Wolf dies after capture in Minnesota for relocation to Isle Royale

Officials say a gray wolf captured in Minnesota for relocation to Isle Royale National Park has died.

The National Park Service plans to move 20 to 30 wolves from the U.S. and Canadian mainlands to the Lake Superior wilderness park in the next few years to rebuild a once thriving population.

A 4-year-old female and a 5-year-old male were successfully flown there from the Grand Portage Indian Reservation in Minnesota and released earlier this week.

But the park service said Friday night that another female died "despite the best efforts of the attending veterinarians" after being trapped, sedated and driven to a holding facility for a medical exam.

The park service said its wolf relocation team has adjusted procedures involving how long a captured wolf is held before transport to the island, as well as sedation measures used to reduce stress.

Plans call for moving four additional wolves to the park this fall and building the population to 20 to 30 over the next few years, restoring numbers that would enable the wily predators to keep the island's abundant moose herd in check as they did for decades after arriving in the late 1940s.

Scientists believe the initial wolves crossed ice bridges from northeastern Minnesota or the Canadian province of Ontario to the park, an archipelago nearly 15 miles off the mainland.

Their numbers rose as high as 50 but generally ranged in the low- to mid-20s before crashing in recent years.

Some fell victim to accidents or diseases. But researchers with Michigan Technological University say the biggest problem was abnormalities resulting from inbreeding, as a warming lake surface has frozen over less often in winter, giving mainland wolves fewer opportunities to cross over, mate and freshen the gene pool.

Meanwhile, the moose population has reached about 1,500. Park managers say if the surge continues, they could overeat trees and shrubs, potentially damaging the ecosystem. Officials decided to intervene when the wolves failed to bounce back on their own, despite the usual policy of letting nature take its course in federally designated wilderness areas.

Managers hope the other wolves to be taken to the island this fall will come from Michigan's Upper Peninsula as well as Minnesota to enhance genetic diversity, she said.

The park service said it will evaluate the project's success by monitoring moose kill rates, genetics, wolf-to-moose ratios and vegetation conditions, among other factors.