concentration in commercial lots of alfalfa hay. Four bales were selected from each of three hay lots and core sampled nine times per side for a total of 54 cores per bale. There was no consistent pattern of forage quality variation within bales. Averaged across lots, any portion of a bale was highly correlated with bale grand means for CP, ADF, NDF, and DM. Three lots of hay were probed six times per bale, one core per bale side from 55, 14, and 14 bales per lot. For determination of CP, ADF, NDF, and DM concentration, total core numbers required to achieve an acceptable standard error (SE) were minimized by sampling once per bale. Bootstrap analysis of data from the most variable hay lot suggested that forage quality of any lot of 400-kg alfalfa hay bales should be adequately represented by 12 bales sampled once per bale.

Sheaffer, C.C.; Martin, N.P.; Jewett, J.G.; Halgerson, J.; Moon, R.D.; Cuomo, G.R.

2000-02-01

470

Can we measure carrying capacity with foraging behavior?  

PubMed

Carrying capacity is one of the most important, yet least understood and rarely estimated, parameters in population management and modeling. A simple behavioral metric of carrying capacity would advance theory, conservation, and management of biological populations. Such a metric should be possible because behavior is finely attuned to variation in environment including population density. We connect optimal foraging theory with population dynamics and life history to develop a simple model that predicts this sort of adaptive density-dependent change in food consumption. We then confirm the model's unexpected and manifold predictions with field experiments. The theory predicts reproductive thresholds that alter the marginal value of energy as well as the value of time. Both effects cause a pronounced discontinuity in quitting-harvest rate that we revealed with foraging experiments. Red-backed voles maintained across a range of high densities foraged at a lower density-dependent rate than the same animals exposed to low-density treatments. The change in harvest rate is diagnostic of populations that exceed their carrying capacity. Ecologists, conservation biologists, and wildlife managers may thus be able to use simple and efficient foraging experiments to estimate carrying capacity and habitat quality. PMID:17503587

Morris, Douglas W; Mukherjee, Shomen

2007-03-01

471

The foraging Gene of Drosophila melanogaster: Spatial-Expression  

E-print Network

in this food-related behavior. J. Comp. Neurol. 504:570­582, 2007. © 2007 Wiley-Liss, Inc. Indexing terms: for The ability to identify and respond to food is essential for survival, yet little is known about the neural substrates that regulate natural variation in food-related traits. The foraging (for) gene in Drosophila

Sokolowski, Marla

472

Managing Manure Nutrients Through Multi-crop Forage Production  

Microsoft Academic Search

Concentrated sources of dairy manure represent sig- nificant water pollution potential. The southern USA may be more vulnerable to water quality problems than someotherregionsbecauseofclimate,typicalfarmsize, and cropping practices. Dairy manure can be an effec- tive source of plant nutrients and large quantities of nutrients can be recycled through forage production, especially when multi-cropping systems are utilized. Linkingforageproductionwithmanureutilizationisan environmentally sound approach for

G. L. Newton; J. K. Bernard; R. K. Hubbard; J. R. Allison; R. R. Lowrance; G. J. Gascho; R. N. Gates; G. Vellidis

2003-01-01

473

Developmental evidence for foraging traditions in wild bottlenose dolphins  

Microsoft Academic Search

Patterns of social learning in bottlenose dolphins (Tursiops spp.) may help explain behavioural variants and selection pressures favouring cultural evolution, but evidence for social transmission derived from field observations is controversial. The dolphins of Shark Bay, Australia are known for diverse, individ- ually specific foraging behaviours, including tool use with marine sponges. We examined the relative contributions of habitat, maternal

Brooke L. Sargeant; Janet Mann

2009-01-01

474

At-sea associations in foraging little penguins.  

