The Difference Between Brown and Grizzly Bears

For my book on Brooks River’s bears and salmon, I find myself digging deep into natural history and ecology of brown bears. Sometimes I uncover research that challenges my long held assumptions. Take the difference between brown and grizzly bears, for example; something I often said was mostly based on geography and diet. As I wrote for Katmai’s website:

All grizzly bears are brown bears , but not all brown bears are grizzly bears. Grizzly bears and brown bears are the same species (Ursus arctos), but grizzly bears are currently considered to be a separate subspecies (U. a. horribilis). Due to a few morphological differences, Kodiak bears are also considered to be a distinct subspecies of brown bear (U. a. middendorffi), but are very similar to Katmai’s brown bears in diet and habits.

Even though grizzlies are considered to be a subspecies of brown bear, the difference between a grizzly bear and a brown bear is fairly arbitrary. In North America, brown bears are generally considered to be those of the species that have access to coastal food resources like salmon. Grizzly bears live further inland and typically do not have access to marine-derived food resources.

These geographic and dietary distinctions seem simple enough. However, there is little scientific evidence to support it. Both brown bears and grizzly bears exist, but the differences between them aren’t what I had long assumed.

bear grazing on vegetation with travertine and forest in background

A grizzly bear grazes on springtime vegetation near Old Faithful in Yellowstone National Park.

bear in water

A brown bear at Brooks Falls in Katmai National Park. (NPS Photo)

Although North American brown, grizzly, and Kodiak bears belong to the same species, Ursus arctos, bear taxonomy underwent many revisions before scientists reached this conclusion. In the nineteenth and twentieth centuries, taxonomists frequently lumped and split brown/grizzly bears into many different species and subspecies. The separation peaked in 1918 with the publication of C. Hart Merriam’s Review of the Grizzly and Big Brown Bears of North America in which Merriam proposed around 80 (not a typo) species and subspecies of North American brown bears. Taxonomists like Merriam relied on morphological characteristics that could be seen or observed to classify living and extinct organisms. Warm-blooded animals that have hair, breathe air, and produce milk for their offspring are mammals, but warm-blooded and air-breathing animals that lay eggs, have feathers and toothless beaks are birds. These are greatly simplified examples, I realize, and such tidy and clear distinctions aren’t necessarily common in nature. They often become more difficult to resolve at the genetic and species level, especially in cases of hybridization or when taxonomic distinctiveness is based on subtle physical differences.

Merriam’s nuanced classifications of brown and grizzly bears were based on differences in skull morphology and dentition, characteristics he examined painstaking detail. Among taxonomists, Merriam was a splitter. On southeast Alaska’s Admiralty Island alone, he classified five distinct species . In the Katmai region, Merriam described two species, Ursus gyas for the Alaska Peninsula and Ursus middendorffi for Kodiak Island , as well as others for bears living in the Cook Inlet area and on the Kenai Peninsula.

If you think his classifications of brown/grizzly bears was a little over the top, you’re not alone. Merriam foreshadowed opposition to his conclusions when he wrote in his Review, “The number of species here given will appear to many as preposterous . To all such I extend a cordial invitation to . . . see for themselves.” And they did. Most of the species or subspecies described by Merriam were later regarded as local variations or individual variants. While all of Merriam’s species have since been lumped together as U. arctos, in the mid 1980s as many as nine extant or extinct subspecies of U. arctos were recognized in North America , but the only names for North American brown bear subspecies in still widely used are U. a. horribilis, the grizzly bear, and U. a. middendorffi, the Kodiak bear. Recently, however, even these classifications have come under question.

In hindsight, it’s easy to scoff at Merriam’s conclusions. Could there really be dozens of brown bear species in North America? Within the methodologies and knowledge of his era, his results aren’t that far fetched. Little was known about the behavior, growth rates, ecology, and population dynamics of North American bears in the nineteenth and early twentieth centuries. Given access to the same tools and information as modern taxonomists, Merriam may have discovered grizzly and brown bears can’t be so easily divided by differences in skull and tooth shape.

