Avian Dynamics

My desk affords a view to the northwest, from the vantage-point of a second-story window that overlooks a cluster of bird feeders. My snowy view of winter white is studded with color:  punctuated by the plumage of the avian visitors that flock to the feeders and congregate in the branches of the Viburnum next to the building. The birds offer an affable distraction, flitting from branch to branch, swooping down to feed on seed, calling or chuckling, fluffing and preening.

Against the snowy backdrop, the brilliant Cardinals and effulgent Blue Jays command the eye. More subtle are the Dark-eyed Juncos, the so-called “banker birds” in their conservative gray suits. Striped Goldfinches in their subtle winter plumage linger in large numbers at the feeders. Woodpeckers, the Downy, the Red-bellied, the Hairy, are especially fond of the suet feeders.  Chickadees, White-breasted Nuthatches, and House Finches round out the usual assembly.

On a recent winter morning, my attention was drawn by the repeated calls of Blue Jays—cries that clearly called alert, alarm, warning. Moving to the window, I looked down to see the bird feeders vacant and the Blue Jays, Cardinals, Chickadees, and Juncos amongst the branches of the Viburnum. Like the other birds, I understood the Blue Jays’ alarm calls to mean that a predator was about. Peering through the window, I scanned the area, wondering whether I might spy a coyote or a feral cat prowling among the shrubs, or perhaps a Red-tailed Hawk perched and alert.

Then she flew by, close to the building and just below my window:  a Cooper’s Hawk with her slate-blue back and narrow, barred tail.

a Cooper's Hawk in flight

a Cooper's Hawk in flight

Birds account for the predominant portion of a Cooper’s Hawk’s diet, so the feathered flyers around our bird feeders did well to heed the Blue Jays’ warnings. Coopers’ Hawks are extremely agile in the air, accustomed to maneuvering between the branches in our oak woods and savannas as they hunt, generally capturing their meal on the wing. An accipiter, the Cooper’s Hawk is less inclined to soar like a buteo, adrift on a thermal of air. With a long, rounded tail serving as a nimble rudder, a Coopers’ Hawk hurtles through narrow spaces in the tree canopy, dipping and twisting to avoid colliding with obstacles while bearing down on its swift passerine prey. I think of the Cooper’s Hawk as a classic savanna bird.

For a little while she came and perched in the Viburnum, sending the other birds scattering. She didn’t, however, linger in the vicinity of the feeders, so soon the other birds were back to their banquet, the snowy scene flecked with birds bedecked in plumage of red, white, blue, and gray.