Free lunch

My Los Angeles neighborhood teems with scavengers: coyotes, crows, raccoons, and rodents. Recently I watched as several dozen vultures, those icons of the ilk, circled lazily overhead. Eyeing them suspiciously, I wondered if their Hollywood image was true--had something large died nearby? Later, an ornithologist friend reassured me that the birds were not hovering over a carcass. The "Questions and Answers" section of the Turkey Vulture Society's Web site (vulturesociety.homestead.com/Attract. html) confirmed my friend's assertion: the flock of vultures, known as a "venue," had no immediate plans to dine. Instead it had formed a "kettle," so named for the birds circling upward on a thermal of rising hot air, reminiscent of bubbles that rise in a kettle of boiling water.

Inspired to delve more deeply into the lives of scavengers, I learned that among the vertebrates there are few true scavengers--animals that feed solely on carrion. But other animals populate a vast gray area. Predators such as lions readily chew on someone else's abandoned kill; animals such as raccoons, regarded mainly as scavengers, also hunt prey. True scavengers are common, however, in the invertebrate world, particularly on the deep ocean floor.

All diners on the dead perform a valuable service by cleaning the planet of rotting and often diseased flesh, thereby recycling nutrients into the food web. The adaptations that enable them to fill their niche are as remarkable as anything in nature.

Please go to our Natural History Web site (www.naturalhistorymag.com), where I report on more tidbits, scavenged from various sites on the Internet, about these remarkable animals.

Robert Anderson is a freelance science writer living in Los Angeles.

COPYRIGHT 2007 Natural History Magazine, Inc.
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