Birding by Misbehavior

The flick of a wing, the flirt of a tail: On their home turf, at least, birders use behavior at least as much as plumage or vocalizations to identify their quarry. The nervous twitching betrays the Northern Cardinal‘s identity even when the pointed crest and bone crusher of a bill are hidden deep in the shade; and in my part of the world, we’re holding our birderly breath for the extravagant tail wag that announces the arrival of the year’s first Eastern Phoebe.

I was at the Great Swamp yesterday morning. As I approached the big open fields on Pleasant Plains Road, I saw in the distance a long, slender raptor perched far out at the end of a dead limb. I blinked once, but it was still there — and it was still a Northern Harrier, calmly surveying all of which she found herself mistress.

Common, familiar, and enormously widespread, the Northern Harrier is one of the first raptors North American birders learn to identify, and most graduate quickly from a somewhat shaky reliance on the bird’s white upper tail coverts (the infamous “white rump”) to an appreciation of its much more distinctive flight habit.

Except in migration, harriers spend most of their time floating low over the ground, hunting the grasses of marshes and fields. When they have caught something, they take a break from their boustrophedon to consume the vole or bird or frog atop a muskrat hut or, most often, right on the ground.

What they don’t do, we birders learn, is hunt field edges from high, conspicuous perches.

Well, of course they do (though the clenched toes of this heavily worn juvenile suggest that she was really just having a nice relaxed nap). The problem is that the “normal” habits of the Northern Harrier are so distinctive, so unlike any other American raptor’s, that we tend to forget how behaviorally versatile this species, or for that matter any predator, has to be.

Over the years, I’ve seen Northern Harriers perched high in trees, flashing through woodlots, and hovering menacingly over prairie-chicken leks. A friend of mine once saw one of these gentle volevores land on a Black-crowned Night-Heron, and Maynard reports watching a harrier in Florida “repeatedly” — repeatedly! — pirate scaup from a Peregrine Falcon.

Those are rare sights, and I don’t expect to see another harrier perched as this morning’s was for quite a while. But seeing her up there was a good reminder that birds do what they have to do — and not necessarily what we expect them to.

This Northern Harrier was perched in a damp clearing well inside a woods in British Columbia: unexpected, but who am I to tell the bird what to do?