Nocturnality in owl monkeys
Owl monkeys (genus Aotus) represent the only taxon of monkeys that are nocturnally active. In field studies in collaboration with The Owl Monkey Project we showed that the nocturnal activity of owl monkeys in northern Argentina is dependent on the availability of moonlight. Monkeys are active during moonlit nights but they shift to a diurnal behavior with the waning moon, changing their ‘temporal niche’ predictably with moon phases. We continue field studies, as well as laboratory studies at the Keeling Center for Comparative Medicine and Research, to elucidate the physiological trade-offs of these predictable nocturnality/diurnality switches.