THE SCENT OF DEATH - CHEMOSENSORY ASSESSMENT OF PREDATION RISK BY PREY ANIMALS

It is well documented that animals take risk of predation into account when making decisions about how to behave in particular situations, o ften trading-off risk against opportunities for mating or acquiring en ergy. Such an ability implies that animals have reliable information a bout the risk of predation at a given place and lime. Chemosensory cue s are an important source of such information. They reliably reveal th e presence of predators (or their presence in the immediate past) and may also provide information on predator activity level and diet. In c ertain circumstances (e.g., in the dark, for animals in hiding) they m ay be the only cues available. Although a vast literature exists on th e responses of prey to predator chemosensory cues (or odours), these s tudies are widely scattered, from marine biology to biological control , and not well known or appreciated by behavioural ecologists. In this paper, we provide an exhaustive review of this literature, primarily in tabular form. We highlight some of the more representative examples in the text, and discuss some ecological and evolutionary aspects of the use of chemosensory information for prey decision making. Curiousl y, only one example illustrates the ability of birds to detect predato r odours and we have found no examples for terrestrial insects, sugges ting a fruitful area for future study.