Chrono‐ethologic investigations on the Queensland koala ( Phascolarctos cinereus adustus ) in captivity

The chronologic behavior pattern of a separately kept pair of koalas at the Tiergarten Schönbrunn (Vienna Zoo) was investigated with regard to how the patterns are distributed over 24 hr and the “zeitgeber” (from German; synonym “entraining agent”) on which they depend. The data was collected continuously by means of infrared video recording over 3 months, January–March 2003 (2,160 hr/animal). Observations were made using the scan‐sampling method at 1‐min intervals. The total activity and each single behavior are described and analyzed in chrono‐ethograms and activity profiles for the first time in this species. The main activity of both koalas occurs between 1:00 AM and 4:00 AM , a continuous sleeping period occurs between 11:00 AM and 3:00 PM (sometimes until 4:00 PM ). They become active 1 hr before darkness and inactive 1 hr before dawn (anticipation). During the day koalas are only awakened and become active due to care measures (feedings/weighing). “Zeitgeber” influencing the koalas' behavior are feeding and weighing as well as the light/dark change. To influence the koalas' endogenous rhythm as little as possible, the keepers' daily routine (time and frequency) has to be modified. Zoo Biol 0:1–12, 2006. © 2006 Wiley‐Liss, Inc.