Category Archives: Global Warming

The Wolves of Isle Royale: Genetic Rescue or Sacrificial Lamb

“The “natural” assumption. 
Most people who are familiar at all with Isle Royale assume that the national park’s famous populations of wolves and moose are “natural” residents of the archipelago. Thus, the impending decision of what to do if wolves became extirpated on Isle Royale seems to be an
easy managerial one: replacement wolves should be brought in. But a historical view of major mammals on Isle Royale in the last hundred years reveals a much more complicated situation.

The first major published study on the wolves and moose of Isle Royale (The Wolves of Isle Royale), makes this very point. An astounding discovery made in a summary table of the “History of Isle Royale Mammals”  shows that all the large mammals on Isle Royale have changed in the 20th century. Coyotes and lynx have gone and wolves appeared. Woodland caribou were extirpated and moose arrived and have become the dominant herbivore. Red fox arrived circa 1925…Otter were missing for much of the 20th century but now are quite common. And a little earlier, in the late 1800s, beaver were nearly extirpated. This radical composition turnover may be an effect of island biogeography. One
primary indication of island biogeography is that the island(s) being studied have only a subset of the animals and plants found on the nearest mainland. Island biogeography also
routinely maps species turnover on islands, as species “wink out” and different ones “wink in.” But also quite often a species winks out and then recolonizes on its own, as happened
with otter and beaver at Isle Royale.
This fact of potential periodic and extensive change needs to be built into any discussions of augmenting wolf numbers in the near term. We need to acknowledge the possibility that the winking out of wolves on Isle Royale might be a natural phenomenon of island biogeography. But unfortunately, our yardstick for making such decisions is compromised: what appears to be the natural island fauna in the 20th century is actually a chimera, greatly altered
by human actions…”

Should we intervene…  
Is it a succession of human actions—inadvertent intervention to be sure—that has had a direct role in wolves “naturally” appearing on Isle Royale. Even if moose and wolves had arrived on Isle Royale as a very direct consequence of human action, does that change the question of whether we should intervene to maintain the wolf population in the national park? For comparison, neither wolves nor moose are present on Michipicoten Island, an archipelago in northeastern Lake Superior that is similar in distance from the mainland as is Isle Royale. Due north of Isle Royale, and much closer to the mainland, wolves made it to the Slate Islands, hunted woodland caribou, and then left in the 1990s. Could the arrival of moose and wolves on Isle Royale be more an aberration than an inevitable event? Furthermore, if recent immigrants to the park were aided directly or indirectly by human actions, does that make them “exotic species” as defined by NPS management policies? NPS defines exotic species as those “that occupy or could occupy park lands directly or indirectly as the result of deliberate or accidental human activities….” The newly crafted resource management recommendation for the NPS, Revisiting Leopold: Resource Stewardship in the National Parks, is written, in part, as a policy response to the array of environmental changes, such as climate change, that are confronting national parks. The report calls for an expanded scientific capacity to guide resource management “to steward NPS resources for continuous change that is not yet fully understood, in order to preserve ecological integrity….” Wolves are clearly native to the region, but perhaps not to Isle Royale. Might their indigenousness to the region and their place in the ecological process in the region outweigh their potential non-native history on Isle Royale? Because wolves are part of a “largely self-sustaining and self-regulating” Isle Royale ecosystem, should we overlook their questionable “natural” tenure? If so, we should at least make this decision transparently. Intervention can be an important tool to maintain a park’s ecological resiliency. But “intervention” as a concept exists on a continuum of human actions that range from unintended consequences (wolf trapping on Ontario) to intervention (radio collaring of wolves and moose on Isle Royale, closures of zones to protect denning areas, closure of the park to dogs and cats) to intentional manipulation (the introduction of the Detroit Zoo wolves).
A historical view of Isle Royale’s mammalian history suggests there are both known and likely unknown limits to species persistence through time. It is likely that many animal species’ tenure on the island is episodic, ranging from a single colonizations of short duration to
persistence lasting decades. It may not always be anthropogenic forces that result in a species winking out or another winking in; an example is the episodic presence of sharptail grouse at Isle Royale.

