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Wetherbee Ross - One of the best experts on this subject based on the ideXlab platform.
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Ectoparasite (Ceratophyllus vagabundus vagabundus) infestations reduce hatching success in precocial birds (Branta leucopsis) nesting in the High Arctic
Norwegian University of Life Sciences Ås, 2016Co-Authors: Wetherbee RossAbstract:Arctic terrestrial ecosystems are ideal systems to study host-parasite interactions because they are sensitive and have fewer confounding interactions than lower latitudes. Since the Arctic is experiencing rapid climate change, research there can provide models to better understand and predict future changes in other systems. The Barnacle Goose (Branta leucopsis) and its ectoparasite the flea (Ceratophyllus vagabundus vagabundus) is an ideal Arctic host-parasite system to study because Barnacle geese have important roles in Arctic ecosystems as selective grazers and prey items and have been intensively studied for decades. Also, recent studies suggest that Arctic avian flea infestations may be increasing, possibly due to climate change. However, few studies have considered the effect of fleas on Arctic nesting birds and little is known of Arctic avian flea ecology, most importantly whether they overwinter in the High Arctic or are reintroduced each summer by migrating birds. Furthermore, sampling methods for avian fleas are time-consuming and semi-invasive to their hosts. Therefore, the project had four aims: (i) contribute to the knowledge of Arctic flea ecology by looking for evidence of overwintering, (ii) use an experimental study to assess the impact of flea infestations on the hatching success of Barnacle Goose Eggs, (iii) assess the simple and disturbance-free method of estimating fleas with photographs of blood spots on Goose Eggs, (iv) and test the results of both the experimental study as well as the application of blood spots as a proxy measure for flea infestations through a larger observational study. It was found that fleas were likely overwintering in empty nest bowls and some evidence indicated that they might be capable of a two-year life cycle in the High Arctic. The findings from the experimental study indicated that heavy flea infestations had a negative impact on the hatching success of Barnacle Goose Eggs. It was also determined that blood spots were a good proxy measure of flea infestations, but become less accurate through incubation due to wear from incubating birds. Finally, the observational study supported the findings of the experimental study and demonstrated the power and simplicity of using blood spots as a proxy measure for flea infestations. Based on these findings, it is suggested that researchers interested in either reproductive success or incubation behavior of Barnacle geese should include a measure of flea infestations in their studies and using blood spots as a proxy measure is a simple and disturbance-free method of doing this.M-ECO
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Ectoparasite (Ceratophyllus vagabundus vagabundus) infestations reduce hatching success in precocial birds (Branta leucopsis) nesting in the High Arctic
Norwegian University of Life Sciences Ås, 2016Co-Authors: Wetherbee RossAbstract:Arctic terrestrial ecosystems are ideal systems to study host-parasite interactions because they are sensitive and have fewer confounding interactions than lower latitudes. Since the Arctic is experiencing rapid climate change, research there can provide models to better understand and predict future changes in other systems. The Barnacle Goose (Branta leucopsis) and its ectoparasite the flea (Ceratophyllus vagabundus vagabundus) is an ideal Arctic host-parasite system to study because Barnacle geese have important roles in Arctic ecosystems as selective grazers and prey items and have been intensively studied for decades. Also, recent studies suggest that Arctic avian flea infestations may be increasing, possibly due to climate change. However, few studies have considered the effect of fleas on Arctic nesting birds and little is known of Arctic avian flea ecology, most importantly whether they overwinter in the High Arctic or are reintroduced each summer by migrating birds. Furthermore, sampling methods for avian fleas are time-consuming and semi-invasive to their hosts. Therefore, the project had four aims: (i) contribute to the knowledge of Arctic flea ecology by looking for evidence of overwintering, (ii) use an experimental study to assess the impact of flea infestations on the hatching success of Barnacle Goose Eggs, (iii) assess the simple and disturbance-free method of estimating fleas with photographs of blood spots on Goose Eggs, (iv) and test the results of both the experimental study as well as the application of blood spots as a proxy measure for flea infestations through a larger observational study. It was found that fleas were likely overwintering in empty nest bowls and some evidence indicated that they might be capable of a two-year life cycle in the High Arctic. The findings from the experimental study indicated that heavy flea infestations had a negative impact on the hatching success of Barnacle Goose Eggs. It was also determined that blood spots were a good proxy measure of flea infestations, but become less accurate through incubation due to wear from incubating birds. Finally, the observational study supported the findings of the experimental study and demonstrated the power and simplicity of using blood spots as a proxy measure for flea infestations. Based on these findings, it is suggested that researchers interested in either reproductive success or incubation behavior of Barnacle geese should include a measure of flea infestations in their studies and using blood spots as a proxy measure is a simple and disturbance-free method of doing this
Jean-françois Giroux - One of the best experts on this subject based on the ideXlab platform.
