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Full-Text Articles in Life Sciences
A Colonial-Nesting Seabird Shows Limited Heart Rate Responses To Natural Variation In Threats Of Polar Bears, Erica A. Geldart, Oliver P. Love, Andrew F. Barnas, Christopher M. Harris, H. Grant Gilchrist, Christina A.D. Semeniuk
A Colonial-Nesting Seabird Shows Limited Heart Rate Responses To Natural Variation In Threats Of Polar Bears, Erica A. Geldart, Oliver P. Love, Andrew F. Barnas, Christopher M. Harris, H. Grant Gilchrist, Christina A.D. Semeniuk
Great Lakes Institute for Environmental Research Publications
Several predator-prey systems are in flux as an indirect result of climate change. In the Arctic, earlier sea-ice loss is driving polar bears (Ursus maritimus) onto land when many colonial nesting seabirds are breeding. The result is a higher threat of nest predation for birds with potential limited ability to respond. We quantified heart rate change in a large common eider (Somateria mollissima) breeding colony in the Canadian Arctic to explore their adaptive capacity to keep pace with the increasing risk of egg predation by polar bears. Eiders displayed on average higher heart rates from baseline when polar bears were …
Favorable Spring Conditions Can Buffer The Impact Of Winter Carryover Effects On A Key Breeding Decision In An Arctic-Breeding Seabird, Rolanda J. Steenweg, Glenn T. Crossin, Holly L. Hennin, H. Grant Gilchrist, Oliver P. Love
Favorable Spring Conditions Can Buffer The Impact Of Winter Carryover Effects On A Key Breeding Decision In An Arctic-Breeding Seabird, Rolanda J. Steenweg, Glenn T. Crossin, Holly L. Hennin, H. Grant Gilchrist, Oliver P. Love
Great Lakes Institute for Environmental Research Publications
The availability and investment of energy among successive life-history stages is a key feature of carryover effects. In migratory organisms, examining how both winter and spring experiences carryover to affect breeding activity is difficult due to the challenges in tracking individuals through these periods without impacting their behavior, thereby biasing results. Using common eiders Somateria mollissima, we examined whether spring conditions at an Arctic breeding colony (East Bay Island, Nunavut, Canada) can buffer the impacts of winter temperatures on body mass and breeding decisions in birds that winter at different locations (Nuuk and Disko Bay, Greenland, and Newfoundland, Canada; assessed …
Plasma Mammalian Leptin Analogue Predicts Reproductive Phenology, But Not Reproductive Output In A Capital-Income Breeding Seaduck, Holly L. Hennin, Pierre Legagneux, H. Grant Gilchrist, Joël Bêty, John P. Mcmurtry, Oliver P. Love
Plasma Mammalian Leptin Analogue Predicts Reproductive Phenology, But Not Reproductive Output In A Capital-Income Breeding Seaduck, Holly L. Hennin, Pierre Legagneux, H. Grant Gilchrist, Joël Bêty, John P. Mcmurtry, Oliver P. Love
Great Lakes Institute for Environmental Research Publications
To invest in energetically demanding life history stages, individuals require a substantial amount of resources. Physiological traits, particularly those related to energetics, can be useful for examining variation in life history decisions and trade-offs because they result from individual responses to environmental variation. Leptin is a protein hormone found in mammals that is proportional to the amount of endogenous fat stores within an individual. Recently, researchers have confirmed that a mammalian leptin analogue (MLA), based on the mammalian sequence of leptin, is present with associated receptors and proteins in avian species, with an inhibitory effect on foraging and body mass …
Higher Rates Of Prebreeding Condition Gain Positively Impacts Clutch Size: A Mechanistic Test Of The Condition-Dependent Individual Optimization Model, Holly L. Hennin, Cody J. Dey, Joël Bêty, H. Grant Gilchrist, Pierre Legagneux, Tony D. Williams, Oliver P. Love
Higher Rates Of Prebreeding Condition Gain Positively Impacts Clutch Size: A Mechanistic Test Of The Condition-Dependent Individual Optimization Model, Holly L. Hennin, Cody J. Dey, Joël Bêty, H. Grant Gilchrist, Pierre Legagneux, Tony D. Williams, Oliver P. Love
Great Lakes Institute for Environmental Research Publications
A combination of timing of and body condition (i.e., mass) at arrival on the breeding grounds interact to influence the optimal combination of the timing of reproduction and clutch size in migratory species. This relationship has been formalized by Rowe et al. in a condition-dependent individual optimization model (American Naturalist, 1994, 143, 689-722), which has been empirically tested and validated in avian species with a capital-based breeding strategy. This model makes a key, but currently untested prediction; that variation in the rate of body condition gain will shift the optimal combination of laying date and clutch size. This prediction is …
Higher Rates Of Prebreeding Condition Gain Positively Impacts Clutch Size: A Mechanistic Test Of The Condition-Dependent Individual Optimization Model, Holly L. Hennin, Cody J. Dey, Joël Bêty, H. Grant Gilchrist, Pierre Legagneux, Tony D. Williams, Oliver P. Love
Higher Rates Of Prebreeding Condition Gain Positively Impacts Clutch Size: A Mechanistic Test Of The Condition-Dependent Individual Optimization Model, Holly L. Hennin, Cody J. Dey, Joël Bêty, H. Grant Gilchrist, Pierre Legagneux, Tony D. Williams, Oliver P. Love
Integrative Biology Publications
A combination of timing of and body condition (i.e., mass) at arrival on the breeding grounds interact to influence the optimal combination of the timing of reproduction and clutch size in migratory species. This relationship has been formalized by Rowe et al. in a condition-dependent individual optimization model (American Naturalist, 1994, 143, 689-722), which has been empirically tested and validated in avian species with a capital-based breeding strategy. This model makes a key, but currently untested prediction; that variation in the rate of body condition gain will shift the optimal combination of laying date and clutch size. This prediction is …
Feather Corticosterone Reveals Effect Of Moulting Conditions In The Autumn On Subsequent Reproductive Output And Survival In An Arctic Migratory Bird, N. Jane Harms, Pierre Legagneux, H. Grant Gilchrist, Joël Bêty, Oliver P. Love, Mark R. Forbes, Gary R. Bortolotti, Catherine Soos
Feather Corticosterone Reveals Effect Of Moulting Conditions In The Autumn On Subsequent Reproductive Output And Survival In An Arctic Migratory Bird, N. Jane Harms, Pierre Legagneux, H. Grant Gilchrist, Joël Bêty, Oliver P. Love, Mark R. Forbes, Gary R. Bortolotti, Catherine Soos
Integrative Biology Publications
For birds, unpredictable environments during the energetically stressful times of moulting and breeding are expected to have negative fitness effects. Detecting those effects however, might be difficult if individuals modulate their physiology and/or behaviours in ways to minimize short-term fitness costs. Corticosterone in feathers (CORTf) is thought to provide information on total baseline and stress-induced CORT levels at moulting and is an integrated measure of hypothalamic-pituitary-adrenal activity during the time feathers are grown.We predicted that CORTf levels in northern common eider females would relate to subsequent body condition, reproductive success and survival, in a population of eiders nesting in the …