The European greenfinch measures 15 cm (5.9 in) in length and has a wingspan of 24.5 to 27.5 cm (9.6 to 10.8 in). Resembling a house sparrow in size and shape, it is predominantly green in color with yellow accents on the wings and tail. The female and young birds have a duller appearance with hints of brown on the back, while the bill is thick and conical. The male's song consists of trilling twitters and wheezes, and he performs a "butterfly" display flight. Interestingly, male greenfinch birds display a greater degree of fluctuating asymmetry, with their bone development being more susceptible to disruption compared to females.