Isle Royale National Park's Wolf Population Down To Just Eight, No New Pups Last Year

Will these three wolves, members of the "West-end Trio," be among among the last to lope across Isle Royale National Park? Photo courtesy of Dr. John Vucetich, Michigan Tech.

Just eight wolves can be found at Isle Royale National Park, the lowest count ever tallied, and no new pups were brought into the population last year, another first that seemingly moves the population closer to extinction.

But against that dire news, National Park Service officials continue to work towards a solution that could reverse the wolves' plight, and a rebounding moose population could contribute by offering the eight a bountiful prey base.

If there's any good news to be found in the annual census released Tuesday, it's that biologists now believe at least four, and maybe five, of the wolves are females; a year ago they thought there were just two.

Tracking the vagaries of wolf dynamics at Isle Royale is difficult, wildlife biologist John Vucetich explained Tuesday, because genetic sampling is used to determine sex, and those tests take time. Lack of funds prevented testing on scat samples collected the past two years until this past January, when the results became known.

Rebuilding the island's wolf population won't be easy, though, as the animals long have suffered from inbreeding.

Three decades ago Isle Royale was home to multiple packs totaling 50 individuals. But lone wolves searching for new territories don't easily find themselves on Isle Royale, as ice bridges that allow them to cross Lake Superior from Ontario to the island are few and fragile due to warming waters and somewhat mild winters. As a result, there hasn't been a refreshing infusion of off-island wolf genes since a Canadian male made that 15-mile ice bridge crossing in 1997.

His arrival did provide a welcome burst of genes. He sired 34 offspring, which in turn produced at least 22 of their own. But the passage of time without additional mainland interlopers has narrowed the gene pool.

Park officials are expected to propose possible solutions later this year. In the meantime, wildlife biologists will be carefully watching to see if any pups are born this spring. Last year's failure to produce a litter was startling.

"For wolves, making pups is a relatively easy thing to do," Dr. Vucetich, who monitors the wolves along with Dr. Rolf Peterson from their Michigan Tech base in Houghton, Michigan, said Tuesday during a phone call. "When they are unable to do it, it certainly is noteworthy."

Adding concern to that failure a year ago was the new realization that there were at least four females for breeding a year ago, said Dr. Vucetich. "What's of a concern now, is that the reason they're not reproducing is not because they can't find females; it's for some other reason," he said.

And yet, that concern could vanish overnight if pups show up next month.

"If they have pups this April, then I guess you'd say (last year's failure) is a fluke, they just couldn't do it," the wildlife biologist said. "But if they don't reproduce two years in a row, then of course, it's already an OK question to ask: Is this the beginning of the end?"

Moose, Vegetation Thriving As Wolves Decline

The steady decline of wolves at Isle Royale comes as other facets of the park's natural kingdom are on the rise.

Alternate Text
Moose are rebounding in number on Isle Royale, and that means a plentiful food base for wolves. Photo courtesy of Dr. John Vucetich.

While the moose population plummeted to as few as 530 in 2009, that decline allowed robust vegetative growth to occur on the 45-mile-long island in Lake Superior. That growth fed a rebound, and today the ungulates number roughly 900.

"Because moose were so low for so long, it gave an opportunity for the vegetation to just rebound in a way that I'd never seen in my time on Isle Royale," Dr. Vucetich said. "Balsam fir has experienced a release of growth that they have not seen in 100 years. Moose are up to their eyeballs in food."

And that bountiful buffet has led to an abundance of moose calves, noted Isle Royale Superintendent Phyllis Green.

It remains to be seen if the burgeoning prey base will be enough to buoy the wolf population. Understanding that, the park superintendent has been working with experts in and out of the Park Service to explore options for giving the wolves a lift.

Those options range from doing nothing and possibly watching the predators vanish from the island to bringing in some new animals to perform a "genetic rescue" by contributing to the currently shallow gene pool.

