Changes in the Secondary Sexual Adornments of Male Mandrills (Mandrillus sphinx) Are Associated with Gain and Loss of Alpha Status

@article{Setchell2001ChangesIT,
  title={Changes in the Secondary Sexual Adornments of Male Mandrills (Mandrillus sphinx) Are Associated with Gain and Loss of Alpha Status},
  author={Joanna M Setchell and Alan F. Dixson},
  journal={Hormones and Behavior},
  year={2001},
  volume={39},
  pages={177-184}
}
Two semifree-ranging mandrill groups, inhabiting large, naturally rainforested enclosures in Gabon, were studied to measure morphological, endocrine, and behavioral changes that occurred when adult males rose, or fell, in dominance rank. Gaining alpha rank (N = 4 males) resulted in increased testicular size and circulating testosterone, reddening of the sexual skin on the face and genitalia, and heightened secretion from the sternal cutaneous gland. Blue sexual skin coloration was unaffected… Expand
Arrested development of secondary sexual adornments in subordinate adult male mandrills (Mandrillus sphinx).
TLDR
It is suggested that only alpha males have sufficient testosterone to develop full secondary sexual characteristics, and possible socioendocrine mechanisms underlying the suppression of testosterone and secondary sexual development in subordinate adults are proposed. Expand
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It is suggested that stained chests are visual and olfactory signals of dominance rank and that clean chests signal lack of competitive intent. Expand
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It was found that male coloration did indicate rank, and that high ranking, strongly colored males were more likely to associate with adult females, and more specifically with fully tumescent females, which indicated that these males also engaged in more sexual activity. Expand
OFFSPRING PROTECTION BY MALE MANDRILLS, MANDRILLUS SPHINX
TLDR
Observations suggesting the existence of male parental care in the mandrill are reported, one of the most sexually dimorphic mammal species known and a species in which, in the wild, males reside in social groups solely for the breeding season. Expand
Effects of dominance and female presence on secondary sexual characteristics in male tufted capuchin monkeys (Sapajus apella)
TLDR
Measurements of secondary sexual characteristics in captive dominant and subordinate male tufted capuchin monkeys (Sapajus apella) with varying access to females found little evidence to suggest that alpha males advertise their status within all‐male groups via sexual secondary characteristics. Expand
Is Fatter Sexier? Reproductive Strategies of Male Squirrel Monkeys (Saimiri sciureus)
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  • Biology
  • International Journal of Primatology
  • 2014
TLDR
Data on wild Saimiri sciureus studied in Brazil is presented to describe male reproductive investment in the species and to examine the hypothesis that male fattening is a product of sexual selection. Expand
Muzzle size, paranasal swelling size and body mass in Mandrillus leucophaeus
TLDR
It is suggested that the growth of the paranasal swellings and possibly the muzzle could be influenced by androgen production and reflect testes size and sperm motility, and may be an indicator of reproductive quality both to potential mates and male competitors. Expand
Social correlates of testosterone and ornamentation in male mandrills
TLDR
It is concluded that male facial redness is likely to represent an honest signal (to other males) of current androgen status, competitive ability and willingness to engage in fights and that females may also use this to assess male condition. Expand
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