Early in the evening on a blustery April day, I heard a bird singing a melodious but changing song. He sang a phrase twice, then switched to another song. I had just been introduced to the song of the brown thrasher (Toxostoma rufum) and was ecstatic to actually capture its song on this afternoon. The brown thrasher has, according to one source, over two thousand phrases, most of which sound like joyous renditions of other birds’ songs. Like a mockingbird, the thrasher can mimic just about any other bird’s proprietary song. He loves to mix it all up, singing this one, then that one, never seeming to repeat. This afternoon he is singing from high in a tree. It turns out this is unusual for him. He and his mate generally prefer to live lower down in scrub bushes and fence rows. Owl Acres has several untamed fence rows, which may serve as excellent habitat for these ground-feeding birds.
The brown thrasher is related to the mockingbird. His song is similar except that where a mockingbird will repeat each phrase five or six times, the brown thrasher confines each phrase to only two utterances. His song is considered more melodious than the mockingbird as well. He may have as many as 2,000 different song phrases which he sings in random order, always repeating a phrase twice before moving on. Researchers studying birds’ brains have discovered that the brown thrasher has the largest proportion of his brain dedicated to song of all birds. They’ve also discovered that bird brains change with the seasons. The song area expands with new neurons during singing season, and contracts to allow other tasks such as remembering where they stashed their food to expand.
The brown thrasher is a big, gangly bird, about the size of an American robin, but with longer legs and tail, and a long, slightly curved beak. He is nine to twelve inches long with a wingspan of 11.5 to 12.5 inches. He weighs a hefty two to three ounces. His back is a reddish (foxy) brown and his wings have black and white bars on them. He’s white with lots of dark streaking on his underside. His face is gray-brown, with startling yellow eyes. Since he lives in low scrubby brush his coloration would blend in well, making him very hard to see most of the time.
He gets his name for the way he thrashes his beak from side to side digging through fallen leaves and other detritus in search of insects. Thrashers are fond of grasshoppers, beetles, worms, grubs, wasps, cicadas and caterpillars, but also eat nuts, berries and seeds in the fall.
Brown thrashers court and mate hidden in brush. They cooperatively build their nest low in a bush or sometimes on the ground, and will defend the nest aggressively, sometimes striking the unwary dog or human intruder with their beak hard enough to draw blood. Both parents share the task of incubating their four to six chicks, and then feeding them until they leave the nest. They may often raise a second brood during the summer before migrating south to spend the winter in warmer climes like Texas and Oklahoma and sometimes down into Mexico.
Owl Acres has some good habitat for thrashers, so we’ll enjoy them through the spring and summer months.
Photo by bobistraveling