RUI: Incidental Nest Predation in Songbirds: Using Behavioral Indicators to Determine Ecological Processes and Scales

0089588. 肯尼斯施密特。 捕食率和捕食者对猎物的后续影响被认为主要取决于捕食者的种群密度。 尽管如此，当捕食者在寻找其主要猎物时偶然遇到次要猎物类型时，可能会发生多面手捕食。 这种偶然捕食是由个体捕食者对替代猎物类型的丰度和分布以及捕食者环境特征的行为反应决定的。 附带捕食在通才中可能极为常见，在专门捕食者中则较少。 由于这种弱相互作用可能稳定群落结构，因此它们具有相当重要的意义。 更具体地说，偶然捕食率可能与无敌人空间（未被捕食者利用的区域）的数量有关。 了解这种机制是至关重要的，因为它的关系的强度的捕食者-猎物的相互作用，以及因为敌人的自由空间影响的稳定性的捕食者-猎物的动态和共存的多个猎物species.The拟议的研究探讨偶然捕食繁殖鸣禽，其卵和雏鸟的小哺乳动物，主要是白足鼠（Peromyscus leucopus）的社会。 它从个体行为和种群动态的角度关注捕食，以及它们对社区现象的影响。 该方法结合了理论，观察和实验成分，最终测试明确的潜在机制。 更具体地说，研究涉及（1）监测常见脊椎动物的密度（白足鼠、东部花栗鼠、灰松鼠）的巢捕食者（2）使用人工鸣禽巢监测巢捕食率，和（3）监测选定鸣禽物种的天然巢的成功，（4）测试无敌人空间是否是偶然捕食的关键控制，（5）评估放弃密度作为多空间尺度生态格局和过程指示器的效用;（6）评估种群密度和捕食者个体行为反应对鸣禽巢存活的影响。

0089588. Kenneth Schmidt. Predation rates and the subsequent impact of predators on prey are thought to be determined mostly by the population density of predators. Nonetheless, much predation by generalist predators may occur when secondary prey types are encountered coincidentally by a predator while searching for its primary prey. Such incidental predation is determined by the behavioral responses of individual predators to the abundance and distribution of alternative prey types, as well as to features of the predator's environment. Incidental predation may be extremely common in generalist, and to a smaller degree in specialist predators. Because such weak interactions potentially stabilize community structure, they are of considerable importance. More specifically, the rate of incidental predation may be related to amount of enemy-free space (areas unutilized by predators). Understanding this mechanism is critical because of its relationship to the strength of the predator-prey interaction, as well because enemy-free space influences the stability of predator-prey dynamics and the coexistence of multiple prey species.The proposed research examines incidental predation in a community of breeding songbirds, whose eggs and nestlings are preyed on by small mammals, primarily the white-footed mouse (Peromyscus leucopus). It focuses on predation from the perspectives of individual behaviors and population dynamics, as well as their repercussions to community-level phenomena. The approach combines theoretical, observational, and experimental components, ultimately to test explicit underlying mechanisms. More specifically, the research involves (1) monitoring the density of common vertebrates (white-footed mouse, eastern chipmunk, gray squirrel) which are nest predators of songbirds (2) monitoring nest predation rates using artificial songbird nests, and (3) monitoring the success of natural nests of selected songbird species, (4) testing if enemy-free space is a key control of incidental predation, (5) evaluating the utility of giving-up densities as indicators of ecological patterns and processes at multiple spatial scales, and (6) estimating the influence of population density and individual behavioral responses of predators on the survival of nests of songbirds.