For the Birds Radio Program: Ovenbird
Most people look for spring, but I prefer to listen for it. The rich notes of the Ovenbird ringing out in our forests tell us for certain that spring is here to stay.
The Ovenbird’s magnificent contralto makes it the Linda Ronstadt of the bird world. It belts out its simple tune with all of Ronstadt’s vigor, vibrancy, and volume. John Burroughs, a famous nature writer of the late 1800’s and early 1900’s, is credited with being the first to translate the song as “teacher, teacher, teacher,” and although the interpretation has helped countless birdwatchers recognize the song, the device’s value is questionable, since most Ovenbirds clearly accent the second rather than the first syllable. Perhaps that is the origin of one of the Ovenbird’s most common nicknames, the “Accentor.”
Most birds that sing in the understory have easily heard songs of moderately low frequencies, but the Ovenbird’s song is also unusually loud–perhaps because it defends an unusually large piece of land. The average size of an Ovenbird’s territory is about 2 ½ acres–over twice the size of a Song Sparrow’s territory and about eight times the size of a robin’s. I’m not exactly sure why Ovenbirds need so much land, since they eat a wide variety of insects, grubs, worms, and even some fruits and seeds. But, then again, a pair of chickadees defends a territory over five times the size of the Ovenbird’s–in comparison, the Ovenbird’s needs seem downright modest.
The rich ringing of the Ovenbird’s song is inescapable, yet the bird itself escapes most people’s notice, hiding within rather than on the edges of the forest. I know several birders with fairly substantial life lists who have never seen a live Ovenbird, and many birders have seen them only on migration, when there are no leaves on the trees to hide them.
Even a glimpse is worth the trouble. Ovenbirds aren’t gaudy like other warblers. They have an understated beauty, with a rich olive brown back, snow white underside spotted with gleaming black, white eye-ring, and orange cap outlined in black.
Unfortunately, Brown-headed Cowbirds are more skillful than we at locating Ovenbirds and following them to their nests, and have had a devastating effect on Ovenbird numbers. Cowbirds don’t enter deep into forests, being open country and edge birds, but where forests are fragmented by developments, clearcuts, or even just logging roads, cowbirds find easy pickin’s. Snakes also have an easy time locating Ovenbird nests, and take large numbers of eggs and nestlings.
If they grow up, migrating Ovenbirds face another terrible hazard: lighted radio and television transmission towers. About 20% of all migrating birds found dead under these structures are Ovenbirds. The dead carcasses littering the ground beneath lights simplifies the work of ornithologists who study migration, and also bird weights. Ovenbirds weigh anywhere between half an ounce and an ounce. The reason for the large spread is that so many of them are weighed on migration, when their bodies are laden with excess fat to fuel their flight–ovenbirds long ago perfected the system of letting their weight go up and down on their yo-yoing diet. Despite all the factors that shorten their life expectancy, banding returns include at least three Ovenbirds that survived for at least seven years, and one that lived to be over eight. Whenever we see or hear one, we rejoice in the tenacity of a fragile and vulnerable little creature.