Endemic to the Madeira islands, it was accidentaly introduced to the Azores by ship trade between the two archipelagos.
http://www.azores.gov.pt/NR/rdonlyres/BED696F8-D676-479E-8037-C03E1568DCB4/528932/Artigo_2010_OsganosAores.pdf
There is a small breeding population on São Miguel.