Comparatively little is known of P. diadema and P. tattersalli, but P. verreauxi is one of the most intensively investigated of the Malagasy prosimians, and the remainder of this account, except as noted, deals with the latter species. In warm weather the sifakas slept at noon, then had a second period of activity, and then settled for sleep at dusk. She studied sifakas in both the northern and the southern parts of their range. The mean distance moved in a day in the north was 1,100 meters in the wet season and 750 meters in the dry season. In the south the respective distances were 1,000 and 550 meters.
Groups are territorial, at least in some areas.
Adult males mark territories with urine and with a scent gland located on the front of the throat. Territorial confrontations between two troops may involve growling, scent marking, and ritualistic leaping toward the enemy territory but not direct physical contact. During the breeding season, however, there are fights and sometimes serious injuries. The dominance hierarchy that existed in the nonmating season may change. A formerly subordinate male may take over his own group or leave his group and attain dominant status in another group.