Increased reliance on socially acquired information while foraging in risky situations?

We undertook three experiments to investigate the hypothesis that as the potential costs of individual learning increase, reliance on social learning also increases. We found no effect of indirect cues of predation risk on use of previously acquired social information by Norway rats, Rattus norvegicus, choosing between unfamiliar foods (experiment 1). We also found decreased (not increased) use of socially acquired information by rats choosing between unfamiliar foods when exposed to direct cues of predation risk (experiment 2). Furthermore, experiences of gastrointestinal upset following ingestion of unfamiliar foods (intended to act as a cue to the presence of toxic potential foods) failed to increase rats' use of social information when choosing between additional unfamiliar foods (experiment 3). The results of our experiments thus failed to confirm predictions of several formal models of the effects of costs of individual assessment of alternatives on use of socially acquired information. (c) 2006 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.