Friday, February 8, 2013

Is it a hawk or an owl?

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In between errands today, I stopped in my favorite birding spot, a group of tilled fields and grassy areas that supports a wonderful variety of birds. I went in there hoping to find some special winter raptors. I had seen two mature Bald Eagles just down the road, sharing a fish from the River. Maybe I would have similar good luck in here.

Here’s what I found straight away: this russet-buff-brown bird sitting in a grassy field:


Looks like a hawk, right?


But what about this face?


Look a little more closely at this remarkable face:


(Sorry it's a little blurry - these are taken on a cell phone camera, through binoculars.)

Is that a hawk or an owl?

It’s a Northern Harrier, a type of hawk found in grasslands, agricultural areas, and shoreline habitats, mostly to our north. We see them during migration and some of them winter where there is apppropriate habitat. This bird is identified as a juvenile by its brilliant golden breast and belly and overall russet coloration. The adult female is streaked brown, and the adult male is a pearly grey. In all plumages, this bird sports a distinctive white rump.

That white rump is easily seen when the bird is hunting. It glides low over the fields and meadows, tipping this way and that as it listens for prey (mostly small rodents).

That’s right, it listens. And that’s why it has that interesting face that reminds us of an owl’s face. Like an owl, a harrier hunts by listening. The round areas around the eyes are called facial disks. They feathers are arranged in a slightly dish-shaped pattern which funnels sound toward the bird’s ears.

When a hunting Harrier hears prey, it whirls, wheels, and drops into the grass feet first. If it’s lucky, it will come up with a mouse or vole in its talons, and might settle right on the spot to eat it. If it comes up empty-clawed, it will lift effortlessly into its gliding, glancing flight for another try.

Unlike our more common Red-tailed Hawk, which sits on a perch high above its hunting area, looking for prey, the rarer Northern Harrier stays pretty close to the ground. It occasionally perches on a low branch, fence post, or the like, but most often it’s on the ground, or perhaps on a grassy hummock. Its eggs are laid in a nest on the ground. I expect that most of my non-birding readers have never seen a Harrier, or even heard of one.

In the context of human interests, Northern Harriers are valuable, as they can consume large numbers of mice and other small animals. Unfortunately, the grassland habitat on which the Harrier depends is fast disappearing under housing developments and commercial facilities.

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The young Harrier is almost the same color as the grass:



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