Could you tell, that this is not the middle Euopean subspecies, but the moreletti-Subspecies from the Azores? Especially as it is a female, it is really hard to recognise.
Kann man erkennen, dass dies nicht die mitteleuropäische Unterart des Buchfinkens ist? Da es ein Weibchen ist, macht es das besonders schwer zu erkennen.

Chaffinch | Buchfink | Fingilla coelebs moreletti | Furnas-lake, São Miguel, Azores, Altlantic Ocean, Portugal | 25 February 2019
Canon EOS 700D  |  Canon 400 mm  f/5.6 L USM  | 400 mm|  1/1000  |  f 5.6  |  ISO 640 | 0 EV | no flash | handheld