The Least Tern has two big problems. It prefers sandy beaches for nesting—the same kinds of places that people love to visit. And, because it nests on the ground, it's vulnerable to attacks by cats, dogs, and other predators, which can destroy a significant portion of a colony's eggs and chicks.
For example, in Alabama in 2014, coyotes predated nearly 50 percent of the nests in a colony of 100 pairs of birds. Only 6 chicks fledged from this colony, demonstrating how much damage a predator can do.
As a result of these threats, the species is classified as threatened or as a species of concern for most states; the “Interior” race, so-called because it is found on major river systems in the continent's interior, is federally listed as Endangered.
As its name implies, the Least Tern is the smallest of the terns of the Americas; species like the Inca Tern are strikingly different. The birds breed in many areas of the United States and winter mainly along the coast of northern South America, including the coasts of Brazil to Colombia.
Groups of Least Terns can often be seen hovering close to the water's surface with quick, flickering wingbeats as they catch small fish and invertebrates. Like other terns, they also plunge-dive, making an impressive sight as they hover above their prey before suddenly dropping into the water to make their catch.
Nests are a shallow scrape in sand, soil, or pebbles. The birds often breed at the same colony sites each year, but fortunately can respond quickly in response to the emergence of new suitable habitat or the disappearance of old. Least Terns sometimes nest on flat gravel rooftops, usually near beaches, a habit which has its own hazards; hot tar can become stuck in the chick's down or burn the feet of chicks.
Good Turns for Least Tern
The Least Tern is a priority species for ABC. Inland, we worked with diverse government partners to improve Interior Least Tern habitat and monitoring. Our staff organized the first range-wide population survey of the Interior Least Tern; in the near future, the species may be removed from the endangered species list.
On the Gulf Coast, our Beach-nesting Birds Program and many partners are cooperating to bring back populations of Least Tern and other vulnerable beach-nesting birds including Black Skimmer, Wilson's Plover, and Snowy Plover. Due in part to our efforts, in Grand Isle, Louisiana, we observed nearly twice the Least Tern breeding pairs and fledglings in 2013 as we did in 2012. (For example, learn more about our efforts on behalf of a Snowy Plover family at risk from crowds in its nesting area.)
We welcome all and every effort to help us "bring back the birds." If you would like to make a donation, please click here. Or visit our Get Involved page to learn more about how you can help. Together, we can make a difference for this special bird.