About Phaetusa simplex (J.F.Gmelin, 1789)
This species, commonly called the large-billed tern, has the scientific name Phaetusa simplex (J.F.Gmelin, 1789). It is a large, short-tailed tern distinguished by a large yellow bill. Adults measure approximately 38 cm (15 in) in total length, and weigh between 208 and 247 g (7.3–8.7 oz). Breeding adults have black crowns and black ear-coverts, grey upperparts, and white secondaries, primary coverts, lores, and underparts. Their legs and feet are yellow. Non-breeding adults have a paler crown and forehead.