The Fieldfare (Turdus pilaris) is the grey-headed thrush that moves in large flocks across open fields and gardens, its winter flocks invading Swedish suburban gardens to raid rowan trees and windfall fruit. It measures 22-27 cm in length, has a wingspan of 39-42 cm and weighs 80-130 grams. It shows a blue-grey crown and nape, a warm chestnut-brown back and a grey rump; the throat is yellowish-white with heavy black streaking, and the richly spotted breast shades into yellow and black tones toward the flanks. In flight the white underwing is conspicuous, and the flight style is somewhat jerky. Unlike most thrushes, it is a highly gregarious species that breeds in loose colonies and forages in flocks.
Its most familiar sound is a hard, rattling "tjack-tjack-tjack", almost constantly heard from flying or resting flocks and usually the first sign the birds are present; the song itself is far less prominent, a scratchy, crackling twitter lacking the fluty tones typical of other thrushes. Breeding throughout Sweden, densest in montane birch forest and the wetland-rich landscapes of Norrland, the population is estimated at 500,000-600,000 pairs, though it is declining according to Swedish bird monitoring. A partial migrant, it moves south to central Europe in October-November while some birds overwinter in southern Sweden, and the size of the wintering flocks varies with the berry crop each year. It breeds in loose colonies, building a sturdy cup of grass and mud in a tree fork, usually 3-10 metres up; the female lays 4-6 eggs, incubated for 11-14 days, with one to two broods per summer, and the colony defends itself collectively by "bombing" approaching predators with droppings. Its diet shifts from earthworms, insects and larvae in summer to rowan berries, other fruit and windfall apples in autumn and winter.
Read about this species in Swedish →