Catch of the Day


by BisonDoc — Jun 01, 2010

Adventures of a modern day bison hunter

“I can’t believe I’m getting paid to do this.”

These words echoed among our team of five wildlife scientists as we skied across snow-covered Hayden Valley on a sunny midwinter day. We were in Yellowstone National Park for a research project on bison, icons of the American West and the subject of intense debate over their role in harboring the cattle disease, brucellosis.

Our mission was to capture an adult female bison, replace her satellite radio transmitter, collect blood and other biological samples, and then release her back to the herd. She was one of about 80 animals in a government-sponsored study to collect biological data being used to better understand brucellosis and manage the bison population. As the team’s veterinarian, I was advising the crew on capture strategies and overseeing bison handling and recoveries.

Yellowstone bison are one of the few remaining herds that are genetically pure, lacking a mix of cattle genes from hybridization with domestic bovines.

Winter travel through most of Yellowstone is by snowmobile, and we had to get an early start to pack all our sampling gear, skis, radios, extra clothing, and drive the 40 miles to Hayden Valley from park headquarters in Mammoth. Snowmobiles are a real asset when you have to move people and equipment in a hurry across vast snowy landscapes like Yellowstone’s.

We followed a snow-covered road to the valley, arriving about 8 am in dense, 10-degree fog. Parking our snowmobiles, we strapped on our skis and began our trek in high spirits. Bison captures are an adrenaline rush, both for the animals and for researchers. We made good time tracking several miles over fresh layers of windblown snow, and as the fog lifted, we could see we were in for a remarkably fair winter day. By 11 o’clock, and after a few dicey crossings over snow bridged streams, we located our bison’s radio signal on the opposite side of Alum Creek. She was with a group of 12-15 cows, accompanied by several dark brown calves.

Shedding our boots and shouldering skis, we waded through bath-like water – a wintertime bonus of working in one of the major geothermal hot spots on the planet. Having forded the creek, we sat on the opposite snow bank for a few minutes, dangling our bare feet in the water.

We could have lingered, relishing the gentle music of the creek and the sensations of the warm footbath, sunshine, and crisp air. But, with our mission and our adventure still ahead of us, we donned our boots and skis and shuffled uphill to a point overlooking the herd.

There, we paused to eat lunch and marvel at the scenery of this high-elevation valley – undulating, pine-topped buttes and snow-covered basins, punctuated by rising columns of steam and small groups of bison taking advantage of a short break from the rigors of winter.

Peanut butter and jelly sandwiches never tasted so good!

Of course, catch-and-release bison hunting is serious business. After our brief rest, like a pack of wolves we sized up the herd and planned our approach. Although the bison were calm – some rested while others swept aside snowdrifts with their massive heads to graze on the meager grasses – there was no doubt they were sizing us up, too. Every capture situation is unique and fraught with risks. Despite their placid appearance, bison are powerful and deceptively fast, having killed unlucky or careless park visitors on rare occasions. Researchers are extremely cautious when handling the chemicals used to immobilize bison, as just a few drops on the skin can be lethal. Finally, the key to all successful captures is to keep the drugged bison away from hazards like creeks or hot springs, predators, and steep or uneven terrain.

Weeks earlier in Hayden Valley we had darted a bison whose group milled around her, anchored by a huge herd bull. When the bison refused to leave her side, we yelled and rushed the herd to drive them off. Although they dashed away at our approach, after a short sprint they circled back and headed our way at top speed. With a stiff breeze at our backs, we quickly dispatched a couple of shots of pepper spray into the air and the group dispersed.

That was way too close for comfort!

Today’s bison capture was less thrilling, but no less rewarding. While the rest of the team watched from a distance, one of the biologists and I approached the herd within darting range. To get close to the bison without endangering ourselves or spooking the animals we had to appear small and nonthreatening while remaining vigilant to the herd’s behavior. At 30 yards, the biologist loaded the dart fired the rifle – “POP” – a perfect shoulder shot into our patient. The bison barely flinched at the impact, and after three minutes of failed attempts to escape through deep snow, she dropped to the ground, quickly losing consciousness. Working rapidly, the team swapped out her old collar for a new one, collected samples, injected the recovery drug and got the bison back on her feet. We ended our day with a fast 6-mile ski trip back down the valley, arriving at our snowmobiles just before sunset.

That night, on my drive home, I thought about how lucky I was to live and work in a place where the wonders of “Animal Planet” can be experienced so personally.