The invasion of Yellowstone Lake by Lake Trout blamed for decline in Yellowstone’s elk

Hypothesis points to how profound indirect effects of human caused ecological changes can be-

For a generation now lake trout (mackinaw) have greatly reduced the formerly hugely abundant Yellowstone cutthroat trout in Yellowstone Lake and in its tributary streams. This decline was made worse by the emergence of whirling disease, a parasite carried by people who don’t clean their waders (and other things that have been in infested bodies of water).

These adverse changes were human caused. The Lake trout was probably a deliberate introduction of a totally useless fish to any bird, mammal, or amphibian in Yellowstone Park. Lake trout eat the cutthroat upon which many species depended. Lake trout do not come to the surface. They eat other fish, die and become nothing more than sediment.

Many park grizzly and black bears heavily used the runs of spawning cutthroat. The cutthroat gone, and bears being both hunger and clever, looked for other sources of food. Yellowstone Park grizzlies became among the most carnivorous of all non-salmon eating bear species. One thing Park bears learned was to key on on elk calves and elk. In addition, bears quickly noticed that wolves provided easy access to elk. It was generally easier for a grizzly to take over a wolf-killed elk from the pack than to chase down and kill an adult elk on their own.

A number of Park elk herds have declined since a few years after wolves were reintroduced. Those people who are not capable of understanding any multi-step argument, have simply said, “Wolves eat elk. Elk numbers are down. Wolves caused the decline since nothing else in Yellowstone has changed.

The person who is even minimally observant and visits regularly knows that many things have changed since the wolves were reintroduced. There has been nearly continuous drought, which is most likely the new and adverse climate. The vital whitebark pine nuts grizzlies eat in autumn have declined greatly too because of fire, drought, and the spread of exotic whitebark pine blister rust.

A recent meta-study of 20 studies of bear diet and elk populations (from 1985 to 2012) gives evidence that the Lake trout invasion led indirectly to elk population decline as the grizzly bears began to seek out elk calves.

Back in about 1980 a fishing guide, I read, praised the Yellowstone cutthroat trout. It also said the hottest place in hell should be reserved for any person who introduced lake trout, and later this pernicious introduction happened. If the person or people who did this are now are dead, many folks will certainly hope they are currently being well roasted.

Here is a link to the study. Trout invasion behind park’s elk decline.

A final note, almost all of the “hits” that grizzly bear food sources have taken inside Yellowstone Park came directly or indirectly from human activities — lake trout, whirling disease, whitebark pine blister rust.




  1. CodyCoyote Avatar

    The conclusion of this published study should not surprise anyone. The ecology of the Greater Yellowstone is a very large mechanism with a lot of intermeshed gears and components. As are all ecosystems, but the GYE just happens to be a singular ecocsystem on a very grand scale.

    The principal author of this study is PhD candidate art Middleton from the University of Wyoming. His other recent published work was principal investogator for the 5-year study known as the Absaroka Elk Ecology Study. The AEES was funded by the elitist blue-ribbon hunting groups ( $ 650,000 total including in-kind contributions , with Rocky Mountain Elk Foundation being the lead fundraiser ), but environmental and nonhunting wildlife conservation groups were excluded from the table. The RMEF, SFW, Safari Club, Boone and Crickett, and Wyo Guides and Outfitters et al set out to buy some science to prove that Wolves were the predominant factor in the decline and distribution of both migratory and local Elk on Yellowstone’s eastern boundary zone , in the Front Range country near Cody.

    Middleton’s team did 3 hard years of very extensive field work with generous assistance from Wyoming Game & Fish helicopers and USFWS and even Wildlife Services among other minor contributions from federal and state agencies. They collared 26 cow elk and studied every aspect of the elk life cycle. They paid special attention to factors contributing to low elk calf recruitment ( survival past first two years).

    What Middleton found was near irrefutable evidence that the biggest factors affecting elk reproduction and recruitment were climate and vegetation, amplified by the sheer abundance of GRIZZLY BEARS pouncing on new elk calves to an extent not previously known. Wolves were entirely a secondary or tertiary factor in elk declines.

    It should also be said that the LOCAL elk herds in the Clarks Fork-Crandall-Sunlight Basin areas that are not migratory back to Yellowstone are thriving. it’s the migratory elk that are declining…those members of the Northern Herd that spend some of the year outside Yellowstone and migrate back into the Park.

    So—Middleton is the man in the middle, really Both his recent published studies point at ecosystem-wide factors regarding food supply and habitat as being the strongest stress factors on wildlife, especially elk which where the focus of the one study. Now we hear from Middleton that the decline to Yellowstone Cutthroat to less than 7 percent of their former numbers has a trophic cascade effect that can only be called ” tsunamic” in its scope.

