DETERMINANTS OF TIME ALLOCATION BY ADULT AND YEARLING BLACK-TAILED PRAIRIE DOGS

The time budgets of all adult and yearling black-tailed prairie dogs i n a wild population were measured in 14 separate samples between late April and mid-August 1989. In general, males were more vigilant and fe d less than females did. This sex difference was due largely to the be havior of males that had sired offspring; non-fathers behaved more lik e females. As the summer progressed, prairie dogs spent more time feed ing and less time vigilant. The lone exception to this pattern was mot hers, who fed less and spent more time vigilant as the summer progress ed. Other influences on time allocation produced similar effects for a ll sex/parental groups: animals were more vigilant while in tall veget ation and in the early morning as opposed to mid-day or evening. Envir onmental (e.g. weather) and social (e.g. number of other adults and pu ps present) effects on time allocation were analyzed via multiple regr ession. Of all potential influences, distance from the nearest burrow seemed to have the most consistent impact on time allocation for all i ndividuals. These results point to strong effects of sex, parental sta tus and environmental context in determining the particular pattern of time allocation observed in an individual prairie dog.