Contested dominance modifies the anovulatory consequences of social subordination in female marmosets

A.I Alencar,M.B.C Sousa,M.E Yamamoto,D.H Abbott

doi:10.1590/s0100-879x2006000500012

A.I Alencar, M.B.C Sousa + Show 2 more

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https://doi.org/10.1590/s0100-879x2006000500012

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Abstract

Dominance status among female marmosets is reflected in agonistic behavior and ovarian function. Socially dominant females receive submissive behavior from subordinates, while exhibiting normal ovulatory function. Subordinate females, however, receive agonistic behavior from dominants, while exhibiting reduced or absent ovulatory function. Such disparity in female fertility is not absolute, and groups with two breeding females have been described. The data reported here were obtained from 8 female-female pairs of captive female marmosets, each housed with a single unrelated male. Pairs were classified into two groups: "uncontested" dominance (UD) and "contested" dominance (CD), with 4 pairs each. Dominant females in UD pairs showed significantly higher frequencies (4.1) of agonism (piloerection, attack and chasing) than their subordinates (0.36), and agonistic behaviors were overall more frequently displayed by CD than by UD pairs. Subordinates in CD pairs exhibited more agonistic behavior (2.9) than subordinates in UD pairs (0.36), which displayed significantly more submissive (6.97) behaviors than their dominants (0.35). The data suggest that there is more than one kind of dominance relationship between female common marmosets. Assessment of progesterone levels showed that while subordinates in UD pairs appeared to be anovulatory, the degree of ovulatory disruption in subordinates of CD pairs was more varied and less complete. We suggest that such variation in female-female social dominance relationships and the associated variation in the degree and reliability of fertility suppression may explain variations of the reproductive condition of free-living groups of common marmosets.

Highlights

Dominance and subordination reflect a relationship between two animals competing for food, mates, territories, or other resources
To qualify the associated characteristics of such differences, we classified the pairs into two groups: uncontested dominance (UD) in which one female exhibited dominant behaviors at least at three times the frequency of the other, and contested dominance (CD) in which one female displayed dominant behaviors at only 1.11.5 times the rate displayed by the other female
There were, no significant differences between the frequencies of given dominant behaviors displayed by dominant females between CD and UD groups (Tukey, P = 0.945)

Summary

Introduction

Dominance and subordination reflect a relationship between two animals competing for food, mates, territories, or other resources. Dominance relationships in primates vary widely from species to species They may remain stable for long periods of time and through all kinds of competition, as observed in Cercopithecus aethiops [2], or may be unpredictable as in Papio anubis, because one animal may be dominant in some aspects but not in others [3]. It has been suggested [4] that there may be different kinds of dominance - clear or uncontested dominance (UD) in which one individual is always dominant in relation to another, or contested dominance (CD) in which subordinate individuals submit, but disputes occasionally occur. These findings have suggested a close relationship between female dominance status and fertility in these non-human primates

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