Catbird can hold its own against the parasitic cowbird
I was sitting at my breakfast table recently, thinking about what I should write about for my next Birdman column, when the answer came tapping on my window. There was my neighbor Bill with a dead catbird in his hand, knocking on the glass.
I popped up from the table and went out to get the story. Bill had found the bird dead in the street, probably the victim of a car strike.
The gray catbird is a little smaller than our robin and much more slender. It’s slate gray overall with a black cap and tail. Bill turned the bird onto its back and remarked that he’d never noticed the rusty feathers under the catbird’s tail. I told him that we birdwatchers call them rufous undertail coverts, fancy talk for a rusty patch under the tail.
The catbird flips its tail as it hops about, yet that rusty patch may be hard to see. Male and female look alike.
Bill has had a pair of catbirds nesting in his garden nearly every year for quite some time. In fact, we saw a pair chasing each other around his yard later that same day.
The genus name for the gray catbird is Dumetella, which means “small thicket.” And that is indeed the preferred nesting site for these birds, a small thicket, the thicker, the better. They seem to seek out thorny shrubs, maybe for defense against predators. And if the bushes have lots of berries, that’s a bonus.
The nest is described as a bulky, open cup, averaging 6 inches across and 4 inches high. The nest is usually within 6 feet of the ground. The female lays an average of four smooth turquoise green eggs. Sometimes they may have little red spots on them.
Catbirds eat a wide variety of insects and small fruits. They’re quite chatty, so you can often hear them before you see them. They seem to babble to each other or perhaps just to themselves. And, true to their name, they punctuate their chatter with a very catlike “meow.” Most cat owners, however, would not be deceived by the sound.
Catbirds are classified in the mimidae family, a collection of mimics that includes mockingbirds and thrashers. For the process of vocalization, instead of a larynx, birds have what’s called a syrinx. And the catbird has a split, or divided, syrinx. They can vocalize through each side independently. That means they can harmonize with themselves.
Their vocabulary includes some 100 different whistles, squeaks and harsh chatters, as well as fragments of the songs of other birds. Their song can last up to 10 minutes with syllables delivered at about 90 a minute.
A birding friend of mine, Ron, told us that several years ago when his kids were much younger, they were camping at a state park. The kids had been exploring the area when suddenly his son came running back, all excited.
“Dad,” he said, “There’s a bird over there and it’s saying my name!”
He led Ron over to some nearby bushes and sure enough, there was a bird calling with a whiny, “Eric! Eric!” His son was impressed with his introduction to the gray catbird.
It’s difficult to see catbirds when they’re in shrubbery. But most of us birders have had success drawing them out by using a soft “pish” sound. The birds are curious and want to see who’s making that threat sound. It’s best not to bother the bird during the nesting season, but a quick encounter is probably not a problem.
In my research for this column, I consulted the Cornell Lab of Ornithology’s Birds of North America Online website. There I learned something that I admire greatly about gray catbirds. Many birds get parasitized by the brownheaded cowbird. The cowbird doesn’t build a nest of its own, but lays its eggs in another bird’s nest when it’s temporarily unattended.
But not so fast there, cowbird, if you’re eyeing a catbird nest. According to an article on the website, catbirds have learned how to roll the offending cowbird egg out of their nest. The article says this isn’t an innate behavior, but it seems to be readily learned by catbirds. The theory is that they see the first egg they’ve laid, their own, and recognize the cowbird egg as foreign.
Catbirds range across most of the U.S. and into southern Canada in the summer. They usually winter from southern New England down to Panama. But we’ve had a gray catbird overwinter here in Lauderdale, using our heated birdbath for water and warmth. It also made use of the suet feeder as a source for energy. Brave, and resourceful, little bird. But, sadly, like many bird species, they haven’t figured out how to survive automobiles.
Clay Christensen lives and writes in Lauderdale. His book, The Birdman of Lauderdale, is available in local bird and bookstores and at BirdmanBook.com.
Red-headed woodpeckers topic at next Audubon meeting
Brittney Yohannes, a master’s candidate in the conservation biology program at the University of Minnesota, will give a presentation on her two-year research study on nesting red-headed woodpeckers at the St. Paul Audubon Society program Thursday, Nov. 12, at 7 p.m. at Fairview Community Center, 1910 W. County Road B, Roseville. The event is free and open to the public. A social time with refreshments will begin at 6:45 p.m.