Fieldfare

The fieldfare (Turdus pilaris) is a large, boldly patterned thrush, about 25 cm long, typically 80–130 g in weight and with a wingspan of 39–42 cm. Adults have an ash-grey head and rump, chestnut-brown back, dark tail and a yellowish breast marked with dark arrowhead-shaped spots. The contrasting grey and brown upperparts make the species distinctive both perched and in flight.

Fieldfares are often more conspicuous by behaviour than by song. Their common call is a loud, dry chattering note, and outside the breeding season they frequently move in noisy flocks, often alongside redwings (Turdus iliacus) and other thrushes.

Fieldfares favour landscapes that combine open feeding ground with trees or shrubs for shelter and nesting. Woodland edges, farmland, orchards, parks, river valleys and mountain birch country can all support breeding birds.

The species can breed from lowland agricultural areas to open northern woodland and subalpine habitats. What matters most is the close combination of suitable nest sites and short or open vegetation where birds can search efficiently for ground-dwelling prey.

During spring and summer fieldfares feed heavily on earthworms and other soil invertebrates, running or hopping across short grass before stopping to probe or pull prey from the ground. Insects, larvae and other small animals are also important, particularly when chicks are being fed.

In autumn and winter the diet shifts strongly towards berries and fruit. Rowan, hawthorn, apples and other rich fruit crops can attract large flocks, and the availability of these foods often determines where the birds remain and when they move on.

The fieldfare is a partial migrant whose movements vary considerably between regions and years. Birds breeding in northern and eastern parts of the range generally move south or west for winter, while some populations farther south remain closer to their breeding areas.

Winter distribution can change quickly with weather and food supply. Large flocks may concentrate wherever berries and fallen fruit are abundant, then move on once a food source is exhausted or severe cold and snow make feeding difficult. This makes winter movements more flexible than a simple fixed journey between two sites.

Nests are usually built in trees, but fieldfares also use shrubs, ledges and structures where trees are scarce. The cup is made from grass, twigs and other plant material, reinforced with mud and lined more softly. Pairs may nest alone, but loose colonies are common where suitable sites are concentrated.

Field studies published in 1980 showed that colonial nesting can reduce nest predation by allowing neighbouring fieldfares to cooperate in driving away avian predators. Adults may mob crows, raptors and other intruders, repeatedly diving at them and sometimes deliberately bombarding them with droppings. Foul plumage can interfere with the flight and insulation of avian predators, making repeated attacks by several fieldfares an effective deterrent. The defence can also be directed at people approaching the nest.

A 15-year study published in 1995 showed that this defence is not equally effective against every predator. Protection is strongest against conspicuous aerial predators, whereas mammalian predators can still exploit concentrations of nests. Colonial breeding therefore brings both the benefit of cooperative defence and the risk of placing many nests in one area.

A clutch usually contains about five or six eggs. The female incubates for around 11–14 days, and the young normally leave the nest after another 12–16 days. Both parents feed the chicks, and pairs in favourable southern parts of the breeding range may raise a second brood.

The fieldfare is classified as least concern on the IUCN Red List. It remains widespread and numerous across northern Eurasia.

Across Europe, breeding numbers were almost unchanged over the long term, but fell by about 22% between 2015 and 2024. Large year-to-year movements driven by weather and fruit crops can still make local numbers fluctuate much more sharply than the wider population.