Noronha Vireo

Overview

The Noronha vireo (Vireo gracilirostris) is a Vulnerable species of bird in the family Vireonidae that is endemic to the island of Fernando de Noronha, Brazil. It is the only vireo present on the island and remains a sedentary year-round resident despite having a very restricted range and a decreasing population estimated between 700 and 1,000 mature individuals.

Identification

• Adults are 14 cm long and weigh between 11.5 and 25.1 g, with dingy grayish olive upperparts that become greener on the rump and tail.
• The throat and underparts are dull buffy whitish, complemented by a buffy supercilium and brownish lores.
• Features include a brownish iris, a brownish horn bill with a paler mandible base, and pale bluish gray legs and feet.
• The song consists of a "melodious weet a weet, chewegoo, whit, whit", with an alarm call described as "tschrrr" and other calls including a harsh screech and a high thin whistle.

Habitat

Found exclusively on Fernando de Noronha island, located approximately 350 km off the coast of northeastern Brazil, the species inhabits any available environment including forest, shrublands, and gardens. Because primary forest has been almost entirely eliminated on the island, the bird persists primarily in secondary forest and secondary growth.

Diet

The Noronha vireo feeds mainly on a variety of insects and also consumes small fruits, foraging at all levels of its habitat. It has developed diverse feeding techniques, including hanging upside-down to take prey from the undersides of leaves and flowers and regularly catching insects in mid-air.

Did you know?

Due to the absence of competing passerine species on its island, the Noronha vireo has evolved a wide variety of feeding techniques, including hanging upside-down to extract prey from the undersides of leaves and flowers.