    The irony of this is not lost on me. The elitists sport hunters of Safari Club, Rocky Mountain Elk, Boone and Crockett and especially Sportsmen for Fish and Wildlife are gonna have to face the findings…those damn fisherman are the cause of their falling trophy bull elk numbers, as much as anything. Wolves are w-a-a-a-a-y down the list.

    Isn’t it deafening, the silence from RMEF and SFW on the findings of Middleton’s elk ecology study going somewhere other than towards wolves as decimators? And now, the dearth of native trout are harbingers of further declines in subalpine elk populations and huntable trophy bulls ?

    So much irony my fingers are rusting….

    1. Ralph Maughan Avatar
      Ralph Maughan

      Thank you Cody Coyote.

      I can imagine RMEF and similar groups will not be funding a real scientist again soon. 😉

    2. JEFF E Avatar
      JEFF E

      watch for all the usual suspects to completely ignore the findings you point out Cody and try to marginalize the study; without any cites of course.

    3. Immer Treue Avatar
      Immer Treue


      I remember when Middleton’s study first appeared. The howls about who “must have funded” said study stretched all the way to Ralph, all the while all one had to do was scroll to the funding organizations.

      I imagine there are many who are shaking their heads at this time. Well here’s hoping they shake them til they fall off. Bob Ferris had a recent piece comparing the intricacies of pointillism
      (art, think Seurat) to nature. One small point doesn’t seem like much, but when you put them all together, one has art. So goes nature.

      “Isn’t it deafening, the silence from RMEF and SFW on the findings of Middleton’s elk ecology study going somewhere other than towards wolves as decimators”

      Delightful summarization.

    4. cobackcountry Avatar

      These people should have thought about the basics of food webs. The late Dr. Nakano could have saved them a lot of money and effort, has they just read about his work.

      Fish are an essential component to any ecosystem they exist in, and even more so to those which begin and end at a stream bank.

      I’d venture an educated guess that elk numbers without wolf introduction, would be even lower at this point. Although I cannot PROVE it, I think the over population and extremely degraded riparian habitats resulting from such, would surely have resulted in a weakened population. Undoubtedly, the artificially sustained and elevated numbers would have eaten themselves out of habitat, much as the herd in Rocky Mountain National Park has….and then they head into yards, onto grazing areas etc. Or, they die or become altered due to the dietary challenges.

      We can only speculate about how the GYE and it’s elk might have evolved without wolves to balance the behavior of herds. I think the current elk numbers likely reflect a more realistic and naturally sustainable number. They behavior of elk and their insincts to move around more is also more natural.I would even speculate those darn wolves may have contributed to the current elk being a healthier, stronger lineage and the remaining Cutthroat trout still being around?

      But I stress, these are just the musings of my own conservation oriented mind. I make no claim that these are facts. Although, facts or musings…this sure is a fine piece of “I told you so” cake with frosting on it to dine on. Thanks for posting this!!!

      1. cobackcountry Avatar

        FOOD WEBS…common sense, real science.

  2. malencid Avatar

    From Cody “those damn fisherman are the cause of their falling trophy bull elk numbers, as much as anything.” I assume this is tongue in cheek, since Yellowstone has been catch and release for years. Also ” Yellowstone Cutthroat to less than 7 percent of their former numbers” Is this accurate and does it apply only to Yellowstone Lake and its spawning tributaries because of the lake trout that are present? What percentage is due to the Lake trout and Whrling disease?

    1. CodyCoyote Avatar

      malencid…by those ” damn fishermen” , I meant the bucket biologists who illegally transplanted the Mackinaw trout into Yellowstone Lake c. 1970 from somewhere west of the Continental Divide, probably Shoshone Lake which is only 12 miles away as the Raven flies.

      The depredation of Yellowstone Cutts is almost entirely due to the Macks.

      Caveat: the remaining meager population of Cutts is also falling prey to the growing numbers of American White Pelicans who migrate to YNP each summer from the Gulf of Mexico. They hit the river hard during the spawn , and are ubiquitous at following all the recreational and working boats on Yellowstone Lake —especially the gill net boats—to gobble on fish parts.

      I’ve spent a LOT of time on a boat in Yellowstone Lake the past thjree summers, fishing the bays of the South and Southeast Arms and the west shoreline, We’ve seen exactly one Osprey. Only a handful of Bald Eagles. Bunches of Pelicans.

      1. cobackcountry Avatar

        There is no proof that fishermen did place the Mac’s in Yellowstone Lake. It is widely speculated that they were dumped during the 88 fires, as part of suppression efforts. They could easily have been air lifted by copters that were dropping water out of other Lakes which held natural populations of Lakers.
        I only bring this up because we should be cautious when pointing fingers, as it could just as easily be turned upon us if we don’t stick to facts.

        1. SaveBears Avatar

          Hate to say it, being careful is not in the vocabulary on either side of the wildlife issue and the species does not matter.

          1. cobackcountry Avatar

            So very true! I don’t always believe in political correctness. It can be synonymous with “crap” or fear of being honest. But I still try (very operative word) to be cautious about blame.

