Introduced mammals are the biggest threat to this species, causing damage to its sheltered habitats and increasing predation. Goats and rabbits brought to the island the Juan Fernández archipelago, graze and trample vegetation, creating large areas that are dangerously exposed for the birds (5). Introduced rats, mice and feral cats all probably prey on this species, posing a threat to the eggs, chicks and adults (2). The only native predator of the Masafuera rayadito on Alejandro Selkirk, the red-backed (or Masafuera) hawk (Buteo polyosoma), has increased in numbers since hunting it became illegal and following an increase of introduced mice and rats on which it can feed (6).
Populations of the Masafuera rayadito are thought to be declining, with the most recent surveys showing just 248 individuals within one third to one quarter of the available suitable habitat (6). Not only are they classified as Critically Endangered on the IUCN Red List, but they are in category two, ‘in danger’, of the Red List of the Terrestrial Vertebrates of Chile; category one is ‘extinct’ (5). In the early 20thcentury the endemic hummingbird that used to share the island with the Masafuera rayadito became the victim of the same threats and is now extinct (3), stressing the seriousness of the situation that the Masafuera rayadito is now in.