Aerial Foraging Over Open Water by Great Egrets and Snowy Egrets on Schooling Freshwater Fish

On 21 June 2002 we observed mixed flocks of Great Egrets (Ardea alba) and Snowy Egrets (Egretta thula) foraging aerially on shad (Dorosoma sp.) forced to the surface by foraging white bass (Morone chrysops) at the Richland-Chambers Reservoir in Freestone County, Texas. These events occurred over open water ranging from 3–12 m deep during a 2-h period of observation. Egrets foraged exclusively by hovering about 3–5 m above the water and then dipping to capture shad. Foraging behavior was interspersed with intervals of vigilance on a nearby shoreline. Here we provide a detailed record of the temporarily exclusive use by egrets of this rare foraging method in fresh water, in water of such depth, and on live schooling prey over open water.