        2. Leslie Avatar

          cobackcountry…I suspect you are probably right. I’ve heard it said that the Park themselves introduced those Lake trout, probably inadvertently.

        3. CodyCoyote Avatar

          cobackcountry – your theory about helicopter water buckets ferrying Mackinaw over the Continental Divide to Yellowstone Lake does not hold much water. The Mackinaw in Yellowstone Lake were taking hold there and full grown for years before the fires of ’88. I have anecdotal evidence they may have been illegally but purposely stocked as far back as the 1960’s.

          Sidebar Anecdote : There used to be a fish hatchery at Lake Hotel , pre-bridge Bay Marina , where among other things the Park biologists actually had the gumption to hybridize a Yellowstone Golden Cutthroat trout. Playing God. In the absence of a mea culpa on who planted the Macks and when , we can only speculate. Freelance bucket biologist is prime suspect .

          I do know some of those Lake Trout lunkers are huge and ancient. Been there a lot longer than 1988…

          1. cobackcountry Avatar

            It isn’t my theory. lol I wish I had a theory which was so widely surveyed.

            Theories on this subject, as you have pointed out, abound. But we cannot prove an origin.

            Lakers also travel, so perhaps they made their way to the lake themselves. They get huge in a hurry, particularly with no competition in a lake which can provide an abundance of food year round.

            Yes, the historical hatchery could be a culprit, or a combination of the afore mentioned could have brought this all about. At this point, I think it is more prudent to figure out if removal is helping, and if not then what will?

            Wildlife and fisheries management is an art which is always evolving with changing circumstances. It is a practice in ‘playing God’ to some extent. The need for management is largely due to the impact of people who take these matters into their own hands.

            I am just happy you have shared this, as it sheds light on the realities of other groups that have played God with our wildlife and fisheries for years, cattle ranchers and groups like RMEF. They do it all the time. The sad part is, they do it without regard to consequence for entire species.

  3. Immer Treue Avatar
    Immer Treue

    Follow the ravens and he shall find the elk calves. Nature.

  4. Robert R Avatar
    Robert R

    Just how does this really work?
    The cutthroat only spawn once a year and depending on the location and elevation they spawn anytime from march to July.
    What does bear feed on when it comes out of its den, sedges and carrion or maybe some grubs/insects.
    What do other bears feed on that don’t have spawning fish to feed on.
    I’ve seen what a grizzly does when the elk are calving but the smorgasbord is short lived after the calves reach a certain age and can travel.
    Someone is making a big deal out of something that has been going on for decades.
    Codycoyote talks about the pelicans eating fish and there is mention of whirling disease. How unlikely would it be for pelicans to carry whirling disease from one body of water to the next. It was not far back that a tag from a tagged fish from the big hole river in Montana was recovered in Idaho some three hundred air miles away where a bunch of pelicans were.–mile-pelican-flight-to/article_405ece05-b01d-5a9f-923e-8e76681572c6.html

    1. cobackcountry Avatar

      It is very possible for whirling disease positive fish to be transferred by pelicans. But Whirling Disease is a rather misleading name for what is actually a process of prion infestation. The disease is the result of prions which are introduced by a tubifex worm. Two hosts are required…the TAN (worm) and the fish.
      The specific tubifex worms are particular, so they won’t be every where. They are also sturdy, so once they are there, they will stay.
      There is a lot of magnificent work being done to find answers for WD. Dr. Eric Featherman is an absolute genius, and I had the privilege of hearing him talk about his research on the subject.
      These factors are all relevant. They are also all factors which need to be considered and managed according to their natural processes. Bears eat, elk will get wise to them as they have done to a great extent with wolves. Pelicans are very prevalent and may need to have numbers managed.
      This is all pretty common stuff, and is probably only a big deal because the powers that be probably thought they had paid for a different outcome to the study.

      1. Mark L Avatar
        Mark L

        I’m curious if there is any paleontological evidence that pelicans have (or have not) historically been in the area (maybe check before the managing begins). They are being described in this thread as if they are an accident of history that needs correcting. They may also be a boon in an ecosystem.

        1. SEAK Mossback Avatar
          SEAK Mossback

          I recall seeing lots of pelicans during canoe trips in the late 1960s around the Molly Islands in the southern part of the lake — they were pretty abundant at least that far back and I suspect much longer. Cutthroats were also very abundant then, too.

        2. aves Avatar

          White pelicans have been at Yellowstone Lake since at least 1890:

          “The birds have been surveyed for more than 30 years, with some data going back to 1890 when nesting
          American white pelicans (Pelecanus erythrorhynchos) and California gulls (Larus californicus) were first
          noted in this area.” (Page 76 of

      2. cobackcountry Avatar

        Sorry, I typed “prion”, I should have typed “parasite”. I have prions on the brains, pun intended…..I was writing a review of a prion lecture when I typed this. I am on disease homework overload.

