As an avid birder and a member of the Backyard Birdwatcher Facebook Group, a heated discussion regarding cowbirds arose. (By heated I mean an increase in the amount of exclamation marks employed when conveying opinions in comments. That’s about as heated as we mild-mannered backyard birders get.)
Brown headed cowbirds rank high on the nuisance bird list. The male sports a dark brown head and black iridescent body. The female’s gray uniform with fine under markings do not conform to their descriptive name. Smaller than a robin and larger than a wren (and not as welcomed as either) they cavort with other nuisance birds. The adage “birds of a feather” comes to mind.
Recently a Backyard Birdwatcher group member posted a photo of a male cowbird visiting her birdfeeder. The post accompanying the photo leaned toward the positive in spotting her avian guest. The response to her post ranged widely. The “majesty of the natural world” and “their song reminds me of water” opinions offset the delight one member felt when his “Bernese mountain dog caught one in midair and ate it.”
With peaked interest, several YouTube videos, and Audubon articles, later, I decided that the nuisance brown headed cowbird shared characteristics with nuisance humans.
If a cowbird could attend school, he would be the student who cut to the front of the lunchroom line. He’d force an unfair trade of his carrot sticks for chocolate chip cookies. He might even bully his classmate out of lunch altogether.
Cowbirds take over feeders and aggressively drive away smaller song birds. A flock or two of these bird bullies drain your feeders, leaving the birders with an empty feeder and an expensive seed bill.
A timeout for a school lunchroom bully would help him reconcile his ways. Another approach is needed for the piggish cowbird. Mixing a less desirable cowbird menu may curb these avian aggressors. Suet, thistle, and safflower are not cowbirds’ favorites. However, the woodpeckers, goldfinches, and nuthatches will love them!
Platform feeders attract bully birds. Tube feeders with small perches discourage cowbirds. The Classic Droll Yankee Tube Feeders works well in my backyard.
If a cowbird could drive, she would be the rude driver that steals the parking spot you had patiently waited to be vacated. She’d nose her way in and cut you off as she angled in. When exiting her car, she would avoid eye contact and be on her way without a shred of remorse.
As a parasitic brooder, a female cowbird watches for other birds actively laying eggs. Then she sneaks in while the other birds are away and lays her eggs in their nest. She often destroys the host’s eggs before leaving. The host parents will tend the alien egg and upon hatching feed the baby cowbird. (Cowbird eggs hatch sooner than most other bird species and therefore gain advantage in feeding attention to the detriment of the host’s own hatchlings.) Although some host birds recognize the unfamiliar egg and attempt to evict it, most do not. Cowbirds have been accused of causing the decline of rare species such as Kirkland’s Warbler and Black-capped Vireos in this manner.
Honking a horn with an exasperated expression at the rude driver (or rather rude parker) may give her pause. A different tactic is necessary for the intrusive egg layer. If you have nesting birds in your yard, resist checking on their nests. This brings attention to their location and aides the cowbird in locating a likely home for their parasitic egg.
Person of Interest
If a cowbird were a person of interest, he would activate a community watch alert. He would be the strange driver parked on your street or a loiterer in the doorway that would trigger texts to neighbors or calls to the police or vigilantism.
As U.S. natives, the Migratory Bird Treaty Act protects cowbirds. It’s unlawful to use lethal control. I’m not sure how this act applies to the Bernese mountain dog referenced above, but mockingbirds and yellow warblers couldn’t give a hoot (or tweet) about the law.
Mockingbirds attack the cowbird as she lays her eggs. This avian vigilante may not successfully drive the intruder away, but saves her own eggs from destruction.
Yellow warblers developed a seet call, a high-pitched call warning of a predator. Upon spying a cowbird, the seet call alerts nesting warblers to protect their homes. Nearby red-winged blackbirds recognize this call as well. Students from the University of Illinois posted a video about their findings.
It’s hypothesized that cowbirds developed their parasitic brooding behavior to survive. Long ago they trailed herds of bison, eating disturbed insects in the wake. Dependent upon the mobile bison, cowbirds followed them. Unable to stay in one area long enough to raise their young, cowbirds layed their eggs in other birds’ nests.
Other than hiring a Bernese mountain hit dog or a yellow warbler stoolpigeon, the Migratory Bird Treaty Act prohibits birders from destroying cowbirds or their eggs. Follow the tips above to deter cowbirds or take the advice of a fellow Backyard Birdwatcher member and realize “All birds have a place. Even vultures can be majestic.”
Anita Borgo writes for children as well as adults. Check out her author website.