[benkuykendall]

This paragraph, later on in the piece, briefly addresses the issue. According to the sources the author cites, the cull is not ecologically justified, but rather to stop the cattle from competing with domestic cattle.

>> Of the estimated 5,000 bison in the park in February, only a few hundred had roamed into Montana, and most of these had already been killed. The goal during 2015 was to "cull," in the language of wildlife management, at least 900 of the creatures, almost 20 percent of the herd. Park Service officials told me that the IBMP had established a maximum population of 3,000 bison in the park, and that this year's cull was a first step toward achieving that number. James Bailey, a retired professor of wildlife biology at Colorado State University and author of the 2013 book American Plains Bison: Rewilding an Icon, told me the ceiling of 3,000 animals is "a political number, not a biological or ecological number. It's what the ranchers will accept.