9520469 Gilliam Human activities have greatly fragmented the landscape, and as a result, critical habitats are often isolated. While it is generally considered desirable to reconnect such isolated habitats by means of corridors, little is known about the movement of animals through corridors. The goal of this study is to investigate the properties of a river corridor that may facilitate or retard the movement of a fish between tributaries. In the study system a predatory fish divided the watershed into two zones: a lower zone in which the predator is common in the river but not adjoining tributaries, and an upper zone in which the predator is absent. The research will test three hypotheses about how the predator, physical structure of the river, and seasonal floods can interact to promote or retard movement of the prey fish along the river corridor connecting tributaries. The hypotheses will be tested by: (1) a large marking experiment with fish in the upper and lower zones of the watershed, in which movement will be followed through wet and dry seasons, (2) a study in an experimental stream facility, on-site, in which predators and physical structure can be manipulated, and (3) a comparative genetic analysis of the populations in the tributaries in the upper and lower zones of the watershed. By focusing on how physical and biological properties of corridors can work to facilitate or retard movement of an organism through a corridor, this project will contribute to our future ability to design realistic corridors reconnecting habitat fragments. Therefore, the research is applicable to conservation of species and management of biodiversity.
