Myth debunked that wolves changed Yellowstone's rivers

[Isela]

Abstract from accuweather.com:

For centuries, the wolf has inspired long-standing myths and legends across the world. In recent years, viral videos online have spun new tales about the wolf, attributing immense ecological changes to the canine, including a cascade of effects powerful enough to alter the flow of rivers in Yellowstone National Park.

While wolves are crucial predators in the Yellowstone food web, the story of a wolf-driven “trophic cascade” promoted in a popular online video is far from the complex reality of the park’s ecosystem.

Full article here: https://www.accuweather.com/en/weather- ... s/70004699

[Writers Block]

Thanks for sharing, Isela! I actually didn't know this, so this was an informative read! I remember reading a NatGeo article several years back about how wolves changed the face of Yellowstone, and I never found any reason to be critical of them so I never doubted the story (I'm more critical of NatGeo these days, but back when I read that article I was young enough to trust everything I read, aha) It's good to have a more realistic view of the situation. c:

[Noctis_]

I remember reading a NatGeo article several years back about how wolves changed the face of Yellowstone, and I never found any reason to be critical of them so I never doubted the story (I'm more critical of NatGeo these days, but back when I read that article I was young enough to trust everything I read, aha) It's good to have a more realistic view of the situation. c:

I've found that to be a problem as well. National Geographic is widely considered to be a very reputable source, so trying to contradict them is usually only ever met with raised eyebrows. I remember a documentary about wolves I once watched by them, in which they used outdated terms such as "alpha", and pack life was suggested to be a strict hierarchy. I brought up this misinformation, and was told I was not as credible as NatGeo. When misinterpretations and misinformation is so well-established, it's difficult to break through.

[Isela]

Keep in mind that, depending on when you read or watched those sources, the information we have presently may not have been known at that time. Science is constantly evolving as we make new discoveries. It's good to question your sources and fact check before immediately believing something is true, but time is a factor as well. The debunked myth about the correlation between wolves and Yellowstone's rivers is a more recent development.

[DaniBeez]

Good find Isela! That article explained the stance of this research group in layman's terms well, I thought.

When watching videos like the one this article talks about, it's easy to forget that food webs aren't simple linear structures. But with genetic sequencing technologies like NGS becoming cheaper and cheaper, we have more evidence that food webs are very complex with multiple interactions at all trophic levels.

[SolitaryHowl]

Interesting, thank you for this good read.

[alethe]

I remember hearing this story at a wolf center where I visited a few years back. I was super young at the time so I didn't think anything of it, but now hearing it... it does sound a bit unrealistic. very interesting, thanks for sharing.

[Koa]

I skimmed most of the article (since this isn’t news to me) but I am curious— did it talk about aspen anywhere? I know it mentioned willows. If I wasn’t hearing about how wolves helped rivers, I was hearing about how wolves helped aspen. My post here breaks down a few claims and includes a quote from Mech saying that, at the time, it was too early to tell whether or not wolves contributed dramatically to any beneficial ecosystem changes. Nevertheless, he expressed his skepticism.

[Isela]

I'm glad this article was informative!

I skimmed most of the article (since this isn’t news to me) but I am curious— did it talk about aspen anywhere? I know it mentioned willows. If I wasn’t hearing about how wolves helped rivers, I was hearing about how wolves helped aspen. My post here breaks down a few claims and includes a quote from Mech saying that, at the time, it was too early to tell whether or not wolves contributed dramatically to any beneficial ecosystem changes. Nevertheless, he expressed his skepticism.

There's no mention of aspen in the article. With willows appearing to be Hobbs' main area of study, that's the centralized focus. But yeah, I've also heard a lot about the correlation (or supposed correlation) between wolves and aspen growth.

When I talked to Mech last summer, he was still skeptic about wolves benefiting aspen populations (although the topic about the rivers was talked about more). It would make sense though. Since it appears as though Yellowstone willow populations are not correlated with wolves, as this study suggests, why would aspen populations be correlated with wolves? Regardless, as far as I know, the aspen study is still going on and is not quite sound yet. I could be wrong though. I haven't heard any news regarding Yellowstone aspens recently. Will have to do a bit of digging.

[alethe]

The center I went to spoke about aspen (or rather, they just said "trees" so whomst knows), and I believe they said it was because the elk population weren't as high with the wolves, so they weren't eating as many sapling aspen trees, so the aspen population boosted. Here's an article from the NY Times about it.

idk if its true or not, but that's the theory of how the wolves and aspen populations relate.

[Koa]

idk if its true or not, but that's the theory of how the wolves and aspen populations relate.

It's outdated and consequently explains outdated concepts, unfortunately. The article you shared was written in 2007. Kauffman's study-- the study that's linked within the post I linked to-- was published in 2010, and specifically states that "an ecosystem-wide recovery of aspen are premature" and that none of these aspen that were studied "appear to be regenerating" post-wolf reintroduction.

It appears, too, that the center you visited also had the nuances of the overarching concept wrong. According to Kauffman's study, the thinking was that more wolves would deter elk from eating aspen saplings precisely because more wolves would mean that there would simply be more threats within the areas that elk frequent. The elk would learn to NOT frequent these areas and the aspen saplings present would have time to regenerate.