"Some people say, 'Why don't you just go out there and throw wolves at the problem?'" she said Tuesday during a call from her office. "Well, wolves kill wolves. They have territorial disputes all the time. So if your intent in doing that was to replenish the genetics that are there, that might not be your end result.

"Whatever action we take has to be extermely well-thought out. We've gained a lot from the research that's been done for the last 50 years, I think. We need to sort out what are the critical things we need to learn in the next 50 years, too."

For now the eight wolves are roaming the island in two packs of three -- the remnants of the old Chippewa Harbor Pack at the east end and the so-called "West-end Trio -- and two lone wolves in between.

While Superintendent Green expects to have a draft proposal for how to manage the wolves for public review in a few months, she noted Tuesday that climate change is bringing a lot of changes to the park and affecting a lot of species. All that information, plus genetic projections, must be considered in looking at the wolves' future.

"We know these wolves are having genetic issues. Other populations that get isolated because of climate change will, too. So there's going to be limited resources to address all of the issues that come out of climate change," she said. "We have to be really smart about where we focus our resources. That's part of this. That's why we need a good discussion internally on policy and wildlife management and intervention vs. non-intervention. The wolves, they're certainly tenuous, but we've got time to be thoughtful."

Comments

I thought the whole purpose of the program and the study was to study the NATURAL history of the population. That may mean allowing the population to cease to exist for a while until new blood and genes cross over on the ice as the moose population skyrockets. If global warming keeps this from happening, then humankind has to decide whether to let nature take its course or whether to intervene, and in doing so, put away all pretense that what is being studied is a natural process and is now more akin to game management without the firearms.

You're absolutely right, Rudy. We discussed just those points two years ago:

http://www.nationalparkstraveler.com/2011/04/how-stable-future-isle-royale-national-parks-wolf-population7994

It certainly will be interesting how the Park Service comes down on the future of the wolves. One of the agency's mandates is to allow natural processes to proceed in the parks.


as ice bridges that allow them to cross Lake Superior from Ontario to the island are few and fragile due to warming waters and somewhat mild winters.


Is that a fair statement? From what I read, the ice bridge of 1948-1949 which led to the initial introduction was a rare and from what I can tell not since repeated event.


If global warming keeps this from happening, then humankind has to decide whether to let nature take its course or whether to intervene, and in doing so, put away all pretense that what is being studied is a natural process and is now more akin to game management without the firearms.


One might argue that if human-induced global warming is preventing an ice bridge from forming, then introducing wolves would be consistent with restoring species extirpated by human activities.


Is that a fair statement? From what I read, the ice bridge of 1948-1949 which led to the initial introduction was a rare and from what I can tell not since repeated event.



a Canadian male made that 15-mile ice bridge crossing in 1997.

ec, according to the scientists, there was a bridge in 1997 that allowed a male to reach the island. See graph 6 above.

So, indeed, a rare event. And not one that seems to have been altered by "warming".

If they sit on their hands, the wolves will die out. Then Isle Royale will revert to what it was before these wolves appeared: what many NPS people called "a barnyard." The moose population will skyrocket, the island will be overgrazed again, the system will be out of whack again. The arrival of the wolves was a godsend and helped rehabilitate that place.

Throw some fresh wolves in there, get some fresh genes. Look, a laissez faire approach to this island isn't particularly correct, because human beings decimated the native species years ago. There used to be lynx and woodland caribou. This place needs aggressive human management. It's not pristine. Because of global warming, the age of regular ice freezes is over. No point in letting it go to seed. Animals can't migrate to that island like they used to. Reintroduction has succeeded in many Natl Parks (Yellowstone wolves, bighorn sheep all over, etc), and I've never understood why the Isle Royale people have always insisted on dragging their feet.


human beings decimated the native species years ago


I think that's another point to consider, CROTALID. Even with the periodic freezing of Lake Superior, there are simply less wolves to wander over.

