The Associated Press reports that the wolf population on Isle Royale is in trouble -- not enough females.
Here is an excerpt from the AP story. You can read the whole thing here.
After surviving a parvovirus epidemic, bitter winters, hunger and warfare between packs, the gray wolves that roam Michigan's Isle Royale National Park may go extinct because of what amounts to an unlucky roll of the biological dice: They're running out of females as the overall population slides.
The number of wolves on the Lake Superior island chain dropped to 16 over the past year, according to a Michigan Tech University tracking report obtained by The Associated Press. Scientists who study the predator-prey relationship between wolves and moose say the number of wolves is the lowest since 1998, when it hit 14 following a huge moose die-off that left the wolves short of food. Earlier that decade, the parvovirus-decimated total was a dozen after peaking at 50 in the early 1980s.
They've always bounced back from such calamities since their ancestors migrated to Isle Royale across an ice bridge from Canada more than six decades ago, producing new generations that defied tough odds imposed by the harsh climate and geographical isolation. But this time, their prospects for reproduction are in serious doubt. Genetic analysis of their droppings, which scientists have dutifully collected and preserved, suggests the 16 remaining wolves include just one or two adult females.
"If both of them were to die before successfully raising pups, that would be the end," John Vucetich, a Michigan Tech wildlife biologist, said Tuesday. "The population would persist for a few years but its fate would almost certainly be sealed."