Birthdate, Birthweight, and Survival in Pronghorn Fawns

Abstract

Neonatal fawns of pronghorn ( Antilocapra americana ) in Middle Park, Colorado, were weighed and marked, and survival was monitored to weaning in 1988–1990. Birthdates were similar for both sexes, and birthdate did not affect survival to weaning. Birthweight tended to decrease with later birthdate. In 1990, female fawns were heavier at birth than male fawns, and females that survived to weaning were heavier at birth than females that did not survive. Birthdate does not appear important for survival of fawns to weaning, but birthweight can be a factor in survival to weaning in some years.