The direct effects of global warming on bird communities: the physiological ecology of die-offs during heat waves

地球表面迅速变暖，以及热浪频率、强度和持续时间将显著增加的预测表明，可能会对动物群造成重大影响。尽管研究很少，但全球变暖对沙漠动物最重要的直接影响可能是与极端热浪相关的灾难性死亡。尽管它们还没有影响到美国西南部的沙漠，但澳大利亚、印度和南非最近的报告表明，由于热应激导致的鸟类死亡正在越来越频繁地发生。这项研究试图将鸟类耐热性的生理和行为机制与应对全球变暖的种群和群落的变化联系起来。该项目将描述个体和物种在耐热性水平上的差异，以及野外和实验室中三大洲鸟类的水合状态如何改变耐热性。通过对身体大小、生态、进化历史和多样性不同的物种进行抽样，这项研究将提供所需的信息，以开发预测模型，估计未来气候对鸟类物种和群落的影响。目前，关于灾难性死亡的自然历史和生理生态，以及可能减轻或加剧对沙漠鸟类群落的影响的因素，只有轶事信息。为了了解这一现象以及沙漠鸟类群落在全球范围内的差异，这项研究将研究三大洲的鸟类群落对热浪的行为和生理反应，作为身体大小、饮食、对免费水资源的相对依赖和鸟类群落结构的函数。此外，还将收集澳大利亚鸟类在死亡事件期间的生理状态、行为和病理的数据，并将其与实验室结果进行比较，以提供关于热浪的自然历史及其对鸟类群落影响的综合看法。这项建议代表了一种了解气候对鸟类群落的直接影响的国际方法。这一合作将促进更好地了解气候变化在全球范围内正在产生的影响，普遍的研究结果将适用于所有鸟类群落。该项目将为本科生和研究生提供旅行机会，并与来自非洲和澳大利亚的研究人员互动。新墨西哥大学是一所西班牙裔服务机构，西班牙裔和美国原住民本科生将通过NSF REU计划从事研究。这项研究将通过提供物种和地区的风险评估来向自然资源管理者提供信息。气候变化是一个全球性的问题，由于鸟类群落可能受到不同因素的影响，如身体大小分布、饮食行会和免费水资源的可获得性，这项研究的发现将增进对气候事件如何改变鸟类群落以及它们所提供的生态系统服务(如授粉和种子传播)的理解。描述鸟类中暑发病机制的研究将引起兽医、比较生物学家和医学研究人员的极大兴趣，并有可能为识别鸟类中暑提供生物标志物。

Rapid warming of the Earth's surface and predictions of significant increases in the frequency, intensity and duration of heat waves suggests the potential for large impacts on animal communities. Although little studied, among the most important direct effects of global warming on desert animals may be catastrophic mortality associated with extreme heat waves. Although they have yet to impact deserts of the southwestern United States, recent reports from Australia, India and South Africa indicate that bird die-offs due to heat stress are occurring with increasing frequency. This research seeks to link physiological and behavioral mechanisms of heat tolerance in birds to changes in populations and communities in response to global warming. This project will characterize individual and species level variation in heat tolerance and how it is modified by hydration status in birds across three continents in the field and laboratory. By sampling species that differ in body size, ecology and evolutionary history and diversity, this research will provide the information needed to develop predictive models that estimate impacts of future climates on bird species, and communities. Currently, there is only anecdotal information on the natural history and physiological ecology of catastrophic die-offs and the factors that potentially mitigate or exacerbate the effects on desert bird communities. To understand this phenomenon and how desert bird communities differ on a global scale, this study will examine the behavioral and physiological responses to heat waves as a function of body size, diet, relative reliance on free water resources and structure of bird communities on three continents. Data will also be collected on the physiological status, behavior and pathology of birds in Australia during mortality events, which will be compared to laboratory findings to provide an integrated view of the natural history of heat waves and their effects on bird communities.This proposal represents an international approach to understanding the direct effects of climate on bird communities. This collaboration will foster a better understanding of the ongoing effects of climate change on a global scale and the generalized findings will be applicable to all bird communities. The project will provide opportunities for undergraduate and graduate students to travel and interact with researchers from Africa and Australia. The University of New Mexico is a Hispanic serving institution and Hispanic and Native American undergraduate students will be engaged in research through the NSF REU program. This research will inform natural resource managers by providing risk assessments for species and regions. Climate change is a global problem and because bird communities are likely to be differentially impacted by factors such as body size distributions, dietary guilds, and the availability of free water resources, findings from this research will improve understanding of how climate events will modify bird communities and thus the ecosystem services (such as pollination and seed dispersal) that they provide. Research describing the pathogenesis of heatstroke in birds will be of great interest to veterinarians, comparative biologists and medical researchers, and has the potential to provide biomarkers for identifying heatstroke in birds.