Rattle calls as individual identifiers in the North American red squirrel (Tamiasciurus hudsonicus).

Abstract

The rattle calls of North American red squirrels (Tamiasciurus hudsonicus) have been theorized to serve as signals of aggressive territorial intent. These calls are produced by males and females periodically when another is trespassing within the territory or in response to another rattle. However, sometimes individuals rattle in the absence of any obvious stimuli. An alternative explanation for the red squirrel’s rattle call is the need to self-identify, which is often crucial to minimize costly encounters with neighbour and stranger conspecifics, as well as potentially identify intruders and mates. Individual squirrels were trapped and released, at Whitemud Creek, in various locations both within and outside of territory boundaries. Upon release squirrels were monitored for 10 minutes and all rattle vocalizations were recorded. Results indicate that squirrels reliably produced calls, within 10 minutes of release, both within and outside of their territory. These results suggest that the rattle call may function as a form of self identification and not predominantly as an aggressive territorial call.

Department: Biology

Faculty Mentor: Dr. Shannon Digweed