A historical view of the relatively short and possibly atypical residence of wolves suggests the proposed reintroduction could become a recurring need to sustain the health and persistence of the population. Do we want to reintroduce wolves to Isle Royale National Park every 50 or so years?
To further explore how much intervention is appropriate, it’s useful to turn to a long-used Isle Royale metaphor, namely, that the national park is an “outdoor laboratory.” Vucetich et al. are proposing a level of intervention for wolves which bespeaks of the park as more of a laboratory. If intervention is too frequent, then Isle Royale stops having the feel of an outdoor laboratory, and its wilderness character is diminished to boot. Periodic interventions would run counter to one component of the Wilderness Act, namely, that “the imprint of man’s work” must be “substantially unnoticeable.” But Isle Royale has not been unimpacted for quite some time. Regional, national, and global impacts have greatly altered the naturalness of the Isle Royale lands and waters, even if the results are sometimes hard to see (source).

Moose on Isle Royale, Michigan. (AP Photo/Courtesy of Michigan Tech University, Rolf Peterson)

 And what about the moose (the primary food source for Isle Royale wolves) which tend to become infested with an astounding number of ticks at one time. Thanks to global warming, one animal which typically can get 30,000 ticks in normal fall weather conditions, now contends with as many as 160,000 ticks during warmer winters and in years with a late first snowfall. The eventual result for heavily tick infested moose is malnutrition and death; a high number of ticks is “almost a death sentence” for calves because they can lose their entire blood supply over just a few months. Climate change magnifies the tick problem because the pests live longer and reproduce in greater numbers if there’s less snow on the ground by spring. Source

During the late 1980s and early 1990s, moose lived longer and gave birth to more calves as predation was down due to a steep decline in wolf survival. The moose population nearly tripled to almost 2,400 by 1996. During the winter of 1996, lack of forage for the moose, an outbreak of moose ticks , and severe winter all conspired against the moose. The winter had been more severe than any in over a century. The moose population collapsed from its all-time high to just 500 moose. The next year, during the winter of 1997, a wolf from Canada immigrated to Isle Royale. He crossed on an ice bridge that now rarely forms between Isle Royale and Canada, and revitalized the wolf population’s genetic diversity. Living in three packs, with 30 individuals, the wolves had been “thriving” until 2006. But with moose becoming increasingly rare (weakened by heat and ticks, fueling high rates of predation, moose dropped to their lowest observed levels) capturing food become increasingly difficult. One wolf pack failed after another. By 2011, the population was reduced to 9 wolves living in one pack and another half dozen wolves, the socially disorganized remnants of another pack (Source). As many as 50 wolves once roamed the island, though scientists think 25 is a more reasonable baseline number,  according to the Wildlife News. Since scientists began keeping records in 1973, ice accumulation in the Great Lakes has declined by over 70 percent, an ice bridge may only form once every 15 years. With Lake Superior warming faster than any large lake on the planet, any hope of a “natural” genetic rescue disappears. John Vucetich, a researcher on the island, asserts that a genetic rescue is critical — not only for animals, but for the entire Isle Royale ecosystem, designated a protected biosphere reserve in 1981 for its pristine lake forest wilderness. “What is really important here is not the presence of wolves, per se,” Vucetich said. “But the wolves need to be able to perform their ecological function — predation. Predation has been essentially nil for the past four years now, and has led to a 22% increase in the moose population for each of the past four years.” This increase has brought the island population of moose up from 500 to 1,200 compromising the ecosystem integrity (An individual moose consumes up to 40 pounds of vegetation a day).

Bring in the wolves…problem solved…or not.

The wolves populated Isle Royale around 1949, and were believed to have been basically isolated ever since, comprised typically of just a couple dozen wolves. Small, isolated populations of wildlife never fare well and always exhibit high rates of inbreeding. The deleterious effects of inbreeding begin to become evident at a COI (coefficient of inbreeding) of about 5%. At a COI of 10%, there is significant loss of vitality in the offspring as well as an increase in the expression of deleterious recessive mutations. The combined effects of these make 10% the threshold of the “extinction vortex” – the level of inbreeding at which smaller litters, higher mortality, and expression of genetic defects have a negative effect on the size of the population, and as the population gets smaller the rate of inbreeding goes up, resulting in a negative feedback loop that eventually drives a population to extinction.

