Species Profile – Masafuera Rayadito

Critically endangered island endemic

Masafuera Rayadito. Photo: Andrea Suardo

Even this bird’s name sounds mysterious and exotic—Masafuera Rayadito. This extremely rare, little-known species is endemic to the 32-square-mile Alexander Selkirk Island, part of the Juan Fernandez archipelago some 400 miles off the coast of Chile. This archipelago is particularly known for its endemic plant and animal species, and is recognized as a Global Biosphere Reserve by UNESCO.

The Masafuera Rayadito is a member of the Furnariidae (Ovenbird) family; land birds found only in the New World neotropics. It is a lively, sparrow-sized, brown and gray bird, closely related to the more common Thorn-tailed Rayadito found on the South American mainland. A distinctive feature of the Rayadito family is the long tail—black and wedge-shaped, without webs on the ends of the feathers, which gives the tail a “thorny” appearance.

Masafuera Rayaditos occur in the forested regions of the island above 2,500 feet. They skulk in dense vegetation, often in pairs, and are detectable mostly by their “churring” calls. They rarely fly above the fern cover they favor. Masafuera Rayaditos are insectivores, gleaning their food mainly from fern fronds, epiphytic mosses, and lichens. They will also clamber up tree trunks like creepers, or hang upside down, chickadee-like, while searching for arthropods.

Recent surveys have shown that the Masafuera Rayadito has an extremely small, declining population. In 2006, researchers estimated the number of individuals on the southern part of the island at a mere 250 birds. The Masafuera Rayadito is now listed as critically endangered by the IUCN.

The species has been affected by severe habitat loss—natural vegetation on the island has been devastated by domestic goats, fires, and timber cutting. Predation by introduced cats, rats, and mice also threatens the rayadito.

Little is known about the breeding biology of the Masafuera Rayadito as only three nests have ever been discovered. In 2006, hoping to add to existing knowledge of the species, researchers funded by an ABC William Belton Conservation Grant, installed a total of 81 artificial nest boxes for the cavity-nesting birds. Work during the 2007 field season includes monitoring the use of the boxes and their success in boosting the rayadito population. Biologists hope that continuing research will lead to more effective conservation for this enigmatic and engaging bird species, preventing it from disappearing forever.