Refer to his blog post dated 12/26/18 about the wild horse ‘problem’ on western rangelands. Opposing comments are not allowed so they are presented here:
Sir, the symptoms you describe are the result of a strong connection to agriculture and the rural lifestyle.
Many of the wild horses and burros now wasting away in long-term holding got there because of livestock and public-lands ranching.
The agency charged with the care of those animals has steadily given more and more of their land (set aside for them by the WHB Act of 1971) to the ranchers and other commercial interests, while gradually reducing the number of horses and burros allowed to live in the remaining areas.
The figures you cited are correct. BLM says the land, 27 million acres in ten western states, can only support 27,000 wild horses and burros. That works out to one animal per thousand acres, almost nothing.
The same agency allows ten to twenty times as many cow/calf pairs on western rangelands, depending on the area. In some cases it’s the same territory set aside for the horses!
You may wish to view this aerial footage from SE Oregon: https://youtu.be/zFofShEuZJk. What do you see at 3:06? At 3:36? Which species is in the majority?
Twenty seven thousand has nothing to do with the carrying capacity of the land. It only represents the forage loss the ranchers, and their allies at the BLM, are willing to tolerate.
By the way, the fossil record shows that horses are a native species in North America. They died off around 12,000 years ago and were reintroduced by Spanish explorers, as you noted.
Keep in mind that many of the horses and burros roam on the harsh landscape of the Great Basin. They have not destroyed their habitat, that’s what the high desert looks like. Here’s an example: https://www.youtube.com/watch?v=HOzB6ltmZ20.