“Fragmentation of natural habitats is associated with population declines of many species. The resulting small and isolated populations are threatened by extinction for several reasons. Such populations are more vulnerable to demographic and environmental stochasticity. They also face several genetic threats. First, due to restricted mating opportunities, inbreeding becomes more likely. Second, if populations remain small and isolated for many generations, they lose genetic variation necessary to respond to environmental challenges (random fixation or loss of alleles through genetic drift). Third, unfavourable mutations are
expected to accumulate because selection operates less efficiently in small populations. Of these processes, inbreeding poses a more immediate threat, whereas
genetic drift and mutation accumulation affect the population in the long term. Environmental, demographic and genetic factors can interact and reinforce each other in a downward spiral, an extinction vortex.”  BMC Evolutionary Biology


“For many decades, the wolves of Isle Royale had been taken as an example of a very small, isolated and highly inbred population which showed no signs of inbreeding depression, the negative impact of inbreeding. But we had it wrong, very wrong. In fact, the population dynamics of Isle Royale wolves have been affected by genetic processes in ways that have been as important as they are subtle.

In 2009, with the help of Jannike Räikkönen, an expert in Canid anatomy from the Swedish National Museum, we systematically inspected the skeletal remains from 50, or so, Isle Royale wolves that had been collected over the past five decades. A surprising number of these wolves suffered from several different kinds of congenital malformity in the spine… A particular kind of deformity, known as a lumbosacral transitional vertebrae (LSTV), is particularly well studied in dogs and wolves. Among healthy, outbred populations LSTV occurs in one out of a 100 wolves. On Isle Royale, a third of the wolves suffered from this malformity.

Not only did Isle Royale wolves exhibit LSTV at a high rate, but the rate of malformities had once been relatively low and increased over the decades…”.  John A. Vucetich

Learn more about Congenital defects in a highly inbred wild wolf population
(Canis lupus) here.


Cause for alarm.

Obviously an isolated and small population of wolves is a bottleneck leading to extinction due to lack of genetic diversity. Without continuous human intervention this will be the case for any wolves brought to Isle Royale in the future, and, as the isolated species spirals downward to the extinction vortex there comes a great deal of suffering due to genetic deformities. The deterioration of the animal takes its toll; one female wolf on Isle Royale died during childbirth when her uterus quit working, trapping the pups inside her while she bled to death. The young wolf pictured here, presumed 


dead, certainly experienced a miserable short existence (I, myself can hardly bear to look at this poor deformed animal). And what of the food supply? As I mentioned earlier the moose population was near 2,400 in 1996, but plummeted in just one year to 500 animals due to an outbreak of moose ticks and a severe winter. When moose became increasingly rare in 2006, with a population of a little over 500, capturing food become increasingly difficult for the wolves.. “One wolf pack failed after another, with the population reduced by half.” The 1,250 moose presently on Isle Royale, weakened from the effects of climate change, can easily be devoured by a couple of dozen wolves and “wink out” leaving the wolves without a key and primary food source.

So, should wolves be reintroduced to Isle Royale?
Really this is a difficult question. For the sake of the ecosystem, then yes, perhaps the wolves should be reintroduced. But what about the wolves… One aspect in all this discussion needs to be the welfare of the wolves captured for augmentation. Wolves for re-introduction on Isle Royale would have to be sourced from multiple populations to give an initial genetic diversity. More wolves would possibly have to be added later to maintain this genetic diversity and prevent inbreeding.
Then, there is the physical collection of wolves which would pose difficulties and is likely to result in some deaths. Would they be collected by trapping, snaring or be incapacitated by dart from a helicopter?
During the collection of animals for the Yellowstone re-introduction programme at least 10 wolves died early in the process through trapping and snaring and at least one died during incapacitation from the helicopter. Perhaps techniques have evolved and improved since then, but some losses would almost certainly occur.

Removal of the alpha animals from a pack would cause huge upheaval, and studies show that it would almost certainly lead to the dissolution of the pack. Packs that may have been in existence for generations could literally be wiped out by the removal of perhaps just one animal (Learn more here).
Wolves may also attempt to make their way back to their own territories. Relocation of wolves in Alaska’s Denali National Park has led to them returning hundreds of miles to their previous locations. Obviously wolves reintroduced to Isle Royale would be unable to do that, but the instinct to return home could, to say the least, be troubling for them.
For the wolves sake, perhaps reintroduction is not a good idea.

