SEX-DIFFERENCES IN OLFACTORY COMMUNICATION IN A PRIMATE, THE MOUSTACHED TAMARIN, SAGUINUS-MYSTAX (CALLITRICHINAE)

This study examines the hypothesis that sexual selection has shaped pa tterns of olfactory communication in wild moustached tamarins, Saguinu s mystax. Do sex differences exist in frequencies and in the intensity of scent marking, in the use of different scent-marking types, and in behavioural responses to scent marks? Scent marking (anogenital, supr apubic, sternal) and behavioural responses (sniffing and overmarking) were recorded in four groups (ten adult and subadult males, seven adul t and subadult females in all groups combined) in north-eastern Peru. Frequencies and intensity of scent marking were significantly higher i n female tamarins. Males and females did not differ in the use of anog enital marking, but suprapubic marking was employed significantly more often by females. Only 10% of scent marks were monitored by another g roup member, and only 5% were overmarked by another group member. Most sniffing of scent marks was done by males. and males sniffed at marks produced by females significantly more often than at marks produced b y males. Both sexes overmarked scent marks with similar frequency, but females overmarked scent marks produced by males significantly more o ften than those produced by females. An increase in frequencies of sce ne marking was observed in two females of one group after the death of the reproducing scent marking remained the same in the males of this group. The female-biased rates of scent marking are consistent with pr edictions made by sexual selection theory for species with substantial male care for offspring and strong reproductive competition between f emale, but frequencies of females. However, a decisive test of the pro posed role of sexual selection will only be possible with more field d ata on patterns of olfactory communication in other callitrichine spec ies.