View article

When faced with the presence of a predator, many species of prey initially approach rather than retreat from such a potential threat. Although seemingly paradoxical, this type of approach behaviour has been noted in a wide variety of taxa. We adopt a cost - benefit perspective on the question of why prey approach potential predators, and aim to outline what is known about the putative costs and benefits of such behaviour. We identify five major types of costs associated with approach behaviour: (i) increased risk of mortality to the approacher, (ii) increased risk of mortality to relatives of the approacher, (iii) lost opportunity costs associated with approaching a predator, (iv) energetic costs of approach, and (v) potential costs of the approacher being 'exploited' by other group members. Benefits of approach behaviour are categorized as (i) acquiring information about the nature of the potential threat, (ii) informing others …