Scientists struggle to preserve the wild dogs of Africa SCIENCE & TECHNOLOGY

October 21, 1990|By J. E. Ferrell | J. E. Ferrell,J. E. Ferrell is a California science writer.

In yet another sorry tale of near-extinction, scientists at th National Museums of Kenya, with the help of a group of U.S. researchers, are working frantically to save the wild dogs of Africa, so decimated that they are outnumbered even by elephants and rhinoceroses.

But saving the wild dogs -- which occupy the same ecological niche as wolves in the Northern Hemisphere -- is not just a matter of persuading ranchers to stop shooting them. Scientists have found that the wild dogs must be protected from the diseases of pet dogs. In a last-ditch effort to save the wild dogs, they are taking controversial steps to vaccinate them.

Vaccinating wildlife against disease associated with humans is not unheard of.

When a Rwanda mountain gorilla belonging to one of the four groups habituated to tourists and researchers was suspected of dying from human measles in 1988, veterinarians immunized about 60 other gorillas against the disease.

This episode and others are convincing scientists that, in modern Africa, where human populations continue to encroach upon wilderness areas and to squeeze the animals into ever-smaller habitats, wild animals susceptible to the diseases of humans or their domesticated animals may have to be immunized routinely.

The wild dogs of Africa are not really dogs, but, as their species name -- Lycaon pictus -- indicates, painted wolves. Each big-eared animal weighs between 44 and 60 pounds, is 30 inches high at the shoulder and displays a different coat pattern of yellow, black and white splotches. They hunt in packs and can maintain speeds of up to 37 mph for several miles. They are the only species left in their genus, which diverged from the domestic dogs and wolves 3 million to 4 million years ago.

The social life of wild dogs makes them endearing to humans. Members of a pack, which ranges in size from two to 30, greet each other with chirping, chattering noises and show the same excitement before a hunt, when they subdue their prey and while they eat. They do not fight, except during breeding season to establish the "alpha" female and male who are the only pair to breed. When one dog wants a piece of meat or to play, it acts humbly by crouching during its request. Weaned pups, sick and injured dogs, and dogs who guard the pups remain in the den during hunts. Afterward, food is regurgitated for all of them by the hunters. If a female that is caring for weaned pups dies, males will raise them.

The killing of food by wild dogs, however, has been described a frightful. Because they are not equipped with the huge talons, paws, shoulder and neck muscles of lions and leopards, they don't make a clean, powerful kill. Instead, they rip their prey to pieces after a hunt.

Like wolves, which were once thought to decimate game, wild dogs actually strengthen herds by culling out the weak and diseased. Scientists also suspect that by keeping herds moving, they contribute to the health of gazelles, gnus and other herbivores, which become susceptible to parasitic diseases by grazing in one area for too long.

Wild dog packs share hundreds of square miles of bushland and roam up to 30 miles a day. They settle in one place only when a litter of seven to 10 pups is born. Within each pack, all the males are related to one another, and all the females to one another, but none of the males and females are related. The females emigrate to new packs, while the males remain with the packs they're born into for their entire life span of 10 years.

At the turn of the century, wild dogs were so numerous that they were seen daily. But as more and more land was taken for agricultural use, ranchers began shooting them, and they began a gradual decline that has taken them to the edge of extinction. In all of Africa, estimates are that only 3,000 to 4,000 dogs remain. In Kenya, no more than 300 wild dogs, in 16 packs, have been counted.

"It's a terribly important problem," said Pat Conrad of the efforts to save the wild dogs. Dr. Conrad, an assistant professor of parasitology at the University of California-Davis School of Veterinary Medicine, worked at the International Laboratory for Research on Animal Diseases in Nairobi, Kenya, for four years. Dr. Conrad is also a member of the U.S. group of researchers who have organized the Kenyan Wild Dog Project to raise funds and who are donating their time to help the Kenyans.

"Rhinoceroses outnumber them 2-to-1, and elephants outnumber them 16-to-1," said Robert Wayne, a population geneticist at the University of California-Los Angeles and another member of the group. "Like wolves in the United States, which used to be in every state, they're viewed as vermin. That's part of the reason for their low numbers. And since they weren't one of the 'disco' animals like elephants, rhinoceroses, lions or cheetahs, not much attention has been paid to them."

Baltimore Sun Articles
Please note the green-lined linked article text has been applied commercially without any involvement from our newsroom editors, reporters or any other editorial staff.