Living Sanibel: Least Tern
True to its nickname sea swallow, this is the smallest tern in the Western Hemisphere. Weighing half that of a robin, this tiny tern feeds on small fish, crustaceans, and sand eels. Its cap is similar to other terns, but its diminutive size and black-tipped yellow bill are the best methods of identifying this bird.
Like several other summer species, the least tern has made Florida its northern nesting site, although several small populations nest as far north as Massachusetts. Once hunted for its plumes, the least tern is still considered threatened in much of its range, and its population is being closely monitored. There is also a West Coast population that summers in California and winters deep into Mexico.
The least tern suffers from habitat and nesting-site loss. It prefers to nest on beaches where it is often in conflict with humans and their pets. If agitated by an unwanted intruder, the least tern has a nasty habit of hovering over the potential predator and defecating, so be forewarned. The least tern is monogamous but always nests in colonies with other terns.