Physiology & Behavior, Vol. 35, pp. 389-393. Copyright ©PergamonPress Ltd., 1985. Printed in the U.S.A. 0031-9384/85 $3.00 + .00 Scent Marking and Mate Choice in the Golden Hamster U. WILLIAM HUCK, ROBERT D. LISK AND ANDREA C. GORE Department of Biology, Princeton University, Princeton, NJ 08544 Received 30 November 1984 HUCK, U. W., R. D. LISK AND A. C. GORE. Scent marking and mate choice in the golden hamster. PHYSIOL BEHAV 35(3) 389-393, 1985.--Test groups consisting of three males and one female were adapted to home areas within a 244x 122 cm enclosure for a 4-day period. Subsequently, agonistic interactions and patterns of scent marking were recorded daily for 30 min over the duration of the female's 4-day estrous cycle. Alpha males flank marked significantly more than the two subordinates. The former accounted for over 95% of flank gland marking by males on the two days prior to the female's period of sexual receptivity. The female showed increased frequencies of both flank gland and vaginal marking over the three nonreceptive days of the cycle with the highest frequency of marking occurring 24 hr prior to sexual receptivity. During the two days prior to receptivity, the female both vaginal marked and flank marked significantly more in and about the home area of the alpha male. We conclude that the female hamster shows mate choice prior to the onset of sexual receptivity and that both vaginal marks and flank marks are employed to facilitate mating with the alpha male. Hamster Scent marking Vaginal marking Flank gland marking Male social rank Mate choice Estrous cycle SCENT marking is employed by mammals as part of the communicative process for identification of species, sex, and reproductive condition (e.g., [22]). Odor cues are important in attraction of and mating preference for conspecifics (hamster [33]; brown lemming [12-14]; bank vole [10]). In a number of species the frequency of scent marking increases significantly either prior to or at the onset of sexual receptiv- ity (hamster [15]; rat [2]; gerbil [36]; house mouse [41]; domestic dog [9]). Scent marking is also employed to adver- tise social status. When stable dominance hierarchies are established, almost all the marking is done by the dominant animal (hamster [17-19]; rabbit [34]; mouse mouse [7]; sugar glider [37]). Female identification of and preference for spe- cific mating partners has been documented in several species (cf. [1, 5, 40]). One basis for female choice is the relative dominance status of the males available to her (hamster [27]; brown lemming [12-14]; house mouse [24, 30, 31]; rabbit [34]). Under laboratory conditions, male golden hamsters (Mesocricetus auratus) readily establish dominant- subordinant relations which remain stable over time even if only limited contact occurs at intervals of several days [8,39]. In a previous study [27] we showed that when a female hamster is exposed to a group of males, mating prior- ity by the alpha male occurs only if the female and males have interacted for several days prior to the female's becom- ing receptive. This observation suggests that events impor- tant for mate selection occur prior to the period of sexual receptivity. The previous f'mdings that vaginal secretions have an excitative effect on the male [28,32] and that the peak level of vaginal marking occurs during the 24 hr period prior to sexual receptivity [19,20] further suggest that vaginal marking plays a role in mating patterns. The experiment below examines the quantitative and spacial relationships between scent marking and dominance status in the male, and scent marking and mate choice by females. METHOD Subjects Twenty multiparous females and 60 males were chosen randomly from animals raised in the Biology Department animal facility from stock originating from Lakeview Ham- ster Colony, Newfield, NJ (LAK:LVG strain). The males were 125-206 days of age (mean= 179.8), weighed 112-165 g (mean= 132.5), and had sired at least two previous litters. Females were 157-198 days of age (mean=IS3.4), and weighed 123-167 g (mean= 138.9). All subjects were main- tained on a reversed 14 hr light-10 hr dark photoperiod with the dark (red light) phase beginning at 1200. Food (commer- cial laboratory chow) and water were available ad lib. Estrous cycles were determined by extravaginal exam- ination [35]. The f'trst day of the 4-day cycle is designated as estrus; ovulation occurs early on this day. The following two days are labeled diestrus-1 and diestrus-2 with the f'mal day of the cycle, proestrus. Receptivity begins before the lights-off period during proestrus and ends on estrus, several hours after ovulation. Apparatus Testing was conducted in two identical 244x 122x40 cm Plexigias enclosures. Each enclosure was partitioned (see 1This research was supported by Grant BNS-8300892 from the National Science Foundation. 389