From Bison to Bisontes

Crossing Borders

Cross the U.S.–Mexico border with a herd of 23 bison and find out how they're helping restore grasslands in Mexico!


By Cara Goodman

A sudden move from South Dakota to Mexico might inflict a bit of culture shock on a lot of folks, but Wind Cave National Park superintendant Vidal Davila is confident that a herd of 23 bison that just crossed the Rio Grande will have no problems adjusting.

The first-ever species donation from the United States National Park Service to the Government of Mexico, the herd will serve as a first step in re-introducing wild bison to Mexico’s grasslands — a place they haven’t lived since the 19th century. learned from Vidal Davila what makes these bison special, and why they’ve gone to live on Rancho El Uno, a Conservancy reserve in Chihuahua, Mexico.
“My greatest hope is that this will be the first step in a successful reintroduction, and that they’ll be a healthy herd, and they will continue to multiply.”

Vidal Davila
Superintendent of Wind Cave National Park

Let’s start from the beginning. You’re superintendant of Wind Cave National Park in South Dakota. Why are you sending a herd of your bison to Mexico?


I wish I could say it was my idea — I worked along the U.S.–Mexico border at Big Bend National Park for a while, and I love the area. But the opportunity to send a herd of Wind Caves' bison to Rancho El Uno came up last year, when some folks from Mexico approached us, and asked would Wind Cave, with its genetically pure bison herd, be willing to work with the Mexican government to do this.

This is a big deal for Mexico — to be reintroducing bison into their grasslands after so many years. Is it a big deal for Wind Cave?


The day our Wind Cave bison crossed the Rio Grande was a great day for international conservation. We’re helping our neighbors to the south to reintroduce this species, and we’re really happy to be a partner with Mexico on this important initiative.

For the National Park Service to work with Mexico on this herd donation is a huge step forward in international conservation collaboration. It was a gigantic, cross-border effort between lots of partners, including the U.S. National Park Service, the U.S. Department of Agriculture, the U.S. Fish and Wildlife Service, the Nature Conservancy-Mexico, the folks here at Wind Cave — including all of the veterinarians who work with us — not to mention all of the government officials and veterinarians and other folks in Mexico who helped arrange it all — even the permits that allowed the bison to cross the border!

Will Wind Cave still have enough bison, after donating 23 to Mexico?


Sure we will. We’ve made many herd donations in the past — some to The Nature Conservancy. We receive requests from Native American tribes, various agencies, non-governmental organizations — for our bison, and we do our best to meet those requests.

On an annual basis we conduct a survey of our herd and our biologist tells us how many bison we have and how many should be culled from the herd based on how many bison the park can support. We then have a bison roundup at Wind Cave. In fact, most years we need to donate some in order to keep our population at a healthy size for the Park.

There are lots of bison across the United States. Why is everyone coming to you — to Wind Cave — to get bison?


During Western Expansion across the U.S., bison were hunted almost to extinction — people shot them from moving trains, not necessarily to eat them, but just to kill them. Those that weren’t killed were often taken in by ranchers, who interbred them with their cattle. So most of the bison around the U.S. today have evidence of cattle genes.

But when Yellowstone National Park was created in 1872, it protected a herd of bison that had not been hybridized with cattle and were protected from hunting or poaching. Wind Cave received a bison donation from Yellowstone and Bronx Zoo in New York City to start our park’s herd, so our bison have no evidence of cattle genes. That’s why everyone wants ours — we’re one of just two public herds in the U.S without evidence of cattle genes.

So you could say the 23 bison now at Rancho El Uno are descendents of that Yellowstone /Bronx Zoo herds?


That is correct.

Who cares if the bison are genetically pure or not?


We along with other conservation minded groups are interested in providing bison that truly represent what used to roam across the Great Plains. Bison from Wind Cave do not have brucellosis which made them ideal for this bison reintroduction initiative in Mexico.

OK, so the bison are well-suited to survival in the wild, but these bison are from South Dakota, and now they’re going to be living in Mexico. Any concerns about them adjusting to their new surroundings?


None at all. Rancho El Uno is in the Janos grasslands — it’s a mixed prairie, just like Wind Cave. Plus, it’s important to remember that bison used to live on those grasslands in Chihuahua, and across the river, in Texas. In Big Bend National Park, there are even a couple of bison pictographs painted on the walls by Native Americans a long time ago. That gives us a pretty good idea that there, bison once roamed.

What’s your hope for this herd?


My greatest hope is that this will be the first step in a successful reintroduction, and that they’ll be a healthy herd, and they will continue to multiply. I hope that history will tell us this was the right thing to do, and that it was an important thing to do.

Vidal Davila is the superintendent of Wind Cave National Park in South Dakota.


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