Social context, competitive interactions and the dynamic nature of antipredator responses of juvenile rainbow trout Oncorhynchus mykiss
Abstract:The effects of food ration and social context, as well as possible interactions, on the antipredator behaviour of juvenile rainbow trout Onchorhynchus mykiss were investigated in a pair of laboratory studies. In experiment 1, pairs of dominant and subordinate O. mykiss were exposed to conspecific alarm cues when maintained under high or low food rations. Under high food rations, dominant individuals responded to predation risk, whereas subordinates used the opportunity to feed. Under low food ration, however, the opposite pattern was observed, where subordinates responded to predation cues and dominants did not. Experiment 2 consisted of performing the same experiment, however separating the dominant and subordinate O. mykiss 3 h before testing. When tested separately, dominant and subordinate individuals did not differ in their responses to alarm cues, regardless of food ration. These results demonstrate that there is a complex interaction between current energy status and social context on decision making by prey animals.
Document Type: Regular Paper
Affiliations: 1: Department of Biology, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec, H4B 1R6, Canada, 2: Fisheries Centre, Aquatic Ecosystems Research Laboratory, University of British Columbia, 2202 Main Mall, Vancouver, British Columbia, V6T 1Z4, Canada and 3: Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan, S7N 5E2, Canada
Publication date: 2009-08-01