Last month, the Montana-based nonprofit organization Yellowstone Voices released a video documenting the slaughter of bison that migrate out of Yellowstone National Park each winter to find forage. As a wildlife advocate, I’ve seen my share of disgusting and unethical treatment of animals (especially predators). But the massacre of Yellowstone bison, which this year claimed more than 1,100 animals from an already endangered herd, represents a new low — and not just because of the unethical and abhorrent nature of the killing and its impact on the bison, but because of the conservation community’s unwillingness to denounce it as well as its equally troubling ostracization of anyone who does.