title: Are rainforest owl monkeys cathemeral? Diurnal activity of black-headed owl monkeys, Aotus nigriceps, at Manu Biosphere Reserve, Peru.
abstract: 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.
authors.affiliation: Nocturnal Primate Research Group, Department of Social Sciences, Faculty of Humanities and Social Sciences, Oxford Brookes University, Gipsy Lane, Oxford, OX3 0BP, UK, shenazkhimji@gmail.com.
authors.forename: Shenaz N
authors.initials: SN
authors.lastname: Khimji
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Donati
mesh_terms: D000818:Animals; D016645:Aotidae / Q000502:physiology*; D001522:Behavior, Animal; D002940:Circadian Rhythm; D002980:Climate; D004777:Environment; D005260:Female; D008029:Lighting; D008297:Male; D016081:Moon; D009043:Motor Activity; D010568:Peru