Sociosexual development, pair bond formation, and mechanisms of fertility suppression in female cotton‐top tamarins (Saguinus oedipus oedipus)

Abstract

The effect of various social environments on sociosexual behavior was examined in six young female cotton-top tamarins (Saguinus oedipus oedipus) and in three established breeding females. Behavioral observations and hormonal samples were collected on young females while they were living with their families, when they were isolated from conspecifics, and after they were paired with an unrelated male. While living with the family, all females showed a suppression of fertility and low frequencies of sociosexual behavior. Following removal from the family, isolated females displayed an increase in rate of scent marking and an increase in hormonal levels. When young females were paired with males, they were exposed to scent secretions from their natal families, from an unfamilar family, and from a control for a total of 24 weeks. After pairing, hormonal levels increased dramatically, and ovarian cyclicity began. An increase in sociosexual behavior and elevated levels of scent marking accompanied this physiological change. Newly paired females had higher rates of affiliative behavior and scent marking than did established breeding females. However, both newly paired and established breeding males were more likely to initiate contact, grooming bouts, and social sniffing than were females. Time to first ovulation was later in females who were exposed to scent secretions from their natal families than it was in those females given a control for the first 8 weeks following pairing. No female conceived during exposure to scent secretions. However, once normal ovarian cycling had begun or a pregnancy was established, exposure to scent secretions had no effect. Thus, the social environment influences the fertility, sociosexual behavior, and pair bond formation of cotton-top tamarins. In addition, chemical stimuli found in the scent secretions produced by the natal family are most likely involved in reproductive suppression.

Reassessment of age of sexual maturity in gibbons (hylobates spp.)

“…This potential role of scent secretions is supported by the observation that scent markings from the natal family have the ability to disrupt reproductive cycles in Saguinus fuscicollis [Epple & Katz, 1984] and to delay the onset of ovulations in newly paired females of S. oedipus [Savage et al, 1988]. In this context, it may be relevant that the presence of a scent gland has recently been discovered in the siamang (Hylobates syndactylus) [Geissmann, 1987a], and macroscopically similar glandular structures seem to be present in (perhaps all) other gibbon species [Geissmann, 1987b;Mootnick et al, 1987].…”

“…A pregnancy of 190 to 225 days (which may be typical of gibbon species closely related to H. lar, see Table II) has been used for calculating Gi's age at conception of the infant. [Abbott, 1984;Abbott & Hearn, 1978;Abbott et al, 1981;Epple & Katz, 1984;French et al, 1984;Savage et al, 1988;Tardif, 1984]. Subordinate animals are apparently released from this social suppression or inhibition of sexual behavior (and fertility) when they are removed and housed with an adult animal of the opposite sex.…”

Reproductive sharing and proximate factors mediating cooperative breeding in the African wild dog (Lycaon pictus)

“…An indirect strategy may also occur, as when subordinates produce elevated glucocorticoids (stress hormones) that, in turn, compromise normal reproduction, as reported for the song sparrow (Melospiza melodia, Wingfield and Silverin 1986). A combination of behavioral and hormonal cues is also well known to limit subordinate reproduction in the common marmoset (Callithrix jacchus, Barrett et al 1993) and cotton-top tamarin (Saguinus oedipus, Savage et al 1988). In the context of demographics, group size and composition are significant.…”

Reproductive suppression in female Damaraland mole–ratsCryptomys damarensis: dominant control or self–restraint?

“…This mechanism requires that reproductive suppression be imposed by aggression and related stress e¡ects, active interference with copulation, pheromonal cues that block ovulation and infanticide. For example, in some cooperatively breeding monkeys (cotton-top tamarin Saguinus oedipus (Savage et al 1988) and common marmoset Callithrix jacchus (Barret et al 1990)), both behavioural and olfactory signals appear to be implicated in reproductive suppression. In contrast, the self-restraint model (SRM) does not involve aggression directed towards non-breeding females.…”

“…Ovulation is physiologically suppressed in female subordinates as a result of reduced pituitary luteinizing hormone (LH) that arises from disrupted secretion of hypothalamic gonadotrophin releasing hormone (GnRH) . Primer pheromones from urine do not play a major role in the suppression of reproduction (Faulkes & Abbott 1993) nor do behavioural (tactile) cues from other non-breeding colony members (Smith et al 1997). Nevertheless, the queen is by far the most aggressive colony member.…”