Federal wildlife managers have been working to return the endangered Mexican gray wolf to the American Southwest for the past 15 years. Every now and then, there's a genetic hiccup.
It happens when a wolf breeds with a domestic dog, producing a litter of hybridized pups.
Just last month, an animal that looked like a wolf was spotted in the mountain community of Reserve near the Arizona-New Mexico border. Experts with the wolf management team say the uncollared animal was most likely a wolf-dog hybrid.
While it doesn't happen often, a spokesman for the U.S. Fish and Wildlife Service says hybridization is a concern. Having a genetically diverse — yet pure — population has been identified by biologists as one of the keys to successfully reintroducing Mexican gray wolves in Arizona and New Mexico.