A study of the rarest canine in the world, the Ethiopian wolf, leads the authors to emphasize the urgent need for a captive-breeding program, as the wolves are most threatened by disease and hybridization with domestic dogs. Also, looks at the reasons why the social organization of the Ethiopian wolf defies common explanations for why wild canids live in packs.
Everything is ready: binoculars, camera, radiotelemetry gear, and data sheets. Only one thing remains: patience. One hour, two hours...and Juno appears. She trots straight to the den, where her six hungry puppies are waiting for her. During the breeding months our lives become closely tied to the growth of the pups. The birth of a new generation means new hope for the survival of any species. And when the species is the endangered Ethiopian wolf, the rarest canid in the world, each pup that reaches maturity and reproduces successfully takes the species one step away from extinction....
The Ethiopian wolf lives only in a few mountain pockets of the Ethiopian Highlands. Its largest population, and probably the only genetically viable one, is found in the adjacent glacial valleys. Known as the roof of Africa, this volcanic tableland is the largest stretch of Afro-alpine habitat on the continent and is protected within the Bale Mountains National Park. We came to the Bale Mountains to work at the urging of Wildlife Conservation Society (WCS) research ecologist Chris Hillman, whose wildlife management plan for the park identified the graceful and long-legged Ethiopian wolf as a priority for study....
Each of the nine packs we've been keeping tabs on holds an exclusive territory, ranging in size from two and a half to four square miles. Pack size varies from three to 13 adults and territories are jealously defended by all pack members. Every morning pack members patrol their territories, trotting the borders in a beeline, sniffing and urine-marking key spots along the invisible line between their territory and that of their neighbors, sending the signal, "Trespassers will be prosecuted."...
The younger pack members usually desert the patrol first to concentrate on something more nutritious: rodents. Eventually, all the animals turn into solitary rodent hunters, criscrossing the grasslands of their common territory in search of mole rats and grass rats. Solitary foraging is a prerequisite for successful rat hunting. Furthermore, there is little to share when the prey can be swallowed almost whole.
A typical Ethiopian wolf pack is an extended family group formed by all males born into the pack during consecutive years and one or two females....
Unfortunately for Juno there are no other adult females to help suckle her pups; Vesta and Minerva will provide most of the solid food but they are not yet able to produce milk. Last year Juno had the help of Flora, a two-year-old wet-nurse that immigrated into the pack from a neighboring family. Taking advantage of the absence of other subordinate females, Flora earned a place helping Juno nurse the litter and patrolling the territory. But with the arrival of a new mating season Juno became extremely aggressive toward her, and Flora eventually left the pack and tried unsuccessfully to produce her own offspring on the edge of Juno's territory....
During our study we have never recorded any instance of a male leaving his natal pack to join a different one. The female strategy is not so clear-cut. All females stay in their natal territory at least until they become sexually mature at two years of age. Sexually active females, however, pose a threat to the alpha female. As Wildlife Conservation Society research zoologist Patty Moehlman concluded after more than 15 years studying golden and silver-backed jackals in Tanzania, the parental care required to rear a litter successfully is such that an alpha female cannot afford to share the males' valuable contributions in the rearing of another female's pups. Usually subordinate females will be forced to emigrate and settle elsewhere as breeders. In the Bale Mountains, however, there are no vacant territories with enough prey to support dispersing animals. Consequently, young adults often delay leaving the family pack, or never strike out on their own. The breeders benefit in two ways: There's extra help to nourish and guard the young, and extra bodies to defend the family turf. By remaining in a known territory with access to high-quality food resources, the subordinate helpers increase the likelihood of their survival. Plus there is always the possibility of inheriting the territory and becoming a breeder.
