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Avian Behavioral and Physiological Responses to Challenging Thermal Environments and Extreme Weather Events
- 2022
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Samlingsverk (redaktörskap) (refereegranskat)abstract
- Birds occupy habitats ranging from Antarctic ice shelves and Arctic tundra to low-latitude deserts and lowland rainforests, and so are exposed to the full range of climates present on Earth. Cold, hot, or variable (on a variety of temporal scales) thermal conditions can present significant thermoregulatory challenges to birds, which typically must maintain body temperatures within narrow physiological tolerance limits. Such challenges may occur in all stages of the annual cycle and in all life stages of birds, so the ability to adjust to these conditions is required to maintain stable populations through time. For this Research Topic, we broadly define a challenging thermal environment as one necessitating behavioral or physiological adjustments to maintain body temperatures at levels appropriate for continued physiological function.Avian abilities to respond to extreme cold and heat are defined by thermoregulatory capacities for heat production or dissipation, respectively. Behavioral responses to temperature challenges can reduce the necessity for and magnitude of physiological adjustments, so together, physiological capacities and behavioral responses determine the probability of survival in thermally challenging situations. Moreover, thermal conditions experienced during reproduction can affect parental investment in the nesting effort and, independently, alter the course of nestling development, with potentially long-term consequences. Behavioral responses to these conditions as well as physiological responses at multiple levels of organization, from organisms to molecules, allow birds to tolerate thermal challenges. Our knowledge of the mechanisms by which birds respond, the time course for such responses, and the impacts on fitness, however, remain incompletely understood. Studies examining behavioral and physiological responses of birds to extreme and/or seasonally variable climates have been a research focus for decades, but recent advances in methods of measurement and analyses of physiological and behavioral traits have led to novel findings regarding the patterns and mechanisms by which birds adjust to challenging thermal environments.This Research Topic examines how thermal conditions in the environment pose challenges to birds and the physiological and behavioral adjustments that birds employ to meet them. Articles for this Research Topic may be original research papers, reviews, or perspectives. Specific themes that we believe are suitable for this Research Topic include, but are not limited to:• Integrative mechanisms underlying bird thermoregulatory capacities contributing to a tolerance of challenging thermal environments and their links to fitness• Influence of thermal conditions during reproduction on parental investment or nestling development• Behavioral responses to challenging thermal conditions and their mechanistic underpinnings• Time courses for physiological adjustments to environmental temperature variation• Physiological and behavioral flexibility associated with daily or seasonal temperature variation• Physiological and behavioral responses and tolerance limits during extreme weather events• Body temperature regulation under challenging thermal conditions and energy or water restrictions, including real-time field measurements and thermal imaging• Body temperature regulation and environmental or ecological drivers of hypometabolic strategies• Physiological consequences of exceeding thermoregulatory capacities
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- Lewden, Agnès, et al.
(författare)
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Body temperature responses to handling stress in wintering Black-capped Chickadees (Poecile atricapillus L.)
- 2017
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Ingår i: Physiology & Behavior. - : Elsevier BV. - 1873-507X .- 0031-9384. ; 179, s. 49-54
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Tidskriftsartikel (refereegranskat)abstract
- Body temperature variation in response to acute stress is typically characterized by peripheral vasoconstriction and a concomitant increase in core body temperature (stress-induced hyperthermia). It is poorly understood how this response differs between species and within individuals of the same species, and how it is affected by the environment. We therefore investigated stress-induced body temperature changes in a non-model species, the Black-capped Chickadee, in two environmental conditions: outdoors in low ambient temperature (mean: − 6.6 °C), and indoors, in milder ambient temperature close to thermoneutrality (mean: 18.7 °C). Our results show that the change in body temperature in response to the same handling stressor differs in these conditions. In cold environments, we noted a significant decrease in core body temperature (− 2.9 °C), whereas the response in mild indoor conditions was weak and non-significant (− 0.6 °C). Heat loss in outdoor birds was exacerbated when birds were handled for longer time. This may highlight the role of behavioral thermoregulation and heat substitution from activity to body temperature maintenance in harsh condition. Importantly, our work also indicates that changes in the physical properties of the bird during handling (conductive cooling from cold hands, decreased insulation from compression of plumage and prevention of ptiloerection) may have large consequences for thermoregulation. This might explain why females, the smaller sex, lost more heat than males in the experiment. Because physiological and physical changes during handling may carry over to affect predation risk and maintenance of energy balance during short winter days, we advice caution when designing experimental protocols entailing prolonged handling of small birds in cold conditions.
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