Olympic Coast National Marine Sanctuary Living Sanctuary section includes Marine Life, Habitats, Ocean Environment, History and Culture
Olympic Coast National Marine Sanctuary Living Sanctuary section includes Marine Life, Habitats, Ocean Environment, History and Culture
Olympic Coast National Marine Sanctuary Living Sanctuary section includes Marine Life, Habitats, Ocean Environment, History and Culture

Caspian Tern

Caspian Tern
(Sterna caspia)

Habitat
A variety of freshwater and inland marine habitats: coastal bays, estuaries, beaches.

Range
Wanders widely around the world. Common locally; On the west coast, breeds as far north as Alaska and south to Mexico, Winters from southern California south to Guatamala. Also found in the interior on large lakes.

Eats
Small fish close to the surface, marine life, large insects.

Feeds
Feeds on surface and dives for small fish. Patrols over open water with bill pointed downward and often hovers briefly before plunge-diving and piercing prey with sharp, pointed bill. Often submerges completely. Small, thin bill good for catching tiny prey such as bait fish, insect larvae and flying insects.
Often steals catches from other seabirds and eats eggs and young of other terns and gulls.

Moves
Strong, soaring flight with broad, streamlined wings pointed at the tip for easy maneuvering.

Behavior
Less gregarious than other terns; quite aggressive. When attacked by predators, the entire colony defends nests by chasing, pecking and defecating on the intruder.

Voice
Deep, harsh scream, much like a heron.

Reproduction
Monogamous, one brood (2-4 eggs) per year. Nests in small colonies on sandbars or gravel banks with sparse vegetation. Most of Washington's population breeds in the Columbia River estuary.

Threats
Human disturbances at nesting sites, loss or degradation of habitat. Coming in to conflict with humans as a competitor for juvenile salmon on the Columbia River, where the largest west coast tern colony is located.

Status
Protected under the Migratory Bird Treaty Act. Washington State Monitored Species

Presence in Olympic Coast National Marine Sanctuary
Summer. Closest breeding colonies to the sanctuary are in Willapa Bay and on Dungeness Spit.

Notes
The largest tern in North America.



Contact for page content: Liam Antrim
Photo of peach coral
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