Common Reed Buntings are a resident coastal species from Lisbon northwards and a winter visitor everywhere else in the country. As its name suggests it prefers reeds and is seldom if ever seen far from them, apart from on migration where it can even be found in the highest places.
It's flight resembles that of Goldfinches in that it is uneven and slightly undulating.
Joomla Gallery makes it better. Balbooa.com