The usual question is: Can we save endangered wildlife? On Isle Royale in Lake Superior, near Thunder Bay, the question is now: Should we? Tom Spears investigates
Photograph by: Gray wolf photo from AP-U.S. Fish and Wildlife , The Ottawa Citizen
On
an island in Lake Superior, biologists are wondering whether to save
some very special wolves from extinction by inbreeding, or let nature
take its course.
Behind this is the bigger question: What's really natural, anyway?
The wolves are on Isle Royale, a huge island off Thunder Bay, Ont. Because of a twist in the international boundary, it's in U.S. waters, though closer to Canada's mainland.
Canadian animals have colonized it twice. In the early 1900s, moose swam over from the mainland and thrived.
And in the late 1940s, a small group of wolves also crossed the 24 kilometres from Ontario when the lake froze.
For the past 55 years, scientists have had a living ecology laboratory like no other, where fixed populations of predators and prey go through their life-and-death cycle.
There are many hundreds of moose, enough of a gene pool to keep breeding. But there are only a few dozen wolves, and they have become increasingly inbred.
Last year, for the first time in 55 years, there were no pups. None has been seen this year either, though it's still early. Only eight wolves are left, down from more than 40 at times.
That leaves the U.S. National Park Service three choices.
■ Do nothing and let the wolves die off, because humans shouldn't interfere with nature. (Isle Royale is a U.S. national park, and also a designated wilderness area);
■ Let them die, then bring in new wolves from the mainland; or
■ Launch a "genetic rescue," bringing in some new wolves as fresh breeding stock with healthy genes.
The usual question is: Can we save endangered wildlife? This time, the question is: Should we?
Isle Royale is big - 74 km long, with 50 inland lakes - and everything on it depends on the wolves.
The moose population is naturally affected most, but so are other animals and even the vegetation.
When moose arrived they had no natural predators and soon there were 3,000 of them, six per square kilometre. They ate their way through everything, changing the face of the island. Then, starvation; the population crashed.
The moose had a domino effect on other birds, insects and mammals that depended on the forest destroyed by moose.
Plants grew back in time, the moose recovered, but it all happened again.
Then after the second crash came the wolves, and Isle Royale has returned to a natural forest state with wolves limiting the moose numbers, but never killing them all.
And scientists have found fascinating things as they look deeper into the role of predator and prey. For instance, moose feed trees.
"If a moose dies or is killed by a wolf and it decomposes on-site, the trees that grow in that area have competitive advantage over others around it," said Canadian wolf biologist Carolyn Callaghan of Luskville.
The carcasses also feed foxes, ravens and eagles.
She says the Isle Royale wolf family "has an extremely special status because of the long-term studies that have gone on."
So, what now? The wolves are inbred and unhealthy (all have spinal problems) and since the 1940s just one other wolf has crossed the ice from the mainland, a male nicknamed Old Gray Guy, in 1997. He brought fresh genes, but all the wolves on the island today are related to him, so inbreeding continues.
Behind this is the bigger question: What's really natural, anyway?
The wolves are on Isle Royale, a huge island off Thunder Bay, Ont. Because of a twist in the international boundary, it's in U.S. waters, though closer to Canada's mainland.
Canadian animals have colonized it twice. In the early 1900s, moose swam over from the mainland and thrived.
And in the late 1940s, a small group of wolves also crossed the 24 kilometres from Ontario when the lake froze.
For the past 55 years, scientists have had a living ecology laboratory like no other, where fixed populations of predators and prey go through their life-and-death cycle.
There are many hundreds of moose, enough of a gene pool to keep breeding. But there are only a few dozen wolves, and they have become increasingly inbred.
Last year, for the first time in 55 years, there were no pups. None has been seen this year either, though it's still early. Only eight wolves are left, down from more than 40 at times.
That leaves the U.S. National Park Service three choices.
