animals brown caballus equus eyes ferus hair head horse nature poney pony rural saavem small fence security animal Asian Asian wild horse color coloration colored coloring coloured colouring distinctive Dzungarian horse endangered equine equus ferus przewalskii grazer grazing herd-animal mammal mane mongolian Mongolian wild horse preservation rare short-legged stocky strong sturdy takh upright-mane wild horse subspecies