Its twittering and wheezing song, and flash of yellow and green as it flies, make this finch a truly colourful character. Nesting in a garden conifer, or feasting on black sunflower seeds, it is a regular garden visitor, able to take advantage of food in rural and urban gardens. Although quite sociable, they may squabble among themselves or with other birds at the bird table.
Greenfinch populations declined during the late 1970s and early 1980s, but increased dramatically during the 1990s. A recent decline in numbers has been linked to an outbreak of trichomonosis, a parasite-induced disease which prevents the birds from feeding properly.
Extract from the RSPB website