Article re: grizzly predation on elk calves in Yellowstone (and possible cause)

[Shrek]

Bitterroot Bulls , you are probably right about the study but the population of grizzly bears depending on cutthroat trout is small and the calf mortality is widespread. In the very local area around the lake it may be a minor influence. Ascribing the greatly increased grizzly predation of elk calves of the Yellowstone herd to the loss of cutthroats and not to the burgeoning grizzly population is the problem I have with the article.
The basic problem is that an unmanaged wild system is a boom and bust cycle and a much lower animal density system overall. The bears and wolves are already way over the carrying capacity of Yellowstone and they are collapsing the prey species. Once the prey completely collapse and and then the predators collapse there will be very few large animals in the park for generations. The parks are islands that cannot sustain a natural system and will continue to be a problem as long as the view of them that they should be left as "pristine wilderness" continues.

 

[ScottR_EHJ]

I'm going to jump in with agreement to Matt's statements:

-I live to the south of Yellowstone, and can pretty confidently say that I catch far fewer cutthroats and browns than we used to. Especially in the lakes and now even more in the reservoirs.

-The introduction of Ling into the GR drainage has had a major impact on the browns. A change in one species can have a major impact on another. There have been Grizzlies in this area for years as well.

-Lake trout spend the majority of their time in deeper water, I catch most of mine at about 30 feet of water. However, any of you that have ice fished for them with a fish finder know how quickly the big fish can move from 85ft+ of water into the shallow to nail a jig. Then head back down immediately. This is not an easy prey for the Grizzly bear.

-Grizzly bears are opportunistic, and if the easy food is not present in the streams, they will move on to the next easiest opportunity. I.E. Elk and moose calves, who are in hiding simply take being smelled out. Spawning fish are easy to catch if you can find them, if you can't find them, not a good opportunity.

-Our feed ground system has also contributed to the problem. Lets congregate huge herds of Elk and see how many we predators we can attract. I know of one feedground that lost 20 elk in one night when a pack of wolves came through. Large groups of ungulates will attract predators, plain and simple.

-The elk are tending to stay in the feeding grounds longer, and in drought years like last they tend to stay closer to water when calving. This sets them up for opportunistic bears who cant find the fish they are used to looking for.

Not a believer that this is a conspiracy theory, however I do believe we need to push hard for hunting management opportunities for Grizzly bears. After getting wolves delisted we need to push our legislators to work on this issue. Set quotas, work hard to manage them.

 

[Jason Snyder]

The entire Yellowstone Basin is enormous, not just a small localized area. The majority of the Greater Yellowstone grizzly population is depending upon these fish as a food source. A burgeoning grizzly population should be able to sustain itself just fine on a normal cutt population. They did for years without man's fingers in the mix.

Contrary to what you read, I don't think the prey species are completely collapsing in the Yellowstone. Last year's counts showed 3900 elk in the northern Yellowstone elk herd. Bison numbers are doing just fine.

 

[Matt Cashell]

That is where I will disagree Jason. The population HAS collapsed. Your 3900 count is pretty accurate, but it is down from 19000 in 1995. This has directly affected hunter opportunity in the surrounding areas including the sad closure of the formerly awesome draw-only Gardiner late hunt in MT.

I think you are right that elk won't be completely exterminated by this increase in predation, but hunter opportunity has definitely been severely affected.

Reasonable predator control around the park makes sense for elk and hunters.

 

[Jason Snyder]

I guess it depends on how reasonable and sustainable one thinks the 19-20k elk population was. I personally think it was way to high, and that it was more of an artificial bubble than a collapse. I think the formerly awesome Gardiner late hunt had a lot to do with it, there were a hell of a lot of elk shot over the years there.

This article was interesting, Tom Lemke talks about the age structure of that population.
http://www.thewildlifenews.com/2008/02/17/robert-fanning-has-his-say/

You're right, hunter opportunity has been severely affected. It will be interesting to see what the population trend is over the next 5-10 years, have thing stabilized and reached an equilibrium, or will elk numbers increase/decrease?

