Beak of the Week – Sandwich Tern

Sandwich Terns are slender, medium-sized terns with shaggy crests. Adults have pale gray backs and wings, and clean white underparts. During the breeding season, adults often develop a slight pinkish wash on their chest and belly. Breeding adults have solid black caps that become mostly white during the non-breeding season. To distinguish them from other terns, note their size– smaller than Royal Terns but larger than Common and Forster’s Terns– and the coloration of their bill: their long, rather thin bills are black with a yellow tip. Their bills are unique among North American terns. Gull-billed Terns, which are also common on the Upper Texas Coast, also have black bills, but their bills are shorter and thicker and lack the yellow tip.

They have a wide distribution, and are found in both the Western and Eastern Hemispheres. In the Western Hemisphere, Sandwich Terns breed along the southern Atlantic Coast and Gulf Coast of the U.S., the West Indies, and along the Atlantic coast of South America. They breed on flat, low-lying islands with little or no vegetation that are close to shore (typically sandy barrier islands and barrier beaches on the Atlantic and Gulf Coasts and cays in the Caribbean). Throughout their range, they nest in mixed-species colonies with gulls and other terns. Sandwich Terns perform courtship displays both in the air on the ground, usually involving the male presenting a fish to the female. Their nests are shallow scrapes or depressions in the ground, made by both adults. Once chicks are old enough to fly, they follow their parents to nearby beaches where the adults continue to bring fish to their young. Juvenile birds are very similar in appearance to adults, but have dark brownish-black bills and some black spotting on their backs.

Sandwich Terns are year-round residents on the Upper Texas Coast, and nest on islands in Galveston Bay. These dashing terns can be seen at Bolivar Flats Shorebird Sanctuary!