Conserving a coyote in wolf's clothing?

Conservationists who seek to preserve the North American red wolf as a unique species may be barking up the wrong tree. For decades, the red wolf has been nearly indistinguishable genetically from either the gray wolf or the coyote, report two population geneticists who have compared DNA "fingerprints" from captive red wolves with those from frozen blood samples and museum skins.

The finding is expected to fuel the debate over whether the red wolf is a separate species -- eligible for conservation under the Endangered Species Actor a hybrid resulting from years of cross-breeding between overlapping populations of gray wolves and coyotes. In general, such hybrids are excluded from protection under the conservation law.

The red wolf became extinct in the wild in 1975, falling prey to systematic hunting and human encroachment into its habitat in the southeastern United States. But just before the last of the red wolves died off, ecologists rounded up several mating pairs and used them to found a captive breeding colony sponsored under the Endangered Species Act. The breeding program has released 25 of its 170 live red wolves into protected areas in North Carolina and on several southeastern coastal islands.

To probe the red wolf's ancestry, Robert K. Wayne of the University of California, Los Angeles, and Susan M. Jenks of the University of California, San Francisco, analyzed mitochondrial DNA samples from the captive colony. Because DNA in the mitochondria -- the cell's energy-producing organelles -- mutates more rapidly than DNA in the nucleus, Wayne and Jenks hoped it would provide a clearer picture of the animal's heritage.

The researchers chopped up mitochondrial DNA taken from the captive red wolves and sorted the pieces on a gel slab according to their size. The fragments formed a characteristic pattern, or DNA fingerprint, identical to that of coyote mitochondrial DNA.

"We were somewhat disappointed," says Wayne, now head of conservation biology for the Zoological Society of London. "We were hoping to find a unique red wolf [gene pattern]."

He and Jenks then turned to frozen samples of blood drawn from 32 wild red wolves before the extinction. More than 80 percent of the samples yielded mitochondrial DNA identical to that of coyotes, and the rest proved identical to gray wolves.

Finally, the researchers examined mitochondrial DNA extracted from six pelts collected from red wolves between 1905 and 1930. All the pelts' DNA fingerprints matched those of either gray wolves or coyotes.

Jenks (now at the University of California, Berkeley) and Wayne report in the June 13 NATURE that their results could support either of two conclusions: that the red wolf is a true hybrid, or that it picked up the genetic similarities sometime in the distant past when its diminishing numbers caused it to mate with gray wolves or coyotes out of desperation.

Either way, Wayne contends that the red wolf should continue to be conserved. "No matter what it was -- hybrid or separate species -- what is being bred today in the captive colony is representative of what was in the wild," he argues. "In that sense, we ought to preserve it."

Doug Inkley, an ecologist with the National Wildlife Federation in Washington, D.C., points out that the red wolf, as a top predator, was important in maintaining the balance of species in the ecosystems in which it lived. The Endangered Species Act specifically provides protection for such key predators, he told SCIENCE NEWS, whether or not they are genetically distinct.

But in an editorial accompanying Wayne and Jenks' paper, zoologists John L. Gittleman and Stuart L. Pimm of the University of Tennessee in Knoxville suggest the red wolf may be getting more protection than it deserves. The reintroduction program, they contend, is not likely to benefit the red wolf because the animal's genetic identity will only be obscured once again by mating with coyotes. In addition, they argue that the important ecological role once performed by red wolves is now being filled by other predators. Gittleman and Pimm question whether "the red wolf's undeniable cuddliness is enough to warrant according it special attention."

The U.S. Fish and Wildlife Service is taking a wait-and-see attitude. "We're just getting a few bits and pieces of the puzzle," says Gary Henry, coordinator of the agency's red wolf conservation program in Asheville N.C. "There needs to be a lot more work done before we'll ever finally sort this out."