To complicate matters, hybrids inherit predator avoidance strategies from both types of parents; the problem is, whitetail and mule deer have drastically different techniques for escaping predators.
The whitetail’s key to escaping is speed. They put their head down, follow established trails, and try to put as much distance between themselves and the predator as possible, as fast as possible. Mule deer, on the other hand, have developed a pogostick-like bounding called "stotting", where all four hooves hit the ground at the same time. This strategy developed in mule deer because they evolved in wide open and rugged country throughout the West. Their escape by stotting is not as fast as the whitetail's, but in rugged terrain it is effective for putting obstacles between the predator and the deer. Mule deer can bound over boulders and stumps that the predator must run around.
Research by Susan Lingle using captive animals in Alberta, has shown that stotting is so specialized that only deer that are 100% mule deer can do it. Even a 1/8 whitetail X 7/8 mule deer fails miserably. The hybrid's escape behavior is chaotic; the deer will typically approach the threat and jump around in confusion. Such behavior is not conducive to passing their genes on to another generation.
