The National Park Service does not wish to start using air guns to vaccinate Yellowstone bison for Brucellosis.
Brucellosis is a disease that can cause bison and other large animals to abort their calves. Currently, the park only vaccinates bison when they leave the park, and even then, only a few animals are vaccinated. But Park Spokesman Al Nash says after some legal disputes regarding bison management over a decade ago, Yellowstone agreed to look into new options.