The Black Noddy is a marine tern that nests colonially on islands in the tropics and subtropics. It is one of 3 species of dark noddies worldwide, along with Lesser (A. tenuirostris) and Brown (A. stolidus) noddies, all characterized by a dark body with a white cap-the reverse of the plumage pattern of most terns. The dark noddies are the only marine terns that build substantial nests, and along with the closely related White Tern (Gygis alba) they are the only tree- and shrub-nesting species in the family Laridae. Noddies exhibit several behaviors that are more characteristic of gulls than of other terns, including feeding chicks by regurgitation. The origin of the name "noddy" is uncertain, and may refer to the Nodding Display that is a common part of their social behavior. However, it is believed that sailors once called them "noddies," which means "simpletons," because these birds are easily caught by hand when on the nest (Pringle 1987). The genus name Anous, which means "unmindful" in Greek, also reflects this perception of early observers that noddies are indifferent to humans.
Black Noddies are gregarious birds that often nest, roost, and forage in densely packed groups.
They build nests in trees and shrubs, and in some locations on ledges of cliffs and sea caves, out of whatever materials are available, such as leaves, grass, seaweed, and feathers. As is characteristic of many tropical seabirds, they are relatively long-lived, do not reach sexual maturity for several years, and lay a single-egg clutch. Black Noddies are unusual among seabirds in that a pair can raise 2 broods in the same nesting season. They are surface feeders, foraging in large flocks over schools of predatory fish, and may sometimes depend on these fish to drive prey to the surface. Because they forage close to shore, and are commonly resident in the colony year-round, Black Noddies are seldom seen far from their nesting and roosting islands.
There are only a few Black Noddy breeding colonies in the Americas, located on islands off the Pacific, Caribbean, and Atlantic coasts of Central and n. South America. They also nest on numerous islands throughout the Pacific Ocean (including the Hawaiian archipelago), on a few additional islands in the Atlantic Ocean, and at Ashmore Reef (Australia) in the Indian Ocean. On several islands they are the most numerous seabird, and the copious guano produced by their large populations may alter both the island vegetation structure and the coral reef ecosystem in the surrounding ocean. Black Noddies are more resistant than ground-nesting terns to disturbance from humans and introduced predators, yet in some locations humans take the eggs, chicks, and adults for food.