The Gull-billed Tern is named for the unusually thick bill for a tern. While other tern species are often seen flying over water and diving for fish, the Gull-billed Tern prefers to feed on insects, and is often found foraging over terrestrial habitats. They are a very widespread species, with populations found in the warmer parts of Europe, Asia, Australia, Africa, and South America, as well as the warmer areas of North America.
Habitat
Found near coastal areas in North America, with notable exceptions of the Salton Sea in California, and some inland areas in southern Florida. Much of their foraging is done on inland habitats adjacent to the coast, particularly open areas such as marshes, wet meadows, or agricultural land.
Diet
Feeds heavily on insects, but will also feed on small crustaceans, mollusks, marine worms, amphibians, small rodents, and small birds and bird eggs.
Behavior
Most foraging is done from flight, with slow observation flights interrupted by dives to the ground or water when food is spotted. They may also catch insects in mid-air. They will also sometimes forage by walking along the shoreline.
Nesting
The nest of Gull-billed Tern is a depression on the ground, lined with plant material and debris. The female lays between 1 and 4 eggs, and both parents help to incubate them. When the eggs hatch, both parent help to feed them. The young fledge at about 5 weeks.
Song
The Gull-billed Tern gives a variety of loud, harsh calls, most commonly sharp, grating kek-kek-kek notes. These vocalizations are used during courtship, territorial defense, and communication within breeding colonies. Adults become especially noisy when predators approach, repeatedly calling while diving at intruders to defend their nests.
Migration
Some are evidently permanent residents along the Gulf Coast. Those on the Atlantic Coast are only present during the summer months, with birds likely wintering along the Gulf Coast, in the Caribbean, or coastal Mexico.
Interactive eBird Map
Click here to access an interactive eBird map of Gull-billed Tern sightings
Similar Species
Sandwich Tern. The Gull-billed Tern is larger and stockier than the Sandwich Tern, with a thick, short black bill and broader wings. Sandwich Terns have a long, slender bill with a yellow tip, a shaggy black crest during the breeding season, and are more specialized for plunge-diving into the ocean for fish, whereas Gull-billed Terns often capture insects, reptiles, and other prey over land as well as in shallow wetlands.
Conservation Status
The Gull-billed Tern is classified as Least Concern by the International Union for Conservation of Nature because of its broad global distribution and large overall population. However, some regional populations have declined due to wetland loss, coastal development, human disturbance at nesting colonies, and predation. Despite these localized threats, the species remains widespread and is not currently considered globally threatened.
Further Information
- eBird - Gull-billed Tern
- Audubon Field Guide - Gull-billed Tern
- Cornell Lab of Ornithology - All About Birds: Gull-billed Tern
Photo Information
Photo taken by Sergey Yeliseev - March 5th, 2011 - Sri Lanka - Photo licensed under Creative Commons Attribution NonCommercial NoDerivs 2.0 Generic License.
