I recently finished labwork to characterize the developmental profiles of fecal androgens and estradiol in wild ring-tailed lemurs from Beza Mahafaly Special Reserve from zero to four years of age. 

These data, combined with detailed data on the social interactions of animals at those ages I collected during fieldwork in 2008-2009, should help sort out the relative contributions of the social environment and individual post-natal physiology to the development of sexually differentiated behavior in this species.