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ORIGINAL PAPER Cache and carry: hoarding behavior of arctic fox
2014Co-Authors: Jean-françois Giroux, Vincent Careau, Dominique Berteaux, -f. J. GirouxAbstract:Abstract Food-hoarding animals are expected to preferentially cache items with lower perishability and/or higher consumption time. We observed arctic foxes (Alopex lagopus) foraging in a greater snow Goose (Anser caerulescens atlanticus) colony where the main prey of foxes consisted of Goose Eggs, goslings, and lemmings (Lemmus and Dicrostonyx spp.). We recorded the number of prey consumed and cached and the time that foxes invested in these activities. Foxes took more time to consume a Goose egg than a lemming or gosling but cached a greater proportion of Eggs than the other prey type. This may be caused by the Eggshell, which presumably decreases the perishability and/or pilfering risk of cached Eggs, but also increases egg consumption time. Arctic foxes usually Communicated by E. Korpimäk
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cache and carry hoarding behavior of arctic fox
Behavioral Ecology and Sociobiology, 2007Co-Authors: Jean-françois Giroux, Vincent Careau, Dominique BerteauxAbstract:Food-hoarding animals are expected to preferentially cache items with lower perishability and/or higher consumption time. We observed arctic foxes (Alopex lagopus) foraging in a greater snow Goose (Anser caerulescens atlanticus) colony where the main prey of foxes consisted of Goose Eggs, goslings, and lemmings (Lemmus and Dicrostonyx spp.). We recorded the number of prey consumed and cached and the time that foxes invested in these activities. Foxes took more time to consume a Goose egg than a lemming or gosling but cached a greater proportion of Eggs than the other prey type. This may be caused by the Eggshell, which presumably decreases the perishability and/or pilfering risk of cached Eggs, but also increases egg consumption time. Arctic foxes usually recached Goose Eggs but rarely recached goslings or lemmings. We tested whether the rapid-sequestering hypothesis could explain this recaching behavior. According to this hypothesis, arctic foxes may adopt a two-stage strategy allowing both to maximize egg acquisition rate in an undefended nest and subsequently secure Eggs in potentially safer sites. Foxes spent more time carrying an egg and traveled greater distances when establishing a secondary than a primary cache. To gain further information on the location and subsequent fate of cached Eggs, we used dummy Eggs containing radio transmitters. Lifespan of primary caches increased with distance from the Goose nest. Secondary caches were generally located farther from the nest and had a longer lifespan than primary caches. Behavioral observations and the radio-tagged egg technique both gave results supporting the rapid-sequestering hypothesis.
