Thursday, July 10, 2014

Appreciating turkey vultures (from the archive)

Appreciating turkey vultures

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If you watch the sky as you travel by car in warm weather, you’re likely to see soaring birds from time to time, even if you don’t count yourself a birder.In our part of the country, most of the large soaring birds you’ll see are turkey vultures, which you can recognize from a long way off without binoculars or a field guide.

Turkey vultures in flight are identified by their large size—they have a six-foot wingspan—their blackish color above and below, and their manner of flight. Turkey vultures hold their wings in a shallow dihedral, or “v” shape, and constantly tilt back and forth. They are so skilled at using rising currents of warm air for lift that you’ll rarely see a turkey vulture flap its wings, even if you watch and wait for it to do so.

A group of turkey vultures circling together is called a kettle. A kettle may form as vultures come together to take advantage of an updraft for gaining altitude, or as they scan the countryside looking for food. It is not, by any means, a sure sign that something below has died.

Turkey vultures are very well equipped to search for food on the wing. They have excellent vision, which is not uncommon in birds, as well as an extraordinary sense of smell, which is. A turkey vulture’s sense of smell allows it to locate carrion even when it is concealed from above by a forest canopy.

Turkey vultures are not at all picky about which animals they eat, as long as they are dead. A turkey vulture’s diet may include anything from dead domestic livestock to roadkilled animals like skunks, raccoons and deer, or even turtles and snakes. This is not to say that turkey vultures have no preferences, as they have been shown to select recently dead animals over more decayed food when given a choice. Turkey vultures also eat varying amounts plant material, presumably more when carrion is scarce.

If you happen to see a turkey vulture close up, you’re likely to notice its red, featherless head. In this feature, as well as its bulky, brownish-black profile, the turkey vulture resembles the wild turkey, which is where it gets its name. Being bald allows the turkey vulture to poke its head right into a carcass and not wind up capturing little bits of its meal in hard-to-clean feathers.

Couple the turkey vulture’s bald head with its cast-iron digestive system, and you’ve got a very effective processor of carrion.

Now, I realize that you might be inclined to leave off contemplating turkey vultures as they soar in the sky, half a mile away. But I think looking at them more closely really can foster a deeper appreciation for the diversity and complexity of life. After all, without turkey vultures and other decomposers, life as we know it simply wouldn’t be possible.