The National Parks Service would like to hear from you. Last year the National Park Service (NPS) began considering a broad range of management actions as part of determining how to manage the moose and wolf populations at Isle Royale National Park for at least the next 20 years. Following public comments and additional internal deliberations, the NPS determined that it will revise and narrow the scope of the EIS to focus on the question of whether to bring wolves to Isle Royale National Park in the near term, and if so, how to do so.

Revised preliminary draft alternative concepts have been included in a public scoping newsletter, which is available online at  As a result of the revised scope, the NPS is offering an additional public comment period that will close 30 days after an amended notice of intent is published in the Federal Register. All comments already submitted have been posted online, however, NPS welcomes additional input at this time.  If you would like to submit additional comments for consideration, you must submit written comments online at or mail: Isle Royale National Park, 800 East Lakeshore Drive, Houghton, Michigan 49931-1896   or hand deliver them to the park. Comment period was originally to close May 16, 2016 at 11:59 PM Mountain Time, but has been extended. The comment period now closes Jul 06, 2016 at 11:59 PM Mountain Time.

Researchers would love to prolong their studies of the predator-prey system on Isle Royale.

I, myself, would like to see an end to the suffering. Perhaps the moose population should be controlled with PZP.

Related content: My Name is Rolf

Featured image: Ian McAllister


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No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written permission of the publisher.


Delisting Grizzlies

Federal delisting and subsequent hunting, as well as the imminent extinction of a key food source, due to global warming, spell disaster for the iconic grizzly bears of the Greater Yellowstone Ecosystem.

Grizzly bears feel the effects of climate change in more ways than just an untimely end to hibernation; as the whitebark pine tree succumbs to the effects of global warming, the grizzlies primary food source (nuts from the tree) is rapidly disappearing with the tree facing possible extinction from the park (80 percent of the stands are dead or dying). Once common in harsh mountain environments, the tree is being pushed out of its sub-alpine habitat thanks to a warming climate, causing the treeline to migrate to higher elevations.

The whitebark pine is also a victim of the pine beetle, the insect responsible for the destruction of hundreds of thousands of acres of forests across the West. Pine bark larvae have higher survival rates in warmer winters and the infestation, at this stage, seems unstoppable (In 2011 the U.S. Fish and Wildlife Service determined the tree warrants protection under the  Endangered Species Act). In the Yellowstone park area the tree is nearly gone: “No amount of science or management will bring the trees back in our lifetime.111114-grizzly-399-135_1.jpg

In 2007, this massive die off of whitebark pine trees added hardship to the misery which the Greater Yellowstone Ecosystem distinct population segment of grizzly bear population had to face, as they were removed from the threatened species list, and the “Conservation Strategy” was implemented. Our warming planet’s effect on grizzly bear habitat and food source was obviously of no great concern to Fish and Wildlife when making this choice to delist the Yellowstone grizzly.

FWS argues that whitebark seeds are not a naturally reliable food source, and that grizzlies have been coping for millennia by switching to other foods when whitebark pine seeds are unavailable by consuming other “readily available” foods such as ungulates, ground squirrels, insects, roots, mushrooms, and other vegetative matter. However, what must, and should, be emphasized is the fact that the grizzly bear population increases at a slower rate when the whitebark seed is scarce. It is well documented that good whitebark cone crops decrease grizzly mortality and increase the number of bear cubs per litter. For Grizzlies, one of the world’s slowest-reproducing mammals, this issue cannot be ignored when considering delisting this iconic species. 


Directly after removal from protections, in 2008, Grizzlies died in record numbers, there were virtually no penalties for killing them. Bear management had been turned over to fish and game agencies of Wyoming, Idaho and Montana who more than welcome the “opportunity to kill a Grizzly”, a bear whose life was made less valuable by delisting. Some 54 grizzly bears  — including 37 shot by humans — were known to have died that year, the highest mortality ever recorded; exceeding the extensive killings of 40 years ago when Yellowstone National Park closed down its garbage dumps leaving the bears to search for food sources in towns and campgrounds.

Thankfully, in 2009, in a strongly worded order, U.S. District Judge Donald W. Molloy, overturned  the delisting ruling, placing grizzly bears back on the threatened species list claiming: (1) the Conservation Strategy was unenforceable, and (2) that the U.S. Fish and Wildlife Service did not adequately consider the impacts of the potential loss of whitebark pine nuts.

