Next time you’re out exploring and hear the sounds of a mechanical disaster, don’t call the National Enquirer to report an alien landing. Pull out your binoculars. You might just catch a glimpse of a yellow-headed blackbird singing his song.
Walking through a local wildlife refuge south of Missoula in the Bitterroot Valley a few weeks ago, I heard a noise like a wheezing mule. Or maybe it was a car horn. Or someone pulling a squeaky red wagon piled with rocks. But as I approached a marsh sunk into the field, I didn’t see the barnyard animals or car crash I expected. Instead, I found brightly colored black and yellow birds perched on top of nodding cattails. Then one opened its beak, launching a chorus of shrieking and honking over the water.
Yellow-headed blackbirds migrate from the southern United States and Mexico, arriving in Montana in early summer. they flock to freshwater marshes and swamps, where they unseat red-winged blackbirds from the prime nesting spots. The yellow-headed blackbirds weave their nests with wet reeds over water. The reeds tighten as they dry, making the nests strong and secure. The scientific name of the bird is Xanthocephalus xanthocephalus or “yellow head, yellow head.” As the name indicates, males have yellow feathers covering their heads and chests. The color deepens into apricot around the face. In females, the yellow is streaked with white, and their bodies are brown rather than black.
Despite this flashy coloring, it is the song of the yellow-headed blackbird that attracts the most attention. The peculiar conglomeration of notes has stumped wordsmiths attempting to capture it. Bird guides describe the noise alternately as “an unmusical squawk,” “an asthmatic old man,” and “the croaking of frogs and the squeaking of unoiled gates.” P.A. Taverner, author of the book Birds of Canada, depicts the bird’s tunes most graphically. He writes that a singing yellow-headed blackbird “lowers its head as if about to be violently ill, and disgorges a series of rough, angular consonants.”
These odd vocalizations have been classified by scientists into two categories: “buzzing” songs and “accent” songs. The buzzing songs typically occur at higher frequencies than the accenting songs, so they don’t carry as well through the dense marsh habitat. Yellow-headed males are more likely to sing a buzzing song when they see another male or female in their territory. The birds may use buzzing noises for face-to-face communication, reserving the accenting songs to broadcast messages over long distances. As these lower frequency noises travel out over the fields, they are heard both by other yellow-headed blackbirds and bewildered birders.
So next time you’re out exploring and hear the sounds of a mechanical disaster, don’t call the National Enquirer to report an alien landing. Pull out your binoculars. You might just catch a glimpse of a yellow-headed blackbird singing his song.
"Field Notes" is produced by the Montana Natural History Center.