MPR: The Satellite Pack: Tracking Wolf Populations

The Satellite Pack: Tracking Wolf Populations
By Leif Enger
October 22, 1997

They're still a rare sight in most of the state, but timber wolves are making a comeback in Minnesota. Held strictly to northeastern forests a few decades ago, wolves are now spreading west and south - toward St. Cloud, Grand Forks, and Elk River. Wildlife officials estimate there are more than 2,000 of the animals in the state - so many, they may soon lose federal protection. Biologists are now using satellite technology to forecast where wolves will show up next.

Audio: Wind, birds, crickets

Ten years ago, no one would've expected to see a wolf in this spot. Camp Ripley - near Little Falls in central Minnesota - was too far south. Besides, it's a military base. The artillery they fire here rattles windows 20 miles away. And what kind of wolf would share its space with army tanks?

Audio: Big old tank lumbering by, birds/bugs/wind

Actually, the military presence is one of the reasons this study is remarkable - you'll see why in a minute. We're parked in a spot state biologists have come to call "Wolf Junction." There's a full-fledged pack nearby, with young ones almost ready to declare independence and set off on their own. They're shy this morning. Sometimes researcher Bill Brown knows they're close not by sight or by sound - but by smell.

Brown: Like a real musky dog, they roll in a lot of matter. And what they eat - they do eat some carrion, and they pick that up.

Brown is helping DNR biologist Sam Merrill with a new kind of wolf study. As with conventional radio telemetry, the animals are first trapped and collared; and at first, the collar in Merrill's fist looks like the standard-issue, Marlon Perkins-type transmitter. It came off a wolf recently - and if you get within ten feet of it, you'll understand what Brown means about the smell. But Merrill says under that eyewatering veneer lurks a space-age piece of equipment.

Merrill: There's a little antenna on top of the collar, and it's looking up into the sky. There's a set of 24 satellites orbiting the earth at all times, and as long as the antenna can see the location of three of those 24 satellites, it can do what's called "triangulate," and determine its location on the earth to a very precise degree.

The technology itself is only somewhat new - it's known as GPS, for Global Position System. Many hunters use similar devices to keep from getting lost. But this is the first time wolves have carried GPS units, and it works this way: every 15 minutes, the collar reads its exact position on the globe. It stores that information on a chip, along with the date and time of the reading. When the battery wears out - in a few months to a year - a tiny explosive charge releases the collar from the wolf's neck.

Merrill: Then I hone in on it, retrieve the collar, hook it up to the computer, and download 1,500 points of beautiful data.

Four to six collars have been in use since spring, with dramatic results. The GPS readings show the wolves' haunts and habits, day and night. The satellite sees what no human in a helicopter can. What's emerging is a whole new picture of the wolf.

Merrill: We at Ripley are now witnessing wolves performing all their normal biological functions in bastions of human activity. Really the whole notion of wolf habitat being this deep-wood phenomenon is turning out to be false. Wolf habitat is in the human mind. It is wherever we will let them be.

Grand Rapids wildlife biologist Bill Berg agrees. He's been studying wolves since they were hunted for bounty - since before GPS, or Sam Merrill existed. The study's real value, he says, will be in forecasting wolf range growth and direction as the collared pups leave home - or disperse.

Berg: - and if these GPS collars work, we're gonna know exactly where they're dispersing to. Are they gonna go north, run into some other wolves? Are they gonna go south, establish a totally new wolf range and pack area? What we really want to know is where wolves are going to end up in the state, and where they can be managed.

Anecdotal evidence suggests wolves continue to migrate to new ground. Government trappers this year have taken a record number of wolves in response to livestock killings as far south as Cambridge. Soon the state will start its biggest wolf census in a decade - it's believed the census will show more than 2000 wolves in Minnesota, far above wolf recovery goals. It's likely they'll be removed from federal protection within two years, and the state will take over wolf management. With that on the horizon, wildlife managers want all the biology they can get their hands on.

Audio: fussing and messing about with maps

In his Camp Ripley office, Merrill rattles two maps across his desk - maps of the military base, overlaid with zigzagging lines. They look like dot-to-dot pictures by someone perplexed at numerical order, but they're actually travelogues - exact records of where the wolves went - and when.

Merrill: So here are the maps of the two pups - GPS maps - and we can confirm that they were traveling together. Then they took this trip up here to the northeast, and one animal went straight home, and the other did not. They split up, and got back together later.

Now here, Merrill says, is why a military base is perfect for this study. Just as every movement of a wolf is recorded, Camp Ripley keeps strenuous records of human activity - every tank, every troop, every firearm is tracked. For example: Wolf Junction, where we were parked a few minutes ago, is near an artillery area. During the week denoted on this map, the family of wolves was sharing its home with live ammunition.

Merrill: You can see that the pups were sleeping quite a lot, in the impact area. They're sleeping in there, while the troops are firing! And they don't leave!

Later this fall, the DNR will hold a series of public meetings on wolf management. Part of the reason is to let people know the wolves are slowly but surely extending their range. They've been seen near Elk River now; they've been seen near Cambridge. No one should be surprised, Merrill says: to an animal so blase about mortar fire, what's an occasional freeway?

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