PubMed

Prey distribution, patch size, and the presence of conspecifics are important factors influencing a predator's feeding tactics, including the decision to feed individually or socially. Little is known about group behaviour in seabirds as they spend most of their lives in the marine environment where it is difficult to observe their foraging activities. In this study, we report on at-sea foraging associations of little penguins (Eudyptula minor) during the breeding season. Individuals could be categorised as (1) not associating; (2) associating when departing from and/or returning to the colony; or (3) at sea when travelling, diving or performing synchronised dives. Out of 84 separate foraging tracks, 58 (69.0%) involved associations with conspecifics. Furthermore, in a total of 39 (46.4%), individuals were found to dive during association and in 32 (38.1%), individuals were found to exhibit synchronous diving. These behaviours suggest little penguins forage in groups, could synchronise their underwater movements and potentially cooperate to concentrate their small schooling prey. PMID:25119718

Berlincourt, Maud; Arnould, John P Y

2014-01-01

475

Canadian waters provide critical foraging habitat for leatherback sea turtles  

E-print Network

Canadian waters provide critical foraging habitat for leatherback sea turtles Michael C. Jamesa University, 1355 Oxford St., Halifax, NS, Canada B3H 4J1 b Nova Scotia Leatherback Turtle Working Group, 2070 851 geo-referenced records of leatherback turtles, Dermoche- lys coriacea, from a volunteer network

Myers, Ransom A.

476

Tim Wilson, MS, PAS Director and Livestock/Forages Agent  

E-print Network

Tim Wilson, MS, PAS Director and Livestock/Forages Agent 904-966-6224 office tim; Avg .responses per County = 53; Bradford County Responses = 74 #12;Tim Wilson, MS, PAS Director = $119,659 4) Scholarships through 4-H Camp Cherry Lake · 44 youth attended in 2010 with a $60

Watson, Craig A.

477

Sociality in river otters: cooperative foraging or reproductive strategies?  

Microsoft Academic Search

We evaluated factors influencing social organization in coastal river otters (Lontra canadensis) to test two hypotheses: group formation is an antipredation strategy, or, alternatively, group information is related to cooperative foraging. Data on group size, group composition, and sociality were obtained through radiotracking 55 otters in Prince William Sound, Alaska, USA, from 1996 through 1998. For males, larger groups occurred

Gail M. Blundell; Merav Ben-David

2002-01-01

478

7 CFR 407.13 - Group risk plan for forage.  

Code of Federal Regulations, 2010 CFR

...calculated by dividing the NASS estimate of the production of hay in the county by the NASS estimate of the acres of hay in...forage field is subdivided into smaller parcels and livestock are moved from one area to another, allowing a...

2010-01-01

479

Estimating Forage Yields For Pastures Management Intensive Grazing  

E-print Network

Estimating Forage Yields For Pastures Management Intensive Grazing The following are expected yield ranges for different soils and fertility levels when utilizing management intensive grazing systems/ac/yr 3.5 tons/ac/yr Rotational Grazing The following are expected yield ranges for management and soil

Guiltinan, Mark

480

FORAGING ECOLOGY OF BALD EAGLES ON A REGULATED RIVER  

Microsoft Academic Search

ABSTRCT.--We studied the habitat, foraging behavior, and prey of eight pairs of Bald Eagles (Haliaeetus leucocephalus) nesting along northern California's Pit River where flows and reservoir elevations were regulated by five hydroelectric facilities. Prey remains (N = 1166) and photographic data (N- 117) indicated that eagles fed on a variety of fishes (88%), birds (9%), and mammals (4%), but one

W. GRAINGER HUNT; MARK JENKINS; RONALD E. JACKMAN; CARL G. THELANDER; ARNOLD T. GERSTELL

1992-01-01

481

Adaptive L?vy Walks in Foraging Fallow Deer  

PubMed Central

Background Lévy flights are random walks, the step lengths of which come from probability distributions with heavy power-law tails, such that clusters of short steps are connected by rare long steps. Lévy walks maximise search efficiency of mobile foragers. Recently, several studies raised some concerns about the reliability of the statistical analysis used in previous analyses. Further, it is unclear whether Lévy walks represent adaptive strategies or emergent properties determined by the interaction between foragers and resource distribution. Thus two fundamental questions still need to be addressed: the presence of Lévy walks in the wild and whether or not they represent a form of adaptive behaviour. Methodology/Principal Findings We studied 235 paths of solitary and clustered (i.e. foraging in group) fallow deer (Dama dama), exploiting the same pasture. We used maximum likelihood estimation for discriminating between a power-tailed distribution and the exponential alternative and rank/frequency plots to discriminate between Lévy walks and composite Brownian walks. We showed that solitary deer perform Lévy searches, while clustered animals did not adopt that strategy. Conclusion/Significance Our demonstration of the presence of Lévy walks is, at our knowledge, the first available which adopts up-to-date statistical methodologies in a terrestrial mammal. Comparing solitary and clustered deer, we concluded that the Lévy walks of solitary deer represent an adaptation maximising encounter rates with forage resources and not an epiphenomenon induced by a peculiar food distribution. PMID:19668369

