Roseate Tern
New York Status: Endangered
Federal Status: Endangered
Description
The roseate tern is a graceful bird, 14 to 17 inches long, with a wingspan of about 30 inches. It resembles the common tern. Its back and upper wings are a light pearly-grey, while its underparts are white. The tip of the white tail extends well beyond its wing tips when the bird is at rest. In the summer it has a black cap, nape and bill. Juveniles have prominent, dark "V"s on the feathers of the back. The flight of this bird is distinctive, with rapid, shallow wingbeats of equal emphasis on the upstroke and downstroke. Its call is a rasping "z-aa-p" or a soft, two-syllabled "chivy." Roseate terns feed primarily on American sand lance, a small marine fish.
Life History
Roseate terns arrive on the breeding grounds in late April or early May and begin nesting one month later. In New York, roseate terns are always found nesting with common terns. The nest may be only a depression in sand, shell, or gravel, and may be lined with bits of grass and other debris. It is usually placed in dense grass clumps, or even under boulders or rip-rap. Both adults incubate the eggs for about 23 days, and the young fledge in 22-29 days. One brood per season is typical, although two broods are sometimes produced. Migration begins in late summer. One banded individual from Great Gull Island, New York was 9 years old when recovered.
Distribution and Habitat
A marine coastal species, the roseate tern breeds along the coasts of the Atlantic, Pacific, and Indian oceans on salt marsh islands and beaches with sparse vegetation. In eastern North America, it breeds from the Canadian Maritime Provinces south to Long Island, although formerly the breeding range extended to Virginia.
In New York, this species breeds only at a few Long Island colonies. The largest colony, more than 1,000 pairs, is located at Great Gull Island off eastern Long Island.
Status
During the 1870s and 1880s, the roseate tern was in serious danger of extirpation from its range in the northeastern U. S. due to hunting for the millinery trade. Protection since 1918 under the Migratory Bird Treaty Act allowed this tern to recover in the 1920s and 1930s.
Threats to roseate tern populations include vegetational changes on the breeding areas, competition with gulls for suitable nesting areas, and predation. The increased presence of humans has contributed to higher predation rates. Predators such as raccoons find tern nests when they are attracted to the garbage left behind by careless beach users.
The roseate tern population is estimated to have fallen by 75% since the 1930s. Recent survey data indicates that 87% of the birds in New York nest in only one colony at Great Gull Island.
Management and Research Needs
Status and distribution of roseate tern populations is monitored annually by the DEC in cooperation with the American Museum of Natural History, The Nature Conservancy, and other researchers. A critical research need is to better understand the species' wintering habits and survival. One of the highest priorities in the recovery plan prepared by the U.S. Fish and Wildlife Service is to extend the species range by restoring some of the historic breeding areas. One success story in New York was the nesting of roseate terns and 60 pairs of common terns on Gardiners Point Island in 1995. This site supported no terns when habitat management began in 1990.
