Publications by authors named "Audrey Le Pogam"
Birds maintain some of the highest body temperatures among endothermic animals. Often deemed a selective advantage for heat tolerance, high body temperatures also limits birds' thermal safety margin before reaching lethal levels. Recent modelling suggests that sustained effort in Arctic birds might be restricted at mild air temperatures, which may require reductions in activity to avoid overheating, with expected negative impacts on reproductive performance.
View Article and Find Full Text PDFSeveral species of passerines leave their nest with unfinished feather growth, resulting in lower feather insulation and increased thermoregulatory demands compared to adults. However, feather insulation is essential for avian species breeding at northern latitudes, where cold conditions or even snowstorms can occur during the breeding season. In altricial arctic species, increased heat loss caused by poor feather insulation during growth could be counter-adaptative as it creates additional energy demands for thermoregulation.
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- Rising global temperatures are making it harder for wildlife, especially Arctic birds like the snow bunting, to reproduce because they need to cool down more to stay active.
- Researchers figured out a specific temperature (11.7°C) where these birds start having trouble providing food to their young.
- Birds in warmer, lower Arctic areas often experience temperatures above this limit, while those in higher Arctic areas may face multiple hot days in a row, leading to challenges in raising their young.
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- Neonicotinoids, like imidacloprid, are common insecticides that negatively affect birds, leading to issues such as reduced fat stores and delayed migration.
- A study on Zebra finches found that low doses of imidacloprid during early growth improved body condition and enabled compensatory growth even under food restrictions.
- The research reveals that early exposure to low doses of neonicotinoids can have lasting effects on adult birds, influencing their lean mass and metabolic rates.
Arctic animals inhabit some of the coldest environments on the planet and have evolved physiological mechanisms for minimizing heat loss under extreme cold. However, the Arctic is warming faster than the global average and how well Arctic animals tolerate even moderately high air temperatures ( ) is unknown.Using flow-through respirometry, we investigated the heat tolerance and evaporative cooling capacity of snow buntings (; ≈31 g, = 42), a cold specialist, Arctic songbird.
View Article and Find Full Text PDFAbstractResident temperate passerines adjust their phenotypes to cope with winter constraints, with peak performance in metabolic traits typically occurring during the coldest months. However, it is sparsely known whether cold-adapted northern species make similar adjustments when faced with variable seasonal environments. Life in near-constant cold could be associated with limited flexibility in traits underlying cold endurance.
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- Wild black-capped chickadees can get better at dealing with cold temperatures before winter, and they can survive really cold days down to -20°C.
- When the temperature suddenly drops from 20°C to 5°C, they were tested to see how they handle stress caused by the cold.
- The study found that the chickadees that are used to the cold (cold-acclimated) handle this stress better than those that are adapting (transition), but overall, their bodies respond slowly to these changes.
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- Scientists studied how black-capped chickadees change their bodies quickly when the temperature drops suddenly.
- They found that chickadees used to cold weather could adjust faster than those used to warm weather.
- In just 3 hours after the temperature dropped, the cold birds changed their muscle structure to help them deal with the cold better.