Roseate Tern: North American Subspecies Sterna Dougallii Dougallii

U.S. Fish & Wildlife Service Roseate Tern: North American Subspecies Sterna dougallii dougallii Introduction The roseate tern is a federally protected and endangered seabird that is mainly found in the Northern Hemisphere on the northeastern coast of North America, extending from Nova Scotia to the southern tip of Florida, as well as several islands in the Caribbean Sea. It is also found in northwestern Europe, south and west Africa, and Western Australia. The roseate tern is divided into four subspecies based on small differences in size and bill color. The North American subspecies is divided into two separate breeding populations; one in the northeastern U.S. and Nova Scotia and another in the southeastern U.S. and Caribbean. Roseate terns are most common in the central portion of this range, from Massachusetts to Kirk Rogers/USFWS Long Island, N.Y. Roseate tern Populations in the northeastern distinguish from common terns, among Life Cycle U.S. greatly declined in the late which it nests in the Northeast. Roseate terns nest on small barrier 19th century due to hunting for the islands, often at ends or breaks. millinery, or hat trade. In the 1930s, During breeding season, it is paler than They nest in hollows or under dense protected under the Migratory Bird other terns, with most of its plumage vegetation, debris or rocks hidden Act Treaty, the population reached a turning silver-gray above and creamy from predators. Roseate terns in high of about 8,500, but since then, white below a rosy-pink chest and a northeastern North America almost population numbers have declined black cap. It also develops long white always nest in colonies with common and stayed in the low range of 2,500 to tail-streamers that it loses after the terns. Roseate terns begin arriving 3,300. The species was listed in 1987 as breeding season. In the northeastern to breeding areas at the end of April endangered in the northeastern U.S. birds, the black bill becomes orange- and begin laying eggs as early as the Populations in Florida, Georgia, North red at the base and the black legs also third or fourth week of May. They lay Carolina, Puerto Rico, South Carolina turn orange-red. about one to two eggs, rarely three, and the Virgin Islands are listed as and rely on the more aggressive Arctic threatened. The roseate tern is a specialist feeder and common terns in the surrounding eating almost exclusively small colony to defend them. Characteristics fish, primarily the American sand The roseate tern is a medium-sized, lance in northeastern populations. In the winter, roseate terns migrate gull-like tern about 15 inches long. It captures food mainly by plunge- south in late August to early When not in breeding season, it has a diving, completely submerging its body September. They migrate from the black bill, black legs, white forehead underwater to catch prey, but it also northeastern U.S. to the waters off and most of the crown, and a long, feeds in shallow waters and even steals Trinidad and northern South America deeply forked tail. During this time, food from common terns. from the Pacific coast of Columbia to the roseate tern is often difficult to eastern Brazil. European roseate populations usually nesting colonies in the Northeast. U.S. Fish and Wildlife Service migrate to western and southern Roseate terns compete with gulls 300 Westgate Center Drive Africa. for nesting sites and food; the Hadley, MA 01035 aggressiveness and larger size of the 413/253 8200 Threats and Recovery Efforts gulls give them an advantage. Gulls Habitat for northeastern North also compete for habitat with terns by Federal Relay Servicec American populations has been nesting before the terns do, leading the for the deaf and hard-of-hearing greatly reduced by human activity roseate terns to retreat and abandon 1 800/877 8339 and development on barrier islands, their historical sites. predation, and competition from U.S. Fish & Wildlife Service expanding numbers of large gulls. The loss of habitat from erosion, a 1 800/344 WILD Roseate terns are highly sensitive possible result of rising sea levels, is http://www.fws.gov to disturbances and will desert a another major factor contributing to whole colony if they feel threatened. the decline of roseate tern populations. May 2011 The move to less desirable, often inadequate areas exposes the roseate The spit—a narrow land comprised tern to high predation and affects its of gravel and sand extending into ability to reproduce. the ocean—on Falkner Island, in the Long Island sound, is home to one Roseate terns often desert their of the largest tern populations in the colonies and eggs at night when they northeastern U.S. It is estimated that become subject to predation, leaving Falkner Island is losing about 800 to eggs and young exposed and vulnerable 900 square feet per year due to erosion, to predatory mammals such as foxes, and in the next two to five years, the skunks and brown rats. Predatory spit will be in a tidal zone, leaving birds, such as the great-horned owl roseate terns without their prime and black-crowned night heron, pose a habitat. greater threat because they can fly to the more protected island nesting sites. In areas like Falkner Island, biologists Roseate terns are quick to abandon a work hard to create artificial habitats nesting site when predators are active. for the terns to counteract the move and make new, less desirable sites An increase in great-blacked gull and appealing. Inverted boxes or half- herring populations has displaced buried tires are commonly used to roseate terns from their traditional provide covered nesting sites. .

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