Goheen, J. R. et al.: Food-hoarding behavior of gray squirrels and North American red squirrels in the central hardwoods region: implications for forest regeneration

Jacob R. Goheen and Robert K. Swihart: Food-hoarding behavior of gray squirrels and North American red squirrels in the central hardwoods region: implications for forest regeneration.
In: Can. J. Zool. 81: 1636–1639 (2003).

Link: http://web.ics.purdue.edu/~rswihart/pdf/CJZ_Hoardingms.pdf

Zitat :

Abstract

The North American red squirrel (Tamiasciurus hudsonicus) has expanded its geographic range into the state of Indiana concurrently with a decline in populations of gray squirrels (Sciurus carolinensis) throughout portions of the central hardwoods region of the United States that have been converted to intensive agriculture. Red squirrels construct larder hoards and function as seed predators throughout much of their geographic range. In contrast, gray squirrels construct scatter hoards and thus function as seed dispersers in addition to eating seeds. We conducted field observations to discern whether hoarding behavior differed between the two species in a deciduous forest stand near the southern limit of the range of red squirrels. Red squirrels were more likely to hoard walnuts and acorns in larders or trees, whereas gray squirrels were more likely to scatter-hoard mast items. We present a simple model to illustrate the potential impact of interspecific differences in hoarding on germination success of black walnut. Our results suggest that red squirrels are unable to compensate completely for the loss of gray squirrels as seed dispersers in portions of the central hardwoods region that have been transformed by agriculture.