Ursus arctos is one of the most widely distributed mammal species on Earth. Historically, brown bears were found from the British Isles south to North Africa and east across northern and central Asia to Alaska and most of western and central North America. Two to three million years ago, they split from a common ancestor shared with black bears . The oldest brown bear fossils are from China and date to about 500,000 years ago. By 250,000 years ago, they spread to Europe. During the last 100,000 years of the Pleistocene, bears immigrated and emigrated across much of the northern hemisphere as climate and habitat dictated. When continental ice sheets advanced, available habitat shrunk and bears became isolated into separate populations. When the ice receded, bears dispersed into the new territory. Beginning around 70,000 years ago, the first brown bears moved into North America. While we know when and where bears lived and live from fossils and historical records, this doesn’t necessarily deduce the genetic relatedness of modern populations.

Phylogeography is a branch of phylogeny, the evolution of an organism or group of related species or populations. As such, phylogeography traces the distribution of genetic variation through time and space. In this regard, mitochondrial DNA (mtDNA) is especially useful to track female ancestry. MtDNA  resides in the mitochondrion, a cell’s powerhouse, and is inherited from the mother only, unlike nuclear DNA which is a recombination of genes from both parents. According to mtDNA analysis, there is no divide between brown and grizzly bears based on an animal’s relationship to the coast or marine food sources, nor does it support the status of U. a. horribilis or U. a. middendorffi or any other historical subspecies in North America. The only historic classification that holds is at the species level—Ursus arctos. Instead, matrilineal ancestry suggests brown bears in North America fall into three main clades.

  • Mainland Alaska, Kodiak Archipelago, and northwest Canada.
  • ABC Islands (Admiralty, Baranof, and Chichagof) in southeast Alaska.
  • Southwestern Canada (Alberta, British Columbia) and the lower 48 States.

Clades are groups of organisms evolved from a common ancestor and consequently share a genetic relationship. The three North American clades, as well as others in Europe and Asia, are believed to be descended from brown bears living in isolated populations in Asia during the late Pleistocene . Since then, the mtDNA has remained geographically separated due to the tendency of female brown bears to be homebodies. Female brown bears are philopatric. They tend to remain near or have partly overlapping home ranges with their mother and do not rapidly invade areas already occupied by other brown bears . This can prevent or at least greatly slow mtDNA from mixing into other bear populations, even long after significant barriers like ice sheets have disappeared.

screen capture of Earth with clades of bears outlined.

Approximate range of brown bear clades in North America based on mtDNA. Different clades are represented by horizontal and vertical lines. The solid red circle marks the location of brown bears on the ABC islands.

Bears on the ABC Islands are the most genetically distinct of all Ursus arctos. Their mtDNA aligns them more closely to polar bears than to other brown bears , a genetic uniqueness most likely resulting from interbreeding with a small number of isolated polar bears at the end of the last ice age. Since then, female brown bears on the islands have not spread their polar bear genes to the mainland. Bears in British Columbia, Alberta, and into the lower 48 represent another lineage who arrived in Alaska around the same time as the ancestors of the ABC bears. During a warm interglacial period, some of these bears moved south into the mid continent before the ice advanced again and sealed them off from their brethren to the north.

All other brown bears in northwest Canada and Alaska, including those on Kodiak, belong to a clade that dispersed from Asia in two separate waves. Those in northwest Canada arrived first, perhaps as early as 33,000 years ago. Bears now occupying mainland Alaska represent the last pulse of ursine migrants onto the continent, arriving just before rising sea levels flooded the Bering Strait and closed the land bridge between Asia and North America. Excluding the ABC islands, all Alaskan brown bears belong to this pedigree, which stretches from northwestern Canada and Alaska west across Russia and into Europe and includes most of the world’s brown bears.

