Willets Kleptoparasitize and Use White Ibis as 'Beaters'

摘要

We report observations of Willets (Catoptrophorus semipalmatus) using White Ibis (Eu-docimus albus) as "beaters" to disturb prey and klep-toparasitizing (stealing) prey from them. Our observations occurred at J. N. "Ding" Darling National Wildlife Refuge on Sanibel Island, Florida on 8 December 2004. We observed these behaviors in four White Ibis-Willet pairs and describe one instance in detail and document it with photographs. To our knowledge this is the first documentation of a Willet using other birds as beaters and the first case of Willets stealing from White Ibis, although many records exist of Willets stealing from other shorebirds. We believe the use of beaters by Willets may be an under-reported foraging behavior.