Infant mortality in Macaca mulatta: neonatal and post-neonatal mortality at the California Primate Research Center, 1968-1972. A retrospective study.

Seven hundred forty-two Macaca mulatta births were recorded at the California Primate Research Center, 1968-1972. The neonatal mortality rate (deaths smaller than or equal to 30 days of age) was 10.8%, and the post-neonatal mortality rate (deaths at 31-183 days) was 6.9%. The neonatal mortality rate was higher in outdoor group cages than in indoor individual cages (24.8 vs. 8.0%). The post-neonatal mortality rate was also higher outdoors than indoors (15.9 vs. 5.9%). Outdoor mortality showed apparent seasonal variation, while indoor mortality did not.