Madeiran chaffinch and the Azores chaffinch

In 2021, thanks to new research, the Madeiran chaffinch and the Azores chaffinch were finally considered species in their own right. These finches differ from each other mainly in plumage color, and to a lesser extent in morphological characteristics. These differences are thought to be mainly due to sexual selection and genetic drift. I have seen both the Azores chaffinch (Terceira, August 2018) and the Madeiran chaffinch (Madeira, April 2022) when they were still considered subspecies by the majority. Even then I found the phenotypic characteristics so different that I wondered if these could not be separate species. It is noteworthy that the Azores chaffinch was first described as a separate species by Jacques Pucheran in 1859, but was later considered a subspecies of the Eurasian chaffinch.

The finch did originally colonize the atlantic islands from the European mainland. First, the Azores would have been colonized some 0.83 million years ago, here we also find the highest genetic diversity. Next, some 0.77 million years ago, the island of Madeira would have been colonized from the Azores, followed by the Canary Islands some 0.70 million years ago. These colonization times are relatively recent compared to the age of most of the islands. This relatively recent colonization could be explained by the fact that Macaronesian laurel forests did not become established until about 2.6 million years ago.

Madeiran chaffinch => https://www.inaturalist.org/observations/111955857

Azores chaffinch => https://www.inaturalist.org/observations/104884945

Publicado el noviembre 13, 2023 06:46 TARDE por ward123