Vital statistics from a laboratory breeding colony of squirrel monkeys (Saimiri sciureus)

An analysis of 512 pregnancies that occurred over a 9-year period in a laboratory colony of squirrel monkeys (Saimiri sciureus) revealed yeat-to-year variation in pregnancy outcome and birth weight. Although births occurred through the year, 72% were between May and August. Male infants outnumbered females 1.31:1 and were heavier at birth. Birth weight was an important determinant of infant survival. Maternal age did not affect birth weight in this sample. Dams present in the colony for long periods tended to deliver smaller infants with a decreased potential for survival. Reproductive causes contributed to 48% of the maternal deaths. Homorrhage at or near the time of delivery was the principle cause of maternal reproductive mortality. Most neonatal deaths were attributable to accident, prematurity or trauma.