Focardi, Stefano; Montanaro, Paolo; Pecchioli, Elena

2009-01-01

482

ORGANOCHLORINE CONTAMINANTS OF WINTERING DUCKS FORAGING ON DETROIT RIVER SEDIMENTS  

EPA Science Inventory

Organochlorine analysis was performed on carcasses of 13 diving ducks from a 1981 wintering population that foraged on contaminated sediments in the lower Detroit River. Mean total PCB concentrations were 10 mg/kg for seven lesser scaups (Aythya affinis), 11 mg/kg for three great...

483

Foraging success of biological Lévy flights recorded in situ.  

PubMed

It is an open question how animals find food in dynamic natural environments where they possess little or no knowledge of where resources are located. Foraging theory predicts that in environments with sparsely distributed target resources, where forager knowledge about resources' locations is incomplete, Lévy flight movements optimize the success of random searches. However, the putative success of Lévy foraging has been demonstrated only in model simulations. Here, we use high-temporal-resolution Global Positioning System (GPS) tracking of wandering (Diomedea exulans) and black-browed albatrosses (Thalassarche melanophrys) with simultaneous recording of prey captures, to show that both species exhibit Lévy and Brownian movement patterns. We find that total prey masses captured by wandering albatrosses during Lévy movements exceed daily energy requirements by nearly fourfold, and approached yields by Brownian movements in other habitats. These results, together with our reanalysis of previously published albatross data, overturn the notion that albatrosses do not exhibit Lévy patterns during foraging, and demonstrate that Lévy flights of predators in dynamic natural environments present a beneficial alternative strategy to simple, spatially intensive behaviors. Our findings add support to the possibility that biological Lévy flight may have naturally evolved as a search strategy in response to sparse resources and scant information. PMID:22529349

Humphries, Nicolas E; Weimerskirch, Henri; Queiroz, Nuno; Southall, Emily J; Sims, David W

2012-05-01

484

HABITAT USE BY FORAGING NORTHERN HARRIERS ON NANTUCKET ISLAND, MASSACHUSETTS  

E-print Network

,2 CURTICE R. GRIFFIN,1 AND KEVIN MCGARIGAL1 ABSTRACT.--The Northern Harrier (Circus cyaneus) is of major reduces foraging habitat. Received 26 January 2009. Accepted 9 July 2009. Northern Harriers (Circus cyaneus) have been identified as a species of national concern by the U.S. Fish and Wildlife Service (USDI

McGarigal, Kevin

485

Terrestrial Foraging by Two Species of Semiaquatic Turtles (Testudines: Emydidae)  

Microsoft Academic Search

I describe terrestrial foraging behavior in Trachemys scripta elegans (Red-eared Slider) and Graptemys pseudogeographica kohnii (Mississippi Map Turtle), two species of semiaquatic turtles. I observed specimens of Red-eared Slider on two occasions in two differ- ent locations climbing onto the bank of a stream and consuming grass blades (Luziola fl uitans (Southern Watergrass) and Eragrostis hypnoides (Teal Lovegrass)), which were

John L. Carr

2008-01-01

486

Social Foraging Theory for Robust Multiagent System Design  

Microsoft Academic Search

An analogy between an agent (e.g., an autonomous vehicle) and a biological forager is extended to a social environment by viewing a communication network as implementing interagent sociality. We first describe engineering design within an evolutionary game-theoretic framework. We then explain why sociality may emerge in some environments and for some agent objectives. Next, we derive the evolutionarily stable design

