invisible birds

June 14, 2005

in Birds,Natural history

You rely a lot on your ears when doing bird surveys, especially in the summertime. Thick foliage obstructs views, females are tending nests or young, and unless they are singing from an exposed perch, males may be hard to locate as well. Listening carefully for songs or call notes usually allows a patient observer to verify an identification, or recognize a behavior that provides confirmation of nesting (in my case, for a state breeding bird atlas project).

Some birds you just hardly ever see, no  matter how long-fused you are waiting around checking out the shrubbery. I’ve encountered several of these enigmatic species so far this breeding season. They are disparate, unrelated birds, similar only in their sneaky, furtive ways.  Here’s a (figurative) look at one of these surreptitious species. (Part 2 here)

Yellow-billed Cuckoos (Coccyzus americanus) are forest ghosts, detectable by their guttural, hollow, just-downright-strange call: ka-ka-ka-ka-kow-kow-kow-kow-kowlp-kowlp. It’s hard to tell if they are near or far. There sure seem to be a lot of them around this year. I think this may be because they had a bumper year for reproduction in 2004 due to the emergence of Brood X of the periodical cicada in this region.  Cuckoos specialize in large insect prey (and hairy caterpillars like tent caterpillars and gypsy moths), responding to an abundant supply by laying more eggs.  They are not obligate brood parasites like Old World cuckoos.  Usually, they raise their own young, but sometimes lay their eggs in the nests of other cuckoos, and occasionally other species. Prey abundance may trigger this behavior.  Sometimes.  Or not.  This is a bird that doesn’t easily give up its secrets.

One aspect of cuckoo development is well-documented, however.  The chicks have exploding feathers.  Yellow-billed Cuckoos have one of the speediest breeding cycles in the avian world, only 17 days from the eggs hitting the nest to the young ones leaving it.  A week after hatching, chicks are covered in long “pin feathers,” growing feathers encased in sheaths*. All at once, the feathers begin erupting from their sheaths and presto! the bird is fully feathered in about two hours.  A correspondent to Bent’s Life Histories of North American Birds reported in wonder: “This process took place with such rapidity that it reminded me of the commotion in a corn popper or a rapidly blooming flower.”

When they know they are being observed, Yellow-billed Cuckoos tend to stop moving and arch their backs to conceal their white underparts.  I have a lot of territory to cover doing my atlas work, so I have yet to even spend the time really trying to see a cuckoo, much less find a nest.  But bursting baby feathers! Next time I hear the wooden notes of the Rain Crow, somewhere in the woods, I may try to stalk this skulking bird.

Or at least listen for a quiet series of little explosions, the repercussions of popping plumage.

*Pin feathers look kind of like aglets, which are the things at the ends of shoelaces.


{ 7 comments }

fred1st June 20, 2005 at 8:59 am

Somehow, just knowing about the popcorn pin feathers makes it even nicer knowing they're out there, though I've not seen one in years. We have quite a few this year, as I would have predicted when our wild cherry trees began to show the tissue of webs in all the crotches in mid-spring.

P.M.Bryant June 27, 2005 at 4:01 pm

Thanks for this post on one of our favorite birds.

Amazingly, due to my poor talents identifying birds by sound, and the good fortune to have yellow-billed cuckoos resident in the area around my house, I have spotted these birds more often than I have heard them.

The closest look we got was when one whacked into a skylight window in our house last summer. It sat stunned on the roof for a while. We went up to the roof to take a look at what had happened and found a yellow-billed cuckoo just sitting there with its beak partially open, not moving. It was alive, but didn't look well. (It gets extremely hot on the roof in the summer here in south Texas!)

My wife decided to get proactive: she put the bird in a small, open box and move it onto a shaded part of the roof, so it wouldn't roast in the sun. We then went inside and she called a friend of ours who studies birds professionally to ask him for advice.

By the time we went back to the roof, the bird had left the box and was just sitting on a branch in an oak tree a few feet away. We watched it for about twenty minutes, during which it moved only a couple times. But we were glad to see that it was clearly going to recover without further help from us.

We've since put up a paper hawk silhouette on that window to prevent any more bird collisions. And it's working so far. And we still see yellow-billed cuckoos with regularity. Perhaps even this same bird, for all we know.

My wife, who is obviously more talented at bird-watching than I am, can now identify them in flight.

walkshills June 29, 2005 at 11:58 am

Cuckcoos are one of my favorite birds, too. I learned to identify them long ago but they are elusive and the average person really doesn't know what they look like. However the Rain Crow's call is familiar to most people because the birds are numerous in this area.

I've always been fascinated by the local folklore about the Rain Crows: that it will rain within three days after they make their calls. (This folklore is from rural sources and long predates me.)

By my observation over several decades, this has proven to be relatively accurate here in Central Texas; not always, but generally. What I have observed it that their calls seem to increase with increasing levels of relative humidity. Part of that may be that their most active period is in the spring and early summer when we have our wettest months: May and June.

I've always wondered if there is some tangible relationship concerning that piece folklore. The other piece of folklore is that it is extremely bad luck to kill a Rain Crow. That may well have stemmed from the cultural relationship with rain in an area quite prone to drought.

I've seen quite a few killed on the local highways; they have a bad habit of swooping low through traffic.

Charles Futch June 29, 2005 at 3:22 pm

I am sure that a pair of YBC's are nesting high in a wild cherry tree in the fence row along our pasture (Tallahassee, FL). We hear a cuckoo frequently up there, but have yet to see one.

Bill July 10, 2006 at 11:17 pm

Is a whipper whill and a rain crow the same bird?

Nuthatch July 11, 2006 at 9:42 am

No, a Whippoorwill is in the nightjar family, and a a rain crow, in this post, is a cuckoo. Not even closely related.

scott schada March 28, 2007 at 5:59 pm

About two years ago I heard a loud thump on my west facing living room picture window, and as occasionally happens, I found a motionless bird on the patio below. But this time it wasn't a robin or sparrow, but a larger and beautiful bird, regrettably dead, but which I had never seen before. I put it in a shoebox in my attic, and today it still looks much the same as it did then, a very nice specimen of what I learned was a
yellow billed cuckoo. Definitely an attractive bird, regardless of its name.

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