One Flew Over the Cuckoo’s Nest

ONE FLEW OVER THE CUCKOO’S NEST

Wednesday, July 18, 2007 (Napanee Beaver)

Friday, July 20, 2007 (Picton Gazette)

No kidding. In 1975, when I went to the old Quinte Mall theatre in Belleville to see One Flew Over the Cuckoo’s Nest, I actually thought it might be a nature film of some sort. I remember wondering why Jack Nicholson and Louise Fletcher would ever appear in a nature film.

I guess I was eager to learn more about cuckoos, for I had seen my first one many years earlier, near the University of Western Ontario campus, in London. No, they are not confined to Europe as we might think, and neither are they as inclined to lay their eggs in the nests of other birds, as the European species. European cuckoos spend much of their time, as do our cowbirds here, skulking about for the nests of other songbirds, in which they will deposit their eggs. Like our cowbirds, European cuckoos have no interest in raising their own offspring, but leave the job instead, to foster parents.

However, our cuckoos here, both the black-billed cuckoo, and the less common and more southern yellow-billed cuckoo, very seldom display this trait, but raise their own young responsibly. There have been at least four black-billed cuckoos calling softly in the woods along the roadside north of our house every morning at daybreak. I have yet to understand why this species becomes more vocal in the late summer, when the oppressive heat and humidity keep most other birds rather quiet. But I’m working on it.

Despite their size, at least as long as a blue jay, cuckoos are not seen in the open all that often. Two years ago, at Prince Edward Point, one sat on a dead limb in plain view, while a group of birders I was leading, spent a full 10 minutes observing it at close range. They all commented that, never before had they ever observed one in the open for such a long period of time, and subsequently thanked me profusely. I saw no reason to admit that neither had I. It was indeed a rare treat. This spring, one was in almost the same spot again, and although I conducted hikes there every morning for 10 days, and it called faithfully every morning, only once did we ever see it, and that was a fleeting glimpse as it passed overhead. That’s the way they are.

While cuckoos have a most amazing voice, especially the yellow-billed which can take 10 years off your life if one should suddenly start hollering, as an individual did in an apple tree one spring that I happened to pass by while on another hike, the most incredible characteristic about both species is their diet. They are one of few species that have evolved the skill of consuming tent caterpillars in their entirety. Most birds avoid tent caterpillars as the hairs and spines tend to puncture the delicate stomach linings of birds. Most birds, when they do eat tent caterpillars, do so by puncturing the soft skin, and devouring the contents, leaving the empty, hairy and dehydrated carcass behind.

Not so with cuckoos. Both species have developed the amazing ability to swallow entire tent caterpillars, consuming the hairy creatures as thought they were fine caviar. When the stomach becomes so congested with indigestible spines and hairs that it cannot hold one more caterpillar, the bird throws up, disgorging the entire indigestible contents, stomach lining and all ! The regurgitated sack probably resembles a miniature Glad Kitchen Catcher. Immediately, the cuckoo grows a new stomach lining, and away he goes again to feast on more tent caterpillars. When tent caterpillars experience a population explosion as they do every 10 years or so, there is a corresponding higher number of cuckoos present that year to consume them. In less than a month, both cuckoos will commence working their way south.

Nature is forever evolving, devising new and intriguing ways to preserve the fittest. If we stick around another thousand years or so, likely the tent caterpillar will have devised a way to once again outwit the hungry cuckoo. For now though, hairs and spines are no problem for these birds with their disposable stomachs.