This integrated approach to understanding the evolution of the nocturnal monkey Aotus
combines new information from field research on behavioral ecology with research results …

Primates show activity patterns ranging from nocturnality to diurnality, with a few species
showing activity both during day and night. Among anthropoids (monkeys, apes and …

The subtropical populations of owl monkeys (Aotus) and some lemurs have flexible patterns
that include activity during both day and night. Early studies on the activity patterns of …

'IMversity Microfilms , International Page 1 INFORMATION TO USERS This reproduction was
made from a copy of a manuscript sent to us for publication and microfilming. While the most …

Early in their evolution, the ancestors of anthropoid primates radiated from a nocturnal to a
diurnal niche. Foraging during the night differs from foraging during the day in terms of the …

Owl monkeys are the only nocturnal primates in the New World and the only nocturnal
anthropoids. They concentrate their activities during the dark phase of the 24-h cycle, with …

Much of the recent research on the evolution of primate visual systems has assumed that a
minimum number of shifts have occurred in circadian activity patterns over the course of …

The study of activity rhythms, their potential zeitgebers and masking factors among free-
ranging primates has received relatively little attention in the past. Most primates are diurnal …

Social complexity is not restricted to day-living primates. Nocturnal primates provide a
remarkably diverse, and largely overlooked, array of species for comparison with the better …

Since primates spend about half of their life at sleeping sites, knowledge of behavior in the
vicinity of sleeping sites and analysis of factors influencing their use is important for …