First experiences with free‐ranging giant day geckos (Phelsuma madagascariensis grandis,Gray 1870) in the masoala rainforest exhibit in Zurich Zoo,Switzerland

Sixty giant day geckos (Phelsuma madagascariensis grandis) have been introduced into the Masoala rainforest exhibit of Zurich Zoo. Eighteen geckos were monitored during a 3‐month study using the telemetry method. In general, the geckos were able to adapt well under these semi‐natural conditions of the exhibit. The geckos accessed to nearly all locations in the exhibit; some of the animals remained stationary, whereas others covered dozens of meters within a week. They preferred four species of plants as well as the artificial structures supporting the walls and roof of the exhibit, and displayed natural behaviors. Animals were observed feeding on all kind of arthropods and nectar substances, and also on food items dropped from feeding stations for other species. Deliberate feeding targeted at the geckos was finally reduced to a calcium‐rich squash along the visitor's main path. Reproduction was observed frequently within the exhibit. These findings suggest that the geckos will be able to build up a self‐sustaining population and contribute to a nearly‐authentic experience for zoo visitors. Zoo Biol 0:1–7, 2006. © 2006 Wiley‐Liss, Inc.