The results from mtDNA only convey information about the maternal line, however. MtDNA cannot trace genes spread exclusively by male brown bears, so it underrepresents the role of males in gene flow. Male brown bears have larger home ranges and disperse away from their mother’s home range more readily than females, especially during their first few years of independence. Males do carry one important bit of DNA that females don’t—the Y chromosome. Like mtDNA, it is only inherited from one parent, but unlike mtDNA it can only be passed from father to son, making the Y chromosome an important marker to trace paternal gene flow and diversity.

While mtDNA shows particularly strong clade differentiation  across the entire range of Ursus arctos, geographic variation in the Y chromosome of brown bears is much shallower . According to analysis of the Y chromosome, no deep genetic or geographical divergences could be found from bears in Eurasia or North America. Brown bears on the ABC islands and mainland Alaska, for example, share closely related haplotypes (a group of genes inherited from a single parent ) found in the Y chromosome. Even brown bears from populations as separate as Norway and the ABC islands have been reported to carry highly similar Y chromosomes . Male genes, therefore, flow across clades.

infographic showing hypothetical inheritance of mitochondrial DNA and Y-chromosome through three generations of bears.

Within mammals, mitochondrial DNA can only be inherited through the maternal line. The Y chromosome is only passed from father to son. MtDNA tends to stay within genetically related clades because female bears are philopatric. Male bears, due to their inclination to disperse farther and have larger home ranges than females, can spread Y chromosomes over bigger areas. Unlike nuclear DNA, neither mtDNA nor the Y chromosome are a mix of maternal and paternal genes.

This isn’t to imply male bears from the Yukon immigrate to Europe or vice versa, just that males are more apt to wander and set up home ranges well away from their mother. If female brown bears, due to their philopatry, differentiate a population’s genetics over time, then male bears homogenize it. In other words, female brown bears like to stay in familiar terrain, but males often spread their seed far and wide.

With evidence of geographically isolated clades through mtDNA but not in the Y chromosome—can we still divide brown bears into biologically significant units? Even though genetic research adds another dimension to our understanding of wildlife, morphology remains an important way to differentiate species, and subspecies don’t necessarily need to be from separate or unique ancestry to be worth protecting. Grizzly and brown bears still exist, just not along a clean geographic and dietary divide. Where we draw the line is less important than the overall conservation of bears. Populations of brown bears—whether they are from Katmai, Kodiak, or Yellowstone—remain ecologically and culturally special no matter their genetic distinctiveness. Bears in Yellowstone are geographically and (at least currently) genetically separated from other “grizzlies.” Kodiak bears aren’t genetically distinct enough to justify them as a separate clade even though they have been isolated from mainland bears for approximately 12,000 years. Hypothetically speaking, if bears are extirpated from Kodiak or Yellowstone then they won’t be coming back and a valuable repository of genetic diversity will be lost forever.

The line between a brown bear and a grizzly, as I used to define it, was always tenuous at best. (Should grizzlies in interior Washington, British Columbia, and Idaho—who may have fed on salmon before runs in the Columbia and Snake watersheds collapsed—be considered brown bears?) Now through DNA analysis we know Ursus arctos cannot be so arbitrarily split based on their geographical closeness to the ocean. It’s still ok to say grizzly, Kodiak, or brown bear—the names can still be incredibly powerful and useful—but maybe the only truly accurate name for them is Ursus arctos.

References:

Bidon, T. , et al. Brown and polar bear Y chromosomes reveal extensive male-biased gene flow within brother lineages. Mol. Biol. Evol. 2014. 31(6): 1353-1363.

Davidson, J., et al. Late-Quaternary biogeographic scenarios for the brown bear (Ursus arctos), a wild mammal model species. Quaternary Science Reviews. 2011. 30:418-430.

Rausch, R. L. Geographic Variation in size in North American brown bears, Ursus arctos L., as indicated by condylobasal length. Canadian Journal of Zoology. 1963. 41(1): 33-45.

