120 research outputs found
Effects of geolocators on hatching success, return rates, breeding movements, and change in body mass in 16 species of Arctic-breeding shorebirds
Additional Authors: Bruce Casler; Maureen Christie; Jonathan T. Coleman; Jesse R. Conklin; Willow B. English; H. River Gates; Olivier Gilg; Marie-Andrée Giroux; Ken Gosbell; Chris Hassell; Jim Helmericks; Andrew Johnson; Borgný Katrínardóttir; Kari Koivula; Jean-Francois Lamarre; Johannes Lang; David B. Lank; Nicolas Lecomte; Joe Liebezeit; Vanessa Loverti; Laura McKinnon; Clive Minton; David Mizrahi; Erica Nol; Veli-Matti Pakanen; Johanna Perz; Ron Porter; Jennie Rausch; Jeroen Reneerkens; Nelli Rönkä; Sarah Saalfeld; Nathan Senner; Benoît Sittler; Paul A. Smith; Kristine Sowl; Audrey Taylor; David H. Ward; Stephen YezerinacCitation: Weiser, E.L., R.B. Lanctot, S.C. Brown, J.A. Alves, P.F. Battley, R. Bentzen, J. Bêty, M.A. Bishop, M. Boldenow, L. Bollache, B. Casler, M. Christie, J.T. Coleman, J.R. Conklin, W.B. English, H.R. Gates, O. Gilg, M.-A. Giroux, K. Gosbell, C. Hassell, J. Helmericks, A. Johnson, B. Katrínardóttir, K. Koivula, E. Kwon, J.-F. Lamarre, J. Lang, D.B. Lank, N. Lecomte, J. Liebezeit, V. Loverti, L. McKinnon, C. Minton, D. Mizrahi, E. Nol, V.-M. Pakanen, J. Perz, R. Porter, J. Rausch, J. Reneerkens, N. Rönkä, S. Saalfeld, N. Senner, B. Sittler, P.A. Smith, K. Sowl, A. Taylor, D.H. Ward, S. Yezerinac, and B.K. Sandercock. 2016. Effects of geolocators on hatching success, return rates, breeding movements and change in body mass in 16 species of Arctic-breeding shorebirds. Movement Ecology 4: art12.
URL: http://movementecologyjournal.biomedcentral.com/articles/10.1186/s40462-016-0077-6Background: Geolocators are useful for tracking movements of long-distance migrants, but potential negative effects on birds have not been well studied. We tested for effects of geolocators (0.8–2.0 g total, representing 0.1–3.9 % of mean body mass) on 16 species of migratory shorebirds, including five species with 2–4 subspecies each for a total of 23 study taxa. Study species spanned a range of body sizes (26–1091 g) and eight genera, and were tagged at 23 breeding and eight nonbreeding sites. We compared breeding performance and return rates of birds with geolocators to control groups while controlling for potential confounding variables. Result: We detected negative effects of tags for three small-bodied species. Geolocators reduced annual return rates for two of 23 taxa: by 63 % for semipalmated sandpipers and by 43 % for the arcticola subspecies of dunlin. High resighting effort for geolocator birds could have masked additional negative effects. Geolocators were more likely to negatively affect return rates if the total mass of geolocators and color markers was 2.5–5.8 % of body mass than if tags were 0.3–2.3 % of body mass. Carrying a geolocator reduced nest success by 42 % for semipalmated sandpipers and tripled the probability of partial clutch failure in semipalmated and western sandpipers. Geolocators mounted perpendicular to the leg on a flag had stronger negative effects on nest success than geolocators mounted parallel to the leg on a band. However, parallel-band geolocators were more likely to reduce return rates and cause injuries to the leg. No effects of geolocators were found on breeding movements or changes in body mass. Among-site variation in geolocator effect size was high, suggesting that local factors were important. Conclusions: Negative effects of geolocators occurred only for three of the smallest species in our dataset, but were substantial when present. Future studies could mitigate impacts of tags by reducing protruding parts and minimizing use of additional markers. Investigators could maximize recovery of tags by strategically deploying geolocators on males, previously marked individuals, and successful breeders, though targeting subsets of a population could bias the resulting migratory movement data in some species
Spatio-temporal patterns in arctic fox (Vulpes alopex) diets revealed by molecular analysis of scats from Northeast Greenland
The arctic fox (Vulpes lagopus) is endemic to the Arctic where it holds a central position in the trophic interactions. The diet of the species has previously been described as being highly flexible, but whether this flexibility is a constant trait through time, or merely reflects fast temporal changes in abundance among prey taxa, has so far been poorly resolved. Using molecular analyses of arctic fox scats from Northeast Greenland, we first examined the temporal dynamics of arctic fox diets during the short snow-free season, and then examined whether local food availability at different sites affected arctic fox dependence on lemmings. Arctic fox diets included most terrestrial vertebrate species found in the region, and exhibited substantial temporal changes, generally reflecting the dynamic changes in prey availability from late winter through autumn. This dietary flexibility was also reflected geographically, with arctic foxes consuming a variety of local prey (mainly waterfowl and lemmings) in summer. Moreover, the dietary response of arctic foxes to changes in lemming abundance depended on access to non-lemming prey. Based on these findings, we discuss whether varying degrees of lemming-dependency, combined with geographical differences in winter food availability, may explain previously published differences in arctic fox breeding patterns in high arctic Greenland.</p
