Isle Royale
Because of its isolation, the Isle Royale National Park is an ideal setting for wildlife study. Now researchers are noting a troubling development on the island- wolf and moose populations are declining.
The population of moose, is at its lowest since wildlife biologists began studying the two species' predator-prey relationship in the park 49 years ago. The annual census turned up 385 moose, down from the previous low of 450 last winter. Wolf numbers fell from 30 to 21 during the same period, largely because of hunger.
Isle Royale had more than 1,000 moose as recently as 2002. But nature has dealt a one-two punch: a run of unusually hot summers and an infestation of ticks.
Instead of fattening themselves for winter, moose are spending too much of the fleeting summers seeking shelter from the sun and trying to remove the parasites by rubbing against trees and biting their hair out. One moose can host tens of thousands of ticks. Weakened by weight and blood loss, many are unable to fight off ravenous wolf packs.
Despite their dramatic slide, it's highly unlikely all the moose will die. The wolves have overcome other dangers, including a virus outbreak that nearly wiped them out in the late 1980s.
Although focusing on the wolves and moose, the scientists also monitor how their ups and downs affect other species. Foxes, for example, are hurting because wolves are eating every morsel of their kills, leaving less for other animals to scavenge.
March 9, 2007 6:42 AM | Category: Animals, Islands, Lake Superior