Wood thrush

The wood thrush (Hylocichla mustelina) is a North American passerine bird in the family Turdidae and is the only species placed in the genus Hylocichla. It is closely related to other thrushes such as the American robin and is widely distributed across North America, wintering in Central America and southern Mexico. The wood thrush is the official bird of the District of Columbia.

The wood thrush is a medium-sized thrush, with brown upper parts with mottled brown and white underparts. The male and female are similar in appearance. The song of the male is often cited as being the most beautiful in North America.

The wood thrush is an omnivore, and feeds preferentially on soil invertebrates and larvae, but will also eat fruits. In the summer, it feeds on insects continuously in order to meet daily metabolic needs. It is solitary, but sometimes forms mixed-species flocks. The wood thrush defends a territory that ranges in size from 800 to 28,000 m² (960 to 33,490 sq yd). The wood thrush is monogamous, and its breeding season begins in the spring; about 50% of all mated pairs are able to raise two broods, ranging in size from two to four chicks.

The wood thrush was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with the thrushes in the genus Turdus and coined the binomial name Turdus mustelinus. Gmelin based his account on the "Tawny thrush" that had been described in 1785 by the Welsh naturalist Thomas Pennant in his book Arctic Zoology. Pennant specified its type locality as the New York (state) region. The wood thrush is now the only species placed in the genus Hylocichla that was introduced in 1864 by the American naturalist S.F. Baird. The species is monotypic: no subspecies are recognised. The generic name is a translation of its common name, derived from the Greek words ύλη (hyle, "woodland") and κιχλη (cichle, "thrush" or "fieldfare"). The species name comes from the Latin mustela "weasel".

This thrush is closely related to the other typical American thrushes of the genus Catharus, and is sometimes merged into that genus. It has been considered close to the long-distance migrant species of that genus, as opposed to the generally resident nightingale-thrushes, but that appears to be an error. The wood thrush also appears to be fairly closely related to the large Turdus thrushes, such as the American robin. "Wood thrush" is the official common name given to the species by the International Ornithologists' Union (IOC).

The adult wood thrush is 18 to 21.5 cm (7.1 to 8.5 in) long, with a wingspan of 30 to 40 cm (12 to 16 in) and a body mass of 48 to 72 g (1.7 to 2.5 oz). Among standard measurements, the wing chord is 9.6 to 11.6 cm (3.8 to 4.6 in), the bill is 1.6 to 2 cm (0.63 to 0.79 in) and the tarsus is 2.8 to 3.3 cm (1.1 to 1.3 in). It is distinctly larger than the Catharus thrushes with which the species is often sympatric but slightly smaller than the common American robin. The longest known lifespan for a wood thrush in the wild is 8 years, 11 months. The crown, nape, and upper back are cinnamon-brown, while the back wings, and tail are a slightly duller brown. The breast and belly are white with large dark brown spots on the breast, sides, and flanks. It has white eye rings and pink legs. Other brownish thrushes have finer spotting on the breast. The juvenile looks similar to adults, but has additional spots on the back, neck, and wing coverts. The male and female are similar in size and plumage.

The wood thrush has been reported to have one of the most beautiful songs of North American birds. American naturalist Henry David Thoreau wrote:

Whenever a man hears it he is young, and Nature is in her spring; wherever he hears it, it is a new world and a free country, and the gates of Heaven are not shut against him.