Recent evidence for food storing in European ground squirrel (Spermophilus citellus)

Whereas European ground squirrels (Spermophilus citellus) do not utilize food caches during hibernation, it has occasionally been reportedthat they store food during the active season. Recent evidence for S.citellusmaintaining food stores in summer aroseduring thelong-term ecological supervision ofa construction project in Vienna, Austria.Fromthe onset of the project in 2012,ground squirrels were observed to forageon tubers of the tuberous vetchling(Lathyrus tuberosus). During the preparation of a building plotin July2016, a cavitycontaining 380g of tubers of L.tuberosus was excavated by a digger when removing the upper30 cm soil layer. Whentheconstruction areawasexpandedin July 2017, a ground squirrel repeatedly inspecteda burrow on a future building plot, oncecarrying a tuber to the burrow.To examine if the burrow was vacant, it was stripped by layer, revealing acache of 290g tubers in a blind-ending tunnelat a depth of about 90 cm. The structure consisted of one chamber without nesting material, and one tunnel containing the cache. We concludethat the burrow may haveserved as a hideoutfacilitatingfood intake while avoiding predation andother adverse external conditions.