True thrush

True thrushes
Mistle thrush (T. viscivorus), the type species of the genus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Turdidae
Genus:	Turdus Linnaeus, 1758
Type species
Turdus viscivorus
Species
See text

The "true" thrushes are medium-sized mostly insectivorous or omnivorous birds in the genus Turdus, in the wider thrush family, Turdidae. The genus name Turdus is Latin for 'thrush'. The term thrush is also used for many other birds in the family Turdidae, as well as for a number of species belonging to several other families.

Some Old World species with fully or largely black plumage are called blackbirds, and one, the ring ouzel, still retains the Old English name ouzel, which, until the 17th century, was also used (as "black ouzel") for the Common blackbird; it is cognate with the German name Amsel for the same species.^[1] Some New World species are called robins, the best known of which is the American robin. Two other species have their own distinct names without "thrush", fieldfare and redwing, from behavioural, and plumage features, respectively.

The genus has a cosmopolitan distribution, with species in Europe, Asia, Africa, and the Americas.^[2] Several species have colonised oceanic islands, and two European species have been introduced by man into Australia and New Zealand.

All the species are uniform in size and structure, with the great majority between 22–28 cm long; the smallest (Vanikoro island thrush) being 17–19 cm, and the largest (great thrush) being 28–33 cm. All have slender, medium-length bills. Plumage is far more variable; the only fully shared character is that the recently fledged juveniles are spotted on the breast and streaked on the back. Adult colours range from the "classical" thrush pattern of a plain brown back and a spotted breast (e.g. mistle thrush, song thrush), through all-brown (e.g. clay-colored thrush, black-billed thrush) or all-black (e.g. common blackbird, glossy-black thrush), pied (e.g. ring ouzel, white-collared blackbird), to orange- to red-breasted, either subtly (e.g. rufous-bellied thrush, grey-backed thrush) or boldly (e.g. American robin, red-throated thrush). Some show sexual dimorphism with the males brighter or more intensely coloured than the often browner females, while in others, the sexes are identical in plumage. All are omnivorous, with a mixed diet of invertebrates, fruit, and small seeds. The temperate northern hemisphere species are migratory to a greater or lesser extent to avoid the harsh freezing winters of northern Eurasia and North America, while the subtropical, tropical, and southern hemisphere species are generally nonmigratory. Many, or most, are noted for their melodious songs. Almost all occur in habitats with trees and shrubs, but many will also use open ground away from trees; some are highly adapted to rocky mountainous habitats, using steep slopes and rocks adeptly in predator avoidance. Many have adapted well to human presence and are common in urban and suburban gardens, while some are shy and avoid human presence, particularly where there is any history of bird hunting.^[2]

While some species have been split out of Turdus, the two small thrushes formerly separated in Platycichla by many authors have been restored to the present genus in recent years.