, Volume 55, Issue 1, pp 19–24

Are rainforest owl monkeys cathemeral? Diurnal activity of black-headed owl monkeys, Aotus nigriceps, at Manu Biosphere Reserve, Peru

News and Perspectives

DOI: 10.1007/s10329-013-0395-x

Cite this article as:
Khimji, S.N. & Donati, G. Primates (2014) 55: 19. doi:10.1007/s10329-013-0395-x


Members of the genus Aotus are traditionally considered strictly nocturnal, however, in recent years cathemeral habits have been described in a single species of owl monkey, Aotus azarai, which occur in the highly seasonal habitat of the Argentinean Chaco. This finding raises the question as to whether other species of Aotus exhibit cathemeral activity in less seasonal habitats. In this study, we observed the diurnal activity of one group of A. nigriceps living in the Manu Biosphere Reserve, Peru over 65 days. The data collected indicate that A. nigriceps has only sporadic diurnal bouts of activity. In addition, nocturnal luminosity of the previous night, rainfall, and temperature did not correlate with the minor diurnal activity exhibited. This suggests that for A. nigriceps the potential costs of shifting to diurnality may outweigh its prospective advantages in this rainforest environment.


Peruvian owl monkey Activity pattern Thermoregulation Moon phase Manu Biosphere Reserve 

Copyright information

© Japan Monkey Centre and Springer Japan 2013

Authors and Affiliations

  1. 1.Nocturnal Primate Research Group, Department of Social Sciences, Faculty of Humanities and Social SciencesOxford Brookes UniversityOxfordUK

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