Meet the Least Tern!

In June, we’re celebrating beach birds! We need YOU to help protect beach birds and their babies. Together, we can defend an important ecosystem that affects many birds and animals.  Learn more about our month-long celebration of beach birds and how YOU can help on our website! []

Today we’re putting the spotlight on the Least Tern. This smallest breed of terns (get it? Least?)– measures only 9” in length – and can be found along sandy or gravelly coastal areas, as well as inland riverbanks and lakes with broad exposed sandbars.

How can I spot a Least Tern?

The best way to identify a Least Tern is to look for their yellow bills. These are the only small coastal birds to have yellow bills, a feature unique to North American terns.  Both sexes look alike sporting a grayish-white body, relatively long, narrow wings, yellow legs and a short, notched tail. For such a small bird, the wingspan is impressive reaching up to 20”!

Click here to listen to the Least Tern’s high-pitched call. These birds are very territorial of their nests and will scare off intruders with the call. If that doesn’t work, well, look out below.  Least Terns are known to defend their nests by defecating on invaders!

Where can I find Least Terns in North Carolina?

Because Least Terns require a shallow sandy beach for nesting and small fish to feed on, they can be found along many coastal beaches, especially near inlets. Season plays a large part in the migratory patterns of the terns as well. They only frequent North American waterways during the summer months. They arrive in early March or late April and begin to depart as soon as their chicks are flying and feeding themselves—usually by early August. From August on, numbers start to decline as they head back to the Caribbean and South America.

To see Least Terns in action this summer, you just need to head to the North Carolina coast! See Least Terns on these beaches:

Remember not to enter the colonies where babies are hidden on the sand!

Can you spot all 3 chicks? Photo by Michelle Chase Frazier.

What do they eat?

The tern’s favorite food is small fish, but they also seek out crustaceans and insects, small mollusks and marine worms. Terns forage by hovering above the water for their meals. Least Terns visually locate their prey (you’ll see them peering down as they hover) before plunging in to catch what lies just beneath the surface.

How do they raise their young?

Least Terns flock to open sand and gravel to scratch out their shallow nests, which they sometimes line with pebbles or shell fragments. If terns don’t build their nest on a sandy beach, which they prefer, the birds will settle for a gravel-covered rooftop, habitat they have been obliged to adapt to as beaches become increasingly crowded with people. As construction materials change, however, these roofs are becoming scarcer, so beaches remain their best hope for nesting success.

Least Terns nest and breed in small colonies, and males and females work together to raise their young. Both sexes contribute to building the nest, incubating the eggs, and caring for the young. You could say they “take terns” filling parental duties.

One to three eggs are laid at a time, having a buff or sometimes a faint green appearance with dark blotches.

Least Tern eggs. Photo by Lindsay Addison.

Once the babies hatch, they quickly gain the ability to walk. These little chicks actually hatch with open eyes, unlike some species like pelicans, which are born with no feathers and closed eyes. A few days after hatching, they leave the nest moving to short vegetation nearby. They need to quickly find shade to avoid overheating on the sand, where surface temperatures regularly exceed 120 F! The baby terns begin to fly at just over three-weeks-old, and may remain with their parents for up to three months.

Least Tern chick. Photo by The National Audubon Society.

The flock will leave North America in the early fall migrating to southern, tropical weather for the winter months.

As a species that relies on beach habitat that humans also value, it is important to be mindful of the tern nests and to not disrupt them. A few tips for enjoying your summer while the terns are in nesting season: remember to respect all bird postings, watch your step, limit beach driving, and keep dogs on leashes and away from colonies when you are around beach birds.


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