SCORDATO, ES*; DREA, CM; Duke University; Duke University: Sex-specific variation in Ringtailed lemur Lemur catta olfactory communication

Prosimians are unique among primates in their reliance on complex olfactory cues as a primary mode of social signaling. Scent marking may serve to demarcate territories, maintain dominance hierarchies, and advertise reproductive state. Male Lemur catta use species-specific brachial, antebrachial, and scrotal glands to scent mark, whereas females employ labial glands. We suggest that different glands convey different types of information. This hypothesis is corroborated by variation in the chemical composition of gland secretions and seasonal variation in gland usage, as revealed by GC/MS and behavioral observation, respectively. To determine if an animal�s reproductive and/or dominance status is encoded in, or influences response to, a particular type of secretion, we conducted behavioral choice tests on 8 adults (4 M; 4 F) during the breeding and non-breeding seasons, using odor samples collected in both seasons from all 4 glands (n = 16 unfamiliar donors). Behavioral responses (approach, sniff, lick, and scent mark) to all odors were stronger in males than in females. Males preferentially investigated female odors, but responded differently across glands (e.g. licking labial, sniffing antebrachial, and scent marking brachial odors). The differing patterns of sniffing and licking suggest that volatile and nonvolatile fractions of scent marks convey different information. Males also licked and scent marked odors from dominant donors more so than from subordinates. Conversely, females responded almost exclusively to female odors, and were influenced by their own reproductive state and by that of the scent donor. These data support functional differences between glands, suggesting that scent marking in males serves in intrasexual competition, whereas female marking is a form of reproductive competition and sexual advertisement.