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shared predators and indirect trophic interactions lemming cycles and arctic nesting geese
Journal of Animal Ecology, 2002Co-Authors: Joel Bety, Gilles Gauthier, Erkki Korpimaki, Jean-françois GirouxAbstract:Summary 1 We investigated the hypothesis that cyclic lemming populations indirectly affect arctic-nesting greater snow geese (Anser caerulescens atlanticus L.) through the behavioural and numerical responses of shared predators. 2 The study took place on Bylot Island in the Canadian High Arctic during two lemming cycles. We recorded changes in foraging behaviour and activity rate of arctic foxes, parasitic jaegers, glaucous gulls and common ravens in a Goose colony during one lemming cycle and we monitored denning activity of foxes for 7 years. We also evaluated the total response of predators (i.e. number of Eggs depredated). 3 Arctic foxes were more successful in attacking lemmings than Goose nests because predators were constrained by Goose nest defence. Predators increased their foraging effort on Goose Eggs following a lemming decline. 4 Activity rates in the Goose colony varied 3·5-fold in arctic foxes and 4·8-fold in parasitic jaegers, and were highest 2 and 3 years after the lemming peak, respectively. The breeding output of arctic foxes appeared to be driven primarily by lemming numbers. 5 Predators consumed 19–88% of the annual Goose nesting production and egg predation intensity varied 2·7-fold, being lowest during peak lemming years. Arctic foxes and parasitic jaegers were the key predators generating marked annual variation in egg predation. 6 Our study provides strong support for short-term, positive indirect effects and long-term, negative indirect effects of lemming populations on arctic-nesting geese. The outcome between these opposing indirect effects is probably an apparent competition between rodents and many terrestrial arctic-nesting birds.
Ernest Winocour - One of the best experts on this subject based on the ideXlab platform.
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adeno associated virus type 2 enhances Goose parvovirus replication in embryonated Goose Eggs
Virology, 2005Co-Authors: Mertyn Malkinson, Ernest WinocourAbstract:The autonomous Goose parvovirus (GPV) and the human helper-dependent adeno-associated virus type 2 (AAV2) share a high degree of homology. To determine if this evolutionary relationship has a biological impact, we studied viral replication in human 293 cells and in embryonated Goose Eggs coinfected with both viruses. Similar experiments were performed with the minute virus of mice (MVM), an autonomous murine parvovirus with less homology to AAV2. In human 293 cells, both GPV and MVM augmented AAV2 replication. In contrast, AAV2 markedly enhanced GPV replication in embryonated Goose Eggs under conditions where a similar effect was not observed with MVM. AAV2 did not replicate in embryonated Goose Eggs and AAV2 inactivated by UV-irradiation also enhanced GPV replication. To our knowledge, this is the first report that a human helper-dependent member of the Parvoviridae can provide helper activity for an autonomous parvovirus in a natural host.
Kurt C. Vercauteren - One of the best experts on this subject based on the ideXlab platform.
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movements of urban canada geese implications for nicarbazin treatment programs
2004Co-Authors: Kurt C. Vercauteren, David R MarksAbstract:Resident Canada Goose (Branta canadensis) and human populations in North America are increasing rapidly. Consequently, human-Goose conflicts also are increasing. A potential approach to manage Canada Goose populations is the use of orally delivered reproductive inhibitors. Nicarbazin, when ingested daily, is a reproductive inhibitor that has the potential to reduce the hatchability of Canada Goose Eggs. To successfully employ reproductive inhibition, managers must understand the behavior of local Canada Goose populations, primarily springtime movements, nesting, and habitat use to develop effective methods for delivering necessary doses. We monitored movement, habitat use, and nesting of 51 resident Canada geese, all adult females, at Bay Beach Wildlife Sanctuary (BBWS), Green Bay, Wisconsin, during 2001 and 2002. Our objective was to determine if geese were sufficiently sedentary during the nest initiation period to allow effective dosage with nicarbazin to assess its potential as a management tool. Our results indicated some geese never departed the area and were available for daily dosing while others departed and never returned. Goose movements and time spent away from BBWS were highly variable among geese; individuals traveled <1 km to 109 km from BBWS. However, movement patterns of individuals did not vary markedly between years. Similarly, nest sites were widely variable among geese but were consistent among years within individuals. Habitat use varied considerably among geese and included industrial complexes, urban lawns and parks, agricultural fields, and remote marshes. Overall, there was high variability among Canada geese in movement patterns, nesting, and habitat use. Such variability presents difficulty in delivering required doses of nicarbazin, or other reproductive inhibitors that must be ingested daily prior to and during egg laying.
