PHYSIOLOGICAL-RESPONSE OF THE EUROPEAN HEDGEHOG TO PREDATOR AND NONPREDATOR ODOR

A respiratory chamber was used to investigate physiological responses of hedgehogs to predator and nonpredator odour cues, introduced by pas sing air through different faecal suspensions. Five recently caught he dgehogs showed a significant increase in oxygen consumption (29% +/- 1 8% at 95% c.i.) when treated with badger (predator) faecal suspension, and 10 hedgehogs held in captivity for ca. 2 years showed no signific ant response. The responses of recently caught hedgehogs to odour from badger (predator) and roe deer (non-predator) faecal suspensions were then investigated, over a range of concentrations spanning 3 orders o f magnitude. Five hedgehogs were tested with badger odour; of these, 3 were also tested with roe deer odour. The mean rise in oxygen consump tion was significantly greater in response to badger than to roe deer faecal suspension, but there was no significant variation in strength of response over the range of concentrations tested, and increased oxy gen consumption was not associated with any increase in levels of visi ble activity. The responses are interpreted as an increase in arousal in response to a potential predatory threat. Lack of response in the c aptive-held animals raises questions about the welfare of such animals following release. Energy costs and foraging inefficiency associated with arousal may be significant factors of foraging decisions involvin g predation risk, but more naturalistic measurements would be required for any quantitative analysis. Copyright (C) 1996 Elsevier Science In c.