Isle Royale's Wolf Population: on the Brink of Extinction
June 15, 2012 8:37 AM Subscribe
posted by Elly Vortex (33 comments total)
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Isle Royale is a 206 square mile island
in Lake Superior, over 15 miles from the mainland. Most years, it is isolated from the mainland. The moose and wolf populations of Isle Royale are isolated, and wholly interconnected
with each other
In the last decade there has been a decline in the wolf population on Isle Royale. Recent evidence shows that the wolf population has collapsed.Durward Allen
initiated the Isle Royale Wolf and Moose study in 1958. The study is now run by the National Science Foundation
, Michigan Tech
, and the National Park Service
. Researchers now have over 50 years of data about the wolf and moose population - the largest continuous predator-prey study in the world.
In 1980, there were 50 wolves on Isle Royale. In 2010, there were about sixteen. In 2011, there were about nine
. Researchers made educated guesses
about why the population has declined. Disease (a dog brought parvovirus over to the Island in the 1990's), lower moose populations to feed the wolves, genetics of this inbred population, further isolation due to land bridges not forming now that Lake Superior freezes over less often, and bad luck: a gender imbalance among the wolf pups.
Their concern turned to alarm when they realized the only one of the remaining nine wolves on Isle Royale was female. This sort of gender imbalance was almost certainly a death knell for the population - but where were the other wolves? In May of 2012, Isle Royale National Park staff made a devastating discovery: three dead wolves
- an Alpha Male, another male, and a female - at the bottom of one of the island's abandoned mine shafts
. If no pups are born to the lone female wolf left on the island, Isle Royale's wolf population will die out in 5-7 years.