The wild side of sex

Acadian Flycatchers, members of the genus Empidonax, are a common breeding bird in the Clear Creek Valley, along the creek, in deep ravines, shady hollows, and along the road where there are heavily wooded slopes. Greenish-gray on the back, whitish beneath with a yellowish wash on the sides, they are about five and a half inches long and usually announce their presence with a sharp hiccup-like note.

An average of about 37 pairs of these birds nest each year in the seven miles of the valley I survey for my annual breeding bird count. The highest number was 54 pairs in 1972; the lowest, oddly enough, was 21 pairs the preceding year.

I usually first notice these little birds during the first week in May, even though the full compliment doesn't arrive until later in the month. It also wouldn't surprise me if the females arrive after the males have staked out their domains. At this time of the year, I frequently see them chasing one another, probably males establishing their territories. That's an educated guess because the sexes are so similar in plumage it's impossible to tell them apart. Sometimes, in their enthusiasm for supremacy, they will pursue birds of other species, even larger birds such as tanagers and orioles.

When courtship activities begin, the males pursue females that have been attracted to their territories, probably by their singing. When actual bonding of a pair begins, I am not sure, nor do I know if the same birds ever remate in subsequent years. I have seen males approach females and attempt to mount them, at which times the female hunkers down in typical passerine fashion with a great deal of shaking and quivering, but until the morning I am going to tell you about, I had never seen them actually copulate. And what I finally did see jolted me out of any doubt that a small nondescript bird couldn't enjoy the wild side of sex.

I have subsequently given the event in question a lot of thought. I have related the experience to other naturalists, I have pored through countless books looking for some recounting of similar behavior- to no avail- and I have been careful not to exaggerate any part of what I saw.

It was the first part of June, early in the morning, and I was walking along Starner Road just a few steps from the old iron bridge. I disturbed a belted kingfisher from his morning fishing and he flew up the stream with a protesting rattle. I could also make out the lazy bee-buzz of a blue-winged warbler, a phoebe relentlessly repeating his name, a yellow warbler - like an animated bit of sunshine - singing from the top of a willow, and from nearby deep woods, a scarlet tanager, a cerulean warbler, and an ovenbird.

All at once, my attention was attracted to a dark flying object that was streaking in circles and figure eights through the trees. In and out it sped, about twenty feet off the ground, through the branches of stream-side willows and sycamores, through the trees and around them into open spaces, then back through the trees again .

What on earth is this? I thought.

They say the mind operates like a computer and any experienced birder can testify to this. During the first unexpected three or four seconds of observing this phenomenon, my mind was literally racing as fast as the what-ever-it-was that I was beholding.

In rapid order, I was ordering up and discarding UFOs, which I don't particularly believe in and, anyway, what I was looking at was Lilliputian, followed by little brown bats, hummingbirds, large insects, and et cetera, et cetera, as the King of Siam was wont to say in exasperated moments. No sooner than I would think of one possible explanation than I would discard it .

On about the third lap traversed by this speeding thingamajig, I was no closer to figuring out what it was than when I had first become aware of it, other than the realization that it was definitely something alive. Alive and flying like a bat out of Hell, only it wasn't a bat.

Suddenly, and exactly how, I'm not sure of to this day, unless my eyes finally managed to lock on some significant detail for a split second, I was able to ascertain that this was not only a bird, it was two birds! Two birds in tandem, and they were rocketing through the trees like there was no tomorrow. Two diminutive birds, and they were coupled together as tight as- as tight as two lovers.

Flying together as they were with four wings beating a tattoo on the air instead of two, they resembled nothing so much as a small animated toy airplane- and a biplane at that.

By about the fifth second, I finally attempted to follow the whirling pair with my binoculars and it was then that I became fairly sure that what I was looking at was a pair of Acadian flycatchers. And, two or three seconds later, when they broke their conjugal embrace and flew to separate perches in the same tree, I became absolutely certain of their identity.

One said, hiccup, and the other, probably the female, responded with a hic, followed by a few twittering notes. In another moment they were busy flying from their perches in pursuit of flying insects and some small moths that were flying about, maybe common canker moths.

To the best of my knowledge, the only birds that regularly copulate on the wing are members of the family Apodidae, the swifts, and some hummingbirds . There is one other explanation of what I had witnessed: It is possible the two birds were both males and that they were locked together in combative and reckless competition for territory or a mate. The final truth I will probably never know.