Greenfinches are about the same size as House Sparrows and have a stout appearance. Males are olive-green in colour, with a greenish-yellow breast and rump. Their appearance is brightened by yellow wing flashes and edging to the tail. Females and immature Greenfinches are duller in appearance, with less yellow visible in their respective plumages. Juveniles are paler in colour and have streaked plumage.

Greenfinch at threat of garden bird disease
The once familiar Greenfinch is now less common in the nation's gardens as a consequence of a disease called trichomonosis, which has hit UK populations since 2006. Outbreaks of this disease peak during late summer, making September an important time to make sure garden bird feeders and feeding areas are clean. Plus, for even greater protection against disease, it is recommended to use a feeder with a FeedSafe™ antibacterial coating that helps protect against microbes and germs, and inhibits the growth of bacteria for up to 10 years!

Background
At the beginning of the last decade, Greenfinch numbers were increasing and the outlook for this species looked secure. Between 2005 and 2011, however, records collected by British Trust for Ornithology (BTO) volunteers* revealed a big fall in Greenfinch numbers as the disease trichomonosis took its toll. Outbreaks tend to peak during late summer, with many affected individuals being spotted in gardens.

Trichomonosis is caused by a parasite that causes lesions in the throat that cause difficulty in swallowing and may bring about secondary infection. The outward symptoms are similar to several other diseases and include fluffed-up plumage, lethargy and drooling. The parasite is transmitted through the bird’s saliva and is sensitive to desiccation (drying out). Any place where birds come together, such as garden feeding stations, may provide an opportunity for the disease to be passed between individuals. As such, it is important to keep your feeders, tables and bird baths clean and to follow best practice advice.

Feeding preferences
Greenfinches are mainly seed-eaters although invertebrates are also taken when they rear their young. A number of different seeds are eaten by Greenfinches in gardens, with sunflower hearts particularly favoured. The large beak of this species also enables it to tackle larger grains.