Wild horses’ fate in question

Supporters, conservationists disagree over N.C. herd

COROLLA, N.C. — Come summer, the beaches of this barrier island will be choked with cars and sunbathers, but in the offseason the land is left to wild horses. Smallish, tending toward chestnut and black, they wander past deserted vacation rentals in harems of five or six.

Thousands of them once roamed the length of the Outer Banks of North Carolina, the likely descendants from mounts that belonged to Spanish explorers five centuries ago. Now their numbers have dwindled to a few hundred, the best-known living on federal parkland at Shackleford Banks.

But the largest herd, which has recently grown to almost 140 strong, occupies more than 7,500 acres of narrow land that stretches from the end of Highway 12 in Corolla to the Virginia border, 11 miles north. Lacking natural predators, and trapped by fences that jut into the choppy Atlantic, the herd is becoming so inbred that its advocates fear a genetic collapse in mere generations.

These supporters are leading a campaign to save the Corolla herd, and they have powerful allies in Congress. In February, the House passed a bill that would sustain the herd at about 120 and allow the importing of new mares from Shackleford for an introduction of fresh genes.

Wildlife conservationists say the issue is not so simple. The beaches, marshes, grasslands and forests near Corolla are a stopover for flocks of endangered migratory birds, and nesting ground for sea turtles. Much of the horses’ range belongs to the Currituck National Wildlife Refuge, and defenders of the native habitat fear the herd’s current size strains the ecosystem.

The future of the horses raises larger questions about whether one animal should be preserved at the expense of others — and who gets to decide.

“This is about values,” said Michael Hutchins, executive director of the Wildlife Society, representing wildlife biologists and managers, which opposes the House measure. “I like horses; I think they are fascinating animals. I also deeply value what little we have left of our native species and their habitats.”

Both sides invoke science to their cause. But data are sparse and a comprehensive study of the horses’ impact is not expected before next year.

The wild horses of Corolla did not arise there; they are domestic animals that have lost their domesticity. Though skeptics question whether the horses are indeed Spanish, an inspection from the American Livestock Breeds Conservancy and other groups has noted the horses’ short backs, low-set tails and other traits that make them distinct from other North American stock. A DNA analysis published in February in Animal Genetics also points to a common origin for the horses, suggesting they may be a living relic of an Iberian breed that exists nowhere else.

The study also confirms fears that the horses are growing perilously inbred. “There are wild herds with lower diversity, but not many,” said Gus Cothran, an expert in equine genetics at Texas A&M University who is lead author of the report. He says a herd of 60 could survive, provided a new mare entered the group every generation (about eight years). The federal bill sets a herd size at 110 to 130, the minimum number Cothran says could slow genetic erosion if the horses remain isolated.

“We are not asking for hundreds of horses,” said Karen Mccalpin, director of the Corolla Wild Horse Fund, which protects and cares for the horses and leads public education about them. The heart of the disagreement with wildlife conservationists is over how many horses the habitat can bear. “If they were that detrimental for the environment,” she asked, “wouldn’t that be evident by now?”

This question would be easier to answer if not for the matter of people. Other herds of Outer Banks horses live in expanses largely free of human intrusion. But the Corolla horses mostly live off people’s land and landscaping. Tourism promoters like to show horses frolicking in sand and surf, their manes blowing majestically, but these animals are just as likely to be spotted grazing alongside driveways.

Genetics aside, tourists pose the biggest threat to the herd, whether from collisions with distracted drivers or from photo-seeking vacationers who flout local code that makes it a crime to feed or get within 50 feet of a horse. Last summer a 2-week-old colt died of an intestinal blockage after eating watermelon rinds fed to it by visitors.

As Corolla becomes more densely developed, the horses could be pushed more and more onto land set aside for wildlife sanctuaries. Last summer, out of concern for a species of bird, the black rail, refuge manager Mike Hoff fenced off a 135-acre swath of marshland after noting too many seasons of depleted grass. “It wasn’t that we wanted to exclude the horses because we don’t like them,” he said.

One of the few studies to examine the horses’ direct impact was published in 2004 in The Journal of Range Management. Researchers from East Carolina University reported that in general, plants on Corolla recovered from one season of grazing by early the next summer. But the data were gathered in 1997, when the horse population was estimated at 43, spread across 11,400 acres. Today, the range is almost 4,000 acres smaller and the herd size has more than tripled.

The continuing study of feral animals, financed jointly by the federal Fish and Wildlife Service and North Carolina State University, is intended to measure the effect of hogs and deer in addition to horses. Teasing out the horses’ impact “is a difficult question,” said Chris Deperno, who is leading the research, but he added, “We think we’ve designed a very, very good study.”

In this case, politics and science may be operating on separate timetables. The Senate could take up the bill before Deperno’s study is complete. Mccalpin lamented that the horses were already bearing hallmarks of genetic failure, with an occasional foal born astoundingly small, or with back knees that lock instead of hinge.

“Time is running out,” she said, adding: “They’ve been here for five centuries. It makes me sad to think they might not be here for more.”