Description:
Adults in breeding plumage have an ashy-gray back, shoulders, wings, and tail. The inner portions of the wings and tail are white. A black crest is present on the crown. The remaining plumage is white, with two small, bright spots on the chest. In non-breeding plumage, the front of the crown is white. Juveniles have plumage with numerous brown markings. The eyes are dark brown. The beak is yellow with a pale green base. Legs are black.
Biology:
Breeds from April to June, laying 1-2 eggs. The primary diet consists of small fish and squid.
Habitat and Ecology:
Lives and nests in colonies offshore. They often come to shore to forage during the southwest monsoon season.
Distribution:
Vietnam: Hoang Sa Archipelago, Truong Sa Archipelago, islands off the central coast, and Con Dao Island.
Worldwide: Coastlines of China, Thailand, and Cambodia.
Value:
Genetic resource protection. Potential for egg harvesting.
Status:
Nesting sites are heavily impacted, and there is rampant egg harvesting. Threat level: Vulnerable.
Proposed Conservation Measures:
Research conservation measures. Prohibit current indiscriminate egg harvesting.