|Differences in caching behaviour between highly-social and relatively non-social corvids|
|Alizée Vernouillet1,2, Dawson Clary2, Debbie M. Kelly2. 1University of Cambridge, Cambridge, Cambridgeshire, United Kingdom; 2University of Manitoba, Winnipeg, Manitoba, Canada
Food-storing animals rely on cached food to survive. For caching to be evolutionarily advantageous, cachers must not only remember where their caches are but also prevent their caches from being stolen by other individuals by engaging in cache protection strategies. We compared the caching behaviour of two cache-dependent corvids: highly social pinyon jays and relatively non-social Clark’s nutcrackers. Birds cached pine nuts in two visually distinct trays under four conditions: Observed by a conspecific, Observed by a heterospecific, in the presence of an Object, and Alone. After caching, the observer could pilfer from one tray, whereas the other was placed out of the cage. When observed by a conspecific, nutcrackers reduced the number of nuts cached, whereas pinyon jays cached more nuts in areas inaccessible to the observer. When observed by a heterospecific, only pinyon jays changed their caching behaviour. Birds cached similarly when alone or with an object. This study is the first to examine whether corvids identify heterospecifics as a threat to their caches and suggests the sociality of a species may influence this ability and their caching behaviour.