An article in The New York Times on March 21 has pointed out a significant problem in keeping the health of many wildlife animals in national parks. In order to supply foods for all animals, wildlife preservationists feed the multiple species using tractors; however, this may pose a disease problem.

Brucellosis is one of several diseases that affect wildlife and domestic animals and that have appeared in the national parks. Controlling them poses a challenge to the National Park Service, which has to decide on strategies and try to meet a number of competing needs of hunters, tourists, ranchers and the animals.
In 2003, brucellosis spread from elk into cattle and forced the destruction of hundreds of head of infected cows. Wyoming lost its disease-free status, as did Idaho when the disease was recently found there. Now every cow leaving those states has to be tested.
Chronic wasting disease looms as a potentially bigger danger. It has been found in deer 65 miles from here.

As a result of brucellosis, many animals are dying, creating less of a tourist attraction and even less of a reason to withhold the land from "captains of industry".
This is not the only problem that wildlife in national parks have had; in 1908 at Jackson Hole, elk began to die of starvation, creating the tractor's role in feeding the varying animals hay and other grasses.