 

[In God We Trust]

Matt has a valid argument. The problem is the majority of hunters are skeptical about the majority of studies released because they are performed by anti hunting organizations or researchers regardless if they are University or privately funded. We were lied to about wolves for 20 years and now we don't want to be lied to about Grizzlies. That being said we need to keep an open mind when we read things and do our homework before we jump to conclusions and look as stupid and fanatical as the anti hunting crowd. We must stay informed!

 

[tstowater]

You cannot loose 80% of your elk herd and almost all of the moose and not have a problem. The specifics of the cutthroat trout decline can be debated elsewhere. The dilemma for this group of hunters (that's who we are) is the impact of the predators (primarily uncontrolled) on the prey species that we want to hunt. We (humans) have messed with the ecosystem and created, directly or indirectly, the imbalance between predator and prey. Therefore, we have the obligation to "balance" the ecosystem in an appropriate way. Now... that is the $64 question as everyone has an opinion as to what is appropriate. If we choose to put some of the predators "off-limits" to the "balancing", then you cannot effectively and fairly balance everything else.

Like it or not, none of these "scientists" and "studies" are objective. By nature, we are all driven by a subjective agenda even if we don't realize it. Sometimes, the interference is innocent and other times more devious with evil intentions. If we fail to make every "study" pass a litmus test of reliability, then we will get what we have coming with less hunting opportunities. I am still skeptical as I fully believe that there is a faction who will do able anything to eliminate hunting.

 

[Matt Cashell]

Those are some good points, Jason.

Why do you think 19000 was unsustainable?
What do you think of the current number of 3900?

I actually think 19000 was sustainable, when kept in check by a liberal off-park harvest. Coughenar and Singer (In a 1996 study) showed the NY herd maintaining well over 10,000 elk per year since the early 70s up to a high of 23000+ in 1986/87. Their study suggested a maximum carrying capacity of around 21000 elk, with an optimum CC of around 14000 elk.

Based on that, I would say that 3900 is WAY TOO low.

However, unlike those researchers, I am biased. I am a hunter, and I like hunting. I would rather have more hunter opportunity and let humans do the controlling of the population than predator populations. I would love to see the return of the late season Gardiner bull hunt. I would love to see freezers being filled with cows off the winter range.

It is impractical to think that wolves and grizzlies are going to be exterminated again, and I don't really want them to be. But I do want them controlled to a point where future hunters have more opportunities to hunt elk.

 

[groc426]

However, unlike those researchers, I am biased. I am a hunter, and I like hunting. I would rather have more hunter opportunity and let humans do the controlling of the population than predator populations.

I compeletely agree with you BB. I also think that there is more weight to your statement than just being selfish. As I see it, less hunting opportunities = less hunters = less conservation efforts for our wild game.

 

[Jason Snyder]

Matt,

Part of the reason I think 19k was unsustainable was the age structure shift of that elk herd over time. Older and less fertile cows can and will directly complete with younger and more fertile cows for food, breeding, etc. I don't profess to have scientific data to back this up, but something tells me that this out of whack age structure was nature's way of correcting a population.

I think 3900 is a rather low number. That is why I'm curious to see how this elk herd responds in the next 5-10 years. I have not read any data about the current age structure, and if it has shifted more to the norm? If it has, I would expect to see elk numbers increase over time.

When one looks at studies showing a grizzly bear kills an elk calf every 2 days, the significance of shifting bear diets is certainly there. How much of an impact is brucellosis having? The reason I bring that up is because the Sun River elk herd does not seem to be experiencing the same dynamics as the Northern Yellowstone herd, and there is certainly an abundance of grizzlies and wolves in the Sun River basin.

I think way too often we try to isolate "the cause", we're all guilty of that. I too am biased. My biggest beef over the years with the wolf reintroduction was the fact that the wolf groups never ponied up to buy winter range to grow more elk. Instead, we hunters have shouldered the burden and very unfairly so.

 

[Shrek]

My biggest beef with the wolf reintroduction was the wolf part.

