This video was posted on an outdoor channel in Eastern Washington:
This guy is a good naturalist, and he has excellent trail camera placement.
But what he’s actually seeing are not hybrids. What he is seeing is the wonderful transition from the mule deer type that is common in the interior West to the black-tailed deer type, which is common more toward the Pacific Coast.
Those two deer are now recognized as a single species (Odocoileus hemionus), though the mule deer type is recognized to have some hybridization from the white-tailed because it possesses white-tail-like mitochondrial DNA.
Hybridization does occur between white-tails and mule deer, but the survival rate is quite low among the F1s. Mule deer have a stotting evasion behavior, which is incompatible with the white-tail’s bounding pattern. The offspring inherit both behaviors, and they cannot effectively evade predators. The stotting behavior is used to communicate to a predator that might be hunting the mule deer on the open range that this deer awfully healthy and that it should try a different target. White-tailed deer are forest deer, and they just bound away from predators.
But apparently, there was an introgression of a white-tailed deer matriline into what became mule deer at the Pleistocene/Holocene boundary.
So this transition from true interior West mule deer to the Pacific blacktails apparently starts in Eastern Washington, and of course, you’re going to see the transition somewhere. These two forms interbreed because they are subspecies, and at some point, you’re going to hit the transtional zone between the two, where it gets hard to tell which is which.
