

Of nine wolves left on the island in Lake Superior, about half are female, according to new DNA analysis of their scat. That's considerably more than the one or two that researchers had believed — a gender imbalance that they theorized could be driving a decline in the population of the famous wolves.



"We are not seeing the courtship behavior that we would expect," said Rolf Peterson, a biologist at Michigan Technilogical University who has tracked the wolf and moose dynamics on the island for decades. "That indicates they are avoiding breeding with close relatives."As far as the researchers could tell, last year there were no pups born on the island — the first time that's happened since 1971, Peterson said. Last year they counted just nine wolves left, the lowest number ever recorded. In the summer, they discovered the carcasses of three that had fallen into an abandoned mine pit and drowned.

However, several of the female wolves are young, born after 2011, and wolves usually don't start mating until they are at least 2 years old. It's possible that as early as this spring they could start reproducing, said Dave Mech, a wolf biologist with the U.S. Geological Survey.

"I've been telling people not to panic," Mech said.



"There are more than 200 now," he said.

Still, a lot depends on how closely related they are, Hedrick said. It is unlikely that wolves that are siblings or father and daughter would mate or do so successfully. The wolves' genetics are only one issue that will drive the park's decision about their future, said Superintendent Phyllis Green. Another factor is the long-term viability of the island's moose, the wolves' primary source of food. For the moment, the moose population is high in large part because the number of wolves is so small. This year, there has been a near record number of twin moose calf births, a surprise to the researchers who have been vividly describing this winter's study on their website.


"At this point, I have more questions than answers," Green said.

Bloody chase




"This was no scrappy dogfight," Vucetich wrote on the researchers' website. "These wolves lunged and sank their teeth into Isabelle with the same fury and power they use to bring down a 900-pound moose. I think they are going to kill her."

They didn't. That day, at least, they backed off, leaving her bleeding on the ice.

"Mercy or torture?" Vucetich wondered.


"The motivation that drove Isabelle's assailant is simple — to eliminate a female who might steal a mate or raise pups," he wrote. What they don't know, he said, "is that Isabelle's reproductive future was very much in doubt before this attack."