Sources of scent used by prairie voles, Microtus ochrogaster, to convey sexual identity to conspecifics MICHAEL H. FERKIN~ Department of Psychology, Cornell University, Ithaca, NY 14853, U.S.A. FREDERICK H. FERKIN BioSystems, 5409 Mariessu Avenue, West Palm Beach, FL 3341 7, U.S.A. AND MILO RICHMOND Department of Natural Resources, Cornell University, Ithaca, NY 14853, U. S.A. Received May 13, 1994 Accepted September 14, 1994 FERKIN, M.H., FERKIN, F.H., and RICHMOND, M. 1994. Sources of scent used by prairie voles, Microtus ochrogaster, to convey sexual identity to conspecifics. Can. J. Zool. 72: 2205 - 2209. The presence or absence of specific odor-producing tissues has been used to suggest phylogenetic relationships among microtine rodents, but has not been related to patterns of social organization. We examined the sources of sex-specific scents in prairie voles, Microtus ochrogaster, using a preference task. Prairie voles have eight sources of sex-specific scents. Four scents, namely those from the urine, feces, anogenital area, and mouth were more attractive to opposite- than same-sex con- specifics. Three scents were attractive to one sex but not the other. Scent from the back of females was attractive to males and scents from the chest and head-neck-ears of males were attractive to females. Scent from the male posterolateral region was attractive to both females and males. We then compared these eight sources of scent with the known sources of scent from meadow voles, Microtus pennsylvanicus, a species whose social system is unlike that of prairie voles. Prairie voles have more sources of sex-specific scent than meadow voles. This difference supports the hypothesis that the number of sources of sex-specific scent is greater in a social species (prairie voles) than in an asocial species (meadow voles). FERKIN, M.H., FERKIN, F.H., et RICHMOND, M. 1994. Sources of scent used by prairie voles, Microtus ochrogaster, to convey sexual identity to conspecifics. Can. J. Zool. 72 : 2205-2209. La prksence (ou l'absence de tissus a odeur spCcifique a CtC utilisCe pour dkterminer les relations phylogCnCtiques entre des rongeurs microtinks, mais n'a jamais CtC examinCe en relation avec l'organisation sociale. Nous avons examink les points de production d'odeurs spCcifiques a chaque sexe chez le Campagnol des Prairies, Microtus ochrogaster, au cours d'une Ctude de prCfCrences. Les Campagnols des Prairies posskdent huit sources de production d'odeurs spCcifiques a chaque sexe. Quatre odeurs, celles de l'urine, des fkces, de la rCgion anogCnitale et de la bouche, sont plus attirantes pour les individus du sexe opposC que pour ceux du meme sexe. Trois odeurs sont attirantes pour un sexe, mais pas pour l'autre. L'odeur qui Cmane du dos des femelles attire les miles, et les odeurs qui Cmanent de la poitrine et de la rkgion tete-cou-orielles des miles attirent les femelles. L'odeur de la rCgion postCrolatCrale du mile attire aussi bien les miles que les femelles. Nous avons ensuite comparC ces huit sources d'odeurs a celles qui prCvalent chez le Campagnol des champs, Microtus pennsylvanicus, une espkce dont le systkme social diffkre de celui du Campagnol des Prairies. Les Campagnols des Prairies ont un nombre plus ClevC de sources d'odeurs spCcifiques a chaque sexe. Cette diffkrence confirme l'hypothkse selon laquelle le nombre de sources d'odeurs spCcifiques a chaque sexe est plus ClevC chez une espkce sociale (Campagnol des Prairies) que chez une espkce asociale (Campagnol des champs). [Traduit par la RCdaction] Introduction In mammals, behaviorally significant odors are produced in most organs that pass chemicals to the external environment. These organs may have been specifically modified for this pur- pose or may liberate odiferous chemicals as a result of their primary function (Eisenberg and Kleiman 1972). Such odors may arise from the integument, the salivary glands, the acces- sory glands of the eye, the sex organs, and digestive exudates like urine and feces (Eisenberg and Kleiman 1972; Bronson 1979; Adams 1980; Vandenbergh 1988; Bigi et al. 1994). Scents from these sources apparently serve a communicative function that is unique to a species (Richmond and Stehn 1976; Thiessen and Rice 1976; Brown 1985; Johnston 1990). How- ever, identification of all the specific sources of scent that con- vey behaviorally significant information for a given species has been limited to a few studies on rodents (Johnston et al. 1993; Ferkin and Johnston 1994; Lai 1994); most studies have examined the behavioral attributes of one or two scents (Johnston 1983). The presence or absence of specific odor-producing tissues has been used to suggest phylogenetic relationships among species of microtine rodents (Quay 1968; Brown 1985; Jannett 1990). No study, however, has directly compared the sources of scent-producing tissues in two closely related species to draw inferences from differences in their social systems. This is somewhat surprising in that the pattern of scent-producing areas on the integument and the attractiveness of their products may be unique and reflect species' differences in social organi- zation (Richmond and Stehn 1976; Viitala and Hoffmeyer 1985; Ferkin 1990). Indeed, a greater array of signals to communicate sex may be found in a species with a more com- plex social structure than one with a less complex social struc- ture (Wilson 1972; Thiessen and Rice 1976). Similarly, the frequency of scent marking was greater in a species of rabbit 'Present address: Department of Biology, King's College, Wilkes- with a complex social organization than in a species with Barre, PA 18711, U.S.A. a simple social organization (Marsden and Holler 1964; Printed in Canada I lmprime au Canada Can. J. Zool. Downloaded from www.nrcresearchpress.com by Nanjing University of Posts and Telecommunications on 06/04/13 For personal use only.