Winter is a tough time for many forms of wildlife. Every day, mule deer, for example, must dig out their winter fare of bitterbrush and tiny plants buried in snow. They also must have thermal cover every night to ward off those nighttime temperatures that can sometimes plummet to below zero.Similarly, there is a group of hawks that have it tough: the accipiters, otherwise known as "bird hawks." True, like most birds in our latitudes, their downy underwear keeps them warm, and their winter food: small birds - flocking together in winter for protection, food and warmth - are dependable prey, but let's not forget Darwin's theories about how animals adapt to change.
My wildlife files are filled with reports from people who have taken the time to tell me about change in nature, and in particular, how accipiters change their tactics while raiding the backyard bird feeder. Such reports lead me to believe that evolution is always underway as far as accipiters and dicky birds are concerned. The sharp-shinned hawk patrolling my place, for example, instead of going off willy-nilly after its prey, seems to be using windows to help it secure a meal in the winter.
From what I have witnessed, it goes something like this: A flock of house sparrows, finches, juncos, quail, grosbeaks, pine siskins or whatever, come to the feeder for much-needed food. About 50 yards away a sharp-shinned, or Cooper's Hawk, is perched stealthily in a bushy pine or juniper, waiting.
The hawk patiently watches as the flock of birds settle down and begin eating, then (I think) it picks out the one it wants. How they do that is way beyond my comprehension - another of those "Darwin" moments. The main idea is to catch and eat the easiest prey, that way minimum energy is expended to secure food that provides more energy to enable the hawk to make it through the winter to reproduce its kind, etc.
Once its prey is selected, the hawk blasts off with those powerful, blunt wings - like an F-16 fighter - and heads right for the feeder. The profile of a bird hawk coming head-on is almost unnoticeable, but songbirds are always watching for the inevitability of a hawk after them. Before the hawk gets into striking range, one bird will see it coming, and as it is with group behavior, when one bird leaps off the feeder, they all do. At that moment, the hawk, with just a twitch of its tail, aims right at the bird it wants. That bird usually panics and goes for the first way to escape - and mistakes the reflection in a window as the best way out.
If the hawk is experienced, and has pulled this off previously, it will open its wings and slow down, giving the prey the opportunity to strike the window. Whack! The prey is usually knocked silly and falls to the ground. Blam! The hawk is on it, and within seconds, it is flying off to a convenient perch to pluck and eat the still-warm victim. (See photo.)
Sometimes, if the hawk is careless (usually immature with little experience) it will try to go after the prey through the window. For the prey it's usually fatal, but sometimes the hawk is injured only slightly, and that's when Gary Landers, Sisters raptor rehabber at "Wild Wings," enters the picture, something, I think, Darwin would have a lot to say about.
The sharpie that uses the birds that come to my feeder for its winter food has the routine down pat. It actually zooms up and away just before the bird hits the window, then rolls over in a split-S, and oftentimes snatches it just as it hits the ground.
If the window strike doesn't work, and the bird dives into a bush for safety, the hawk will usually follow it - a trick most dickybirds don't know is in the accipiter's bag of tricks. The hawk merely folds those blunt wings against its body, and using its long tail to steer, goes flashing into a currant bush or rabbit brush after a junco, and it works almost 100 percent of the time. It has to if the hawk is to survive and reproduce its kind.
But, please don't hate hawks because they are getting your birds. There is no "good" or "bad" or "right" or "wrong" in nature, it just "is." The sparrow feeds insects to its babies in spring and eats seeds the rest of the year. The accipiter is on top of the food chain and keeps the flow of nature going smoothly. Without these checks and balances, the system would not operate as it should.
My favorite poet, Robert Service, put it this way in his epic poem, "The World's All Right":
The World's all right; serene I sit,
And cease to puzzle over it.
There's much that's mighty strange, no doubt;
But Nature knows what she's about;
And in a million years or so
We'll know more than to-day we know.
Old Evolution's under way -
What ho! The World's all right, I say.