November 8, 2012 | 1
The last wolves in Africa face a difficult road if they are going to survive. Just 500 Ethiopian wolves (Canis simensis) remain in the mountains of the country for which they are named. The animals now live in six fragmented populations located hundreds of kilometers apart from one another; three of these populations have fewer than 25 wolves each. According to a study published last month in Animal Conservation, the Ethiopian wolf now suffers from low genetic diversity and a weak flow of genes between packs. As we have seen with other rare species such as Florida panthers, Tasmanian devils and great Indian bustards, low genetic diversity can result in inbreeding, impaired birth rates and the inability to adapt to diseases or other ecological threats. The danger for Ethiopian wolves is not theoretical—rabies outbreaks in 1991–92 and 2003 each killed several hundred wolves.
The 12-year study, conducted by researchers from the Zoological Society of London and other organizations, examined the genetics of 72 wild Ethiopian wolves from seven different populations. One of those populations, at Mount Choke, died out over the course of the study. The researchers found very little gene flow between the populations and conclude that restoring this flow—possibly by relocating some males or restoring migration corridors—could help increase the number of wolves while reducing the likelihood of inbreeding.
The animals aren’t likely to travel between populations on their own. Ethiopian wolves, which arrived in the region 100,000 years ago during glacial times, have adapted to grassy, mountainous ecosystems 3,000 meters above sea level, where they prey almost exclusively on high-altitude rodents such as the big-headed mole rat (Tachyoryctes macrocephalus). Meanwhile, Ethiopia’s human population continues to expand, from 48 million in 1990 to 84.7 million in 2011, making travel between wolf packs even more dangerous and unlikely.
Travel barriers and fragmentation aren’t the only threats the wolves face. The animals are legally protected in Ethiopia but according to the Ethiopian Wolf Conservation Programme they still face persecution by farmers afraid of potential livestock predation. Overgrazing by cattle has also damaged existing habitats and reduced the rodent populations that the wolves depend on for food. Even domestic dogs pose a danger—they have been blamed for the rabies outbreaks and have even, on occasion, bred with the wolves. Although widespread hybridization has not yet been observed, this poses yet another threat to the gene pool for the already endangered animals.
Photo: James Hopkirk via Flickr. Used under Creative Commons license