Predation Risk and Foraging in Juvenile Pink (Oncorhynchus gorbuscha) and Chum Salmon (O. keta)

Publisher Website
Google Scholar
Abstract
Habitat choice and foraging activities of juvenile pink (Oncorhynchus gorbuscha) and chum salmon (O. keta) from the Fraser River estuary [Canada] were studied to determine whether their behavior changed in response to predation risk and hunger level. In aquaria with and without predators, the fish were given a choice of two habitats, open water with a high prey density and vegetation with a low prey density; these habitats have advantages of high energy intake and protection from predators, respectively. Pink salmon were found more frequently in the vegetation when predators were present than otherwise. When hungry, however, pink salmon occupied the open area to a greater extent than when satiated. Chum salmon did not show as much difference in habitat choice as pink. In the presence of predators, satiated pink salmon ate less than hungry ones and also less than the fish without predators. Chum salmon did not show any differences in food intake in the different treatments. Thus, pink salmon responded to predation risk to a greater extent than did chum, in terms of habitat choice and food intake, and demonstrated a trade-off between predator avoidance and foraging.

This publication has 9 references indexed in Scilit: