CONTEXT-SPECIFIC ALARM CALLS OF THE EASTERN CHIPMUNK, TAMIAS-STRIATUS

The structure and context of alarm calls produced by chipmunks (Tamias striatus) at a field site in southern Quebec were recorded during opp ortunistic field observations and experimentally simulated hawk attack s. Chipmunks produced three call types in the presence of predators. C hipping consisted of a series of high frequency notes with a rapid dow nward frequency slope (9.6 to 2.8 kHz) and was given in the presence o f mammalian predators by chipmunks perched on a raised vantage point. Chucking consisted of a series of lower frequency notes also sloping d ownwards (2.5 to 0.4 kHz), given in the presence of avian predators by perched animals. The trill was a lower amplitude, multi-note call usu ally given only once by animals before reaching a refuge while fleeing from either type of predator. The average trill contained 6-11 downwa rd sloping notes (7.3 to 0.8 kHz). The alarm call types of eastern chi pmunks appear to be similar to those reported for western chipmunks. H owever, they differ in the clear separation of the calls for aerial an d terrestrial predators. Chipmunks differ from most other terrestrial sciurids in giving repeated calls' for aerial as well as terrestrial p redators and in using a call just before reaching a secure refuge.