Several Lemur catta troops at Berenty, Madagascar have been censused repeatedly since 1963. In 1972, the entire reserve was censused. A recensus in 1975 showed that although some minor changes have occurred in the number of animals in individual troops, the population of the reserve as a whole, the core areas of the lemurs’ territories, and their home range boundaries have all remained stable ever since the first complete census 3 years earlier.

Because ring-tailed lemurs (Lemur catta) are a female-dominant, female-philopatric species in which the females provide the majority of parental care and troop defense, resource defense is a possible function of female lemur scent marking. To test this hypothesis, I conducted three studies. First, I presented captive, individually housed females with a series of samples of female scent, each from a different female, to determine whether they would respond to those samples and discriminate between them. Second, I reanalyzed data from a focal animal study of four females in two adjacent troops in Berenty Reserve, Madagascar, to determine female marking rates before, during, and after the mating season, and to clarify the relationship among positions of feeding, intertroop defense, and scent marking. The third study was based on ad libitum observations of the sniffing and marking behavior of a troop in Berenty Reserve during a year when they traveled far out of their home range. The females in study 1 investigated female scent samples but provided no evidence that they discriminated between them. In study 2 the wild females marked throughout the study and did not limit their marking to the mating season. They deposited significantly more of their marks in a zone of confrontation with adjacent troops, where they also did the majority of their feeding, and they increased their rate of marking during agonistic intertroop confrontations. The females determined the positions of their scent marks and deposited the first mark in the majority of countermarking sequences. When the females traveled out of their defended range in study 3, they significantly decreased their rate of marking and increased their rate of sniffing spots but not marking them. All evidence gathered so far supports the hypothesis that one function of female ring-tailed lemur scent marking is to provide intergroup information that is then used to reinforce the border of the defended resource.

Over 350 h of observations were collected using focal animal sampling of scent-marking behavior by 2 troops of ring-tailed lemurs (Lemur catta) in the field in Madagascar. Although they did not mark any branch species preferentially, they did have preferred marking sites. Significantly more scent marks were deposited in the area of home range overlap between troops than in the area of exclusive use. However, few marks were deposited at the periphery of the area of overlap. Instead, the majority of the marks were in a narrow band within the area of overlap that coincided with the positions of intertroop confrontations. Female genital marks and male arm marks, as well as the accompanying male shoulder rubs thus appear to demarcate territorial borders.

No abstract

Field observations of a troop of sifaka revealed that they scent mark the boundary areas of their territory far more than they do the interior, both during normal daily movements and during battles between adjacent troops. They are active throughout the territory but spend more time and have a higher frequency of marking at the periphery.