In 1988 Yellowstone and environs burned up. The road system was a huge hazard to travel. Dead hazard trees presented real and deadly hazard for visitors and park workers. The NPS resisted efforts for some time to remove the hazard trees along the roadways because it was not within their mandate to manage 'natural systems'. I traveled through the park in 1989 and it was really strange to see the accumulated logging equipment everywhere removing those trees. I'm sure the Park Service hated doing it. It was clearly reasonable to remove those trees so la touristas weren't unnecessarily maimed.

Fuel loading on Chapin Mesa in Mesa Verde has been excessive for many years.In the mid ninties Mesa Verde had a large fire, the Chapin 5, that ran through Chapin Mesa. It burned around the visitor center, actually ignited a small piece of the Far View Lodge. It burned up most of the guardrails along the highway and destroyed the parks most significant petroglyph panel. The fire was suppressed but some thousands of acres was torched. The Fire Management Officer for the park had become something of a pariah at Mesa Verde because he had recognized the danger to park facilities and tourists and wanted to do a bit of fuel management. He had not been successful.

After the fire, management was willing to consider doing some mitigation work on the mesa. Hot shot crews were stationed there during the summer when not engaged in fire suppression and they did lots of fuels mitigation, largely out of public view.

A couple of years later the Pony fire raged out of the Ute Mountain Reservation on the west side of the park and burned more facilities and roadways. After that the Bircher fire came up from Mancos and burned most of what was left from the east side.

The park service then got serious about fuels work. This time, it was clearly in public view and was interpreted for the public. Work had just been accomplished around the employees residence area and the Chapin museum when the Long Mesa fire erupted. A couple of homes were burned but the fuels work had minimized the damage. they still lost their million or more gallon water tank that brought all the parks potable water up from the valley bottom. The FMO was no longer the goat.

In both of these cases, the public was 'ok' with what the Park Service was doing. It was just the Park Service that had reservations about "the mission".'

I guess the point of this is that management has to make decisions and not simply rely on policy for their parks. I don't have an opinion on whether or not they should re-introduce wolves or not but it's clear to me that these areas are not the static systems they were once viewed as and sometimes, management needs to do something different. I think that might hold true for their budgeting too....


Because of global warming, the age of regular ice freezes is over.


Regular freezes? It was an "unusually cold winter" in 1948-1949 which allowed for the first recorded crossing. There wasn't another documented crossing until 1997 - well after the proverbial (and discredited) "hockey stick" and into the supposed warmest year on record. Global warming has nothing to do with this.


Dead hazard trees presented real and deadly hazard for visitors and park workers.


Like you mike, but you are wrong here. Check out the work of Jack Cohen, with the National Forest Service or some of the studies of the Yellowstone fire. The NFS and NPS made mistakes not allowing natural fires to burn but they are wasting dollars cutting "hazard" trees.

Thanks EC. I should have been more clear. The hazard trees I'm speaking of were those standing dead that would fall directly upon roadways or other improvements if not removed. Generally, those trees fall, without warning, within 3 to 10 years. Leaving those trees is tantamount to pitching your tent under a dead snag with wind predicted.

Mr. Jack Cohen is the relevant authority for mitigation work. I've read a lot of his stuff, heard him speak and met him on two occasions. I agree that simply removing trees isn't effective mitigation but that isn't what I was speaking of.

Aahh, Mike we are on the same page. Mitigation along roads, camp grounds, utilities et al makes sense. Unfortunately, the NFS and local officials here in Summit County, CO and elsewhere in the state have wasted $100s of thousands of dollars cutting trees in the middle of nowhere that will have no impact. But it makes people feel good that " something" is being done - even though it is a total waste, or even counter productive. Sound familiar?

Of additional interest:

"Should Isle Royale Wolves be Reintroduced? A Case Study on Wilderness Management
in a Changing World"

Since ecbuck has retrieved this story, here's a recent Op-ed from Isle Royale biologists on the issue of wolf re-introduction:

http://www.nytimes.com/2013/05/09/opinion/save-the-wolves-of-isle-royale-national-park.html