Scientists say the gray wolves in Michigan's Isle Royale National Park are in growing danger of extinction and may have stopped reproducing.
A report given Monday to The Associated Press says scientists with Michigan Technological University saw no evidence that pups were born in the past year during their recent winter trip to the park. It's believed to be the first time since scientists began monitoring the wolves' reproduction in 1971 that no offspring were born.
The report also says only eight wolves remain on the island chain in Lake Superior. Just five years ago, there were 24.
Biologist John Vucetich (VYOO-sih-tich) says unless more pups are born, the wolves will die out in a few years.
The report will be released publicly Tuesday.