Brown thrashers are medium-sized songbirds found throughout the eastern and central United States. Here are some fascinating facts about these vocal mimics.
What do brown thrashers look like?
Brown thrashers are robin-sized birds that get their name from their brownish-gray plumage. They have a long tail that they habitually pump up and down. Their underside is a light tan color with dark brown streaks. They have a long, curved bill that is black on top and yellow on the bottom.
Where do brown thrashers live?
Brown thrashers are found throughout the eastern and central United States. Their breeding range stretches from southern Canada down through the eastern United States to Texas and central Florida. They prefer open woodland areas with dense, low vegetation like forests, woodland edges, overgrown fields, hedgerows and thickets. During the winter they migrate to the southeastern United States, eastern Mexico and Cuba.
What do brown thrashers eat?
Brown thrashers are omnivores, meaning they eat both plant and animal material. Their diet consists mainly of insects and other invertebrates like beetles, caterpillars, crickets, spiders, snails and worms. They also eat fruits and berries in the fall and winter. Less commonly they will eat small vertebrates like lizards, frogs, snakes and rodents.
Brown thrashers find food by rummaging through leaf litter on the forest floor. They use their long bill to probe into the ground and flip over leaves to uncover insects and other prey.
What’s special about the brown thrasher’s bill?
The brown thrasher has a particularly long, curved bill that is perfectly adapted for its feeding style. At over an inch long, their bill allows them to dig deeper into the leaf litter than other songbirds with shorter bills. The bill’s slight downward curve is ideal for probing into crevices. And the bill’s slender shape helps them pick out prey from narrow spaces.
What kind of nests do they build?
Brown thrashers build large, bulky nests out of twigs, grass, leaves, bark strips, roots and stems. They are open-cup nests, meaning they don’t have a roof. The nests are typically placed 3-10 feet off the ground in shrubs, small trees or dense vines.
Both the male and female work together to construct the nest over 6-10 days. The female incubates the eggs and broods the young, but both parents help feed the nestlings.
How many eggs do brown thrashers lay?
The typical brown thrasher clutch size is 3-5 eggs. The eggs are pale blue or greenish-blue with reddish-brown spotting. The female incubates the eggs for 12-14 days before they hatch. Both parents feed the nestlings, which leave the nest at 10-12 days old but remain dependent on the parents for 2-3 more weeks.
Brown thrashers generally have one brood per breeding season. But they may raise a second brood if the first is lost early enough in the year.
What’s their conservation status?
Brown thrashers have a large range and are fairly common in most areas. Their total population is estimated at around 13 million. Their numbers declined somewhat between 1966-2015, prompting them to be listed as a species of Least Concern by the IUCN Red List.
Habitat loss is the biggest threat facing brown thrashers. As scrublands, open woodlands and hedgerows are cleared for development, they lose nesting and foraging sites. Pesticides may also impact their food supply of insects. But generally brown thrashers remain widespread and adaptable to human activity.
What do brown thrashers sound like?
Brown thrashers are famous for their song, which is one of the most complex of any North American bird. Each male has a repertoire of over 1,100 different song types! They can mimic the sounds of at least 43 other bird species.
Their songs are loud and melodious, with phrases repeated 2-3 times each before switching to a new tune. The variety of tones, notes and sequences is unparalleled in the bird world.
Here are some of the birds they like to imitate:
- Northern cardinal
- Tufted titmouse
- American robin
- House wren
- Chipping sparrow
- Killdeer
- Eastern wood-pewee
- Scarlet tanager
- Wood thrush
- Eastern bluebird
Brown thrashers sing the most early in the breeding season to attract a mate. But they continue to vocalize through the summer and fall. Both males and females are talented singers.
Why do they mimic so many birds?
There are a few key reasons brown thrashers have evolved to mimic other birds:
- To attract females – A male thrasher with a large repertoire signals to females that he is fit and father quality offspring.
- To defend territories – Their songs warn rivals that the territory is occupied.
- Camouflage – Mimicry makes it hard for predators to target them amid other birds.
- Fill in gaps – They “borrow” songs from birds with voices different than their own.
Whatever the reasons, their mimicry talent is unmatched in the avian world!
What are some other cool facts about brown thrashers?
- They got their name “thrasher” from their habit of noisily thrashing the underbrush with their bill to stir up prey.
- Brown thrashers are shy and secretive despite their bold songs. They tend to hide in dense foliage.
- They migrate at night and are some of the earliest spring migrants in the eastern US.
- Males and females look alike. Juveniles have darker spotting underneath.
- While shy of humans, they will aggressively defend their nests by chasing off threats.
- They rub foul smelling ants on their feathers, possibly to deter parasites.
- Their oldest recorded age in the wild is 10 years 9 months.
Conclusion
In summary, brown thrashers are master vocal mimics and one of the most talented songbirds in North America. They have a varied diet, large stick nests and shy, secretive habits despite their bold voices. While common in most of their range, loss of scrubby habitat is a concern for the future of these birds. But for now, anyone living in eastern or central US habitats may be treated to the incredible song diversity of the brown thrasher drifting through the trees.