Having lived on The North Slope I will tell you this about Caribou: If there is a nuclear holocaust, the 3 surviving species will be rats, cockroaches, and caribou. Some of the migrating birds are another story, they truly are hyper-sensitive to habitat alteration. But anybody who brings up "save the caribou" as a cause has never had one eat the railing off of their porch, or strut past their barking dog, or had a herd envelope their convoy of trucks.