Speaking of Nature: A melodious mimic

  • The brown thrasher sports cinnamon-brown feathers of the head, wings and back, an extremely long tail, and yellow eyes. For the Recorder/Bill Danielson


For the Recorder
Monday, May 21, 2018

We are quickly approaching that time of year when there will be enough greenery in the landscape to begin to support North America’s vast community of insect life that draws so many birds out of the tropics for the breeding season. The northern lands are now free of snow and soon they will be bursting with food. The topic could keep me writing for the next 20 years if I dove down deep into the class insecta (maybe even 50 years if I took a more shallow dive into the order arthropoda), but for now I will content myself with a splash in the kiddy pool of the familiar — birds, class aves.

Those familiar visitors are now “home.” They have transitioned from the phase of new arrivals and have started the process of setting down roots, so to speak. I say that because these particular creatures don’t really stay anywhere for very long. They zip up north to exploit the vast nature of the northern real estate market and the cornucopia of sustenance that, though temporary, is the engine that drives the communities and ecosystems of the north. Then, just as soon as they arrive, they are gone again, fleeing south to the warm bosom of the tropics.

Many species have arrived, and even though a few are still missing from the guest list, I think it is safe to say the party has started. The phoebe that nests by my front door has five white eggs in her nest. The house wrens, bluebirds and tree swallows have started to stake their claims on the nest boxes in my yard, and the singing that has been going on in my backyard suggests that territories have been established, though they will certainly be contested in the weeks to come.

Among those mellifluous voices is one that really stands out from the fugue: the brown thrasher. There is something about the particular male that has set up shop in my yard this year that has really caught my attention. He is loud, he is prolific in his singing and for some reason, he seems to be performing from perches that are closer to the house than those used in previous years. This guy can sing!

The brown thrasher belongs to a small family of songbirds called the mimids. This name comes from the Latin word mimicus, which, I think you have pieced together by now, means “to imitate.” In North America, where about a third of all mimids can be found, we have 11 species. In the northeast, however, we must be content with only three species: the northern mockingbird, the gray catbird and the brown thrasher. Of the three species, the thrasher may be the least familiar.

The catbird is the smallest of the trio with a length (including the tail) of 8.5 inches. The mockingbird holds the No. 2 spot with a length of 10 inches, while the thrasher holds the top spot with a length of 11.5 inches. Each species sports a long tail, but the tails get longer and more flamboyant as the birds get larger. In the case of the thrasher, the tail accounts for about half of the total length.

The brown thrasher is a sumptuous cinnamon-brown that definitely has a red-orange look to its feathers. The throat, breast and abdominal feathers are all white, but bold black streaks add a bit of razzle-dazzle to the bird’s overall appearance. And, just as in the mockingbird, the eyes of the thrasher are not the typical black seen in so many other passerine species, but bright yellow with a black pupil. This gives the bird a certain “crazed look” that I find particularly humorous.

Males will set up a territory and defend it with one of the most impressive repertoires of any bird in the world. Some estimate that each male may have over 1,000 distinct notes in its personal playlist, and some are so convincing that I often find myself being fooled. The great giveaway is the fact that each note is repeated only twice. It takes some practice, but detecting a thrasher does get easier over time.

While the male is singing his guts out, the female will set up shop in the underbrush somewhere in her mate’s territory. The male and female will build the nest together, and the female will lay a clutch of four to five eggs. In the tradition of thrushes, the eggs will be a pale blue, but thrashers decorated their eggs with fine reddish-brown spots. The sexes will cooperate in the domestic chores, taking shifts in the duties of incubation over a period of 11 to 14 days. The cooperation continues in the chick phase, which only lasts for 9 to 13 days, but fledglings will still get some support after leaving the nest.

Thrashers take full advantage of the breeding season by immediately starting a second nest, which means that by the end of the breeding season, a single pair can produce an average of 8 to 10 offspring. All of the birds are then content to spend the remainder of the summer fattening up for the southern migration in the fall. By the middle of October, they are pretty much gone.

If you go looking for a brown thrasher, you should focus on areas with a lot of old-field brushy habitat. Mockingbirds can be found on golf courses and college campuses, and catbirds can be found in areas with abundant brush, but there is something particular about thrasher habitat that is different somehow. I never saw a thrasher until I took an ornithology course, and even today I don’t see them everywhere. The only thing to do is keep your ears open for those amazing songs and your eyes peeled for a flash of those cinnamon-orange feathers.

Bill Danielson has been a professional writer and nature photographer for 20 years. He has worked for the National Park Service, the U.S. Forest Service and Massachusetts State Parks, and currently teaches high school biology and physics. Visit www.speakingofnature.com for more information, or go to Speaking of Nature on Facebook.