Martha Hahn, director of science at Grand Canyon National Park, says that heavy grazing by the bison has led to soil erosion and invasive plant species. Carrie Jung

Arizona resident Jim Ingram held strong in his belief that the bison are an important part of our culture, and at least a few of them needed to remain in the park.

“I hope to see future generations in this country have more buffalo present in more places,” said Ingram. He was also very upset to hear the park was considering lethal tactics. “And that’s not going to fly,” he added.

According to Hahn, a reduction in numbers is necessary, as the impact of the bison herd is becoming hard to manage at Grand Canyon. One of the most noticeable problems to visitors is the ubiquitous presence of their poop.

As Hahn continued her hike, she looked down as she walked to avoid stepping in a cow pie. In open areas of the park, piles of bison feces lie just feet from each other, and the smell of manure permeates the air.

To produce that manure, these bovines must also consume a large amount of grass, which is causing other problems. Their hefty appetites have left much the area’s grassland dotted with bare spots.

“If you look, this meadow looks like a well-manicured lawn,” said Hahn as she gazed across the landscape. She explained that the grass here should naturally be at least a foot tall. Instead, much of it barely reaches an inch in height.

Hahn added that such heavy grazing and soil erosion have left the area vulnerable to an infestation of invasive plant species. She said that while the native plants have so far managed to keep a stronghold in the park, “we are seeing more and more invasives, especially where the bison are.”