Common Tern

Wheeling about in mid-air to a stationary hover, the Common Tern quickly dives headfirst into the water, often bouncing up to the surface with a small fish in its thin bill. Terns are effortless fliers and some of the greatest migrants. The Arctic Tern, which passes the eastern toe of the Rockies, migrates more than 11,000 mi. (17,700 km) in its yearly round-trip journey from the Arctic to the Antarctic. Recently, a Common Tern banded in Great Britain was recovered in Australia- a record distance. Common Tern colonies are loud and noisy. If an intruder approaches a nest, the parent will dive repeatedly, often defecating quite accurately during the lowest point of the dive.

Sterna hirundo

I.D.: Sexes similar. Breeding: black cap; thin, red, black-tipped bill; light gray wing covers; red legs; white rump; mostly white tail; white underparts. Non-breeding: lacks the black cap; black nape. In flight: shallowly forked tail; long, pointed wings.

Size: L 13-16 in. (33-41 cm);

W 30 in. (76 cm).

Range: rare migrant in the southern Rockies; uncommon migrant north of Glacier NP and through the Canadian Rockies.

Habitat: large lakes, open wetlands and slow-moving rivers, primarily up to the montane.

Nesting: typically east of the Rockies; usually colonial; usually on a beach or other open area without vegetation; in a small scrape lined sparsely with pebbles, vegetation or shells; pair incubates 3 eggs for up to 27 days.

Feeding: hovers over the water and plunges headfirst after small fish and aquatic invertebrates.

Voice: high-pitched, drawn-out keee-are, most commonly heard at colonies, but also in foraging flights.

Similar Species: Forster's Tern: yellow-orange bill and legs; mostly gray tail; silver-tipped primaries; black mask in winter. Arctic Tern: rare in migration; all-deep red bill; deeply forked tail; light primaries. Caspian Tern: much larger; heavy, all-red bill.