Proximate causes of the red face of the bald uakari monkey (Cacajao calvus)

P. Mayor, J. Mamani, D. Montes, C. González-Crespo, M. A. Sebastián, M. Bowler

Research output: Contribution to journalArticleResearchpeer-review

5 Citations (Scopus)


© 2015 The Authors. In social species, such as primates, facial appearances transmit a variety of social signals. Although it is suggested that the intense red colour of the face of the bald uakari monkey might be an indicator of health, this hypothesis still has not been verified. This study describes the histological structure of the skin of the face in the bald uakari, compared with other non-red neotropical primates, to better understand the maintenance of its colour. The facial skin of the bald uakari monkey is characterized by a thinner epidermis, absence of melanin pigments and a high density of vascular capillaries that spread below the epidermis. These vascular capillaries are larger and more tortuous than in other neotropical primates. The skin of the face of the bald uakari monkey allows a direct external assessment of haematological status, suggesting that the colour of the face would be an honest indicator of health, but could also signal sexual or behavioural states.
Original languageEnglish
Article number150145
JournalRoyal Society Open Science
Publication statusPublished - 1 Jul 2015


  • Cacajao calvus
  • Coloration
  • Face
  • Health indicator
  • Uakari


Dive into the research topics of 'Proximate causes of the red face of the bald uakari monkey (Cacajao calvus)'. Together they form a unique fingerprint.

Cite this