Schwartz, C.C. et al. “Grizzly Bear,” in Wild Mammals of North America: Biology, Management, and Conservation. 2nd Edition. Editors Feldhamer, George A., Bruce C. Thompson, and Joseph A. Chapman. John Hopkins University Press. 2003.

Talbot S. L., et al. Genetic characterization of brown bears on the Kodiak Archipelago. Final Report to Kodiak National Wildife Refuge, U.S. Fish and Wildlife Service. 2006.

Waits L. P., et al. “Genetics of the bears of the world.” In Bears: Status Survey and Conservation Action Plan. Compiled by Christopher Servheen, Stephen Herrero, and Bernard Peyton. IUCN/SSC. 1999.

Waits, L. P., et al. Mitochondrial DNA Phylogeography of the North American Brown Bear and Implications for Conservation. Conservation Biology. 1998. 12(2): 408-417.

 

Restoring Grizzlies is not a Threat to Wilderness

Wilderness Watch, a non-profit advocacy and watchdog group for the National Wilderness Preservation System, opposes active restoration of grizzly bears in the North Cascades ecosystem. While their strict adherence to wilderness values is laudable, in this case it could lead to the extirpation of grizzlies from the ecosystem. Arbitrary wilderness values are not more important than the restoration of grizzlies.

Wilderness, as defined by the 1964 Wilderness Act, is “an area where the earth and its community of life are untrammeled by man, where man himself is a visitor who does not remain.” Importantly, the Wilderness Act states wilderness areas also preserve “wilderness character,” a set of values that link wilderness conditions with legislative intent. Federal land management agencies must manage wilderness so it maintains all aspects of wilderness character. Wilderness must remain untrammeled, natural, undeveloped, provide opportunities for solitude or primitive and unconfined recreation, and protect other features of value.

Bare mountain peak with lake below

Green view lake sits below Goode Mountain in the Stephen Mather Wilderness, North Cascades National Park.

Any ecosystem manipulation in designated wilderness will affect some of these values, especially during the effort to restore grizzlies. Specifically, the Draft Grizzly Bear Restoration Plan will temporarily trammel the land by manipulating a species’ population. Additionally, helicopters flights can impact opportunities for solitude, and tracking collars on bears will affect the wilderness’s naturalness and undeveloped characteristics. For these reasons, Wilderness Watch advocates for a natural recovery alternative, which would allow bears to return on their own and offer the greatest adherence to wilderness character and values. They state:

  • Information is lacking on the status of grizzlies on the Canadian side of the border where two moderately sized provincial parks provide some protection for the bears.
  • For dubious reasons, a natural recovery alternative was rejected for further analysis. Instead, the DEIS considers only heavy-handed management alternatives.
  • The extensive use of helicopters would continue indefinitely for monitoring bear movement and numbers. This heavy-handed management would be detrimental to Wilderness and bears alike.
  • None of the current action alternatives, involving translocating bears, are compatible with Wilderness.

However, some of these assertions are incorrect. There is a “natural recovery alternative” in the draft restoration plan. It’s the no action alternative, or Alternative A. This alternative may need further revision to achieve Wilderness Watch’s goals, but it hasn’t been rejected for further analysis or excluded. Perhaps most importantly, if Wilderness Watch’s position is adopted by the National Park Service and U.S. Fish and Wildlife Service, it will likely lead to the extirpation of grizzlies in the ecosystem, where only six bears are thought to remain (Draft Grizzly Bear Restoration Plan, p. 90).

Grizzly bears are not doing well in southwestern British Columbia. Adjacent populations to the north are only slightly more numerous. Fewer than 30 grizzlies are estimated to live within the Stein-Nahatlatch and Garibaldi-Pitt areas (interactive map of grizzly populations in British Columbia). Under current conditions, no grizzly population in Canada or the U.S. is likely to expand and occupy the North Cascades region (Draft Grizzly Bear Restoration Plan, p. 88-89).

