Blue jays (Cyanocitta cristata) do not spontaneously eavesdrop on red squirrel (Tamiasciurus hudsonicus) squeals to locate food

Abstract

Organisms often eavesdrop on the cues and signals produced by other species to obtain information about their environment. Blue jays have dietary overlap with red squirrels, and learn to associate novel stimuli with food rewards in an experimental setting. Red squirrels produce “squeals” when contesting food resources with conspecifics. We tested whether blue jays eavesdrop on red squirrels by playing back red squirrel squeals, red squirrel rattles, white noise, and chick-a-dee calls to blue jays in Winnipeg, Manitoba . Additionally we examined the response of passerine birds in general to the playbacks, and attempted to condition free-living blue jays to respond to the playback of the squeal treatments. Results of the playbacks suggested that neither blue jays nor other passerines eavesdrop on vocalizations emitted in the context of red squirrel disputes over food. Conditioning trials did not produce any conditioned responses from blue jays; however, the limited number of trials performed does not constitute a robust test of the possible acquisition of a classically-conditioned response. Blue jays may also refrain from eavesdropping on red squirrel squeals as they are not reliable indicators of food resources, or because in an urban environment, blue jays readily learn the locations of bird feeders or other reliable food sources without eavesdropping on red squirrels.