        1. Mark L Avatar
          Mark L

          So, you’re a prisoner of prion preoccupation with parasitic puns?

          1. cobackcountry Avatar

            Mark L.
            Huge sigh, after a large laugh, I am.

  5. Leslie Avatar

    Cody, This info was in Arthur’s defense of his dissertation last spring. I’m not sure why its only now being talked about as this research has been public for over a year.

    I posed this question to G&F through our game warden-is the elk herd Middleton studied (namely our Sunlight herd) being affected by the decline in cutthroats? His response was that this only affects elk herds and bears that are near the Lake.

    Amazingly, the warden also said historical records show low cow/calf ratios in the Sunlight/Lamar herd. So then I wondered, why do the study? Just to blame wolves?

    Yet the truth is there are just more bears in the landscape now and Arthur’s dissertation talked about how the Lamar herd calves at higher elevations where there is an abundance of bears.

    After all that money, as well as support from G&F, I am not seeing G&F incorporate this data into their wolf plans. Last hunt called for 8 wolves to be killed in the Sunlight area. With barely 8 wolves here, the result was that 3 YNP Lamar wolves were killed. At this time, it is uncertain there is even a resident pack in Sunlight and the fall hunt calls for 4 wolves. The idea here is to cull the wolves in order to help the Sunlight cow/calf ratio. Why spend all the time, money and effort if you’re not going to use the data to change your management actions?

    1. Ralph Maughan Avatar
      Ralph Maughan


      You wrote, “I’m not sure why its only now being talked about as this research has been public for over a year.”

      I was alerted to the story by George Wuerthner with link to the newspaper in Australia put in my story. From there I wrote the story based on what Middleton found and my own knowledge of the the various issues raised.

      This morning I discovered the likely source of the sudden interest — a news release from the University of Wyoming. New UW Research Shows Grizzly Diet Shift Hits Elk Herds

      The actual paper is Arthur D. Middleton, Thomas A. Morrison, Jennifer K. Fortin, Charles T. Robbins, Kelly M. Proffitt, P. J. White, Douglas E. McWhirter, Todd M. Koel, Douglas G. Brimeyer, W. Sue Fairbanks, and Matthew J. Kauffman. Grizzly bear predation links the loss of native trout to the demography of migratory elk in Yellowstone

      1. Leslie Avatar

        thanks Ralph. Looks like they are digging deeper into what Middleton was referring to in his dissertation. As I recall, he was referencing other researchers working on this issue at that time. Glad to see McWhirter’s name on that paper. He works around here.

  6. Immer Treue Avatar
    Immer Treue

    Could be wrong here with time and place, but I seem to remember reading/hearing someplace, that lake trout were taken from the Great Lakes prior to the opening of the St. Lawrence sea way were sent to Yellowstone. Needless to say, sea lamprey reek havoc with Great Lakes lake trout.

    Once sea lamprey were “controlled” offspring of lake trout that we’re sent to Yellowstone were used to repopulate
    Great Lakes.

  7. Mike Avatar

    There’s no science behind this comment, just voodoo. But the last several falls in Yellowstone have not felt right at all. Very few animals, and crunchy brown landscapes.

    Yellowstone is a park in trouble, and not just from climate change.

    I feel sadness when sitting along the banks of the Yellowstone near the big lake. I look down into the river from Fishing Bridge and get a sense that things were much more electric in years past, with healthy runs of cutthroat, and numerous osprey working up and down the river. The riverway, although beautiful, feels like a ghost.

    I’d also like to see the park implement a permit system for the summer months. The place is just hammered, again and again by the locals.

  8. CodyCoyote Avatar

    Some footnotes to this ecological article:

    Several years back I was surprised to see two Wyoming Game and Fish redshirts in hipwaders braving the LeHardy Rapids a yew miles down the river from Yellowstone Lake, with nets in hand, during the Cutthroat spawning run. They were live-catching trout. There were a couple white pelicans perched nearby offering advice.

    Why would Wyo G&F be doing this ? Well, they have an interesting program to restore Yellowstone Cutthroats to watersheds outside the Park. They will remove all the trout in a suitable stream using the organic piscicide Rotenone, wait a year, then reintroduce Yellowstone Cutt spawn. They’ve done this in a few places, and about to do it farther afield by transplanting Cutts to the Big Horn Mountains 125 miles east of Yellowstone, in Porcupine Creek above Yellowtail Reservoir.

    Wyo G&F is doing this to provide ” hedge” populations of yellowstone Cutts outside the Park proper ; for insurance. And of course seed stock. Y-Cutts do not spawn as well in a manmade hatchery as other trout. High country rushing streams are what this fish needs.