A Migratory Divide Among Red-Necked Phalaropes in the Western Palearctic Reveals Contrasting Migration and Wintering Movement Strategies
Non-breeding movement strategies of migratory birds may be expected to be flexibly adjusted to the distribution and quality of habitat, but only few studies compare movement strategies between populations using distinct migration routes and wintering areas. In thisour study, individual movement strategies of Rred-necked pPhalaropes Phalaropus lobatus, a long-distance migratory wader using saline waters in the non-breeding period, were studied using light-level geolocators. Results revealed the existence of two populations with distinct migration routes and wintering areas: one breeding in the north-eastern North Atlantic and migrating ca. 10,000 km oversea to the tropical eastern Pacific Ocean and the other breeding in Fennoscandia and Russia migrating ca. 6,000 km – largely over land – to the Arabian Sea (Indian Ocean). In line with our expectations, the transoceanic migration between the North Atlantic and the Pacific was associated with proportionately longer wings, a more even spread of stopovers in autumn and a higher migration speed in spring compared to the migration between Fennoscandian-Russian breeding grounds and the Arabian Sea. In the wintering period, birds wintering in the Pacific were stationaryresided in roughly a singlethe same area, whereas individuals wintering in the Arabian Sea showed individually consistent movementsd extensively between different areas, reflecting differences in spatio-temporal variation in primary productivity between the two wintering areas. Our study is unique in showing how habitat distribution shapes movement strategies over the entire non-breeding period within a species.Peer reviewe
State-dependent pairing behaviour in male Gammarus pulex (L.) (Crustacea, Amphipoda): effects of time left to moult and prior pairing status
International audienc
Sélection sexuelle, parasitisme et patterns d'appariement chez le crustacé amphipode Gammarus pulex
La biologie de reproduction de Gammarus lupex est caractérisée par une phase de gardiennage précopulatoire couramment analysée comme une stratégie compétitive développée par les mâles afin d'assurer leur reproduction. Une homogamie en fonction de la taille est fréquemment observée lors de cette phase de gardiennage, tel que les grands mâles sont appariés aux grandes femelles, et les mâles d'une taille moindre aux femelles plus petites. Un suivi sur le terrain de plusieurs populations naturelles, complété par des expériences au laboratoire ont permis de préciser le ou les processus responsables de l'homogamie pour la taille chez Gammarus pulex. En confrontant les prédictions propres à chaque hypothèse avec le pattern observé dans les populations naturelles, les hypothèses de contraintes et de disponibilité des partenaires ont pu être réfutées. La sélection sexuelle apparaît désormais comme le processus majeur permettant d'expliquer l'homogamie. Nous avons comparé dans un second temps les effets de deux parasites acanthocéphales, Pomphorhyncus laevis et Polymorphus minutus sur le succès d'appariement des individus des deux sexes chez Gammarus pulex. Le succès d'appariement des mâles et des femelles parasitées s'avère être fortement affecté sur le terrain. Les mâles parasités sont moins compétitifs que les mâles sains, et les femelles infectées moins attractives que les femelles saines, principalement due à une diminution de leur fécondité. Le succès des mâles et des femelles parasités par P. minutus est plus faible que celui des individus parasités par P. laevis. Les différences observées entre les deux parasites doivent vraisemblablement être liées à leur impact au niveau de la physiologie de leur hôte intermédiaire, sans que l'on sache encore ce qui, à ce niveau, diffère réellement entre les deux espèces parasitaires.LYON1-BU.Sciences (692662101) / SudocSudocFranceF
Effects of temperature on persistence times of native and invasive gammarid species in the stomachs of Cottus gobio.
5 pagesInternational audienc
Sexual selection on male body size and assortative pairing in Gammarus pulex (Crustacea: Amphipoda): field surveys and laboratory experiments
International audienc
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