Social influences on the development of ringtailed lemur feeding ecology

As they grow, young individuals can use both social and individual learning strategies to develop species-typical feeding ecology, and the utility of these strategies may vary phylogenetically and with environmental stability. Focused learning from mothers and other group members is critical in monkeys, with behaviours such as co-feeding playing strong roles in determining postweaning survival. While adult lemurs are capable of social learning, it is unknown how social information is incorporated during the development of feeding or what social learning strategies are used in this process. Here we evaluate the use of social learning behaviours and the potential for social learning in young ringtailed lemurs, Lemur catta, at the Beza Mahafaly Special Reserve, Madagascar. We show that infant and juvenile ringtailed lemurs use basic and generalized stimulus enhancement that occurs through behavioural synchrony with older nearest neighbours. More focused co-feeding occurred at low levels, and many of the social learning behaviours observed in the other social primate taxa were absent. High levels of individual exploration also contributed to learning, evidenced through high dietary diversity in juveniles relative to other group members. Our observations are consistent with the idea that simple social learning rules are responsible for the development of ecological complexity in many generalist vertebrate species, and that more complicated learning behaviours may not be necessary to learn complex and varied diets.