Birth seasonality,infant sex ratio,and interbirth interval in captive northern pig-tailed macaques (Macaca leonina): the first evidence based on an 11 year record

Based on the record of 11 consecutive years,this study for the first time describes reproduction in the northern pig-tailed macaque (macaca leonina). totally 10 infants were born as singletons across the whole survey period. 60% of infants were males and sex ratio did not significantly deviate from 1:1,which to some extent supports local resource competition hypothesis. the birth date ranged from early february to late may,in which seventy percent of infants were born in march. the interbirth interval was 401±146 days on average. there was no significant difference between interbirth interval after the birth of male infants and that after the birth of female infants. all infants survived over the first year of their ages. the reproductive parameters in captive m. leonina were discussed in the context of other captive primate studies,and positive suggestions on zoo breeding and management have been proposed. copyright 2015 zoological society of pakistan.