Western Azores goldcrest explained

The Western Azores goldcrest (Regulus regulus inermis), Estrelinha-de-poupa in Portuguese, is a very small passerine bird in the kinglet family. It is endemic to the Azores archipelago, in the North Atlantic Ocean, where it is a non-migratory resident of the islands of Flores, Faial, Terceira, São Jorge and Pico.^[1]

Notes and References

1. Päckert, Martin; & Martens, Jochen. (2004). Song dialects on the Atlantic islands: goldcrests of the Azores (Regulus regulus azoricus, R. r. sanctae-mariae, R. r. inermis). Journal of Ornithology 145(1): 23-30.https://archive.today/20121208150549/http://www.springerlink.com/content/mg0nvr30mb2pee1d/