Why Birders Make Lousy Bridge Players -- by Kenneth Turner Blackshaw
Here we are at the Salt Marsh Center and I've foolishly sat where I can see out the window to the harbor. It's ice as far as I can see out there and bitterly cold. I'm suddenly entranced by a Rosarch-like pattern, changing shape dramatically over the ice. The shape is like a globe, then an oval, then an hourglass, and then quickly splits in two as an object dives through the middle of it. My initial take was that these were Starlings, but I came to realize they were Rock Pigeons, roughly twelve inches from beak to tail.
The interloper has created panic in the flock and the pigeons fly chaotically for a few seconds. I'm sure some collisions occur. By now, the bridge game is completely forgotten and I'm standing by the window. A lone pigeon flies desperately to the left across the water with a brown form in hot pursuit. Since the chaser is almost the same size as the prey, it is most likely to be a Sharp-shinned Hawk -- a male. Did the hawk get a late lunch? We'll have to guess because they disappeared behind the Town Pier.
Sharp-shinned Hawks are among the least familiar of hawks. Many people know the Red-tails we see soaring over the moors, or the Northern Harriers flying low and precariously over the brush. Falcons get a lot of publicity. But what is a Sharp-shin?
Actually this is one of a species group known as Accipiters. Falconers know them as 'true' hawks, and indeed the Genus Accipiter, comes from the Latin meaning 'hawk'. Two other members are the Cooper's Hawk, and the Goshawk, both larger, and rarer than this one.
Accipiters differ from other hawks by having relatively short, rounded wings and long tails. Their flight is often very direct, with a flap-flap-sail pattern. Beginning birders learn "flap-flap-sail, and a long square tail" as a key to identifying a Sharp-shin. The larger Cooper's Hawk has a more rounded tail.
'Sharpies' as we call them, and Cooper's, specialize in preying on other birds. Bent's Life History of this species reports an interesting 1893 study "Of 159 stomachs examined, 6 contained poultry or game birds; 99, other birds; 6, mice; 5, insects; and 52 were empty." So, if you see a Sharp-shin, chances are it's either just eaten another bird or is desperately seeking one that is not paying attention. Many people express horror to that one bird would eat another, but then, WE eat other mammals.
Unfortunately, most accipiter sightings are more of the nature, "There goes a … oooops, it went into the trees." If you are lucky, you will spot one on a calm clear Nantucket day when there are nice thermals. Then you can see them circling above you and get familiar with their flight pattern.
Another method is the squeaking sound I make in order to bring songbirds in for identification, mimicking the sound of an animal in dire distress. This sometimes attracts a Sharp-shin, and remember, one third have empty stomachs. Too often I look up and see orange eyes, yellow talons, growing rapidly larger as the hawk dives right at me. Now is a good time to stop squeaking! I have never been hit, but several times I've had the hawk land almost at arm's length, staring with frightening intensity to see just what happened to dinner.
Most Sharp-shins we see are brown striped, first year birds, but an adult is spectacular. The top of the head and back are a lovely slate blue and from the throat down they are barred horizontally with rusty orange. The sexes are similarly colored but the female is much larger. The part of the bird's leg we see as the 'shin' is actually below the bird's ankle. If you examine a museum specimen, you can see that it has a sharp ridge down it, but that's not much good as the bird flies past you.
On Nantucket, Sharpies used to be found only rarely in the autumn. Global warming, and/or bird feeding has now brought them to us throughout the winter. They have been reported on every Christmas Bird Count in since 1973, with a high of 15 in 1993.
Watch for these little hawks from September until the end of April. They are more common in October when so many migrate past. If you feed the birds you may notice that suddenly there are none there. If you look closely, you may see a few 'frozen' in position. This is your clue that one of these accipiters has appeared. It's a jungle out there. Enjoy Nantucket's 'wild kingdom'.
Michael DiGiorgio illustrated this article.
If you enjoy social birding, every Sunday a group meets in the parking lot in front of the Nantucket High School at 8 a.m.
To hear about rare birds, or to leave a bird report call the Massachusetts Audubon hot line at 888-224-6444, option 4.