Alt Text: Map of Grizzly Bear Population Status in British Columbia (Red=Extirpated, Yellow=Threatened, Green=Viable)

This map shows the current status of grizzly bear populations in British Columbia. Many areas of B.C. have healthy populations of grizzlies, but every population in southwest B.C. is either threatened or already extirpated. Red Circle is approximate area of North Cascades ecosystem.

Wilderness Watch is correct when they write, “None of the current action alternatives, involving translocating bears, are compatible with Wilderness.” In this case, helicopters and intensive management of translocated bears would impact the area’s wilderness character. The impacts may be unavoidable, but under certain conditions wilderness character can be manipulated for safety and management needs (i.e. invasive species removal). The NPS and USFWS would need to diligently consider ways to minimize impacts.

Anyone who is willing to share the ecosystem with bears and also wishes to preserve wilderness character should support Alternative B in the draft restoration plan, which proposes to introduce a small number of grizzly bears into the area, monitor them, then reevaluate whether more bears should be introduced. This offers the best compromise, in my opinion, between the no action (natural restoration) alternative and other options (alternatives C and D) that are much more heavy handed.

Wilderness and wilderness character is worth protecting. Groups like Wilderness Watch should continue to be a watchdog for designated wilderness. Yet, the effort to restore a healthy, self-sustaining population of grizzlies in North Cascades transcends arbitrary wilderness values. Bears need wild areas more than people.

I wish we could step back and let grizzly bears restore themselves. Nothing I’ve read indicates that’s a successful solution though. The North Cascades ecosystem was identified as one of six recovery zones for grizzlies in the Lower 48 partly because of its large, natural, and healthy wilderness areas. Bears can survive here, if we give them a push. I believe we can sacrifice a bit of our cultural need for an idealized, untrammeled wilderness to benefit grizzly bears. If we don’t act, if we allow grizzlies to disappear, then that would be one of the greatest trammels of all.

You can submit comments on the Draft Grizzly Bear Restoration Plan through April 28, 2017.

Related Posts:
Stehekin Grizzly Bear Meeting
Go Further So Bears Can Go Farther

Stehekin Grizzly Bear Meeting

On Feb. 28, I attended an informational meeting about the draft plan to restore grizzly bears into the North Cascades ecosystem. I believe animals and ecosystems should receive more protection and I’m largely in favor of the plan to restore grizzlies here, but I listened through the whole meeting, not speaking a word. This wasn’t a forum for debate. I wanted to hear to the perspectives of other people who think differently. There are times when it’s more insightful to listen than to speak.

I took copious notes, trying to capture the essence of what was said. Below are a few paraphrased questions and comments from local Stehekin residents. I know who made each comment, but I won’t divulge their identities. I’m sure they’d share the same opinions with anyone who asked, but the meeting was not a formal public open house where people could provide testimony that would be entered into the official record, and as such they probably didn’t expect anyone to broadcast their name and comments all over the internet.

Many of the first few questions were about bear biology and the practicalities of restoration. How did you determine 200 bears (the number of animals the plan aims to restore)? What happens if Alternative C doesn’t work? What is prime grizzly habitat? What’s the typical grizzly bear territory? Will the habitat still be suitable for these bears if the climate changes?

brown bear standing in grass

A viable population of grizzly bears may soon roam the North Cascades ecosystem. Not everyone favors the idea.

Then the comments and questions drifted into more contentious territory. Grizzly bears and endangered species are words that provoke strong emotions. Worry, loss, skepticism, and suspicion were many of the emotions local residents expressed. Bears could potentially bring more unwanted government regulation. Residents, understandably, expressed concerns about safety and loss of access to land. Few who spoke at the meeting seemed to believe the active restoration of bears is desirable.

