Scatterhoarding and Larderhoarding by Red Squirrels: Size, Dispersion, and Allocation of Hoards

We quantified the degree of scatterhoarding and larderhoarding exhibited during late summer and early autumn by 10 individuals within a population of red squirrels (Tamiasciurus hudsonicus) in the Cypress Hills, Alberta, Canada. All squirrels made extensive and obvious larderhoards in central middens. In addition, sampling quadrats and behavioral observations revealed that ca. 43% of total stores were scatterhoarded throughout territories. Across individuals, the number of cones scatterhoarded was related inversely to the number stored in the midden. Nearest-neighbor analyses indicated that cones were distributed in a spatially clumped manner throughout each territory. However, the hoards themselves, independent of size, tended to be dispersed randomly. Cones hoarded in middens did not differ from scatterhoarded cones in terms of content of seeds, nor were they treated differently by the squirrels in terms of carrying distance. At the end of our study, seasonal hoarding was not yet complete, but squirrels already had hoarded sufficient cones to meet their energetic requirements for ≥3 months. We conclude that the characteristic pattern of storage of food by red squirrels is a deliberate mixture of distinct larderhoarding and scatterhoarding tactics.