 

[Matt Cashell]

Jason,

It is nice to have a reasonable discussion of a hot-button topic, even among hunters.

Some studies, including Lemke's referenced above , pointed at predation (bears and wolves), as a cause of the age structure problems you mentioned. That is, more calves were killed by predators, and additional pressure on winter range cows by wolves, led to less calf recruitment. So, to me, it makes more sense the older age structure was nature's way of bringing the population in balance with new, additional predators, rather than balancing with the carrying capacity of the habitat, which had not been a problem for the 20ish years prior.

 

[Jason Snyder]

Matt,

The predation may very well be part of the cause of the age structure. I tried to find calving rates for this herd but couldn't. Current data estimates about 90% pregnancy rates. However, if brucellosis is prevelant in this herd that could contribute to significant difference between pregnancy rates and calving rates. I'm just thinking out loud here, and I don't claim to have all the answers.

As a hunter, my first bias is to have more elk for hunters. But, I can certainly see where the NPS doesn't have much of a vested interest in subsidizing a late elk hunt instead of recreating a complete ecosystem. The lake trout issue is a prime example of how quickly things can go askew by messing with things.

Unfortunately, I think for the future the NY elk herd is what it is. I doubt you'll ever see any efforts to reduce grizzlies and wolves in the park, and I understand why we shouldn't .

The grizzlies in the Northern Continental Divide ecosystem are much more vegetarian oriented than their Yellowstone brethren. Maybe that's why they haven't had the same impact on the Sun River elk herd?

 

[tstowater]

It is nice to have a reasonable discussion of a hot-button topic, even among hunters.

Matt, my wife says that I am not a reasonable person, especially when I am discussing hunting issues.

I do enjoy getting out of my cave (or out from under my rock) and seeing what is going on out there.

 

[Shrek]

Tstowater , anthropomorphism in popular entertainment is the root of the reintroduction fad. Without the romanticized portrayal of animals in movies , television , books combined with an urban lifestyle that totally isolates people from the reality of animals like wolves , grizzly bears , and loins there would be zero public support for reintroduction. If the people who support the modern Sierra Club , ect were living with bears and wolves in their back yards and were trying to raise livestock or hunt for the meat they consume there would be no wolves or bears. Send that teacher some statistics of just how many sheep and calves the wolves are eating and some stories of the hardship those losses are to families trying to ranch. Add some pictures like the grizzly chasing calves and wolves killing calfs. Once you replace the image in her mind of the noble wolf that is just misunderstood with the image of the wolf as a heartless killing machine we have an allie for life. The next Sierra Club fund raising letter that shows a wolf on the cover with the tag line save me will be the end of her support of those creeps.

 

[Kevin Root]

I saw the OP's article posted on the Rocky Mountain Elk Foundation page yesterday. It was an interesting read on Grizzly food sources and their historic food choices. Surly just one of the many contributions that can adjust population levels in the ecosystem.

I'm not surprised on the Lake Trout being a contributing cause of decimation of the cutthroat population due to predation, competition and disease. The same thing happened out our way in CA in 1887 with the planting of the Mackinaw (lake) trout in Lake Tahoe. The Lahontan cutthroat trout was the native fish in that watershed and became extinct in the Truckee River system about 1940.

I hope they can get a handle and get the Yellowstone trout population back to their historic levels again. 90% decline of the native fish since the 1990's is sad and it just seems like history has a way of repeating itself at times.

 

[Shrek]

Another way of looking at it is that the lake trout is a stronger , more resilient species and has moved in and the cutthroat trout are less adaptable and should be supplanted in the ecosystem and the rest of the system will adjust. Just because things have changed doesn't necessarily mean it's bad. I haven't fished for cutthroats or lake trout but there is probably a reason people wanted them introduced. All natural systems are constantly changing and adapting and it's a fantasy to think we can preserve any system in the face of human interaction. It is obvious that the lake trout are better able to utilize the lake. What is the value to humans in the lake trout vs cutthroat debate. If the fishing is better I can kill all the grizzly bears I need to preserve the elk I value.