Characteristics

Physical Appearance:

The Black-naped Tern (Sterna sumatrana) possesses a distinctive appearance characterized by its black nape patch, which extends down the back of its neck. Its plumage is predominantly white, with grey upperparts and a black cap extending from the eyes to the nape. During the breeding season, adults may exhibit slightly more vibrant plumage, with a darker black cap and more pronounced contrast between the black and white feathers.

Size and Dimensions:

Adult Black-naped Terns typically measure between 25 to 30 centimeters in length, with a wingspan ranging from 55 to 60 centimeters. They are relatively lightweight birds, weighing approximately 70 to 90 grams. Despite their small size, they possess elongated wings and a streamlined body, facilitating swift and agile flight as they hunt for prey over the ocean's surface.

Flight Characteristics:

Their flight is characterized by a combination of gliding, soaring, and occasional flapping, enabling them to cover long distances efficiently. When hunting, they often employ plunge-diving techniques, descending rapidly from heights to capture fish or other prey below the water's surface.

Habitat and Distribution:

These seabirds inhabit coastal areas, offshore islands, and occasionally venture further out to sea in search of food. Their distribution also extends to other regions with suitable coastal habitats, such as India, Bangladesh, Sri Lanka, Taiwan, Japan, and parts of Australia.

Behavior and Feeding Habits:

They hunt by plunge-diving into the water from heights, using their keen eyesight to locate prey below the surface. Additionally, they may also consume small crustaceans, squid, and other marine invertebrates, supplementing their diet with a variety of prey depending on availability and location.

Breeding and Reproduction:

Breeding colonies of Black-naped Terns are often established on remote islands or coastal cliffs, providing nesting pairs with a safe environment away from terrestrial predators. They typically lay one to two eggs per clutch, which are incubated by both parents for several weeks until they hatch.

Conservation Status:

While the Black-naped Tern is not currently considered globally threatened, it faces various conservation challenges, including habitat loss, disturbance at nesting sites, overfishing, and pollution of coastal waters.