“The effect of super-abundant food on territory defence in the Oriental White Stork.”
In Tajima district, the northernmost part of Hyogo Prefecture, the re-introduction project of the Oriental White Stork (OWS) was started in 2005, and in 2007 one chick fledged successfully in the wild after 46 years from extinction of the stork breeding population in Japan. At present, 81 storks live in the wild mainly within Toyooka basin. As the core facility of the re-introduction project, Hyogo Park of the Oriental White Stork (HP-OWS) was established in 1999, where about 90 storks are kept in captivity now. HP-OWS has a roofless open cage where flightless 9 birds are kept that functions as a display site of live storks for tourists. Because of the roofless style of the cage, wild storks can easily invade the cage to take the fish that are provided for captive birds. This study clarifies the effect of the open cage on social organization of the wild storks, in which I compare two pair territories that are situated in different distances from HP-OWS.
OWS requires at least 3 years for sexual maturation and hence there exist many young storks as single floaters within Toyooka Basin. In my presentation I show that young floaters are allowed to stay and take their food within territories of the two pairs. I focus on their staying pattern and elucidate how the open cage affects the social organization of the re-introduced wild stork population.