Behavioral and physiological suppression of fertility in subordinate marmoset monkeys

Abstract

In laboratory groups of common marmosets (Callithrix jacchus jacchus), socially induced reproductive suppression among subordinates and offspring effectively maintained a monogamous breeding system. Male subordinates or male offspring were inhibited or restrained from showing sexual behavior, while similarly placed females could also suffer from complete ovarian failure. In well-established families, a familiarity or inbreeding taboo restricted reproduction among otherwise fertile offspring. However, only one daughter ovulated in any family, and in up to 50% of family groups, all daughters were inhibited from ovulating. This differential effect on daughters may have reflected a qualitative shift in the mother-daughter relationship: the ovulating daughter may have represented the next breeding female and may no longer have regarded the mother as an inhibitory influence. In newly established peer groups of pubertal and postpubertal offspring, one male and female dominated all others in each group and overtly inhibited sexual behavior in subordinates of their own sex. Ovulation was suppressed in all subordinate females because of inadequate gonadotrophin secretion. This was not related to increased secretion of cortisol or prolactin, but may have been related to hypothalamic inhibition of luteinizing hormone-releasing hormone (LHRH) secretion.

Reproductive skew in female common marmosets: what can proximate mechanisms tell us about ultimate causes?

“…In addition, an age-related dominance hierarchy is often apparent, either within each sex or in both sexes combined (Sutcliffe & Poole 1984;Digby 1995b). Both males and females may be highly aggressive to unfamiliar or extragroup individuals of the same sex, but within established groups, aggression is usually mild and infrequent (Epple 1967;Abbott 1984;Saltzman et al 1994Saltzman et al , 1997cDigby 1995b;Sousa et al 2005).…”

“…Reproductive skew in female marmosets W. Saltzman et al 391 (Rothe 1975;Abbott 1984;Saltzman et al 1997c) and in the field (Digby 1999;Sousa et al 2005). Several investigators have, on rare occasions, observed dominant females disrupting subordinate females' sexual interactions with males (Epple 1967;Rothe 1975;Abbott 1984 Abbott 1999, unpublished data) and, in the laboratory groups, most subordinate females are never seen even attempting to mate (Rothe 1975;Abbott 1984). Thus, interference by dominant females is unlikely to be a primary cause of sexual inhibition in subordinates.…”

Fine Structure of the Vomeronasal Organ in the Chinchilla (<I>Chinchilla laniger</I>)

“…The vomeronasal organ (VNO) is thought to be related to the reproductive and social behaviors by perceiving pheromonal molecules to send olfactory information to the accessory olfactory bulb [1,8,11,22,31]. Phylogenetically, the VNO first appears in amphibians, is well developed in reptiles, but absent in birds [4,11,13,14].…”

Fecal androgen levels in common marmoset (Callithrix jacchus) males living in captive family groups

“…Due to intense reproductive competition in the species, the dominance relationship among females has been very well studied. However, documentation about escape from inhibition by subordinate calli-thrichid females in laboratory groups (among mothers and daughters or among unrelated females) has shown that reproductive inhibition is not as stringent as thought (7)(8)(9)(10)(11). The escape from inhibition by subordinate females (daughters) was also recorded in a monogamous wild group of common marmosets (12).…”