At midday, the sun roasts the Sanetti Plain. Most rodents hole up and the wolves stop hunting to take a little siesta....Suddenly, Vulcano lifts his head and draws air into his nostrils, detecting danger with every breath. Jupiter also sniffs deeply, and both males stare in the same direction. Two hundred yards away two armed horsemen are herding their cattle to a nearby spring. The men have not seen the wolves, but Vulcano and Jupiter rise to their feet and move off, making certain high-pitched alarm calls, probably to divert attention from the den. The Bale Mountains are inhabited by the Oromo highlanders, pastoralists who live in round huts with mud walls and thatched roofs. They keep their cattle and sheep in nearby enclosures at night....
Until very recently, Ethiopian wolves were not directly affected by the presence of humans. The Oromos were indifferent to them because, although the wolves may kill a lamb if given the opportunity, spotted hyenas are responsible for most livestock losses. Following the overthrow of the Mengistu government in May 1991, however, unrest mounted in the countryside. Many locals in Bale took advantage of the subsequent lack of law enforcement and moved into the park, cutting trees, burning and clearing heather, and killing wildlife with automatic weapons sold by former soldiers....Oromo presence also means overgrazing by cattle, which causes the erosion of the fragile Afro-alpine habitat and leaves little forage to support a healthy rodent population.
But the biggest threat to the wolves is the domestic dogs that the Oromos keep to protect their herds from hyenas. The dogs are irregularly fed and roam the highlands freely, posing a three-pronged threat to the wolves: They compete with them for food; transmit diseases, such as rabies; and mate with their wild relatives, hybridizing the species. If this crossbreeding continues, more and more of the dogs' genetic coding will be transmitted into the wild population, eventually overwhelming the genes that make the Ethiopian wolf uniquely itself. The result will be genetic extinction. To avoid this, it is essential that captive-breeding program with purebred founders is initiated without delay....
What we have learned about Ethiopian wolf social organization defies common explanations for why canid species live in groups. Most past studies of social canids have linked pack formation with cooperative hunting: Large canids, such as the gray wolf, African wild dog, and Asian dhole, live in groups to aid in bringing down large prey; whereas smaller carnivores, such as meerkats and mongooses, do so to ward off predators. Neither of these factors fully explains group-living in the case of Ethiopian wolves: Their rodent prey does not lend itself to pack hunting, and they are not under predator pressure. In this instance, environmental pressure is the key to the evolution of their social system. The fact that there is no high-quality (rodent-rich), wolf-free habitat left to take over seems to be the incentive for forming family packs, even though animals never hunt together.
In 1990 we submitted a report to the Ethiopian government with recommendations for conserving and managing the Ethiopian wolf and its habitat. We made clear the urgent need for controlling the number and activities of people living inside the park, and for removing the population of domestic dogs. Given the current rates of habitat destruction, persecution, disease, and hybridization, captive breeding has become a critical priority.
Relatively few people inhabit the Bale Mountains, owing to the extreme high-altitude conditions and low productivity of the soil, which yields little vegetation for livestock. But as the human population in the surrounding lowlands increases, there will be more need for grazing pasture farther up the mountains. Regulation, not exclusion, of human activities may be the key. Any attempt to totally exclude humans would only alienate the park from the local people and political administration.
Education is the most important component of any conservation project. Unfortunately, socio-political issues of greater short-term importance in Ethiopia have prevented the conservation of wildlife from making steady progress....
(Dada Gottelli and Claudio Sillero-Zubiri graduated as zoologists from Universidad Nacional de la Plata in their native Argentina.)
Ethiopian Wolf Survival Status
Scientific name: Canis simensis
Common names: Simien jackal or Simien fox (named for the Simien Mountains where it was first observed); Abyssinian wolf
Estimated population: 500 adults
Range: Half a dozen locations on the Ethiopian Highlands, all above 10,000 feet
Survival problems: Habitat destruction caused by cattle and sheep herding; persecution by pastoralists; disease and hybridization with domestic dogs
Official conservation status: IUCN Red List of Threatened Species -- Endangered; in danger of extinction everywhere, with the possible exception of the Bale Mountains; protected by Ethiopian law