Vocalizations associated with predator-type do not elicit predator-specific escape responses in grey squirrels

Abstract

Eastern gray squirrels produce moans for aerial predators and quaas for terrestrial threats. One commonly-supported hypothesis for such predator-associated signals is that they elicit predator-specific escape responses in conspecifics. With simulated aerial predators, squirrels ran to the far side of tree trunks. In response to simulated terrestrial predators, squirrels frequently ran to where they could see the predator but could quickly flee to the far side of the tree trunk. Playbacks of quaas and moans elicited flight behaviour, but without association between escape location and alarm call type. Locations elicited by alarm calls differed from those elicited by simulated predators, with squirrels pausing on the side facing the call’s source. While grey squirrel alarms and escape strategies differ by predator type, the vocalizations do not function to elicit divergent escape strategies in conspecifics. This result stands in contrast to observed functions in other species with calls differing by predator type.