Burton W. Andrews; Kevin M. Passino; Thomas A. Waite

2007-01-01

487

Green Crab (Carcinus maenas) Foraging Efficiency Reduced by Fast Flows  

PubMed Central

Predators can strongly influence prey populations and the structure and function of ecosystems, but these effects can be modified by environmental stress. For example, fluid velocity and turbulence can alter the impact of predators by limiting their environmental range and altering their foraging ability. We investigated how hydrodynamics affected the foraging behavior of the green crab (Carcinus maenas), which is invading marine habitats throughout the world. High flow velocities are known to reduce green crab predation rates and our study sought to identify the mechanisms by which flow affects green crabs. We performed a series of experiments with green crabs to determine: 1) if their ability to find prey was altered by flow in the field, 2) how flow velocity influenced their foraging efficiency, and 3) how flow velocity affected their handling time of prey. In a field study, we caught significantly fewer crabs in baited traps at sites with fast versus slow flows even though crabs were more abundant in high flow areas. This finding suggests that higher velocity flows impair the ability of green crabs to locate prey. In laboratory flume assays, green crabs foraged less efficiently when flow velocity was increased. Moreover, green crabs required significantly more time to consume prey in high velocity flows. Our data indicate that flow can impose significant chemosensory and physical constraints on green crabs. Hence, hydrodynamics may strongly influence the role that green crabs and other predators play in rocky intertidal communities. PMID:21687742

Robinson, Elizabeth M.; Smee, Delbert L.; Trussell, Geoffrey C.

2011-01-01

488

Cervid forage utilization in noncommercially thinned ponderosa pine forests  

USGS Publications Warehouse

To evaluate effects of noncommercial thinning, utilization of forages consumed by elk (Cervus elaphus L.), mule deer (Odocoileus hemionus Raf.), and white-tailed deer (Odocoileus virginianus Raf.) was measured in ponderosa pine (Pinus ponderosa P. & C. Lawson) stands in Custer State Park, S. D. Treatments consisted of unthinned (control; 22 to 32 m2/ha basal area), moderately thinned (12 to 22 m2/ha basal area), and heavily thinned (3 to 13 m2/ha basal area) stands of ponderosa pine. During June, July, and August, 1991 and 1992, about 7,000 individual plants were marked along permanent transects and percent-weight-removed by grazing was ocularly estimated. Sample plots were established along transects and plants within plots were clipped to estimate standing biomass. Pellet groups were counted throughout the study area to determine summer habitat use of elk and deer. Diet composition was evaluated using microhistological analysis of fecal samples. Average percent-weight-removed from all marked plants and percent-plants-grazed were used to evaluate forage utilization. Standing biomass of graminoids, shrubs, and forbs increased (P 0.05) across treatments. Forb use averaged less than 5% within sampling periods when measured as percent-weight-removed and percent-of-plants grazed and did not differ among treatments. Results of pellet group surveys indicated that cervids were primarily using meadow habitats. When averaged over the 2 years, forbs were the major forage class in deer diets, whereas graminoids were the major forage class in diets of elk.

Gibbs, M. C.; Jenks, J. A.; Deperno, C. S.; Sowell, B. F.; Jenkins, Kurt J.

2004-01-01

489

Nitrogen fixation in six forage legumes in Mediterranean central Chile  

Microsoft Academic Search

The contribution of biological nitrogen fixation (BNF) to the N nutrition of six annual forage legumes, subterranean clover (Trifolium subterraneum), burr medic (Medicago polymorpha), balansa clover (Trifolium michelianum), Persian clover (Trifolium resupinatum), yellow serradela (Ornithopus compressus), and pink serradela (Ornithopus sativus) was evaluated by the N natural abundance technique, using four grass species (Briza máxima, Bromus mollis, Hordeum berteroanum,Avena barbata)

C. Ovalle; S. Urquiaga; A. Del Pozo; E. Zagal; S. Arredondo

2006-01-01

490

[Cytochemical characteristics of the labrocyte-like cells in the capsule of the plerocercoids of Triaenophorus nodulosus (Pallas, 1781) and Diphyllobothrium dendriticum (Nitzsch, 1824) cestodes].  

