The influence of social status, reproductive and agonistic contexts and environmental change on scent-marking and allomarking rates were studied in captive groups of Lemur fulvus and Lemur macaco. No evidence of female social dominance over males appeared in either species. In L. fulvus, intrasexual relationships were characterized by the dominance of one adult male over another and by the existence of female affiliative association (‘central’ vs. ‘peripheral’ females). In L. macaco, no intrasexual dominance relationships were apparent except for a brief ostracism of one female. In both species, (1) intrasexual differences in social status were related to differences in marking rates, (2) no direct relation appeared between marking rates and aggression or reproduction, (3) allomarking was not differentially directed towards specific individuals and (4) physical environmental factors clearly influenced scent-marking and allomarking rates. These results are discussed in relation to the possible functions of marking behaviour in intragroup relations.

We investigated the vocal repertoire of a Malagasy primate: the black lemur (Eulemur macaco macaco). The first study allowed the characterization of 16 different vocal signals on the basis of acoustic parameters. Black lemurs emit sparse harmonic sounds, dense harmonic sounds, spectrally structured noise (Beeman, 1998) and a wide variety of grunts. The second study focused on the behavioral context of emission of these signals and used the pre- and post-event histogram method (Douglass and Sudd, 1980; Preuschoft, 1995a). It provides statistical demonstration of the association between a signal and other behaviors of the emitter, thus giving insight into the latter’s motivations. Four signals are linked to affiliative and agonistic interactions. Three signals express a state of alarm, and two appear related to discomfort. Most grunts are linked to contact and signal precisely the emitter’s level of vigilance. Other interdisciplinary communication studies could benefit from methodology and software used here.

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Although the brown lemur (Eulemur fulvus) and the black lemur (Eulemur macaco) share many life parameters and are genetically closed, they show considerable difference in social organization. Dominance relationships with no systematic effect of gender characterize the former, whereas the latter is based on female dominance. The present study was done on two captive groups of brown lemurs and one semi-free-ranging group of black lemurs. To reveal links between the specific pattern of social organization and agonistic behaviors, agonistic interactions were analyzed for each species as for their context of occurrence, symmetry, initiation, and outcome. The effect of gender in the initiation of conflicts appeared as the only notable interspecific difference, aggression being mostly initiated by females in E. macaco and by males in E. fulvus. Conflict outcome was generally in favor of the initiator, regardless of gender in both species. The analysis of postconflict behaviors revealed conciliatory processes in the brown lemur, whereas reconciliation seemed to be absent in the black lemur, a characteristic shared with the ring-tailed lemur (Lemur catta), another lemur species with female dominance. Aggr. Behav. 28:62-74, 2002.

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