Hybrid deer

A number of deer hybrids are bred to improve animal protein yield in farmed deer. American elk and Red Deer from the Old World can produce fertile offspring in captivity, and were once measured one species. Hybrid offspring, however, must be able to escape and defend themselves against predators, and these hybrid offspring are not capable to do so in the wild state. Recent DNA, animal actions studies, and morphology and antler characteristics have shown there are not one but three varieties of Red Deer. The hybrids are about 30% more efficient in producing antler by compare velvet to body weight. Wapiti have been introduced into some European Red Deer herds to improve the Red Deer type, but not always with the proposed improvement.

Both male Mule Deer/female White-tailed Deer and male White-tailed Deer/female Mule Deer matting have formed hybrids. Hybrids have been reported in the wild but are disadvantaged because they don't correctly inherit survival strategies. Mule Deer move with bounding leap to escape predators. Slotting is so specialized that only 100% heritably pure Mule Deer seem able to do it. In captive hybrids, even a one-eighth White-tail/seven-eighths Mule Deer hybrid has erratic escape performance and would be unlikely to survive to breeding age. Hybrids do survive on game ranches where both species are kept and where predators are prohibited by man.