- Sternula antillarum
- 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
it is very noticeably smaller than other North American beach terns.
Northern birds migrate, and the species is found to Brazil in winter.
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 Yellow-billed Tern S. superciliaris and Peruvian Tern S. lorata, both from South America. In the past, all were usually included in the genus Sterna.
There are 3 subspecies:
- S. a. browni:
- S. a. athalassos:
- S. a. antillarum:
Breeds and winters in coastal areas, and to some extent uses inland waters such as rivers. Migrates along coasts but also more pelagic.
Mostly feeds on fish caught with plunge-dives, but can also take insects in the air.
Normally nests colonially. Very aggressive in breeding season.
- 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
- BirdForum Opus contributors. (2021) Least Tern. In: BirdForum, the forum for wild birds and birding. Retrieved 10 May 2021 from https://www.birdforum.net/wiki/Least_Tern