Monday, January 19, 2009

The Kestrel and the Vole

Today was a holiday and a rare sunny, almost warm day in January, so Glen and I decided to get outside and look for salamanders at McClane Creek. But in the way of nature watching, our best plans went awry: the pond was still half frozen and the ground frosty - not good salamander weather. So we left, a little disappointed and were driving home along Delphi road, enjoying the sun as it painted the late afternoon fields a golden hue. Suddenly we spotted the distinct silhouette of a hawk on a telephone wire; as we passed under it we identified a male American Kestrel. Glen grabbed the camera, while I stopped the car and watched for traffic. He managed to get some great silhouette shots of this bird, and also the dead vole this falcon was clutching in his talons.

This is a real treat. These birds are uncommon residents in Thurston County; in my experience I only see them in pasture habitat, which is increasingly rare. This particular field had telephone wires strung along the length of it, which makes it especially attractive to kestrels: They hunt from their wire perches, keeping those hawk eyes trained on the grass for the slightest twitch of a vole.

Clearly, this kestrel had just succeeded in catching a sizable meal for himself. We had missed the actual hunt, but it is likely he hovered over the grassy field, keeping an eye out for an unwary vole, then dropped down at speeds of up to 60 mph and pounced on it. Kestrels like all falcons have a special notch on their upper beak, called the killing tooth. The special tooth is designed to slip down into the prey’s cervical vertebrae, snapping it, breaking the neck and causing instant death. From the limp hanging quality of this vole, we speculated that the killing tooth had been applied to great effect.

From long years of experience watching kestrels, I knew he would then fly off to a favored “plucking post”. These are usually flat tops of fences or telephone poles, where the kestrel can prepare its dinner, and also keep a wary eye out for predators or food thieves. At the post, the fur will fly as the kestrel plucks its vole, taking special care to clear the abdomen area. Then the kestrel will dive in, feasting on choice blood-dense organ meats.

Since it was late in the day, we speculated that this kestrel would quickly eat the best bits, then cache the rest of the vole away in a hollow tree: someplace where it could be easily retrieved in a few hours or days. If our recent cold foggy weather pattern continues, this kestrel may well ensure its continued survival with this cache.

After feeding, this kestrel will most likely find a hidden place for a night roost, perhaps deep in an evergreen tree near the trunk: a place safe from owl eyes.

We know this is a male: male kestrels have a distinct blue back. He probably is holding these fields as a winter territory. He will continue to hunt & feed, keeping himself going until warmer days bring on migration and seasonal shifts of territories. With these shifts, other kestrels, perhaps a female, may venture into these fields and a new season of life for all.


"A Field Guide to Hawks of North America" by William S. Clark
Kestrel on wire photo by Glen
Hovering kestrel by Kevin Cole at flickr. creativecommons
Kestrel on fence post by Lip Kee at flickr.creativecommons0

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