Food sharing among captive Leontopithecus rosalia.

Captive L. rosalia were observed to exchange food routinely in family groups, a process varying from donation to theft. Donation involved the use of 'invitational' signals which operated most efficiently in parent-infant sharing and in donating live prey. Food moved, by sharing and theft, toward: (a) males prior to the female's first conception; (b) females during late pregnancy; (c) carriers of infants; (d) weanlings; (e) juveniles when infants died; (f) third animals in trios, regardless of their age and relatedness to the pair. Successful reproduction, a complex behavior involving all group members in cooperative infant care and provisioning, is probably enhanced by captive L. rosalia's food-sharing habits.