    One place they have successfully transplanted the Y-Cutts is in Dead Indian Creek , a major tributary of the Clark Fork River parallel to Sunlight Creek. Dead Indian Creek has some waterfalls a few miles above the road that will prevent fish from going up any further, or upstream fish from travelling down from there. So Yellowstone Cutthroat now reside above those falls all the way to the headwaters. (Frequent commentor here Leslie lives near it.) Sunlight Creek also has barrier waterfalls along its course.

    I mention this location because Dead Indian Creek is/was in Art Middleton’s Absaroka Elk Ecology Study area, and is prime Grizzly habitat if there ever was any. One of the crucial ” choke points” for elk migrating in and out of Yellowstone from the headwaters of the Lamar River is the trail into Sunlight Creek. That’s where the grizzlies hit the elk calves, and hit them hard. There are several of those elk migration chokepoints in the Yellowstone boundary mountains, and believe me, the apex predators do stake them out coming and going. That’s all I’m gonna say about that.

    We’ll see if the Sunlight-Dead Indian Creeks drainage grizzly population develops any affinity for Dead Indian Yellowstone Cutthroat in years to come. I personally hope Wyo G&F keeps up with this fish restoration program where it can.

    We should keep in mind that most of the trout in our Wyoming headwaters are nonnative species…Browns, Rainbows, Brook etc …but the rapidly diminishing Yellowstone Cutthroat is native to the region. In fact, we call them Natives when we land one. All others are alien exotic trout that were d stocked as ” put and take” fish for sport fishermen. I think we are seeing the consequences today of that naive management policy done many decades ago. Wyo G&F engages in a helluva lot of ” put and take” hatchery stocking for sport fishing. They like fishing license revenues but must guarantee ample amount of product.

    Still, it’s interesting to go to the Copper Lakes up in the head of Sunlight Creek and fish for Golden Trout. Those crimson beauties were brought to the Absarokas , Beartooths, and Wind Rivers from the Sierra Nevada Mountains of Kern County California back in the 1930’s, and are prized by Wyoming anglers as trophy fish.

    My other footnote here is we have an invasive predatory fish increasing in numbers in Buffalo Bill Reservoir near Cody , at the confluence of the North Fork and South Fork of the mighty Shoshone River drainages. Those rivers have native Cutthroat trout as well, but are now endangered by the reintroduction by bucket biologists of Walleye Pike. The Pike likely came from Yellowtail Reservoir over along the foot of the Big Horns, or maybe Boysen Reservoir down near Thermopolis WY. Northern Walleye are not native to Wyoming, but have been put here for fisherman to enjoy in the deep reservoirs behind the BuRec dams. The Walleye have spun out of control.

    Buffalo Bill Reservoir also has had Mackinaw-Lake trout as long as I can remember. SOme have lived long enough to reach 25 – 35 lbs in weight. A Mack has to live a long time and eat a lot of other fish to get that big, but every so often a 25 pounder is landed at Buffalo Bill. The Shoshone cutthroats that winter in Buffalo Bill and spawn in the upper rivers seemed to do OK despite having the predatory macks in their midst. The recent reintroduction of the Walleye has changed the equation in a negative way for the cutthroat. The Pike are hammering them these days.

    Wyo G&F now has a scale model of Yellowstone Lake to deal with at Buffalo Bill…nonnative illegally introduced predatory fish as decimating the native trout.

    All this causes me to wonder mightily about the way we manage fish in the Rocky Mountain headwaters these days. Playing God, or at least a demigod.

    1. cobackcountry Avatar

      Think of what would happen if we didn’t. Yikes.
      The thing is, we manage fisheries that are not in protected areas or reserves, for sportsmen. Literally, we decide what fish we cultivate based on demand of sports anglers.

      Initially, I think biologists had no idea of the far reaching ramifications of their actions. Once they started to figure it out, they had to experiment on how to best nullify their errors. So, they introduced “this” to take care of “that”. To some degree, the strategies are working.

      The Pyramid Lake Cutthroat is an example of success. The Colorado Greenback is still a work in progress.

      We continue to do these things, based on policy, law, and socioeconomics.

      A large majority of management is handled on a state level. What we do in National Parks is going to be more highly scrutinized.

      Cross your fingers, and hope for the best!

      1. rork Avatar

        Indeed, mismanagement to please anglers (I’m one) is way overdone.
        In Michigan our biologists (and anglers) say how great the decisions to bring non-native salmonids has been, saying little about our failure to protect Lake Trout and Lake Sturgeon genetic diversity – where the planet relies on us to be doing a very good job. We are sticking Atlantic Salmon into Lake Huron again – just for jollies ya see. Our brook trout are hit, so we make more browns and rainbows. Making grayling and some special whitefish species extinct is part of our history too. We’ve stocked native fish in the past, just to have more available for anglers, even though any biologist worth a shit should have known that’s bad for the genetic diversity.

