LTREB: Ecological and Evolutionary Determinants of Habitat Selection and Risk of Nest Predation among Coexisting Species

9707598在共存物种中进行马丁栖息地选择通常被认为反映了将生态成本降至最低并使适合度最大化的选择。共存物种之间的生态过程往往被强调为微生境选择差异的潜在解释。然而，过程和过程背后的机制很少被直接测试。捕食有利于共存物种之间的微生境差异，这是一个可以直接测试的过程。然而，栖息地的选择也可能受到作为物种进化历史函数的生理耐受性的限制，不同的进化史或生理耐受性可能为物种间资源利用的差异提供另一种解释。这种生物和非生物影响的替代作用在小气候梯度上特别突出，因为物种通常沿着小气候梯度隔离。这项研究将解决这样一个问题：“物种沿环境梯度的分布是否反映了生理限制或对生态成本的反应，如巢穴捕食或植被偏好？”继续对这一系统和巢址转移进行长期研究是重要的，因为这种转移提供了一个前所未有的机会，可以根据潜在环境影响的动态变化来研究生物和非生物影响对栖息地选择和物种共存的潜在作用。这项长期工作的继续将促进我们对巢穴捕食的潜在机制的理解，因为这是一个影响栖息地选择、物种共存和父母活动模式的过程。这些数据将为物种的长期保护提供重要信息；成功繁殖的栖息地要求对保护至关重要，该项目下收集的数据目前正被美国林业局用来影响对正在研究的森林的土地管理决策。

9707598 Martin Habitat selection among coexisting species is generally thought to reflect choices that minimize ecological costs and maximize fitness. Ecological processes among coexisting species are often emphasized as a potential explanation for differences in microhabitat choices. Yet, processes and the mechanisms underlying processes are rarely directly tested. Predation can favor microhabitat differences among coexisting species and is a process that can be tested directly. However, habitat selection also may be constrained by physiological tolerances as a function of the evolutionary history of a species and different evolutionary histories or physiological tolerances may provide an alternative explanation for differences in resource use among species. Such alternative actions of biotic versus abiotic influences are particularly highlighted along microclimate gradients because species commonly segregate along microclimate gradients. This study will address the question, "Does the distribution of species along an environmental gradient reflect physiological constraints or responses to ecological costs such as nest predation or vegetation preferences?" Continued long term study of this system and nest site shifts is important because such shifts provide an unprecedented opportunity to examine the potential role of biotic versus abiotic influences on habitat selection and species coexistence based on dynamic changes in potential environmental influences. Continuation of this long-term work will advance our understanding of mechanisms underlying nest predation as a process influencing habitat selection, species coexistence, and parental activity patterns. These data will provide important information for long-term conservation of species; habitat requirements for successful reproduction are critical for conservation and data being collected under this project is currently being used by the US Forest Service to affect land management decisions on the forests being studied.