Food transfer: a case of wild mother and infant aye-aye in Sangasanga Forest, Madagascar

Food transfer occurs when part or all of a food item is passed from one individual to another. Adult transfer of solid food to infants has been reported in 45 primate species. For aye-ayes, this behaviour was recorded in captivity where individuals were provisioned, but little is known about this behaviour in the wild. Wild aye-ayes consume hard-to-process foods that are inaccessible to infants such as wood-boring larvae embedded in trees and the endosperm of Canarium spp. seeds which are protected by a hard coat. Learning to process these food resources may be essential for aye-aye development. We used ad libitum sampling to record the social activities and behaviours of a mother and her male infant from January to December 2020 in Sangasanga Forest, Kianjavato, Madagascar. We collected in total 4 hours 57 minutes and 57 seconds of social behaviours. Over two days in December, we observed eight occurrences of the 11-month-old infant usurping Canarium sp. seeds from his mother. Our findings suggest that, due to physical limitations, the infant aye-aye primarily resorted to food transfer via theft to obtain hard-to-process food. Transfer of larvae, their main resource, was not observed, though it may occur until young aye-aye have the bite force needed to gouge holes in substrates and the coordination to retrieve and extract wood-boring larvae. Future research should explore if food transfer differs across individuals' sex, sites and type of food as well as the effects of anthropogenic disturbances on foraging.