Scientists: Isle Royale gray wolf population drops to 3
Traverse City — Scientists say the gray wolf population at Isle Royale National Park has dropped to three and is on the verge of disappearing.
Researchers with Michigan Technological University released their annual report on the park’s wolves and moose Friday. They said the wolf count has continued a sharp decline since 1989, when it stood at 24. It was nine last year.
Fewer wolves are on the Lake Superior island chain now than at any time since scientists began studying them in the 1950s.
The report said the moose population has risen to 1,250 as the number of wolves to prey on them has plummeted, demonstrating the wolves’ declining influence and continuing a trend that could lead to long-term problems for the Lake Superior archipelago's ecosystems. In the 1990s, following another wolf decline, moose numbers reached about 2,400, leading to mass starvation during the harsh winter of 1996, when about two-thirds of the moose died.
Wolves and moose are relatively recent arrivals to the 45-mile-long park, which consists of one large island and hundreds of smaller ones. Moose made their way there in the early 1900s, possibly by swimming 15 miles from Canada. Wolves are believed to have wandered there in the late 1940s over a winter ice bridge.
Study leaders Rolf Peterson and John Vucetich have called repeatedly for park officials to bring more wolves to the island to replenish the gene pool.
Last year, they cited growing evidence that the Isle Royale wolves have lasted because newcomers periodically crossed ice bridges and mated with island wolves. Analyzing decades of field notes, the study leaders concluded that a pack of seven or eight wolves migrated to Isle Royale in 1967. A lone male immigrant in 1997 had such an effect that by 2008, most of the island's wolves were his descendants.
But ice bridges are forming less frequently, lowering the odds that more wolves will arrive on their own, the scientists said. Although ice provided a pathway for 25 days this winter, no wolves are believed to have traveled to the island and one used the occasion to escape, only to be shot dead on the mainland.
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