Pre-Sleep and Sleeping Platform Construction Behavior in Captive Orangutans (Pongo spp.): Implications for Ape Health and Welfare.

The nightly construction of a 'nest' or sleeping platform is a behavior that has been observed in every wild great ape population studied, yet in captivity, few analyses have been performed on sleep related behavior. Here, we report on such behavior in three female and two male captive orangutans (Pongo spp.), in a natural light setting, at the Indianapolis Zoo.