FRANK, C.L.: The nutritional ecology of food hoarding by red squirrels

It has proposed that granivory and food hoarding coevolved repeatedly in mammals because seeds tend to retain their nutritional quality during storage, although this hypothesis has not been tested. The effects of prolonged storage on the nutritional composition of five conifer seed species hoarded by Mount Graham red squirrels,Tamiasciurus hudsonicus grahamensis, were examined in order to better understand the evolution of food storage. The results demonstrate that the nutritional quality of all conifer seed species examined decreases during storage by red squirrels, and three of the seed species no longer met the minimal nutritional requirements of red squirrels after 3-8 months of storage. This study demonstrates that the evolution of food hoarding by red squirrels was probably actually constrained by the nutritional properties of their primary food.