The Brown thrasher is a fairly large songbird that belongs to the family of New World catbirds and mockingbirds. It has brown upperparts with a white under part with dark streaks. Because of this, it is often confused with the smaller Wood thrush, among other species. The Brown thrasher is noted for having over 1000 song types, and the largest song repertoire of birds. However, each note is usually repeated only in two or three phrases.
Brown thrashers breed in the United States and Canada east of the Rocky Mountains. These birds are strong, but partial migrants, as they are year-round residents in the southern portion of their range. Brown thrashers live in various habitats. They prefer woodland edges, thickets, and dense brush. They can also inhabit areas that are agricultural and near suburban areas but are less likely to live near housing.
Brown thrashes are elusive birds and usually seen solo or in pars. They fly low to the ground and when they feel bothered, thrashers usually hide into thickets and give cackling calls. These birds spend most of their time on ground level or near it. When seen, it is commonly the males that are singing from unadorned branches. The males' singing voice usually contains a melodic tone and their song are coherent phrases that are iterated no more than three times. By the fall, the males sing with smoother sub-songs and during the winter, they may also sing in short spurts during altercations with neighboring males. Brown thrashers feed by day and use their vision while scouring for food. They usually forage for food under leaves, brushes, and soil debris on the ground using their bill. They then swipe the floor in side-to-side motions and investigate the area they recently foraged in. Brown thrashers have an array of sounds they will make in various situations. Both male and females make 'smack' and 'teeooo-like' alarm calls when provoked, and 'hijjj' sounds at dusk and dawn. Other calls may consist of an acute, sudden 'chakk', 'rrrrr', a 'Tcheh' sound in the beginning that ends with an 'eeeur', 'kakaka', and sounds reminiscent of a stick scraping a concrete sidewalk.
Brown thrashers are omnivores. Their diet includes insects, berries, nuts, and seeds, as well as earthworms, snails, and sometimes lizards, salamanders, small or young snakes, and frogs.
Brown thrashers are monogamous birds and form pairs, but mate-switching does occur, at times during the same season. Their breeding season varies by region. In the southeastern United States, the breeding months begin in February and March, while May and June see the commencement of breeding in the northern portion of their breeding range. When males enter the breeding grounds, their territory can range from 2 to 10 acres (0.81 to 4.05 ha). Around this time of the year, the males are usually at their most active, singing loudly to attract potential mates, and are found on top of perches. The courting ritual involves the exchanging of probable nesting material. Males will sing gentler as they sight a female, and this enacts the female to grab a twig or leaf and present it to the male, with flapping wings and chirping sounds. The males might also present a gift in response and approach the female. Once mates find each other both sexes will take part in nest building. The nest is built twiggy, lined with grass, leaves, and other forms of dead vegetation. The nests are typically built in a dense shrub or low in a tree, usually up to 2.1 m (6.9 ft) high, but maybe located as high as 6 m (20 ft). Brown thrashers also on occasion build their nests on the ground. The female lays 3 to 5 eggs, that usually appear with a blueish or greenish tint along with reddish-brown spots. Between 11 to 14 days, the eggs hatch. Both parents incubate and feed the young, with the female doing most of the incubating. Nine to thirteen days after hatching, altricial chicks begin to fledge and become independent from their parents 17-19 days later. Brown thrashers raise two, sometimes even three broods in a year.
Although Brown thrashers are widespread and still common, they have declined in numbers in some areas due to loss of suitable habitat. Northern cardinals and Grey catbirds are major competitors for thrashers in terms of territorial gain. Because of the apparent lack of opportunistic behavior around species like these, thrashers are prone to be driven out of zones for territory competition. Brown thrashers have tendencies to double-brood or have failures on their first nesting attempts due to predation. Grey catbirds have been seen invading Brown thrashers' nests and breaking their eggs. Other than the catbird, snakes, birds of prey, and cats are among the top predators of the thrasher. Other reasons that cause mortality of Brown thrashers include collisions with cars and communication towers especially during migration and the use of pesticides.
According to Partners in Flight resource, the total population of the Brown thrasher is around 6,200,000 breeding individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.