For the Birds Radio Program: Scavenging
The life of a scavenger has a lot to recommend it. (3:59) Date confirmed.
(Recording of a vulture)
I have many friends who are vegetarians, and every time I drive behind a cattle truck I’m tempted to join them—especially now that I’m done nursing babies and don’t need all that much protein anymore. But I’m afraid I’m just not a natural-born vegetarian. Of course, I’m not a natural hunter, either—I seem to be most closely related to Turkey Vultures. Like these scavengers, I don’t have the heart to kill my own meat, but I do take advantage of already-killed carcasses that I find in the refrigerator. Actually lots of people are like vultures, lacking a killer instinct but somehow craving meat all the same. The only difference between us and buzzards is that we don’t sit on a roadside waiting for cars to dispatch our meals—instead we hire farmers and butchers and retailers or raise our own animals to ensure that there will be a steady supply for everyone.
Like people, very few birds are true vegetarians. Most species eat insects, fish, mammals, or other birds for protein. Even seed-eating finches and fruit-eating waxwings spend part of their life cycle hunting and killing insects–only a few cardueline finches live out an entire life eating seeds alone.
There are definite advantages to scavenging over hunting. As any deer hunter knows, it’s not all that easy to actually bag your prey. I’ve watched owls, hawks, and shrikes close in for the kill dozens of times, but have only seen them succeed a handful of times in all my years of birding. And the hungrier and more desperate a predator is, the weaker it becomes. Then too, live prey can fight back. There are many cases of birds being killed by their prey–bitten by rattlesnakes, stabbed by porcupine quills, infected by squirrel bites, eyes scratched out. It’s a jungle out there.
That’s why many birds that are normally hunters take advantage of pre-killed meat whenever they can find it. Bald Eagles, which are perfectly capable fishermen, seem to prefer picking up dead or stunned fish at dams or stealing the catch from Ospreys—I’m sure if grocery stores were just a little more user-friendly eagles would be happy to buy their fish at the nearest Red Owl. Many hawks and owls eat roadkills and other dead animals they find. Sandpipers and plovers clean up dead invertebrates washed ashore on beaches. Even Black-capped Chickadees, woodpeckers, and nuthatches often pick at carcasses for extra protein, especially in winter.
Obviously there are certain risks that come with the scavenging lifestyle. The possibility of bacterial-borne disease exists whenever a dead animal of uncertain freshness is involved—vultures have special adaptations in their digestive tracts to destroy most bacteria, but other birds will generally only scavenge on very fresh meat. Even then there is a definite risk of catching diseases, or of picking up a lethal dose of lead shot. If they aren’t extremely wary, scavengers of roadkills often end up joining their meal on the pavement. And then there is the real problem of food availability—there aren’t always enough previously-killed animals to go around.
I find it ironic when people disparage vultures—not only do they provide a valuable service in warm areas where decaying animals constitute a real human health hazard, but also these noble birds have found the perfect way to eat meat without being responsible for the suffering or death of any creature. Scavenging—it’s not such a disgusting thing after all.
(Recording of a Herring Gull)
This is Laura Erickson, and this program has been “For the Birds.”