EFFECTS OF FOOD RESOURCE DISTRIBUTION ON THE SOCIAL SYSTEM OF GUNNISON PRAIRIE DOG (CYNOMYS-GUNNISONI)

We tested the predictions of Slobodchikoff's habitat variability - mat ing system model using the social system of Gunnison's prairie dog (Cy nomys gunnisoni). The model predicts that when resources are abundant and patchily distributed, social groups will include several females, while scarce, uniformly distributed resources will lead to smaller gro ups with single females. Gunnison's prairie dogs form family groups co nsisting of a single adult male and female(s), and their young of the year, which occupy fixed spatial territories within a colonial framewo rk. Resource abundances and distributions were characterized and compa red at two colonies in northern Arizona. Resource abundance did not va ry between colonies, while two separate measures showed resource distr ibution to be significantly more patchy at one colony than at the othe r. As predicted, there were significantly more territories with multip le females at the patchy colony, while single-female territories predo minated at the uniform colony. While the differences in resource abund ance between colonies were not significant from a statistical standpoi nt, sizable differences were observed, with the direction of the diffe rence opposite to that predicted by the model.