It isn’t just male birds who sing, female birds can too
Here in Central PA, many summer birds have already raised their first brood of youngsters. There is less singing than a month ago, but, as some pairs settle in for another brood, there is plenty of sound out there for people who want to find or just listen to birds.
The male has long been considered the singer, using his songs to establish breeding territory and attract mates, while the female is silent or communicates in chips. But is this just a stereotype based on insufficient data?
Take the Northern cardinal. The downward whistling “CHEER, CHEER” of the cardinal is closely associated in the minds of birders with that splendid, black-masked crimson bird. But, as Donald Kroodsma notes in Birdsong for the Curious Naturalist, fine singing in cardinals is not limited to the male.
The female cardinal often sings from treetops early in the spring, just as the male does. The female also sings from the nest while incubating eggs, while her mate sings nearby. Often the female’s song matches her mate’s, so birders must get their eyes on the singing bird to determine if it is the male or the female.
The female Baltimore oriole also responds to the song of her mate while incubating her eggs in the sock-like hanging nest that swings high in the tree branches. The male oriole has a clear fruity song, so associated in our minds with spring, while the female chimes in with a soft chip or her own rhythmic, rollicking song.
The Female Bird Song Project is investigating why the gender stereotype in birds has arisen. Scientists Karan Odom of Cornell Lab of Ornithology and Lauryn Benedict of the University of Northern Colorado note that several species in North America exhibit female bird song, including the black-capped chickadee, tufted titmouse, house wren, northern cardinal, song sparrow, dark-eyed junco, and yellow warbler.
Female birds in the tropics, where many of our migratory songbirds spend their winters, often do sing. In fact, Odom’s 2014 study showed that in 71% of the 32 bird families studied females sang during part or all of their lifecycles. Yet there are very few recorded records of female birdsong in the Lab’s archives.
Odom and her colleagues traced the singing trait in birds back to a common ancestor, concluding that singing was the original default trait for both genders. They theorize that in the tropics, where many birds live year-round, the females must constantly defend their territories and so they sing to establish possession. Migratory birds, though, only defend nesting territory for a few months a year.The male takes on the singing job, while the female invests her energies in nest-building and raising young.
Odom and Benedict point out that recordings of birdsong have until recently been conducted mostly in the temperate regions of the northern hemisphere, so that recordings of female birdsong are rarer. The Female Bird Song Project is hoping to correct this regional bias against the existence of singing females.
Scientists are calling on birders to help identify singing female birds, by reporting positive songs on the eBird app. Birders can make a recording by phone to upload with the checklist, and also report to femalebirdsong.org.
Citizen-scientist observations can help correct the imbalance in the song records for female birds and highlight their beautiful songs.
Kay Cramer is president of Seven Mountains Audubon, based in Lewisburg. She advocates to reverse the significant declines in our bird and insect populations by addressing climate change and planting native trees, shrubs and flowers through the Bird-Friendly Blooms project of Audubon Mid-Atlantic.