Food of the Yellow Bittern Ixobrychus sinensis in boluses regurgitated by nestlings

Abstract

I analyzed the Yellow Bittern Ixobrychus sinensis foods obtained from boluses regurgitated by nestlings in 1991 at Akigase paddy field, Saitama, Japan. Main foods of the Yellow Bittern were fishes and frogs. Of all food items identified, 68% were loachs, 12% were small fishes, Motsugo, and 14% were two species of frogs. A few crayfishes and spiders were obtained. Bitterns did not select the sizes of tree frogs. The Yellow Bittern seemed an opportunistic forager.