        In Washington, they can’t seem to decide between walleye being pests or desirable game fish, so the regs treat them as being a little bit of both, or some such craziness.
        In Ontario (ma femme!) they have now introduced smelt into Lake Nipigon, which is a sacred place for me, so I call this sacrilege. Deliberately, hoping to increase the productivity of the lake for certain “desirable” fish, like Walleye – not just for anglers, it’s for commercial fishing too. This unbelievable place, and we do uncontrolled, irreversible experiments. I hope it’s not too disastrous.

        Maybe it’s cause I’m older, and caught lots of fish, and fished superabundant pristine places, but I’d rather have the managers tell me I can’t take fish, or even can’t fish at all, rather than doing crazy stuff out there so folks can catch “rubber fish”.

        1. Mike Avatar

          The Michigan DNR doesn’t care about rare species. They care about resource extraction. They denied the presence of cougars for decades despite evidence. They worried more about restrictions on loggers and miners in case lynx and cougar started showing up (they did,and will).

          Approving a mine in the headwaters of the last, true Michigan coaster brook trout stream says all you need to know about how things work in Michigan. Good luck finding a pine tree with an 18 inch diameter or more (not on a stream) in Baraga County.

          The U.P. is still special country, but there’s so much that could be done to make it what it should be. Those cold upland rivers running into Superior are gems, and the coasters should be restored.

    2. Mike Avatar

      ++They will remove all the trout in a suitable stream using the organic piscicide Rotenone++

      Rotenone is extremely toxic to insects and aquatic life, and in effect wipes out a stream, robbing animals like mink and osprey their hunting grounds.

      If a human were to digest this stuff, it would be fatal. It’s also been linked to Parkinson’s disease in rats.

      1. cobackcountry Avatar

        That is true. It is toxic, but it is also very short lived, and they control dilution to the greatest extent possible.

        I don’t know of a biologist who thinks it is as easy fix. It is usually a last resort.

        I’m glad to see so many people are becoming educated on these issues. It makes me hopeful about it all. (Caution: Hope can result in disappointment).

        1. Mike Avatar

          I agree, these are not easy choices.

          Almost all pesticides are incredibly toxic to a wide variety of animals. There’s a giant industry based on gullible guys thinking they need to order toxic chemicals. Lawn chemical services are one such outfit. Most people don’t know that RoundUp kills frogs pretty much on contact.

          Pesticides should only be used in life or death circumstances, such as failing food supplies. Our ability to produce these chemicals dwarfs our ability to properly test for the full array of side effects.

          Europe looks to be ahead of the game in this regard.

          I’ve been doing research into nanobot technology for species restoration. This is the way we will go in the future (if we don’t kill ourselves). A thousand programmed nanobots could wipe out the lake trout in Yellowstone lake in a few months, and then be used again for other purposes.

    3. Ida Lupine Avatar
      Ida Lupine

      I see humanity more like the divine mischief-makers than gods – sometimes doing good, but many times screwing up, having the hubris to try to improve upon what was perfect already.

      1. Mike Avatar

        Curious chimps knocking that boulder down the hill just because.

  9. Leslie Avatar

    Cody, I’m no fisherman, or fisherwoman, but I did catch some big cutthroats over at Sunshine reservoir. I’ve tried a few times my hand at fishing at dead indian creek since they did the kill and restock, but haven’t seen any fish yet. I’m glad they are doing the cutthroat reintro. I was told it was for insurance so that cutthroats wouldn’t be listed and fishing would then be restricted in certain creeks.

    1. CodyCoyote Avatar


      Sunshine Reservoir is privately owned, a co-op of Greybull Valley irrigators, mainly for farmers down around Burlington and Emblem. A couple of time in the past three decades, it has been drained completely in low water years…irrigators took every drop. Upper Sunshine is dumped into Lower Sunshine, and it’s the lower lake that works the river. So Wyo G&F had to restock Upper Sunshine from scratch. The last time that happened I think was about 1993-ish…dunno. My friend is the ditchrider/lake manager there and I could ask him. I have photos from the late 80’s of a dry lakebed.

      That is not entirely bad…they get rid of the Suckers when they do that .

      Any Cutthroats you caught there were put there in recent years , into a virgin lake.

  10. Rancher Bob Avatar
    Rancher Bob

    Can anyone/everyone tell me how the drought in YNP has caused the elk numbers to decline, when Eastern Montana which for the most part has had a worse drought has seen elk numbers increasing. I would guess the same could be said for parts of Wyoming. Wouldn’t the effects of drought have the same result both in and out of the park?

    1. Immer Treue Avatar
      Immer Treue

      Rancher Bob,

      I’m just throwing something out there, not looking for a fight on this issue, but is there more hunting pressure in the western portion of Montana based upon human population density in Montana?

      1. Rancher Bob Avatar
        Rancher Bob

        Not sure of the answer, but I’ll do some looking. If I look at Montana hunting regulation book, elk permit drawing statistics show that percentage of success seems even through out the state. I’m always surprised by the number of hunters who travel long distances to hunt, me, I step out my back door.