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4,4′‐Dinitrocarbanilide (DNC) concentrations in egg shells as a predictor of nicarbazin consumption and DNC dose in Goose Eggs
Pest management science, 2003Co-Authors: Randal S. Stahl, Kurt C. Vercauteren, Dennis J. Kohler, John J. JohnstonAbstract:Nicarbazin is being investigated as an infertility agent for the control of non-migratory Canada geese (Branta canadensis L) populations. Nicarbazin is presently registered for use as a coccidiostat for poultry. Geese fed sufficient quantities of nicarbazin will lay non-viable Eggs. We established nicarbazin consumption by measuring the concentration of a component of the formulation, 4,4'-dinitrocarbanilide (DNC) in the egg contents (yolk, albumin) in non-viable Eggs. To estimate the nicarbazin consumption of birds that laid viable Eggs (Eggs that hatched or contained an embryo), a high-performance liquid chromatography method was developed to measure the concentration of DNC in egg shells. A statistically significant correlation was established using linear regression between the mean concentrations of DNC in the egg shell and in the egg contents in non-viable Eggs. Viable Eggs were estimated to contain lower levels of DNC than non-viable Eggs. DNC concentrations in both the egg contents and the egg shell increased with increases in nicarbazin dose in feed. Our method allows for the estimation of nicarbazin consumption and DNC dose in Eggs under field conditions, which is important in developing an effective infertility agent for over-abundant non-migratory Goose populations.
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evaluations of nicarbazin treated pellets for reducing the laying and viability of canada Goose Eggs
2000Co-Authors: Kurt C. Vercauteren, Michael J Pipas, Kenneth L TopeAbstract:ta canaden : The number of Canada geese (Bran sis) nesting in the United States is increasin and problems
David Mizrahi - One of the best experts on this subject based on the ideXlab platform.
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lead mercury cadmium chromium and arsenic levels in Eggs feathers and tissues of canada geese of the new jersey meadowlands
Environmental Research, 2011Co-Authors: Nellie Tsipoura, Joanna Burger, Michael Newhouse, Christian Jeitner, Michael Gochfeld, David MizrahiAbstract:Abstract The New Jersey Meadowlands are located within the heavily urbanized New York/New Jersey Harbor Estuary and have been subject to contamination due to effluent and runoff from industry, traffic, and homes along the Hackensack River and nearby waterways. These extensive wetlands, though heavily impacted by development and pollution, support a wide array of bird and other wildlife species. Persistent contaminants may pose threats to birds in these habitats, affecting reproduction, egg hatchability, nestling survival, and neurobehavioral development. Metals of concern in the Meadowlands include arsenic, cadmium, chromium, lead, and mercury. These metals were analyzed in Eggs, feathers, muscle, and liver of Canada geese (Branta canadensis) breeding in four wetland sites. We sampled geese collected during control culling (n=26) and collected Eggs from Goose nests (n=34). Levels of arsenic were below the minimum quantification level (MQL) in most samples, and cadmium and mercury were low in all tissues sampled. Chromium levels were high in feather samples. Mercury levels in Eggs of Canada geese, an almost exclusively herbivorous species, were lower (mean ±SE 4.29±0.30 μg/g wet weight) than in Eggs of omnivorous mallards (Anas platyrhynchos), and insectivorous red-winged blackbirds (Agelaius phoeniceus) and marsh wrens (Cistothorus palustris) from the Meadowlands, consistent with trophic level differences. However, lead levels were higher in the Goose Eggs (161±36.7 ng/g) than in the other species. Geese also had higher levels of lead in feathers (1910±386 ng/g) than those seen in Meadowlands passerines. By contrast, muscle and liver lead levels were within the range reported in waterfowl elsewhere, possibly a reflection of metal sequestration in Eggs and feathers. Elevated lead levels may be the result of sediment ingestion or ingestion of lead shot and sinkers. Finally, lead levels in Goose liver (249±44.7 ng/g) and Eggs (161±36.7 ng/g) may pose a risk if consumed frequently by humans. Mill Creek, the site with the most documented prior contamination, had significantly elevated cadmium, chromium, mercury, and lead in Goose tissues.
