9311508 Holmes Alarm calls are vocalizations elicited by predators that can alert other members of the species to impending danger. Alarm calls have functional value only if they are responded to appropriately for the type of predator. Ms. Jill M. Mateo's doctoral-dissertation research seeks to determine when and how responses to alarm calls develop in young Belding's ground squirrels, as her pilot data show that alarm-call responses are not fully developed when young ground squirrels first emerge from the burrow where they were born. Ms. Mateo will test three predictions about the relative importance of auditory experience and social context for the development of alarm-call responses: (1) experience with the mother's vocalizations before weaning helps the young to discriminate alarm calls after weaning; (2) development of alarm-call responses after weaning is socially facilitated by observing adult alarm-call responses, and (3) the quality of juvenile alarm-call responses improves rapidly if they repeatedly hear alarm calls in the presence of other responding individuals. These predictions will be tested by playing back tape-recordings of alarm calls and recording the cardiac responses of unweaned pups and the behavioral responses of juveniles housed in a semi-natural environment or living in the field. Results will help explain how social influences contribute to the development of a critical survival skill, and will advance our understanding of how behavior develops through tightly-woven interactions between the organism and the series of environments it encounters throughout its life.