Residents wondered about bear attacks and the effectiveness of bear spray. One person even read a lengthy description of a bear attack from this Facebook post. He also asked whether bears would inhibit the reopening of the upper Stehekin Valley Road, which has been a long standing issue for some local residents. The same person who read the bear attack description also expressed the opinion that humans are part of nature and the extirpation of grizzly bears across most of their former range in the Lower 48 was natural and okay.

A couple of people seemed to question the historical presence of grizzly bears in the ecosystem, a conclusion that surprised me, since the historical and archeological record confirms grizzlies were here. One person suggested that native tribes didn’t settle permanently because the mountainous terrain was rough and grizzlies could’ve been one of the factors. 

To their credit, the representatives for North Cascades National Park Service Complex and the U.S. Fish and Wildlife Service avoided debating any point. That would’ve been inappropriate given the context of the meeting. They did explain, however, that these lands are federal and must be managed in the national interest. Local interests, therefore, are not necessarily the most important. They also explained how this population of bears could be designated as experimental under section 10(j) of Endangered Species Act. 10(j) status would allow more flexible management of the restored grizzly population compared to a population listed strictly as threatened and endangered.

Many of the concerns boil down to a difference in worldview from my own. Many people believe bears don’t need more space, especially if their space comes at the cost to people. They exist in healthy numbers throughout much of British Columbia and Alaska. Additionally, grizzly bears are not needed in North Cascades to fulfill a missing ecosystem function. Why make the effort to restore bears?

I wrote this post not to criticize, debate, or debunk any point. I wrote it because if you’re like me, you often do not have the opportunity to hear opposing perspectives concerning wildlife conservation issues. Those of us who think wildlife and wildlife habitat should be given greater levels of protection need to carefully consider the wants and needs of other people. Sure, I can read or listen to so-called balanced news articles about the grizzly bear restoration plan, but that’s not the same as listening to your neighbors, many of whom may feel very differently about the issue.

You can comment on the draft North Cascades grizzly bear restoration plan through March 14, 2017.

Go Further So Bears Can Go Farther

Plans are afoot to restore grizzly bears to the North Cascades ecosystem. The draft plan includes four alternatives. Only one (Alternative A) takes no action. The others, through various strategies, all aim to restore a self sustaining population of bears in the ecosystem, an effort I support. Grizzlies should be in North Cascades, but that can’t be the end game. We need to go further to allow wildlife to go father.

The story of the grizzly bear is well documented. Like bison, grizzlies suffered immensely from westward American expansion. Once found from California to Missouri and Alaska to Mexico, this iconic species is now restricted to Alaska, western Canada, and a few isolated pockets in the Lower 48.

The grizzly bear was listed as a threatened species in the Lower 48 under the Endangered Species Act in 1975. At the time, grizzlies were known or thought to exist in only four states. Since then, its range has not expanded substantially, but the most famous grizzly population in Yellowstone National Park has grown to over 700 individuals, at or near the Yellowstone ecosystem’s carrying capacity, and the Northern Continental Divide population, centered around Glacier National Park in Montana, is also doing well with over 1000 animals.

Elsewhere in the Lower 48, grizzly bears remain rare or non-existent. The Selkirk ecosystem, in northwest Washington and adjacent British Columbia, harbors only 80 grizzly bears. The Cabinet-Yaak ecosystem in northwest Montana and northern Idaho has about 50. No grizzly bears are known from the Bitterroot ecosystem in central Idaho, nor in the San Juan Mountains of Colorado where they were rumored to exist. They are extinct in Mexico.

Grizzly bears aren’t spreading far and wide, despite a high level of protection since the 1970s. They are slow to reproduce, need isolation from people, and roam over large areas of undeveloped habitat. They maintain a foothold only where they weren’t extirpated and where humans tolerate them.

