Field Notes - Eyes in the Skies

Scrunched into the cockpit in a seat next to Capt. Mike Trenholm, a wildlife biologist peers into a treetop eagle nest and checks its location on a topographical map. She is one of many DNR specialists who fly with DNR pilots to get a bird's-eye view of Minnesota's lands, waters, fish, and wildlife.

Trenholm, DNR conservation officer chief pilot, does natural resources and law enforcement work high above the treetops in a single-engine Cessna 185 airplane. From his office in Brainerd, he also supervises five full-time and three part-time DNR pilots, stationed at Bemidji, Grand Rapids, New Ulm, and Brainerd.

From the air, wildlife biologists can count ducks, deer, moose, and wolves. Sometimes fisheries biologists can more easily track radio-tagged fish in the Mississippi River from the air.

For law enforcement work, CO pilots usually fly alone. They look for violations of snowmobile and off-highway vehicle regulations, wetlands that are illegally drained or altered to accommodate construction, and any other violation of Minnesota's natural resources laws. In addition, pilots might be called by local law enforcement to monitor a car chase from the air or to assist in search-and-rescue operations.

"It's pretty varied work," Trenholm said. "We spend about 40 percent of our time on law enforcement and 60 percent supporting natural resources work."

Flying offers several advantages over ground work. When DNR staff need to reach remote destinations, such as a lake on the Canadian border or a series of prairie potholes in southwestern Minnesota, air travel saves a lot of time. Airplanes also provide an efficient way to find and count migrating waterfowl and wildlife that range across a large area.

Certain violations, such as illegal deer shining, are easy to spot from the air. In Minnesota, with certain exceptions for raccoon hunters and trappers, it is against the law to shine artificial lights to locate or take a wild animal from 10 p.m. to 6 a.m., Sept. 1 to Dec. 31. Late at night in the fall of 2002, Trenholm was looking for the telltale spotlights of deer shiners from an altitude of 4,000 feet. He spotted powerful lights beaming from the passenger windows of two pickups traveling slowly on a country road.

"One pickup pulled off into a farmyard, and the other pickup continued," Trenholm said. "That's when I decided to get other conservation officers involved." He radioed officers on the ground to investigate both vehicles.

"It turned out that the occupants in the first pickup ran out of beer, so they all got into the second vehicle, where they had a keg," he said. Besides the keg, officers found 13 teenagers, loaded rifles, and spotlights.

Jason Abraham