Bridled Tern

The Bridled Tern is a slender, tropical seabird closely related to the Sooty Tern, sharing its largely pelagic lifestyle but generally staying somewhat closer to land and floating debris. It breeds on islands and cays across warm tropical and subtropical seas worldwide.

Appearance

Adults have grayish-brown upperparts (paler than Sooty Tern), white underparts, a black cap, and a narrow white line above the eye that extends back toward the nape, giving the "bridled" appearance. A pale grayish collar separates the dark cap from the back. The tail is long and deeply forked with white outer feathers.

Key field marks

• Grayish-brown (not sooty black) upperparts
• Thin white supercilium extending behind the eye
• Pale collar around the hindneck separating the cap from the back
• Often seen resting on floating debris, unlike the more strictly aerial Sooty Tern

Similar species

Sooty Tern is the closest match but is darker and more sharply blackish-brown above, has a forehead patch that does not extend behind the eye, and lacks a pale collar. Bridled Tern's paler, browner tones and habit of resting on flotsam help distinguish it at sea.

Habitat and range

Bridled Terns breed on rocky or vegetated tropical islands and cays in the Atlantic, Indian, and Pacific Oceans, nesting in crevices, under vegetation, or in other sheltered spots rather than in the open. Outside the breeding season they range widely over warm offshore and pelagic waters.

Migration

Many populations disperse widely after breeding, following warm ocean currents, and can be seen well offshore during migration, sometimes appearing after tropical storms push birds toward continental coastlines.

Behavior

Bridled Terns feed by dipping to the sea surface for small fish and squid, often associating with drifting seaweed mats or debris that shelter prey, and less frequently over large predatory fish schools than Sooty Terns.

Voice

Calls include a soft, barking "wep" or "yip," quieter and less incessant than the calls of Sooty Tern colonies.

Nesting and breeding

Unlike the more exposed nest sites of Sooty Terns, Bridled Terns typically nest singly or in loose groups in sheltered crevices, rock ledges, or beneath vegetation, laying a single egg. Both parents share incubation and chick-rearing duties.