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One-Ton Teamwork for High Tech Animal Tracking

You would be surprised by how slowly a dart filled with sedative travels through the air. You can see it as it leaves the shaft of the gun and slowly floats toward its target. With any luck, the dart lands in its rather large destination – a bison’s hindquarters.

Earlier this week, our team headed out across the snow-covered prairie to conduct health testing and outfit some of the animals with GPS collars. After several similar attempts in the last few weeks, the weather finally warmed up enough so that the sedative in the aluminum darts wouldn’t freeze while we searched for the herd. With more than 30,000 acres for the bison to roam, it’s not an easy journey. The crew consists of wildlife biologist and long-time bison expert Kyran Kunkel, my wife Ellen, and Damien Austin, a Reserve Supervisor.

As part of our ongoing efforts to monitor the restoration of bison to northeastern Montana, we use GPS collars to understand how bison use and affect the prairie as well as how this changes as the population grows. Once the collar is in place, the data is easily accessed from anywhere in the world – it’s the collar placement that’s the tricky part. Unlike domesticated cattle, bison are not used to human interaction, so roundups and confinement in corrals can be very stressful and potentially dangerous (for both the animals and people). Using sedatives and darts, we can prevent much stress and disruption of the bison’s normal movements.

At about 30 meters from a targeted cow, we take the shot, waiting patiently for the tight-knit herd to spread out enough to get a good view. She jumps a little at the sting and then returns to grazing for about 5-10 minutes before starting to sway and eventually laying down. The team waits while the cow slips into slumber.

We approach her quietly, first touching her neck to make sure she is fully anesthetized and then lifting her thick shaggy nape to fasten the collar and check the fit. A blood sample is taken that we’ll use to screen for diseases, and a lucky helper collects a fecal sample. Within minutes, the drugs are reversed with another quick prick of the needle. In the several minutes that follow, the cow is back on her feet, walking off to rejoin the herd. Many of the bison stare at her, perhaps wondering what had happened, maybe glad she was coming back to join them, or maybe just really thinking about eating more grass.

Bison are amazingly social animals and one common reaction we see when darting is that bison will come over to investigate the oddly behaving darted animal. Sometimes, they try to get an animal up on its feet again to stay with the herd, an amazing behavior that we don’t see in elk or deer or pronghorn. Perhaps it is a behavior to keep everyone safe from predators.

Working with the bison up close always gives me a greater appreciation for how tough and unique they are. The hair over their backs and legs is so soft and tufted, while their bonnets and pantaloons are wiry and unruly. The bulls we dart are massive, shaggy, and beautiful creatures but seem to go down easier and faster than cows and calves. The heads of the bulls are so gigantic it is a wonder that they don’t tip over forwards.

As we finish with the last bull, the sun sets in the south on the edge of the prairie and big clouds of steam come out of the noses of the bulls in the zero degree weather. We will go in for a warm meal, in a warm ranch house, and the bison will take in another below-zero night eating their dinner across the seemingly endless prairie.