Isolation of sixteen autosomal loci and a sex-linked polymorphic microsatellite locus from the Milne-Edwards' sportive lemur (Lepilemur edwardsi).

We isolated 21 microsatellites from the Milne-Edwards' sportive lemur, Lepilemur edwardsi. Eighteen microsatellite sequences possessed sufficient flanking DNA for primer design. Seventeen loci amplified and were found to be polymorphic displaying two to 17 alleles in 32 unrelated individuals from a population from the National Park of Ankarafantsika in northwest Madagascar. One locus (Led-12) was found to be sex linked located on the X chromosome and can be used to sex-type 40% of female L. edwardsi lemurs. These 17 loci were characterized to investigate family structure and the phylogeography of L. edwardsi.

Female dominance in captive gray mouse lemurs (Microcebus murinus).

Female dominance or female feeding priority seem to be characteristic for many lemur species, but are rare traits in other primates and mammals in general. The nocturnal lemur species, however, are underrepresented in the quantitative studies on social dominance. The aim of this study is to investigate the pattern of intersexual dominance relationships in the gray mouse lemur (Microcebus murinus), a species that is generally thought to possess a number of ancestral lemur traits. The context, distribution, and outcome of intersexual conflicts are analyzed in four captive groups of gray mouse lemurs. Intersexual conflicts occurred in the study groups in different behavioral contexts and were mostly spatial interactions (chasing/fleeing, approach/avoidance). The majority of conflicts were decided, and were in all but one case won by females. This is the first evidence suggesting unconditional female dominance in a cheirogaleid primate. The existence of female dominance in most families of the Lemuriformes suggests it is an ancient trait that evolved in their common ancestor.

Sociality in the gray mouse lemur (Microcebus murinus) in northwestern Madagascar.

The mating system and social organization of the gray mouse lemur (Microcebus murinus) was investigated in two three-month field studies (covering a period before, during, and after the first mating season) in Ampijoroa, northwestern Madagascar. The spatial and temporal distribution of the sexes within a population was studied using mark/recapture techniques and radiotelemetry to assess possible contest or scramble competition between the males. Sociality was inferred from the occurrence and probability of nocturnal social encounters, the temporal stability of daily sleeping groups, and nocturnal ranging patterns of co-sleepers. Males and females were evenly distributed in the study area within a network of highly overlapping home ranges. No indications were found for the spatial monopolization of the females by certain dominant males. Males and females had spatial access to several potential mates; the mating system is therefore characterized as a multi-male/multi-female system. Male home range sizes increased during the first mating season, which was interpreted as an indicator for scramble competition between the males. Competitive mate searching, sperm competition, and temporary mate guarding as well as female mate choice are suggested as the most probable reproductive strategies. Over the course of the study the animals lived continually within the study area, and most females formed stable individualized sleeping associations. Females that slept together shared a higher percentage of their home range than did females that slept at different sites. It is suggested that this network of social relationships should be described as a dispersed but individualized neighborhood.

Sex-specific usage patterns of sleeping sites in grey mouse lemurs (Microcebus murinus) in northwestern Madagascar.

Sleeping sites are a potentially important resource for grey mouse lemurs since they are confronted with high daily temperature fluctuations and a high predation pressure. In order to determine the existence and degree of resource competition, sleeping site characteristics, locations, and usage patterns as well as sleeping group compositions were investigated in a 3 month field study in a dry deciduous forest of northwestern Madagascar. The daily sleeping sites of females were on average better insulated and safer than those of males. Males used more sleeping sites and changed the site more often than females. During the whole study, males slept alone, whereas the females formed stable sleeping groups in on average 83.7% of the days. Sex-specific differences in usage patterns might be explained by intersexual resource competition and female dominance and could possibly be related to differential parental investment of the sexes. The underlying study indicates that sleeping sites may be a restricted and defendable resource for grey mouse lemurs. The investigation gives new insights into the distribution patterns and social organization of this species.