Malfunctioning transmitters prompt second moose roundup near Duluth
Helicopter crews had to recapture eight moose last week on the Grand Portage Indian Reservation because their satellite collars weren't transmitting data properly.
The moose were among nine that had been collared just 11 days earlier. One component of the eight malfunctioning collars had been unknowingly disabled, preventing the collars from correctly transmitting information to satellites, and biologists on the ground were not receiving data.
"We knew something went wrong, terribly wrong," said Seth Moore, director of biology for the Grand Portage Band of Lake Superior Chippewa.
Moore said scientists involved in the project had been rushed in programming the collars before the first capture.
"The responsibility is shared between the project investigators [biologists] and the collar company," Moore said. "The collars arrived later than we intended them to, and the helicopter flight needed to occur earlier than intended.
"It was our belief the collars were operating perfectly. What we learned is that when the data was downloaded, it shut off the GPS/ARGOS [satellite] part of the collar. It's not identified in any of the instructions. ... There was no way for us to know that part wasn't functioning."
"Obviously, we would have preferred not to recapture them," said Ron Moen, a biologist with the University of Minnesota Duluth's Natural Resources Research Institute, a partner in the project. "But if you do something like this and have collars on an animal, you want to get the best information you can."
The recapture effort was "beautifully executed" on Friday, Moore said. The moose were located by radio telemetry signals. In all but one case, helicopter crews dropped mesh nets over the animals.
One moose wouldn't come out into the open, and it had to be immobilized with a drug.
The netted moose, still fully awake, were hobbled. Biologists arrived on the ground, activated the satellite-transmission switches, took additional blood samples and released the moose. The process took six to seven minutes, Moore said.
The collars are all functioning properly now.
Moose do undergo stress when they're captured, said Erika Butler, state wildlife veterinarian with the Minnesota Department of Natural Resources, who worked the original capture.
"Anytime you handle wild animals, there's definitely stress involved," Butler said. "We weighed that. ... We felt confident that what we were doing wasn't doing unnecessary harm."
The recapture effort likely will cost about $15,000, about the same as the first, Moore said. The Grand Portage band received a grant for $200,000 from the U.S. Fish and Wildlife Service for the four-year research project, he said.
The recapture cost will be covered by an additional grant or will be absorbed from the budgets of the participating agencies, Moore said. Those agencies include the Grand Portage band, UMD and the 1854 Treaty Authority based in Duluth.
The purpose of the study is to gain detailed information about how moose behavior and habitat use is affected by a warming climate, Moore said. It's part of a paired study Moen is conducting in partnership with Voyageurs National Park. Twelve moose there were fitted with the same kind of collars last week.
Unlike VHF radio-telemetry collars used in an ongoing moose research project elsewhere in Northeastern Minnesota, these $5,000 satellite/GPS collars will give biologists a moose's location and the ambient air temperature every 15 minutes, Moore said. The animal's movements will be transmitted once daily by satellite to biologists. Temperature data will be collected when the moose are recaptured a year from now and the collars are recovered, Moore said.
A 1986 study showed that moose feel heat stress when the winter temperature is over 20 degrees and the summer temperature is over 57 degrees. They show that stress by feeding less and panting more, Moore said.
The data from Grand Portage and Voyageurs National Park should be valuable, Moen said.
"We'll be able to say how are the moose responding to changes in temperature and weather changes," he said.