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

0089588。肯尼斯·施密特。捕食率和捕食者随后对猎物的影响被认为主要由捕食者的种群密度决定。然而，当捕食者在寻找其主要猎物时巧合地遇到次要猎物类型时，多面手捕食者的许多捕食行为可能会发生。这种附带捕食是由个体捕食者对可供选择的猎物类型的丰富和分布以及捕食者的环境特征的行为反应决定的。偶然捕食在多面手中可能非常常见，在专业捕食者中程度较小。由于这种弱相互作用可能会稳定群落结构，因此它们具有相当重要的意义。更具体地说，偶然捕食的速度可能与敌人的自由空间(未被捕食者利用的区域)有关。了解这一机制是至关重要的，因为它与捕食者-猎物相互作用的强度有关，也因为无敌人空间影响捕食者-猎物动态的稳定性和多个猎物物种的共存。拟议的研究考察了繁殖的鸣鸟群落中的偶然捕食，其蛋和雏鸟被小型哺乳动物捕食，主要是白脚小鼠(Permyscus Leucopus)。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、观察和实验的组成部分，最终测试了显性的潜在机制。更具体地说，这项研究涉及(1)监测常见脊椎动物(白脚鼠、东部花栗鼠、灰松鼠)的密度，这些脊椎动物是鸣禽的巢捕食者(2)监测人工鸣鸟巢的捕食率，以及(3)监测选定鸣鸟物种的自然巢穴的成功，(4)测试无敌空间是否是偶然捕食的关键控制因素，(5)评估放弃密度作为多个空间尺度上的生态模式和过程的指示器的效用，以及(6)估计种群密度和捕食者的个体行为反应对鸣鸟巢的生存的影响。

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.