Differences in Blood Levels of Androgens in Female Talapoin Monkeys Related to Their Social Status

Abstract

Serum testosterone and androstenedione levels were lower in the subordinate female talapoin monkeys of four social groups than either dominant or intermediate-ranking females. This was found in both intact or ovariectomized (oestrogen-treated) animals, which suggests that androgen from the adrenals contributed to this rank-related endocrine effect. These differences disappeared when the females were housed singly, levels in all animals becoming similar to those in subordinates in the group cage. There were no rank-related differences in progesterone levels during either the follicular or luteal phase of the cycle in intact females, or in those of ovariectomized females of different rank, but cortisol was highest in dominant group-living animals in these experiments. Significant correlations were found between androgen levels in group-living females and the amount of sexual interest shown in them by males; the amount of aggressive interaction involving each female did not correlate with her androgen levels. Social rank is defined according to the direction, not the amount, of aggression. These findings suggest that the social hierarchy regulates androgen levels in these female monkeys; there may also be effects on the ability of females to respond to their own, or to administered, androgen. Similar findings have been made previously in male talapoins. Since androgens fill a critical role in the sexual behaviour of both sexes in primates, this may be a neuroendocrine mechanism of general significance relating behaviour to social rank.

Androgen levels and female social dominance inLemur catta

“…(c) Only the rank indices and not the androgen concentrations were correlated with the relative testis size (stepwise forward multiple regression, rank index bˆ0.25 § 0.08 and p 5 0.05, and androgen concentration bˆ0.00 § 0.00 and n.s.). Bouissou 1983a,b;Floody 1983) and that high-ranking females can have higher androgen concentrations (Batty et al 1986;Faulkes & Abbott 1997) suggested that female dominance in lemurs may be associated with increased levels of testosterone or other androgens. Even though the ranges of androgen levels in female ring-tailed lemurs appear high in relation to male levels (cf.…”

Social modulation of stress responses

“…Another example of sexual dimorphism involves talapoin monkeys (Miopithecus talapoin). Dominant females have higher circulating cortisol concentrations and engage in more aggressive interactions than subordinate females [37]. However, when individually housed, previously dominant and subordinate female monkeys have similar blood cortisol concentrations, which suggests that elevated cortisol concentrations in dominant females are observed only in a social context [37].…”

“…Dominant females have higher circulating cortisol concentrations and engage in more aggressive interactions than subordinate females [37]. However, when individually housed, previously dominant and subordinate female monkeys have similar blood cortisol concentrations, which suggests that elevated cortisol concentrations in dominant females are observed only in a social context [37]. In male talapoin monkeys, cortisol concentration is correlated with dominance rank, but it is the subordinate monkeys that receive the majority of the aggressive attacks and have the highest cortisol concentrations [38].…”

Experimental endocrine manipulation by contraceptive regimen in the male marmoset (Callithrix jacchus)

“…Such females, for example, start to cycle immediately (Abbott et al 1988). As the androgen levels of male and female NHPs were shown to be linked also to behavioural traits that influence social rank (Batty et al 1986, Ross et al 2004, it might be that, specifically in the marmoset, androgens play a minor role in the regulation of the reproductive organs but are of higher importance for maintenance of social status compared with other primate species. This assumption could explain why we observed complete spermatogenesis and maintained fertility in the treated males, although serum testosterone as well as pituitary CG responded to the TU/NETE treatment largely as expected.…”