In 1982, the U.S. Fish and Wildlife Service identified the North Cascades ecosystem as a recovery zone for grizzlies in the Lower 48. The ecosystem includes over six million acres stretching from extreme southwest British Columbia to Cle Elum and the Interstate 90 corridor in Washington. The core of the ecosystem is a 2.6 million acre federal wilderness complex. The wilderness areas encompass most of North Cascades National Park, Lake Chelan National Recreation Area, and a significant portion of the Okanogan-Wenatchee and Mount Baker-Snoqualmie national forests.

Map of North Cascades area showing public land and land management agencies. Black line outlines boundary of the ecosystem.

The North Cascades Ecosystem in Washington. (From the Draft Grizzly Bear Restoration Plan, pg. 2).

A handful of grizzly bears persist in the British Columbia portion of the ecosystem, but none are known in Washington. The last verified sighting of a grizzly bear in this area of Washington was in 1996. The last time a female with cubs was seen was 1991. (A possible sighting in 2010 was likely a black bear.) According to the restoration plan, it is unlikely that the North Cascades area contains a viable grizzly bear population and grizzlies are at risk of local extinction in this ecosystem if no measures are taken to introduce more bears.

Mountain valley scene. Steep walled mountains with red-berried shrub in foreground.

Many places in the North Cascades ecosystem, like the upper Stehekin River valley, provide excellent habitat for grizzly bears.

I believe it is worthwhile to make an effort to prevent the extirpation of grizzlies in the North Cascades ecosystem, even though these bears aren’t keystones like salmon or sea otters. The bears may not create substantial changes in the area, but they will have many effects. Grizzly bears are an umbrella species. If we protect habitat for and maintain healthy populations of grizzly bears, then that large core of habitat is protected for the vast majority of other species in the area.

For grizzly bears and other large carnivores, like wolves, to regain their full potential as umbrella species, we need to do more than tolerate their existence in a few isolated areas. This is where the Draft Grizzly Bear Restoration Plan falls short. The plan aims to restore a population, not create connectivity with others. For grizzly bears to remain truly viable and self sustaining, their populations need connectivity.

The Yellowstone to Yukon Conservation Initiative is probably the most famous example of this concept. It’s an effort to protect a corridor of habitat from Yellowstone National Park north through the Rocky Mountains into the Yukon Territory. It would not only provide habitat for bears, but wolves, wolverines, elk, deer, moose, and many, many other animals and plants. It would provide animals with habitat corridors so they could migrate and shift their range as conditions dictate.

Perhaps we need to provide animals and plants on the west coast of North America with a similar corridor, one stretching from Alaska and British Columbia to Baja California. The current hodgepodge of national forests and parks along the Cascade Mountains and Sierra Nevada could provide the core. To achieve continuity between ecosystems, it would only be a (not so) simple matter of connecting those pieces together in ways to adhere habitats. (I also dream about similar conservation corridors across North America—the Appalachians, a bison commons on the high plains, and Florida among others.)

I’m not sure I will include a vision for the British Columbia to Baja corridor in any comments I might submit on the draft grizzly bear restoration plan. I already know the response: “This is outside the scope of the restoration plan.” The response is completely legit. The lead agencies for the restoration plan, the National Park Service and U.S. Fish and Wildlife Service, have no authority to create such an entity. It’ll need legislation, funding, time, and the strong support of citizens and non-government organizations to be successful.

When we have an opportunity to rewild a landscape, we should. When we have an opportunity to give a little back to wildlife, we should. But, we can do better than simply restoring grizzlies to the North Cascades. Earth’s systems don’t work in isolation. We know enough now to build resiliency into our efforts to protect wild lands and wildlife. We can provide grizzly bears with the habitat to roam into Oregon, California, and other parts of the West again. We can give the ecosystems more room to be resilient. Our goal shouldn’t be to simply have bears in a few isolated areas, but provide continuous habitat so bears can survive future changes without us. That’s how we know we’ve gone far enough.

You can submit comments on the Draft Grizzly Bear Restoration Plan through April 28, 2017.