Breeding ecology of Caspian terns at colonies on the Columbia Plateau

We investigated the breeding ecology and diet of Caspian terns on the Columbia Plateau in southeastern Washington and north-eastern Oregon. We examined trends in colony size and area during 1996-2001, and estimated numberof breeding pairs, nesting density, fledging success, and diet composition at selected colony sites in 2000 and 2001. We found six tern colonies totaling ∼1,000 breeding pairs, ranging in size from < 50 to nearly 700 pairs....