■ Do nothing and let the wolves die off, because humans shouldn't interfere with nature. (Isle Royale is a U.S. national park, and also a designated wilderness area);
■ Let them die, then bring in new wolves from the mainland; or
■ Launch a "genetic rescue," bringing in some new wolves as fresh breeding stock with healthy genes.
The usual question is: Can we save endangered wildlife? This time, the question is: Should we?
Isle Royale is big - 74 km long, with 50 inland lakes - and everything on it depends on the wolves.
The moose population is naturally affected most, but so are other animals and even the vegetation.
When moose arrived they had no natural predators and soon there were 3,000 of them, six per square kilometre. They ate their way through everything, changing the face of the island. Then, starvation; the population crashed.
The moose had a domino effect on other birds, insects and mammals that depended on the forest destroyed by moose.
Plants grew back in time, the moose recovered, but it all happened again.
Then after the second crash came the wolves, and Isle Royale has returned to a natural forest state with wolves limiting the moose numbers, but never killing them all.
And scientists have found fascinating things as they look deeper into the role of predator and prey. For instance, moose feed trees.
"If a moose dies or is killed by a wolf and it decomposes on-site, the trees that grow in that area have competitive advantage over others around it," said Canadian wolf biologist Carolyn Callaghan of Luskville.
The carcasses also feed foxes, ravens and eagles.
She says the Isle Royale wolf family "has an extremely special status because of the long-term studies that have gone on."
So, what now? The wolves are inbred and unhealthy (all have spinal problems) and since the 1940s just one other wolf has crossed the ice from the mainland, a male nicknamed Old Gray Guy, in 1997. He brought fresh genes, but all the wolves on the island today are related to him, so inbreeding continues.
"It raises ethical questions in terms of what is a wilderness area and what is our role as managers," Callaghan said.
"Minimal intervention" is the rule. The U.S. Wilderness Act of 1964 stipulates that in such an area "the earth and its community of life are untrammelled by man, (and) man himself is a visitor who does not remain."
That's not a dreamy suggestion; it's federal law.
But what if humans played a role in causing the problem?
Twice in the past decades, disease brought accidentally by humans has caused a crash in the wolf population, and reduced the gene pool further. Visitors with dogs brought parvovirus - harmless to humans but sometimes lethal to wolf pups.
That suggests the inbreeding is partly our fault. Some also argue that climate change caused by humans has led to milder winters. The ice no longer connects the island and mainland, "and it's a long way to swim," Callaghan notes.
Three biologists who study these wolves recently wrote in favour of keeping them on the island somehow. "Where no place on the planet is untouched by humans, faith in non-intervention makes little sense," wrote John Vucetich and Rolf Peterson of Michigan Tech University and Michael Nelson of Oregon State.
"In a world increasingly out of balance, Isle Royale is a place with all its parts," they write - but only so long as the wolves remain.
source
"Minimal intervention" is the rule. The U.S. Wilderness Act of 1964 stipulates that in such an area "the earth and its community of life are untrammelled by man, (and) man himself is a visitor who does not remain."
That's not a dreamy suggestion; it's federal law.
But what if humans played a role in causing the problem?
Twice in the past decades, disease brought accidentally by humans has caused a crash in the wolf population, and reduced the gene pool further. Visitors with dogs brought parvovirus - harmless to humans but sometimes lethal to wolf pups.
That suggests the inbreeding is partly our fault. Some also argue that climate change caused by humans has led to milder winters. The ice no longer connects the island and mainland, "and it's a long way to swim," Callaghan notes.
Three biologists who study these wolves recently wrote in favour of keeping them on the island somehow. "Where no place on the planet is untouched by humans, faith in non-intervention makes little sense," wrote John Vucetich and Rolf Peterson of Michigan Tech University and Michael Nelson of Oregon State.
"In a world increasingly out of balance, Isle Royale is a place with all its parts," they write - but only so long as the wolves remain.
source
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