A guide in Yellowstone National Park on Monday shared stunning footage showing a black wolf partially obscured by mist as other wolves remained mostly hidden in the background. “This was the ...

The first shows a black wolf slowly padding through the stream before jumping onto the bank, followed by a gray-colored wolf. The second clip shows two black wolves crossing the stream.

For most animal biologists, seeing an all-black variant of their studied species would be a once-in-a-lifetime experience. But in North America, especially in Yellowstone National Park where a large ...