        1. Immer Treue Avatar
          Immer Treue



      2. SAP Avatar

        Unless it’s for archery season in the Missouri Breaks, I almost never hear of anyone from here in southwest MT going east of the mountains to hunt elk. Pronghorn, yes. Turkeys, yes. Not elk. Conversely, I sure see a lot of rigs from eastern counties out here in elk season.

        I figure the reason folks travel to hunt is just to go somewhere different, see some new country.

        As to elk populations on the rise east of the mountains: I hear that land ownership patterns might play a role — vast tracts of private land, much of it leased to outfitters. So human hunting pressure is purposefully light. And virtually no other major predators to contend with — much of the country would work against mountain lions, very few black bears, virtually zero grizzlies and just sporadic wolf presence.

        Compare that with western MT — lots of hunters of all kinds. Much better access for the average hunter (especially day or weekend hunts within an hour or two of the biggest towns in the state). Factor in the energetics of life in the mountains versus life on the rolling plains with plenty of high quality dryland wheat and other unprotected crops to eat.

        1. Robert R Avatar
          Robert R

          This is what most don’t understand when they mention that elk numbers have increased.

          Rancher Bob says:
          Can anyone/everyone tell me how the drought in YNP has caused the elk numbers to decline, when Eastern Montana which for the most part has had a worse drought has seen elk numbers increasing. Yes lack of two apex predators.

          Some just make excuses and with all there education just don’t understand.

  11. spudgun Avatar

    2 questions:
    1) Whirling disease – this is a disease that has primarily affected rainbow trout in the last 5-6 years – not sure how this relates to HISTORICAL populations of cut-throat? There is some recent (2011 onwards) evidence of small isolated populatins of Cutts ahveing a minimal effect as a result of WD, but the historical decline in Cutts is more attributable to mans influence than WD. Also, whirling disease is generally not spread by fisherman’s waders – it’s spread by hatchery fish

    ” 11. How is whirling disease transmitted? top

    Whirling disease is transmitted by infected fish and fish parts. It may also be transmitted by birds and it is possible anglers can carry the parasite on fishing equipment. However, infected fish and fish parts are the main vector for the spread of the disease. A single fish can be infected with many thousands of spores (up to a million or more)!”

    2) Not sure how bears survived on spawning runs of cut-throat? Is this confusing the magnitude of the cut-throat spawning run with that of the pacific salmons as seen in Alaska.

    I’m tempted to say this is a load of garbage, but having read it several times the language used makes it self evident that this is poorly researched, unlikely hypothesis heavy, proof light, quasi-scientific sensationalism at best

    1. Ken Cole Avatar

      You seem uninformed.

      look at this:

      and this (page 30):

      For example, whirling disease is believed to have caused the virtual extirpation of spawning Yellowstone cutthroat trout ascending Pelican Creek from Yellowstone Lake (Koel et al. 2005). This tributary once supported thousands of spawning cutthroat trout from the lake (Gresswell et al. 1994).

      1. spudgun Avatar

        1) COULD be transmitted by fishing waders – not IS. the primary and traceable cause of WD is stocked rainbow trout. Colorados own fisheries have admiteed tostocking infected fish – no doubt simialr fubars have occureed in MT, but haven’t been reported.

        2) That’s one stream out of how many in the Yellowstone catchment – let alone MT as a whole

    2. SAP Avatar

      Spudgun – grizzlies eat a lot of different things, for sure. They’re not pandas. No credible person is saying that all grizzlies will go extinct without cutthroat spawning runs, nor are they saying they’ll go extinct without whitebark pine.

      What they are saying is that close to 20 percent of the GYE grizzly population used to get a nice big hit of protein every spring from those spawning streams, and now they don’t. With a pretty tight annual nutrition budget, they need to make up that slice of calories somewhere. The cutthroat spawning runs overlap temporarlly with elk parturition.

      I can assure you that Arthur Middleton, along with his co-authors and peer reviewers, are not confusing cutthroats with Pacific salmon.

      Sure, the biomass is not quite the same, nor are the numbers or size of bears feeding on the fish. Nonetheless, those spawning streams were impressive. I’ve seen 5# cutthroats wiggling through 3″ of water making their way up those streams. Bears, otters, ospreys were all stuffing themselves, yet fish were still getting through and spawning.

      I just re-read U Wyoming’s release, and they mention whirling disease only as a secondary factor in the decline of Yellowstone cutthroats. It’s the illegally introduced lake trout that destroyed the cutthroat spawning runs. The cutts spawned in those shallow little tributaries, something lake trout don’t do.

      1. Ralph Maughan Avatar
        Ralph Maughan


        I should add that the Yellowstone cutts also swam way up the Yellowstone River and its upstream tributaries, south of the Park in the Teton Wilderness, supporting grizzlies and other wildlife deep in the Teton Wilderness.

