Wide variety of habitats for breeding, but very specific requirements due to vulnerability to predators. Habitats include coastal estuarine, salt marsh, and barrier Islands. Nests on flat rocky islands, beaches, and sandy shores, sparsely vegetated and littered with driftwood (Cuthbert and Wires 1999).
Cuthbert, F. J. and L. R. Wires. 1999. Caspian Tern (Sterna caspia). In The Birds of North America, No. 403 (A. Poole and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists’ Union.