Caspian Tern

Large, stocky tern; bill orange to coral red, much thicker than Royal Tern. In flight, shows dark underside of primaries; tail is less deeply forked than in Royal. Adult acquires black cap in breeding season; in nonbreeding plumage and immature, crown is dusky or streaked; Caspian Terns nest in small colonies along coasts and inland lakes, rivers, and marshes.