Thalasseus – Crested terns

The genus Thalasseus is a group of elegant and agile seabirds known as crested terns found along coastlines, islands, and estuaries around the world. These birds are part of the tern family (Laridae) and are famous for their sharp flight skills, loud calls, and stylish feather crests. Members of this genus are medium to large-sized terns with slender bodies, long wings, forked tails, and long, pointed bills — usually bright yellow or orange. They’re often seen diving headfirst into the water to catch fish, flying in neat flocks above the waves, or roosting in noisy colonies on sandy beaches.

Some of the best-known species in the Thalasseus genus include the Royal tern (Thalasseus maximus), Sandwich tern (Thalasseus sandvicensis), Elegant tern (Thalasseus elegans), and Lesser crested tern (Thalasseus bengalensis). These species share similar features, like a black cap or crest on their heads during breeding season, and a graceful, buoyant flight style. Despite their shared appearance, each species has its own range and behavior. For example, the Royal tern is common along the Americas’ Atlantic and Pacific coasts, while the Sandwich tern breeds in Europe and winters in Africa and the Caribbean. The Elegant tern is mainly found along the Pacific coast of North and South America.

One of the most distinctive behaviors of Thalasseus terns is their plunge-diving technique. When hunting, they hover briefly over the water, spot their prey — usually small fish — and then dive straight down, often with a dramatic splash. Their slender, pointed bills help them grab fish mid-dive. These birds typically nest in large colonies, laying their eggs in shallow scrapes on sandy or gravelly ground. Chicks are precocial, meaning they can move around soon after hatching, and parents recognize their young by sound in the crowded colony.