Oh, give them a home where boulevard roams
Wild bison grazing on sunflower-studded prairie at Rocky Mountain Arsenal National Wildlife Refuge are in business — as greeters of millions of travelers.
Denver International Airport officials confirm a deal-in-the-making to let bison roam on 200 acres of airport property, which would bring them right up to Peña Boulevard leading to the white-tented terminal.
Federal wildlife refuge managers also this summer doubled the fenced space at the refuge, north of Denver, for their bison herd, which grew this year, with 18 calves, to a record 122. The feds plan to import 25 more genetically robust bison in October. And wild bison behavior, such as raging bulls battling for females and tearing through fences, is on the rise.
This expansion boosts the national project of restoring bison, nearly extinct a century ago, across their native Great Plains. The U.S. Fish and Wildlife Service and other federal agencies are coordinating the effort, partly to keep bison off the endangered species list, and also to reap environmental benefits of reviving depleted shortgrass prairie.
“Having that wildlife refuge next door is an unbelievable opportunity for us,” DIA manager Kim Day said of the plan to let bison roam on some airport land. “It is something you will not see in Des Moines.”
The airport’s biggest worry is keeping bison off Peña Boulevard, Day said. “How do we keep them enclosed and still allow you to see them from the road?”
Gov. John Hickenlooper has supported the concept of letting the legions of travelers at DIA see bison, perhaps using viewing stations overlooking the 16,000-acre refuge and the distant snow-capped mountains.
The challenge of “connectivity” still
looms for federal wildlife biologists — and bison — because expanding cities and suburbs, including those at the eastern edge of metro Denver, close off routes to open prairie.
Bison are migratory animals. They once numbered 20 million lumbering across grasslands of North America until hunters reduced them to near extinction. Today’s federal Bison Conservation Initiative aims to restore a wild population of fewer than 10,000 nationwide.
“As humans, we must be stewards. Bison were here a long time before we nearly wiped them off the planet. We have a responsibility to keep our eyes on the future and make sure they have a place in our world,” refuge manager Dave Lucas said.
DIA officials warmed to bison last year after completing an environmental plan for their 52.4-squaremile property — the biggest U.S. airport property, more than double the size of New York’s Manhattan Island. Most of the land remains open.
Environmental planners looked at “how we related to the wildlife refuge, how we view the mountains, how we relate to the First Creek, Second Creek and Third Creek that run across airport land,” Day said.
“We’re trying to maximize the potential for DIA passengers and employees to take advantage of the refuge,” she said.
New development at the edge of the airport is spreading, mostly fitting formulaic residential and commercial growth patterns, bringing more vehicle traffic and closing off opportunities for the bison to reach open prairie.
“DIA’S new planning efforts are long-term and truly consider conservation, which we think is very cool,” Lucas said. “The fact they are conservation-minded — while running one of the busiest airports in the world — shows the potential we all have to work together. Kim and her staff are leaders, and a good example for others.
“The opportunity for millions of people to possibly see wild bison on their trip to and from DIA is remarkable. When people physically connect with wildlife — fishing, hunting, photography, observation — it is a good thing. More connections means more conservation.”
For years, refuge crews have been relying on irrigation, seeding and prescribed fires to revive short-grass prairie where previous Army owners had planted crested wheat. the bison herd that started with fewer than 20 animals a decade ago had grown to 76 in 2015, according to federal records. Bison eat up to 50 pounds of grass a day.
This year, the crews installed 10 miles of new fencing to add 3,391 acres of secure habitat for bison at the southeastern edge of the refuge, which sits in Commerce City and 10 miles from downtown Denver. Bison now roam across 6,373 acres.
“The bison are thriving,” refuge wildlife specialist Tom Ronning said. “We’re just trying to get the diversity back.”
Details of the DIA deal still are being hashed out. Among the challenges: barriers to protect people and the bison, which weigh up to 2,500 pounds. Federal and city officials considered a passive moat barrier. “But we don’t want bison falling into a moat. There will be a barrier to keep them in,” Day said.
Nor will bison be allowed to roam anywhere near airport facilities and runways — or the DIA’S 32-foot-tall Blue Mustang sculpture. (Lucas suggests adding a bison sculpture.) DIA officials have to manage some wildlife, such as birds, that could pose aviation safety risks near runways.
Letting bison migrate across DIA property beyond the runways has not been discussed, Day said, and airport officials haven’t been part of talks around the massive Gaylord Rockies resort project west of Peña Boulevard that might include possibilities to create migration corridors.
Bison bulls fighting this summer for the first time tore through internal fencing, three times in a week. The heavy-gauge fences sprang back up, and refuge crews repaired them. Double fencing has been the norm at the refuge. Federal officials said they plan on installing one 8-foot fence next to Peña Boulevard and a shorter fence inside. Peña runs on an elevated grade above the refuge, they said, so the fencing may be practically invisible to visitors.