Thrush

Quick Take

• Cowbirds routinely hijack thrush nests, yet thrushes have a surprisingly clever way to fight back. See the cowbird fact →
• Don't let the sweet song fool you. Thrushes have a fierce side that catches most people off guard. Discover their aggressive side →
• One thrush species uses a tool the same way every single time and always returns to the exact same spot. See their foraging technique →
• There's one thrush that thrives in the worst weather, and it does something no other bird would dare. Meet the storm singer →

Thrushes are smallish to medium-sized passerines or songbirds. They have a stocky build and large eyes, sometimes with rings around them. Thrushes are found all over the world, and though most of them have rather drab plumage, they are known for the bluish color of their eggs and loved for their beautiful songs.

5 Amazing Thrush Facts

• There are more American robins in North America than any other kind of bird. There are as many as 370 million robins.
• The American robin is the largest thrush in North America. The great thrush, 11 to 13 inches in length, is the largest in South America.
• Cowbirds love to parasitize the nests of thrushes. The cowbird lays its egg in the nest of a thrush and expects the thrush parents to raise its chick as their own. However, sometimes the thrush can tell the difference between the eggs and rolls the cowbird egg out of the nest.
• The mistle thrush, which is found in Europe and Russia, is also called the storm cock because it will climb to the top of a tree and sing in rough weather.
• The song thrush bashes open the shells of snails against a flat stone. It repeatedly returns to the same stone for this purpose.

Where To Find Thrushes

Thrushes are found around the world in woods, the edges of forests, roadsides, and scrubland. It’s also common to see some species in public parks, gardens, orchards, and backyards.

Some species of thrush migrate while others don’t. The American robin lives in most of the United States and southern Canada and spends its winters as far south as Guatemala. The common blackbird often migrates from the south of Norway down to Scotland or Ireland. Varied thrushes, which breed in Alaska, Canada, and down to northern California, Oregon, Idaho, and Montana, winter along the Pacific Coast from Alaska to California.

Nests

These birds are known for their cup-shaped nests. The female builds them out of twigs, feathers, grasses, mosses, and bits of paper. She’ll line them with mud, then add moss or soft grasses. Thrushes tend to build their nests in trees or shrubbery or even on building ledges, but some build their nests on the ground.

Most thrushes have two or three broods during their breeding season, and some species use the old nest for the next batch of chicks. Others, like robins, build new nests.

Classification and Scientific Name

Thrushes belong to the Turdidae family. Turdidae is from the Latin word for thrush, which is turdus. There are 17 genera in the family, and these genera encompass hundreds of species and subspecies. Genera include:

• Cichlopsis
• Catharus
• Hylocichla
• Turdus
• Ixoreus

Appearance

Most thrushes are compact birds that range from the little forest rock thrush of Madagascar to the great thrush of South America. Most species have gray or brown plumage with speckled breasts and bellies, though this is not true for all of them. The male mountain bluebird is a cerulean blue all over, and the blue whistling thrush, found across South and Southeast Asia, has pale blue to white spangled tips on its dark violet-blue feathers that make them seem iridescent. Common blackbirds are completely black, though male ring ouzels are black with a white crescent on the chest.

These birds also tend to have large eyes with eye rings, medium-length tails, and long, sturdy legs that allow them to run or hop over terrain as they look for food. Birds that migrate have pointed wings and a wide wingspan that allows them to be more aerodynamic as they fly to and from their wintering grounds.

Thrush Behavior

Birds that live in warmer climates tend to stay there all year, while those that breed in colder climates migrate to warmer places during the winter. Despite the sweetness of their songs, their small size, and their bright eyes, they can be rather aggressive, especially during the breeding season. Thrush parents have no problem seeing off larger predators, including humans. Both male and female birds compete for the best nesting sites and fiercely defend their territories.

Outside of the breeding season, many species of thrushes can form huge flocks. This includes the fieldfare, which is found in the United Kingdom as a winter visitor. This thrush can form flocks of several hundred birds, and they are so in sync that they actually sleep facing the same direction.

Diet

These birds are omnivores, with a diet of insects and other small invertebrates as well as berries. While they’ll eat invertebrates found on the ground, they will land on trees and shrubs to get at the fruit. A bird that’s hunting for prey on the ground often uses a technique called ‘run and stop’. It’ll run or hop a little way, listen for the sound of prey, then zero in on it. They’ll also rummage through fallen leaves and probe rotting wood for prey.

What does the thrush eat?

The bird eats worms, beetles, grubs, grasshoppers, wasps, caterpillars, and other insect larvae, snails, and slugs. Thrushes have also been known to eat small reptiles and amphibians. They eat soft fruits such as blackberries, raspberries, blueberries, the berries of pyracantha bushes, and the berries of rowan trees.

Predators and Threats

A great variety of creatures prey on both adult and baby birds. They include snakes, squirrels, raccoons, weasels, chipmunks, mice, and the scourge of songbirds, the pet cat. These birds are also preyed upon by other birds, including species of jays, crows, ravens, and birds of prey such as owls and sharp-shinned hawks. Even humans used to eat thrushes.

These birds are also subject to parasites such as mites, ticks, lice, and louse flies. These parasites can spread Spirochaetes bacteria, which can cause a type of septicemia in birds.

Reproduction, Babies, and Lifespan

These birds start to reproduce in spring, and the song of the male robin returning from his winter retreat can be heard as early as late winter.

Male birds set up a breeding territory and will drive off any other male that enters it. A male may even be aggressive toward an interested female until he recognizes her intentions. Other thrush species go through elaborate courtship rituals, which include singing and feeding each other. After this, the female builds the nest, either on the ground, in trees, or, in the case of bluebirds, in tree cavities. The eggs of thrushes are famously colored in shades of blue and may have brown freckles.

Most species seem to be monogamous, at least for the breeding season.

In most species, the incubation period is about 12 to 14 days. As the female incubates the eggs, the male brings her food.

The chicks are helpless when they hatch and are fed by both parents. In some species, the male brings food to the female, who in turn feeds it to the chicks. The parents take care to remove the chicks’ fecal sacs from the nests.

The chicks start to fledge when they’re 10 to 15 days old in most cases, but even then, they will still follow their parents around and beg for food. Two weeks after they fledge, the chicks can fly reasonably well. In some species, the fledglings remain in their parents’ territory for some weeks.

The lifespan of these birds varies; for most robins it is about two years, though this figure includes the many individuals that do not survive their first year. Some of them have been known to live a decade or more.

Population

The population of many of these birds is stable or increasing, and in some species, the population is quite large. Besides the hundreds of millions of robins in the world, there are about 70 million hermit thrushes. However, other species of thrushes have declined, such as the wood thrush. Others have gone extinct, largely due to habitat destruction or overhunting. One was the Grand Cayman thrush of the Caribbean, which was hunted to extinction and probably went extinct in the late 1930s or early 1940s.