Can you tell the difference between a wolf and a coyote? Can wolves and coyotes? A new whole-genome sequence analysis of different species of wolves, coyotes and dogs shows the line between the species is getting blurry and that will have an effect on conservation efforts and the future of both animals.
These animals don’t walk around with little name tags on them in the field. So hybrids or admixed animals don’t always look very different from a pure coyote or pure wolf.
Princeton University biologist Bridgett vonHoldt describes what she and her colleagues dealt with when researching 23 wolves for a new study published in Science Advances. The U.S. wolf population – which has been defined as distinct species of gray wolves, red wolves, eastern wolves and Mexican wolves – doesn’t maintain those distinctions under genetic scrutiny. What they found was that the red wolf (Canis rufus) genome actually contains only 25 percent wolf genes and 75 percent coyote genes. The genome of the eastern wolf (Canis lycaon) can contain up to 50 percent coyote genes.
Then there’s the gray wolf (Canis lupus) and its subspecies, the Mexican wolf (Canis baileyi),. Once the most common wolf in North America, it was hunted to near-extinction. The specimens saved by the Endangered Species Act and reintroduced into the wild were thought to be pure gray wolves, but this genetic study found that gray wolves are also showing some recent additions of coyote genes. What’s more, the genes of the gray, red and eastern wolves are much closer than once believed.
How did this happen? Doug Smith, a biologist who leads the Wolf Restoration Program in Yellowstone National Park, says the near extinction of the gray wolves gave the red and eastern wolves a chance to spread, but territory alone was not enough for their survival and they were forced to mate with the coyotes who were already established in the eastern United States.
This blurring of the lines between wolves and coyotes is bad for wolves. While individual species like the gray are protected, hybrids are not and the hybridization shows signs of increasing. Climate change, habitat loss and the undeserved hatred of wolves are on the rise. Can even the genes of wolves be saved? The researchers have one final thought.
Species and taxonomic concepts are varied, complex, and difficult to apply in practice. Of greater importance are the preservation of evolutionary and ecological processes and the role of an endangered taxon in this dynamic. Admixture is one critical example of a process that may enhance adaptation and evolution in the rapidly changing environment of the modern world.
Save the hybrids!