Wild Side: Hawks and doves

A mourning dove lets her guard down.

Matthew L. Pelikan

As usual for this time of year, the production of more mourning doves is in full swing in our small Oak Bluffs yard. But it’s not going well.

Things did get off to a great start. A pair of doves had claimed the yard by the second week of March, the male giving the eerie, cooing song of this species (“A woo-ah, ooh, ooh, ooh!”) as the female stood by admiringly. Every morning, I’d find them copulating on the railing of our back porch as sunrise neared, then sitting companionably until the sun was fully up. They began constructing a typical nest for this species, a shallow structure, barely cup-like, made from loosely tangled twigs. (Mourning dove nests are often so poorly built that an egg drops right on through to the ground. No big deal: The prolific female simply lays another!)

A steadily growing collection of dove droppings on the railing marked this as a favorite perch. I can see why: The broad boards make a secure, probably comfortable perch; the site is ideal for basking, with full sunlight for half the day; and the rail is an elevated vantage point that affords the doves ample warning if any kind of mammalian predator, such as the neighbors’ rotund, free-ranging tuxedo cat, tries to creep within striking range.

Then, last Saturday morning, the doves weren’t at their usual early morning amore. And as I carried a pot of coffee grounds out to dump on the garden, I found a feather. No: Feathers, plural. Dove feathers, a white-tipped tail feather, a couple of grayish contour feathers from the body, a clump of down. Birds do, of course, molt worn feathers periodically and may lose a healthy feather from time to time. But they don’t give up fresh feathers willingly, and on finding this smattering of plucked plumage, I suspected mayhem.

The afternoon before, my wife, Lori, had mentioned seeing a smallish hawk dash past, southwest to northeast, a course that would have taken it through our backyard. From her description, I was confident the bird had been a Cooper’s hawk — an agile, short-winged raptor that specializes in catching and eating smaller birds. Nothing up to the size of a pigeon stands much of a chance once it’s in the crosshairs of a Cooper’s hawk, and mourning doves are favored prey, offering a prime mix of a large meal in a package that isn’t hard or dangerous to subdue.

Our doves had grown complacent, secure in their familiar, hedge-bound territory, confident that they could detect, dodge, or outrun any threat. Like fast aircraft generally, the mourning dove features a high power-to-weight ratio (that is, a high percentage of its body mass is devoted to the breast muscles that power the wings) and a high wing loading (that is, small wings flap hard and fast to support a fairly heavy bird). Add an elongated, streamlined body, and you’ve got a bullet of a bird.
Given a running start, a mourning dove attacked by a Cooper’s hawk would simply open the throttle and leave its pursuer in the dust. Cooper’s hawks surely know this; unless desperately starved or a naïve youngster, one would never waste energy trying to run down a dove in open flight. But these potent predators must kill to live, and accordingly, they’ve developed tactics that neutralize the speed or maneuverability of their favored prey species.

Hugging the terrain — skimming rooflines and hedges, veering around tree canopies, flashing just inches over the tops of thickets — Cooper’s hawks spend much of their time patrolling likely habitat for smaller birds. Sooner or later, the hawk surprises something. The victim panics and tries to escape; the hawk adjusts its course to intercept, and that’s all she wrote.

In the case of our doves, the hawk that Lori saw approach must have jinked around the end of one row of cedars, turned more sharply around a second row, and entered our backyard perhaps 8 feet off the ground, primed to tackle whatever it surprised. The doves, no doubt, were loafing on their favorite railing, preening a bit or just basking, enjoying being doves on a mild spring day.

They’d have had only a fraction of a second to react to the briskly moving hawk that suddenly materialized 20 feet away. Perhaps they managed to get airborne — birds have remarkably fast reflexes — but in the moments after take-off, they’d have had no speed and no ability to maneuver. The hawk, hardly needing to steer, zeroed in on the nearer of the two doves, extended its feet, drove its talons into its victim, and kept right on going.

I think it was the female that was taken; by Sunday evening, a male dove (I assume it was our original one) was once again calling from the peak of our roof, advertising for a new mate. When you’re a dove, you learn to bounce back from adversity.