Social influences on sexual maturation of female Saguinus oedipus oedipus

Abstract

The hypothesis tested was that Saguinus oedipus oedipus females housed with adult males would mature, sexually, at an earlier age than females remaining in their natal family groups. Six females were housed with strange, unrelated males. Five females remained in their natal groups. Blood samples were taken twice weekly, and the plasma was assayed for progesterone. Sexual maturation was operationally defined as that age at which plasma progesterone levels became consistently detectable. Females housing with males did mature at an earlier age than females remaining in their natal groups. In addition, it was noted that the presence or absence of a healthy, reproductive mother in the natal group was not related to the daughter's maturation age. However, whether the natal group, as a whole, inhibited maturation of young females, or an unrelated male accelerated maturation, or both, remains unknown.

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

“…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.…”

“…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. In addition, it has been be shown that maturing tamarins (males and females of Saguinus fuscicollis and females of S. oedipus) can fulfill the behavioral roles of pair bonded adults and also breed at a much earlier age when they live under the influence of an adult sex partner, in comparison with animals cohabiting with a sex partner of their own age [Epple, 1981;Epple & Katz, 1980], or remaining in their family group [Tardif, 1984]. It may, therefore, be significant that four of the gibbons presented in the case reports of this study had been separated from their natal group, and had, at a relatively young age, been brought together with a much older potential mate (case reports 1, 2, 4, 6).…”

Hormonal monitoring of age at sexual maturation in female Goeldi's monkeys (Callimico goeldii) in their family groups

“…Often following removal from the dominant female, and certainly following subsequent pairing with an unfamiliar, unrelated male, ovulatory-cycles occur immediately [Abbott, 1984;Carlson et al, 1997;Epple and Katz, 1984;Savage et al, 1988;Tardif, 1984]. However, several studies revealed that escape from suppression of ovulation can occur in subordinate daughters housed in their natal group [Abbott, 1984;Saltzman et al, 1994;Tardif, 1984;Hubrecht, 1989]. Thus, status-dependent reproductive suppression of the onset of ovulation is mainly pronounced between female non-kin, but nonetheless is also common between kin, with mothers often suppressing the sexual maturation of their daughters.…”

Adult male replacement and subsequent infant care by male and siblings in socially monogamous owl monkeys (Aotus azarai)

“…It has been suggested that in monogamous species, given the relatively high costs to a female of raising and caring for offspring, males may care directly for infants or provide some kind of indirect services to females (Tardif 1984;Wright 1984;Wright 1986;Van Schaik and Dunbar 1990;Tardif 1994;Van Schaik and Kappeler 1997;Runcie 2000;Sommer 2000). The male care hypothesis predicts that males should provide infant care when paternity certainty is high or in exchange for future reproductive opportunities even when paternity certainty is low (Smuts and Gubernick 54 1992).…”