A maze of shallow channels snakes before us through golden marsh grasses and mud-stained pickerel weeds. Autumn light illuminates every blade of cordgrass. Hummocks rise like gentle waves through the marsh on this still afternoon. Our kayaks sit silently on the black water. A breeze half-heartedly stirs the reeds.

To my left, a treeline separates the marsh from the Nanticoke River. A hawk is coursing along the ridge line. He rocks back and forth on the invisible breeze, and then turns toward us.

Gray on top and white below, he has black wing-tips and a long, narrow tail. The bird glides up with startling speed. He eyes us for a moment before effortlessly wheeling away. His white rump is in plain view as he soars back to the treeline, apparently having satisfied whatever passes for avian curiosity.

The northern harrier (Circus cyaneus) is a master of low altitude, low speed flight. With its slender body and long wings and tail, it can fly almost motionless as it works tracts of fields and marshes, looking for food. The bird has an owllike facial disc that captures and amplifies sounds, enabling it to hear mice and other small prey scuttling through the grass. Coupled with the visual acuity common among hawks, the northern harrier is a formidable hunter across virtually all of the United States.

The slow-motion flight profile above a marshy habitat makes the northern harrier easy to identify. The white rump is another easy identifier. That's a good thing, because the adult male, adult female and first year juvenile can look like three different birds if one tries to go by feather color and size alone.

Male northern harriers, like the one who just checked us out, show the blue-gray color that gives the bird the second half of his Latin name (cyaneus). The color extends from his head across his back and to the edges of his wings, which are tipped in black. That black edge is visible from underneath as well, but the blue is replaced by white speckles with a bit of red. The white underside of the male's tail shows a faint banding. The female, who is larger than her mate, wears a range of browns above and a mix of browns and whites below. The juvenile has a distinctively cinnamon hue to its chest that washes out onto the underside of his wings. Mom, dad and junior all have that diagnostic white rump patch, though, and all exhibit the same feeding behavior.

Harriers don't spend all of their time over low marshes, of course. As they fly overhead they can present an array of flight profiles, vaguely resembling everything from turkey vultures to red-shouldered hawks to peregrine falcons.

Luckily for relatively unskilled birders like me, they spend a considerable portion of their days engaged in their easily identified slow-motion flights over open fields.

They can sustain low speeds because of the long, narrow outer primary feathers that spread out into fingers that spill air, providing lift and helping the birds to avoid stalling. They hunt from their coursing flight or by taking off from a low perch. In addition to feeding on mice, voles and the like, harriers will take small birds that frequent marshes and farm fields. To do so, they can alter their flight profiles with amazing speed, going from a lazy, hesitant flight to a rapid and deadly plunge.

Harriers summer from Newfoundland to Alaska and south into the northern plains and mid-Atlantic. They migrate during the day, like most raptors, spending their winters in the southern and southwestern United States and down into Mexico and beyond. The birds can be found year-round in a broad swath that extends from Ohio to California. The Chesapeake region represents a transitional area for migrating birds. It is the southernmost summer breeding range and also the northernmost wintering grounds. The long stretches of salt marshes and farm fields here are a strong lure regardless of the season.

Unlike other hawks, the northern harrier makes its nest on the ground, often under a small bush. The larger female stays with the nest almost full time, leaving the hunting duties to the male. After the young have fledged, they will continue to stay with the parents for a time, and the whole family will roost together on the ground for the night.

The harrier I'm watching silently slips out of sight around a stand of trees. Soon, I will return to work and the thousand tasks of modern life, taking my awkward strides through a vastly different landscape.

For now, however, I will do my best to imitate the grace and ease of nature. My paddle slips back into the buoyant black waters that lift my kayak. The northern harrier and its serene marshes have already lifted my spirit.