As if we hadn’t learned our lesson from prior grizzly strategies, we find ourselves at the crossroads of further endangering the very existence of our beloved Grizzlies by delisting a species struggling to survive in our ever-changing and warming world. Further complicating the situation (as if it wasn’t bad enough, already) the Yellowstone grizzly bear population suffers from increasingly fragmented and disconnected habitats, according to a report released by the Endangered Species Coalition, which highlights ten rare or endangered species that lack safe, navigable corridors to connect them to important habitat or other populations. Without wildlife corridors, migration routes, and other connected habitat, wildlife like grizzlies cannot continue to reproduce, find food, disperse, and maintain enough diversity in their populations to survive into the future.

Before I continue, let’s take a moment out to watch and enjoy a Yellowstone National Park Grizzly Bear Mother and her cubs on Vimeo.


Delisting Grizzlies in the face of undeniable threats to the bear’s future as a species is hardly a decision based on sound science. Turning the bears’ management over to the fish and game agencies of Wyoming, Idaho and Montana, who not only accept practically any hunter explanation (self-defense or otherwise) for taking a grizzly but who find it perfectly acceptable to “euthanize” a 13 year old mother grizzly, who had cubs by her side for eating apples from a tree! The officials in Idaho determined the adult bear had become “habituated to human-related food”. 

And what of Grizzly 399, an elderly 20 year old grizzly, who has brought joy to countless park visitors, famous for tolerating people and for teaching her cubs how to live amicably near roads and developed areas? What will happen when 399 and other park bears lose their Endangered Species Act (ESA) protections—possibly as soon as this spring—when the states of Wyoming, Montana, and Idaho jump at the opportunity to implement a “sport” hunt that could kill as many as 30 bears in the next year alone? I shudder at the thought of the betrayal these bears will face. From Counterpunch:

“The first bears to be killed in a trophy sport hunt are likely to be celebrities such as Grizzly 399 that make their living along roadsides in Grand Teton and Yellowstone Parks, where they give thousands of visitors the thrill of a lifetime. These tolerant bears, which live partly on National Forest lands outside parks, would be especially vulnerable to hunting if federal protections are lifted later this year. These bears are comfortable with people and would be relatively easy to find. Moreover, certain local thugs have stated outright that they will be out to kill these much-beloved grizzlies—out of spite.”

With the quality of grizzly habitat eroding due to global warming, and whitebark pine nuts almost completely eliminated from grizzly bear diets, grizzlies in this island ecosystem will be severely stressed. Yellowstone grizzlies will require more public land to roam, not only for “readily available” food sources but also so they can maintain genetic diversity by breeding with other grizzly bear populations.

The most important move the government could make (other than an effective plan to help people and bears avoid conflicts) would be to keep the grizzly population of Yellowstone protected under the ESA.

Please submit your comment against removing ESA protections for the grizzlies of the Greater Yellowstone Ecosystem here. Please note that submissions merely supporting or opposing a potential delisting, without supporting documentation, will not be considered in making a determination.

Comments are due May 10 2016, at 11:59 PM Eastern time.

Please sign these petitions:

Protect Grizzly Bears in Idaho, Montana and Wyoming

Please continue Endangered Species Act protections for grizzly bears of the Greater Yellowstone Ecosystem.

Keep Yellowstone Grizzlies Protected under the ESA

Don’t delist YNP Grizzlies

Don’t kill protections for Yellowstone Grizzlies

Help protect grizzly bears in the Greater Yellowstone Ecosystem!

Protect the Greater Yellowstone grizzly– Stop the delisting!

Facebook pages devoted to Yellowstone bears: Hey Bear | GOAL Tribal Coalition  and Greater Yellowstone Bears. Also reach out to Campaign for Yellowstone’s Wolves who will be holding rallies this summer for the benefit of the park bears and wolves.

.@USFWS @DirectorDanAshe Please maintain Endangered Species Act protections 4 #GrizzlyBears #DontDelistGrizzlies Send a tweet for grizzlies

All images used in this blog post are of Grizzly 399 and are by Bradly J. Boner (with the exception of the vimeo)

Op-Ed by Doug Peacock who has been writing and lecturing about Yellowstone bears for more than 40 years.

Related content


Copyright © 2015 [COPYRIGHT Intheshadowofthewolf, name and webpage]. All Rights Reserved.

No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written permission of the publisher.