        1. SAP Avatar

          Excellent point, Ralph. Bigger policy picture, I’d like to see burden of proof squarely on those who think we can maintain a minimum of 500 wild bears in the Primary Conservation Area without these seasonal calorie bonanzas (whitebark pine and cutthroats in particular). The debate needs to focus on meeting that 500 goal, not on straw man arguments about immediate extinction.

          1. cobackcountry Avatar

            The number of bears which are to be protected is not based on proof that anyone CAN maintain them. Rather, it is based on the premise that we have an obligation to protect at least those 500 bears for present and future generations. The laws and policies which outline the circumstances under which a species is to be protected also specify that we are to manage their habitat in order to assure those numbers can be maintained. That includes taking measures to assure food supplies are available. Lake Trout are not a viable food source for grizzly bears. Cutthroat are. We have don’t a burden of proof to show we can maintain a certain amount of fish or pine seeds, we have a legal obligation to assure that any and all species protected under the ESA are provided the protections outlined in it. If an EIS is in place saying that grizzlies require cutthroat, then cutthroat they must have.

      2. spudgun Avatar

        No, but Mr Maughan’s sensationalist piece definitely tries to point the finger at recreational fishers as a causal effect

    3. SEAK Mossback Avatar
      SEAK Mossback

      It seems like its really the timing overlap that of the food sources that is key — cutthroats are spring spawners, overlapping the early period for elk calves. I remember watching them in June in Grouse and Chipmunk Creeks stacked like cordwood similar to salmn in pools ready to move up and spawn, and there were grizzly tracks around (although we did our best not to see any bears). In Alaska, it likely works the opposite because salmon abundance is large enough in many areas to have a major positive influence on the number of bears that can be supported year round — one study of black bears concluded that one day on a salmon stream supports 5 days in the den. However, salmon are not much available where they can be caught by bears before mid-July at the earliest, starting in this area with summer chums, then pinks, sockeyes and chinooks (on a few streams) and finally cohos and fall chums clear into the winter. None of these overlap significantly with very young ungulates, but bears are definitely prowling for food in May and June –so areas with lots of salmon that support lots of bears are not particularly favorable drainages or islands for young deer and moose survival.

  12. Snaildarter Avatar

    People are leaving Eastern MT they have a human population loss going on there. So more land for elk, even in a stressful drought is a good thing.

  13. Snaildarter Avatar

    Personally I love this study, lake trout were probably introduced by the same misguided wolf haters who want to ruin the natural world so they can have an overpopulation of elk that they can shoot without having to get out of their pickup truck.

    1. Robert R Avatar
      Robert R

      “It is no mystery how the Lake Trout found it’s way to Yellowstone Park. The Bureau of Fisheries Department is the responsible party for the initial introduction of Lake Trout into Yellowstone Park (along with other non-indigenous species). Although there is no documentation to prove they planted the fish directly into Yellowstone Lake itself, they were responsible for the species finding a home in the two lakes closest to Yellowstone Lake. The practice of trapping bait fish has been wide spread, legal and used by sportsman (largely ice fisherman) for decades if not centuries. This practice spawns (no pun intended) the spread of fish species from one body of water to another. The dumping of bait “down the hole” at the end of the day or season is and was commonplace. That said, the issue of “who is responsible” is a moot point at this stage of the game.”
      The same could be said for all lakes and streams.
      One of the biggest baitfish problems were the chubs brought in from Utah. Hebgen lake proably holds the biggest population of Utah chubs, but the brown trout like them.

  14. Snaildarter Avatar

    thanks that’s very interesting if you talk to a park ranger they always make it sound like someone did it on purpose. Still it points out that when humans alter an ecosystem to achieve an unnatural goal, its usually bad idea.

  15. jay rasmussen Avatar
    jay rasmussen

    i think you’ll find that most hunters and sportsman’s groups will be receptive to these findings that the griz plays a larger role then once thought[compared to the wolf] in the decline of the doesn’t come as any surprise that it’s man’s bumbling and short sightedness that is at the heart of the matter. i don’t hunt much any more, kind of lost my taste for wild game but i was and still am concerned about game management more then the politics. it shouldn’t be about who’s right or wrong but how best to insure the healthy populations of the prey and predators.i was against wolf reintroduction to begin with mainly because it looked like they would be given amnesty and not treated like a game animal but i am forming new opinions, these opinions vary depending on location and several other factors.


Dr. Ralph Maughan is professor emeritus of political science at Idaho State University. He was a Western Watersheds Project Board Member off and on for many years, and was also its President for several years. For a long time he produced Ralph Maughan’s Wolf Report. He was a founder of the Greater Yellowstone Coalition. He and Jackie Johnson Maughan wrote three editions of “Hiking Idaho.” He also wrote “Beyond the Tetons” and “Backpacking Wyoming’s Teton and Washakie Wilderness.” He created and is the administrator of The Wildlife News.

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Ralph Maughan