Elegant Tern

Thalasseus elegans

(c) Glen Tepke
  • LARIDAE
  • Gulls, Terns, and Skimmers
  • Charadriiformes
  • Charrán elegante
  • Sterne élégante
Introduction

This shaggy-crested tern has the most restricted breeding distribution of any tern in North America. Formerly just a late summer visitor to the Pacific Coast of the United States, the Elegant Tern was first found nesting in San Diego, California in 1959 and has since expanded northward, while simultaneously disappearing from former nesting sites in Mexico.

(c) Glen Tepke
Appearance Description
Elegant Terns weigh an average of nine ounces, and are 17 inches long, with a wingspan of 34 inches. These medium-sized terns have long orange bills, black caps with shaggy crests, light gray upper parts, white under parts that sometimes include a pink flush on the belly-feathers, and black legs. Elegant Terns are very similar in appearance to the larger Royal Terns, but can be differentiated by their longer, thinner, downcurved bills and larger crests.
Range Map
Courtesy Kenn Kaufman
Range Distribution
Elegant Terns breed in only five nesting colonies—two in southern California, and three in northwestern Mexico. More than 90% of the world's Elegant Terns nest on Isla Rasa in Mexico's Gulf of California. Following the breeding season, birds typically disperse northward to central and northern California, but they can move as far north as Oregon and Washington. In southern California, breeding success and dispersal patterns appear related to oceanographic conditions, which affect the distribution of the birds' key prey, the northern anchovy. In winter, Elegant Terns are found along the Pacific Coast from central Mexico south to Chile.
Habitat
Elegant Terns are typically found along the shallow waters of estuaries and bays along the ocean. During the breeding season, they nest on isolated sandy or rocky islands, usually in the company of larger, more aggressive birds, such as Heermann's Gulls and Caspian Terns.
Feeding
Elegant Terns forage by hovering over shallow water and then plunging into the water after fish. This tern can transport a single fish at a time crosswise in its bill. Elegant Terns forage on a variety of different schooling fish, with northern anchovy (Engraulis mordax) being their most important prey item. Other prey species include sardines, silversides, gobies, mackerels, and rarely, crustaceans. When feeding in flocks, these gregarious terns call frequently.
Reproduction
A strongly social bird, this tern nests in tight groups. Like many other terns, Elegant Tern nests consist of a shallow scrape on the ground. Their typical clutch size is one egg, buff to white marked with dark brown, which is probably incubated by both parents. After a period of at least three weeks, the single chick hatches and spends a few days in the nest before joining a creche—a group of young birds who are still fed by their own parents. Post-fledging parental care lasts up to six months, during which time the chicks learn foraging skills.
Migration
After breeding, Elegant Terns disperse north along the Pacific coast to northern California, or, in years of warm water intrusions, to southern British Columbia. These terns winter primarily in South America, but small numbers winter locally along the Pacific coast north to Nayarit, Mexico.
  • 70,500
  • 70,500
Population Status Trends
Although California populations are expanding in range, population trends are unknown. In 1995, the Elegant Tern was designated as a "migratory non-game bird of management concern" in the U.S. The Elegant Tern is currently listed as a "species of special concern" in California, and has been designated as "near threatened" by BirdLife International on behalf of the World Conservation Union (IUCN).
Conservation Issues
Historically, at least a dozen Elegant Tern breeding colonies existed, but commercial egging and the introduction of mammalian predators have eliminated most of them. Today, Elegant Terns face a number of threats common to colonially nesting seabirds, but given these terns' heavily-concentrated breeding population, these threats are particularly serious for them. This species is highly susceptible to disturbance at their breeding colonies and roost sites; the introduction of non-native mammalian predators; entanglement in fishing equipment; and nesting site degradation, especially as a result of urban development in southern California. Rising coastal California water temperatures may also shift northern anchovy distributions and abundance, impacting Elegant Terns. In addition, Elegant Terns nesting at the species' main colony on Isla Rasa in Mexico are threatened by egg harvesting, extensive guano mining, and disruptive tourist visitation.

In California, Audubon's Orange Coast Wetlands Important Bird Area includes the Bolsa Chica Ecological Area, where 4,000 pairs of Elegant Terns nest. In Mexico, the Important Bird Area of Isla Rasa in the Gulf of California has been declared a bird refuge and is included in the Islas del Golfo de California Biosphere Reserve. Establishment of this reserve has alleviated the population crash. Further recommendations include escalated enforcement in restricted-use areas, integrated with ecotourism and regional planning, as well as regular patrols in breeding season; clear, bilingual warnings about the impacts of disturbance; and roped trails for tourists.
What You Can Do
Never leave fishing lines, lures, or hooks on beaches; entanglement kills numerous terns each year.

Don't dump garbage or fishing bait which feeds competing gulls.

Use alternatives to pesticides. Dispose of old pesticides responsibly.

Don't disturb nesting tern colonies when hiking or landing boats; prevent dogs and children from disturbing them. When parent terns abandon nests, eggs or chicks can overheat or become wet and chilled, often resulting in death.

Make environmentally-friendly seafood choices which encourage sustainable fisheries; this helps to protect the fish that Elegant Terns and many other seabirds depend upon. 

Find out about actions you can take including Audubon programs and activities.
More Information
Audubon's Important Bird Area program is a vital tool for the conservation of Elegant Terns and other species. 

Mexico also has an Important Bird Areas program that is working to protect habitat for Elegant Tern and many other species. Learn more about Mexico's Important Bird Areas program and how you can help. Learn more about Pronatura, the BirdLife partner in Mexico.  To translate these pages to English, use the Google tool here

Learn more about this species and other birds through these resources.
Natural History References
Burness, G. P., K. Lefevre, and C. T. Collins. 1999. Elegant Tern (Sterna elegans). In The Birds of North America, No. 404 (A. Poole and F. Gill, Eds.). The Birds of North America, Inc., Philadelphia, PA.

del Coro Arizmendi, Ma. and L. M. Valdelamar. Áreas de Importancia para la Conservación de las Aves en México. Cipamex AC, Mexico City. 2000.

Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York. 1996.

Sibley, David A. The Sibley Guide to Birds. Alfred A. Knopf, New York. 2000.
Conservation Status References
BirdLife International (2007) Species factsheet: Sterna elegans.

Burness, G. P., K. Lefevre, and C. T. Collins. 1999. Elegant Tern (Sterna elegans). In The Birds of North America, No. 404 (A. Poole and F. Gill, Eds.). The Birds of North America, Inc., Philadelphia, PA.

del Coro Arizmendi, Ma. and L. M. Valdelamar. Áreas de Importancia para la Conservación de las Aves en México. Cipamex AC, Mexico City. 2000.

Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York. 1996.

Sibley, David A. The Sibley Guide to Birds. Alfred A. Knopf, New York. 2000.