Collaborative Research: Prey Movement in Hazardous Environments: Studies in a Tropical Stream Fish System

摘要：james F. gilliam北卡罗莱纳州立大学，合作研究：危险环境中的猎物运动：热带河流鱼类群落的研究本研究的目的是探讨捕食者和个体变异两种现象对热带河流鱼类扩散的影响。它们对扩散的影响尚不清楚。第一个问题是，随着掠食性鱼类的增加，掠食性威胁的增加是否会减缓猎物在河流受威胁区域的扩散速度（之前的一项研究发现，掠食性鱼类会增加而不是抑制猎物的运动）。第二个问题评估的是，个体在探索家园范围之外的趋势中的勇气是否有助于种群内的分散率，如果是这样，个体差异是否遗传。田野调查将在特立尼达的天然溪流中进行，这些溪流包含猎物物种，但它们包含的捕食者物种数量不同。每个流中的移动将由标记重新捕获程序确定。大胆度的个体差异将通过行为分析来评估，其遗传力将通过饲养运动者和非运动者的后代来评估。为了直接确定个体大胆度的变化是否有助于自然界的扩散速度，将在一条河流的两条姊妹支流中进行互惠移植实验，其中一条支流的移动者将与另一条支流的停留者交换。如果勇敢是一种个体特征，那么这两条河流最终应该包含在扩散速度上不同的种群。拟议的鱼类研究结果有望为了解热带河流自然栖息地中影响扩散的因素开辟新的途径。

AbstractProposal Number DEB-0108439James F. GilliamNorth Carolina State UniversityRUI: COLLABORATIVE RESEARCH: PREY MOVEMENT IN HAZARDOUS ENVIRONMENTS: STUDIES IN A TROPICAL STREAM FISH COMMUNITYThe goal of this study is to explore the effects of two phenomena, predators and individual variation, on the dispersal of a tropical stream fish. Their effects on dispersal are unknown. The first question addresses whether increasing predator threat, with the addition of predatory fish species, slows dispersal rate of the prey species through threatened zones of a river (a previous study found that a predatory fish increased rather than suppressed prey movement). The second question evaluates if individual boldness in the tendency to explore beyond the home range contributes to dispersal rate within a population and if so, whether individual differences are inherited. Fieldwork will be done in natural streams in Trinidad that contain the prey species, but which differ in the number of predator species that they contain. Movement in each stream will be determined by mark-recapture procedures. Individual variation in boldness will be evaluated through behavioral assays, and its heritability assessed by rearing offspring of movers and non-movers. To directly determine whether individual variation in boldness contributes to dispersal rate in nature, a reciprocal transplant experiment will be done in two sister tributaries of a river in which movers in one tributary will be exchanged for stayers in the other. If boldness is an individual characteristic, the two streams should eventually contain populations that differ in rates of dispersal. The results of the proposed studies with fish are expected to open new avenues to understanding the factors that affect the dispersal in natural habitats of tropical rivers.