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Abstract
Individuals are at risk when communicating because conspicuous signals attract both conspecifics and eavesdropping predators. This predation cost of communicating has typically been attributed to signalling individuals because of their conspicuous role. But if predators are attracted to signals, then receivers, both intended or otherwise, may also find themselves at risk of predation. In this thesis, I used olfactorily communicating house mice Mus domesticus to address several key questions regarding the predation risks to receivers of conspecific signals. Using field experiments, I established that several predator species are rapidly attracted to the scent signals of their mouse prey. Male house mice were sensitive to this risk of predation when receiving conspecific signals. Mice traded off the predation risks of receiving with the perceived social value of a conspecific scent signal, however, and were more willing to receive signals of high social value than those of low social value when in the presence of a predation cue. But mice did not relinquish all antipredatory behaviours to receive signals. Instead, spatial point pattern analyses revealed that they used small-scale changes in space use to maintain receiving rates of conspecific signals, while minimising excess movements likely to attract a predator’s attention. Mice were also sensitive to the risks posed by scents in different spatial configurations. They perceived patchily distributed scents as more risky than randomly or regularly distributed scents, highlighting the importance of considering scale when examining predator:prey interactions. I further extended the concept of risky receiving to show that it includes interspecific eavesdropping – greatly generalising our concept of the landscape of fear. In a final laboratory experiment, I reveal a mechanism for the otherwise maladaptive maintenance of receiving under predation risk. The effects of social isolation on aggressive and anti-social behaviours were gradually attenuated by exposing male mice to the scents of an increasing number of conspecifics, despite a lack of physical contact. Thus, while prey are sensitive to the increased risks of predation when receiving con- and hetero-specific signals, they must balance this risk against the perceived social benefits of receiving a signal, and the potentially severe social costs of not doing so.