Collaborative Research: Responses of Desert Endotherms to Rapid Recent Climate Change

气候变化对动植物分布的影响存在着相当大的不确定性。大多数关于近期气候变化对物种地理分布的影响的研究都是基于计算机模型的预测，而不是实地研究的测量结果。这项研究采用了一种非常不同的多层次方法，通过使用具有必要精度的历史记录和标本，地理和时间尺度以及观测到的气候变化幅度，对气候和非气候因素对物种地理分布变化的直接和间接影响产生重要见解。这项研究将重新调查美国西南部70多年前最后一次调查的实地，这不仅将促进我们对环境变化的理解，而且将为未来变化的比较建立一个新的基准。联邦土地管理机构将受益于对敏感物种和野生动物对气候变化反应的更多了解。收集的样本和录音将用于辅助研究。结果将通过讲座、大众报刊和媒体以及博物馆展览，包括圣地亚哥自然历史博物馆和加州奥克兰博物馆的新展品，广泛地向公众推广。国家公园服务科学和教育办公室将通过视频和播客广泛传播结果，以培训他们的口译员了解环境变化的生物影响，并为他们的游客中心提供口译材料。本科生，研究生和博士后研究人员将参与这项研究，学习现场和实验室技术，自然历史，生理方法和建模。结果和数据将通过网站和在线数据库与科学家和公众分享。该项目将重新调查从1908-1945年取样的地点，以研究20世纪世纪气候变化对索诺兰、莫哈韦和大盆地沙漠小型哺乳动物和鸟类群落的影响。这些地区在过去50年里大大变暖，年平均气温上升了2°C。这项研究将通过以下方式促进对动物对气候变化反应的理解：开发新的模型，通过温度和水分胁迫的重要生理阈值将气候联系起来，机械地预测物种的范围;开发新的测试，以检查气候变化是否导致物种个别地改变其地理范围，或者整个物种群落是否发生类似的变化;并测试物种的体型和饮食是否对气候变化做出了反应。将在105个地点重新调查鸟类和哺乳动物。将收集音频和实物凭证样本，供今后重新分析。将收集鸟类和哺乳动物头骨的标准形态学数据。将从组织中测量碳和氮同位素的比率。多物种占用模型将说明历史和当前调查的可检测性，以制定当地殖民化和物种灭绝的无偏估计数，并根据地点一级的特征对群落组成的变化作出反应。将对12种哺乳动物在热中性区上限及以上的热应力和水应力进行测量，以建立可验证的热应力模型。

Considerable uncertainty exists about the effects of changing climates on the distributions of plants and animals. Most studies of recent climate change on species' geographic ranges are based on projections from computer models rather than measured responses from field studies. This research takes a very different and multi-tiered approach by using historical records and specimens with the necessary precision, geographic and temporal scale, and magnitude of observed climate change to produce important insights into the direct and indirect effects of climatic and nonclimatic factors on changes in species' geographic distributions. This research will resurvey field sites in the southwest United States last surveyed more than 70 years ago, which will not only advance our understanding of environmental changes but will establish a new benchmark for comparison of future changes. Federal land-management agencies will benefit from greater knowledge of the status of sensitive species and wildlife responses to climate change. Specimens and audio recordings collected will be available for ancillary studies. Results will be extended broadly to the public through talks, popular press and media, and museum displays, including new exhibits of the San Diego Natural History Museum and the Oakland Museum of California. The National Park Service Science and Education Office will distribute results widely through videos and podcasts to train their interpreters on the biological effects of environmental change and to provide interpretive materials for their visitor centers. Undergraduates, graduate student and postdoctoral researchers will participate in this study, learning field and lab techniques, natural history, physiological methods and modeling. Results and data will be shared with scientists and the general public through websites and online databases. This project will resurvey sites that were sampled from 1908-1945 to examine the impact of 20th century climate change on small mammal and bird communities in Sonoran, Mojave, and Great Basin deserts. These areas have warmed greatly over the last 50 years, with the average annual temperatures increasing up to 2°C. The research will advance understanding of animal responses to climate change by: developing new models that mechanistically project species' ranges by linking climate through important physiological thresholds of temperature and water stress; developing novel tests to examine whether climate change results in species shifting their geographic ranges individually or whether whole communities of species shift similarly; and testing if body sizes and diets of species have responded to climate change. Birds and mammals will be resurveyed at 105 sites. Both audio and physical voucher specimens will be collected and made available for future reanalysis. Standard morphological data will be collected for birds and mammal skulls. Ratios of carbon and nitrogen isotopes will be measured from tissues. Multispecies occupancy models will account for detectability in historical and current surveys to develop unbiased estimators of local colonization and extinction of species and changes in community composition in response to site-level characteristics. Measures of thermal and hydric stress at and above the upper limit of the thermal neutral zone will be made for 12 species of mammals to develop models of heat stress that can be validated.