Male care of infants in a siamang ( Symphalangus syndactylus ) population including socially monogamous and polyandrous groups

摘要: While male parental care is uncommon in mammals, siamang (Symphalangus syndactylus) males provide for infants the form of infant carrying. I collected behavioral data from a cohort five wild early infancy until age 15–24 months to identify factors affecting and assess consequences males, females, population including socially monogamous groups polyandrous groups. There was substantial variation caring behavior. All provided infants, but substantially more than groups, even when combined effort all group considered. These results suggest that polyandry siamangs unlikely be promoted by need “helpers.” Infants receiving did not receive overall because females compensated increases reducing their own effort. no significant relationship between indicators male–female social bond strength time spent carrying onset associated with change copulation rates. Females providing had significantly longer interbirth intervals. Male may reduce energetic costs reproduction permitting higher female reproductive