Least Tern
Sternula antillarum
Tiny tern with quick flicking wingbeats. A real beach bum, rarely straying far from sand, both on the coast and along inland rivers and lakes. Breeding adults have yellow bill, stumpy yellow feet, white forehead, and black cap. Nonbreeding and immatures have a black bill, blackish nape, and dark shoulder bar, but still always identifiable by size and quick wingbeats. Often seen with other terns. Listen for shrill high-pitched calls.
Taxonomy
- Scientific name
- Sternula antillarum
- Authority
- Lesson, RP, 1847
- Order
- Charadriiformes
- Family
- Laridae
- Genus
- Sternula
Range and habitat
- Breeding range
- NA, MA : Great Plains to Texas and n Louisiana; c California and Gulf of California coasts to Oaxaca (w Mexico), El Salvador and Nicaragua; w North Atlantic coast from Maine to Florida, Gulf of Mexico and Caribbean Sea from Bahamas to Lesser Antilles, islands off Yucatan Pen., Belize and n Honduras, and islands n of Venezuela
- Non-breeding range
- n SA coast
- Migration
- Complete migrants
Conservation
The population is about 21,500 pairs; it is not currently considered federally threatened, though it is considered threatened in many of the states in which it breeds. Threats include egg and fledgling predators, high tides and recreational use of nesting beaches.<p>The interior subspecies, with a current population of about 7000 pairs, was listed as an endangered subspecies in 1985 (estimated 1000 breeding pairs), due to loss of habitat caused by dams, reservoirs, channelization, and other changes to river systems. It was delisted on 13 January 2021.<p>The western population, the California least tern, was listed as an endangered species in 1972 with a population of about 600 pairs. With aggressive management, mainly by the exclusion of humans via fencing, the Californian population has rebounded in recent years to about 4500 pairs, a marked increase from 582 pairs in 1974 when census work began, though it is still listed as an endangered subspecies. The California subspecies breeds on beaches and bays of the Pacific Ocean within a very limited range of southern California, in San Francisco Bay and in northwestern Mexico. While numbers have gradually increased with its protected status, it is still vulnerable to predators, natural disasters or further disturbance by humans. Recent threats include the gull-billed tern (Sterna nilotica), which can decrease reproductive success in a colony to less than 10%.
- Population trend
- declining
Photos
Distribution
Bird Calls
Other Birds
Scaly-crowned Babbler
Malacopteron cinereum
Small, dull, brownish babbler. Pale underparts. Faintly scaled crown is orangish and sets it apart from the dark-crowned but otherwise fairly similar Sooty-capped Babbler. Birds north of the Malay Peninsula and southern Thailand have a bicolored crown, with chestnut on the front half and dark on the back. Inhabits lowland and foothill forests, often in wet areas. Forages in noisy flocks, giving rapid-fire series of ticking notes.
Ashy-bellied White-eye
Zosterops citrinella
Small songbird with bright yellowish upperparts and white “goggles.” Most subspecies have gray underparts; subspecies “unicus” of Sumbawa and Flores has a yellow belly. Compare with other white-eyes in various parts of their range; note present species combination of dark iris and yellow back. Inhabits a wide range of different wooded habitats across its range, including coastal scrub, mangroves, inland forests, and forest edge. Forages actively in small to medium-sized flocks, sometimes mixing with other species. Can be quite common on small islands. Twittering song is bright but unremarkable. Most frequently given call is a somewhat variable high-pitched, descending “djee.”
Ash-browed Spinetail
Cranioleuca curtata
Fairly small rufous-brown bird found on the east slope of the Andes from Colombia to Bolivia. Wings and tail are bright rufous, contrasting with duller brown body and head. Note rufous cap and slightly paler eyebrow. Compare with Red-faced Spinetail, which has entirely rufous cheek and crown. Look for singles or pairs in the middle levels and canopy of montane forest and edge from around 900 to 2,000 m. Forages with mixed-species flocks, hitching along branches and probing into patches of moss and clumps of dead leaves.
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