Social structure and seasonal variation in the behaviour of Eulemur mongoz

Data presented here were collected during a 10-month study carried out on t he mongoose lemur, Eulemur mongoz, at Anjamena in northwestern Madagascar. Baseline information is provided on behaviour and assessed for seasonal var iation. Given the high ly seasonal nature of the environment, remarkably li ttle behavioural variation was observed. This may be directly linked to the cathemeral activity pattern, where differential movement into either the d iurnal or the nocturnal 'niche' could reduce the effect of selective season al pressures, thus reducing behavioural and ecological adaptation to season al variation. The behavioural mechanisms of reinforcement of the pair bond through close proximity, mutual anogenital marking, paternal participation in the care of offspring and territoriality are all in accord with the gene ral characteristics of monogamy in primates. The feature of mate monopoliza tion by males, proposed as typical of monogamous social systems, seems to b e more attributable to females in E. mongoz, as only they exhibit high leve ls of intrasexual aggression. Female dominance, characteristic of most spec ies of lemur, may thus include more than just female feeding priority in E. mongoz.