PubMed

Out of six fish species examined (Esox lucius, Paracottus kessleri, Perca fluviatilis, Leuciscus leuciscus baicalensis, Coregonus autumnalis migratorius, Thymallus arcticus baicalensis) labrocyte-like cells were detected in Esox lucius, Leuciscus leuciscus baicalensis, Coregonus autumnalis migratotius. The cells contain large metachromatic granules. Histochemical methods revealed in them sulfated and carboxylic acid mucopolysacharides. The amount of labrocyte-like cells in the capsules around plerocercoids of Triaenophrus nodulosis from Esox lucits liver depends on the age of the capsule and that of the plerocercoid. It increases when the connective tissue papsule is forming and decreases again under aging and degeneration of the capsule containing plerocercoid. The amount of labrocyte-like cells in the cestodes capsules of Raillietina increases sharply when they locate in an accidental organ (liver). This demonstrates the acuteness of organ reactivity to a nonspecific helminth. PMID:143258

Pronina, S V

1977-07-01

491

Habitat selection and web plasticity by the orb spider Argiope keyserlingi (Argiopidae): Do they compromise foraging success for predator avoidance?  

Microsoft Academic Search

Orb web spiders face a dilemma: forage in open habitats and risk predation or forage in closed habitats to minimize risk but at reduced foraging profitability.We tested whether Argiope keyserlingi opts for safer habitats at the expense of foraging success by (i) determining habitat selection indices in open and closed habitats; (ii) marking and releasing individual juvenile, subadult and adults

SEAN J. BLAMIRES; MICHAEL B. THOMPSON; DIETER F. HOCHULI

2007-01-01

492

Individual foraging, activity level and longevity in the stingless bee Melipona beecheii in Costa Rica (Hymenoptera, Apidae, Meliponinae)  

Microsoft Academic Search

Summary: Foraging behaviour of individually marked workers of Melipona beecheii (Meliponinae) was monitored in Costa Rica to investigate individual specialisation for different materials and how this influences foraging longevity. The majority of the individuals harvested one commodity (pollen, nectar or resin) during a single day. Half of the age-marked foragers specialised on nectar or pollen during their complete foraging career,

J. C. Biesmeijer; E. Tóth

1998-01-01

493

The dilemma of foraging herbivores: dealing with food and fear.  

PubMed

For foraging herbivores, both food quality and predation risk vary across the landscape. Animals should avoid low-quality food patches in favour of high-quality ones, and seek safe patches while avoiding risky ones. Herbivores often face the foraging dilemma, however, of choosing between high-quality food in risky places or low-quality food in safe places. Here, we explore how and why the interaction between food quality and predation risk affects foraging decisions of mammalian herbivores, focusing on browsers confronting plant toxins in a landscape of fear. We draw together themes of plant-herbivore and predator-prey interactions, and the roles of animal ecophysiology, behaviour and personality. The response of herbivores to the dual costs of food and fear depends on the interplay of physiology and behaviour. We discuss detoxification physiology in dealing with plant toxins, and stress physiology associated with perceived predation risk. We argue that behaviour is the interface enabling herbivores to stay or quit food patches in response to their physiological tolerance to these risks. We hypothesise that generalist and specialist herbivores perceive the relative costs of plant defence and predation risk differently and intra-specifically, individuals with different personalities and physiologies should do so too, creating individualised landscapes of food and fear. We explore the ecological significance and emergent impacts of these individual-based foraging outcomes on populations and communities, and offer predictions that can be clearly tested. In doing so, we provide an integrated platform advancing herbivore foraging theory with food quality and predation risk at its core. PMID:25270335

McArthur, Clare; Banks, Peter B; Boonstra, Rudy; Forbey, Jennifer Sorensen

2014-11-01

494

Infected honeybee foragers incur a higher loss in efficiency than in the rate of energetic gain.  

PubMed

Parasites, by altering the nutritional and energetic state of their hosts, can significantly alter their foraging behaviour. In honeybees, an infection with Nosema ceranae has been shown to lower the energetic state of individual bees, bringing about changes in behaviours associated with foraging. Comparing the foraging trip times, hive times in between trips, and the crop contents of uninfected and infected foragers as they depart on foraging trips and return from them, this study examined how any differences in these variables influence alternative foraging currencies. The results show that infected bees take longer foraging trips, spend shorter time in the hive between successive trips and bring back less sugar from each trip. These changes have a stronger adverse effect on their efficiency of energetic gain as compared with their rate of energetic gain, which has important implications for individual and colony life history. PMID:25376802

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