From Opus

Photo by John Dempsey
Cuba, May 2003

Sternula antillarum

Sterna antillarum

[edit] Identification

L. 22-24cm

• Pale grey upperparts
• White underparts
• White lower head
• Black cap down to the level of the eyes
• White front of head that intersects black back to above eyes
• Yellow bill that becomes black outside of breeding season
• Yellow legs
• Grey wings with black markings on outermost primaries

Least Tern in fishing posture
Photo by HelenB
Quintana Jetty, Upper Texas Coast, June 2010

[edit] Similar Species

it is very noticeably smaller than other North American beach terns.

[edit] Distribution

Breeds in coastal and inland North America north to California and Maine, in Central America, the Caribbean and northern South America (mainly islands off Venezuela).

Northern birds migrate, and the species is found to Brazil in winter.

[edit] Taxonomy

Juvenile
Photo by Chato
Brooklyn, New York, July 2012

This species was formerly placed in the genus Sterna
Least Tern is closely related to, and was formerly often considered conspecific with, the Little Tern S. albifrons of the Old World. Other close relatives include the Yellow-billed Tern S. superciliaris and Peruvian Tern S. lorata, both from South America.

[edit] Subspecies

There are 3 subspecies^[1]:

• S. a. browni:

• Southern California to Baja and western Mexico; winters to Central America

• S. a. athalassos:

• North Great Plains to Louisiana and Texas; winters to northern Brazil

• S. a. antillarum:

• Eastern US to Honduras, Caribbean and Guianas; winters to northern Brazil

[edit] Habitat

Breeds and winters in coastal areas, and to some extent uses inland waters such as rivers. Migrates along coasts but also more pelagic.

[edit] Behaviour

[edit] Diet

Mostly feeds on fish caught with plunge-dives, but can also take insects in the air.

[edit] Breeding

Normally nests colonially. Very aggressive in breeding season.

[edit] References

1. Clements, JF. 2010. The Clements Checklist of Birds of the World. 6th ed., with updates to December 2010. Ithaca: Cornell Univ. Press. ISBN 978-0801445019. Spreadsheet available at http://www.birds.cornell.edu/clementschecklist/Clements%206.5.xls/view

• List of references

[edit] External Links

• An identification essay comparing Least Tern with Yellow-billed Tern