Under her maiden name, she first published "Control of the Hand in Lower Primates" in 1962. Jolly began studying lemur behavior at Berenty in 1963 and was first to propose female dominance in a primate society. She encouraged field studies that contributed to knowledge about Malagasy wildlife and advised many researchers; she briefed Jane Wilson-Howarth and colleagues before their first expedition to Madagascar in 1981. Since 1990 Jolly had returned for every birthing season to carry out research assisted by student volunteers. She focused on ring-tailed lemur demography, ranging, and especially inter-troop and territorial behavior, in the context of the fivefold difference in population density from front to back of the reserve.