The Mistle thrush is a bird common to much of Europe, parts of Asia, and North Africa. It has pale grey-brown upperparts, the chin and throat are greyish-white, and the yellowish-buff breast and off-white belly are marked with round black spots. The long tail has white tips on the outer feathers, and the underwing coverts are white. The eyes are dark brown and the bill is blackish with a yellowish base to the lower mandible. The legs and feet are yellowish-brown. There are no plumage differences between the male and the female. Juveniles are similar to adults, but they have paler upperparts with creamy centers to many of the feathers and smaller spots on the yellowish underparts. By their first winter, they are very similar to adults, but the underparts are usually more buff-toned.
Mistle thrushes breed in much of Europe and temperate Asia, although they are absent from the treeless far north, and their range becomes discontinuous in southeast Europe, Turkey, and the Middle East. These birds are year-round residents in a large part of their range, but northern and eastern populations migrate south for the winter. Mistle thrushes are found in a wide range of habitats containing trees, including forests, plantations, hedges, and town parks. More open habitats, such as agricultural land, moors, and grassy hills, are extensively used in winter or on migration.
Mistle thrushes are quite terrestrial birds; they move by hopping with their head held up and body erect. When excited, they will flick their wings and tail. Mistle thrushes can be found solo or in pairs for much of the year, although families forage together in late summer, and when food sources are plentiful they may form large flocks. It is not uncommon for up to 50 thrushes to feed together at that time of year. They roost at night in trees or bushes, again typically as individuals or pairs, except in late summer or autumn when families may roost together. These birds normally feed on the ground or from low bushes and defend their feeding areas against other thrushes as well as birds such as the bullfinch and great spotted woodpecker. In order to communicate with each other Mistle thrushes use various calls. Males have a loud melodious song with fluted whistles, sounding like 'chewee-trewuu ... trureetruuruu' or similar, used to advertise their territory, attract a mate, and maintain the pair bond. They usually sing from a treetop or other elevated position mainly from November to early June. The main call, given by both sexes, is a dry chattering 'krrrr', louder when the birds are alarmed or excited. There is also a squeaky 'tuk' contact call.
Mistle thrushes are carnivores and herbivores (frugivores, granivores). They feed mainly on invertebrates, fruit, and berries. Animal prey include earthworms, insects, and other arthropods, slugs, and snails. Plant food includes the fruits and seeds of bushes and trees, mainly holly, yew, ivy, and mistletoe, but also, for example, blackberry, cherry, alder, hawthorn, olive, and rose. It may eat the flowers and shoots of grasses and other plants and will take fallen apples and plums.
Mistle thrushes are monogamous and stay as a pair throughout the year in areas where they are not migratory. The pair occupies the same territory in subsequent years and the male will attack any intruders into its breeding area, including birds of prey and corvids, and sometimes cats or humans. Breeding typically occurs in mid-March in the south and west of Europe (late February in Britain), but not till early May in Finland. There are normally two broods, except in Siberia, where there is only one, the male feeding the fledglings from the first brood while the female sits on the second clutch. Sometimes the same nest is reused for both broods. The nest is usually built in a tree in the fork of a branch or against the trunk, although hedges, ledges on buildings and cliff faces may also be used. The nest site may be up to 20 m (66 ft) above the ground, although 2-9 m (6.6-29.5 ft) is more typical; it is a large cup of sticks, dry grass, roots, and moss, coated on the inside with a layer of mud and lined with fine grass and leaves. The nest is built by the female, although the male may help. The female lays 3 to 5 eggs, which are usually whitish-buff or greenish-blue and are spotted with red, purple, or brown. The eggs are incubated for 12-15 days, mainly by the female. The chicks are altricial (helpless) and downy and are fed by both parents. They fledge about 14-16 days after hatching but remain dependent on their parents 15 to 20 days more. The young reach reproductive maturity in the year subsequent to their hatching.
Mistle thrushes are not considered globally threatened at present; however, their population now appears to be declining due to the loss of invertebrate-rich pastures and mixed farms through conversion to arable agriculture or more intensively managed grassland. Adult survival, clutch size, and fledging success are all lower in arable landscapes than in areas with extensive pasture. In Finland, the loss of ancient forests is thought to have led to a local decline and in Spain, these birds suffer from hunting.
According to the IUCN Red List, the total Mistle thrush population size is around 13,000,000-29,999,999 mature individuals. In Europe, the breeding population consists of 4,120,000-8,960,000 pairs, which equates to 8,250,000-17,900,000 mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.
As their name implies, Mistle thrushes are important in propagating the mistletoe, an aerial parasite, which needs its seeds to be deposited on the branches of suitable trees. Thrushes prefer highly nutritious fruits; they digest the flesh and leave the sticky seeds to be excreted, possibly in a suitable location for germination.