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How Wolves Change Rivers [video] (vimeo.com)
253 points by enraged_camel on Oct 13, 2014 | hide | past | web | favorite | 54 comments

I always wonder how much weight should be given to the accuracy of "irrelevant" details. I tend to believe that spotting small errors that seem obvious to me mean that there are likely other larger errors that I would recognize if I were more knowledgeable about the subject. I presume that if the author isn't concerned or knowledgeable enough to strive for accuracy in the minor details, they are more likely (intentionally or not) to make errors in the major details.

In the case of this video, Monbiot speaks of 'deer' and then shows pictures of American Elk (Cervus canadensis). This is defensible, as he's British, and the European Red Deer (Cervus elaphus) is very closely related and likely more familiar to his anticipated viewers. But midway through, the video cuts to pictures of a Mule Deer (Odocoileus hemionus), which an expert is unlikely to conflate with an elk.

This could be considered an "irrelevant" detail, but one of the major differences is that the American Elk primarily graze as they have a digestive system that allows them to efficiently digest grasses, but the Mule Deer do not: they eat some grass, but primarily "browse" on woody vegetation. So while they will both have an effect on streamside vegetation, it's going to be a very different effect.

In a piece that purports to explain the science behind the cascading effects of wolves on the ecosystem, this feels like a disconcerting blunder. Should it cause me to doubt the credibility of the piece as a whole? I don't know. But it makes it more difficult for me to treat Monbiot as an authority on the topic.

It's pretty clear from the audio that he's lecturing somewhere, so it seems likely the filmmakers selected images to go along with his pre-existing speech.

You are right, the audio is from Monbiot's 2013 Ted talk: http://www.ted.com/talks/george_monbiot_for_more_wonder_rewi...

That wasn't clear to me. Rather, I presumed (I think reasonably) from the tag "Sustainable Man Original" that it was something that that Monbiot had participated in the creation of. I've now read the comments on the Sustainable Man page (http://sustainableman.org/blog/2014/02/17/how-wolves-change-...), and see that other have pointed out that the video also uses uncredited video of English badgers and Slovenian bears.

The creator of the video responds "Hi, we “steal” footage from lots of sources all in a non-commercial effort to raise awareness about sustainability.". The removes most of the criticism I'd have toward Monbiot, and retargets it toward Sustainable Man. The video is clearly more concerned with rhetoric rather than accuracy. Regardless of the goodness of the cause, I think in the end this sloppiness with facts will do more harm than good.

Wonderful and enjoyable video. It's sad that the accuracy of it is debatable: http://www.nytimes.com/2014/03/10/opinion/is-the-wolf-a-real...

That opinion piece says the impacts affecting the park are more nuanced and complicated than the popular narrative of the reintroduction of wolves would lead one to believe, it doesn't say it's entirely wrong.

Um, quoting exactly:

"[The aforementioned] study, which focused on willows, showed that the decades without wolves changed Yellowstone too much to undo. After humans exterminated wolves nearly a century ago, elk grew so abundant that they all but eliminated willow shrubs. Without willows to eat, beavers declined. Without beaver dams, fast-flowing streams cut deeper into the terrain. The water table dropped below the reach of willow roots. Now it’s too late for even high levels of wolf predation to restore the willows."


"When we tell the wolf story, we get the Yellowstone story wrong. Perhaps the greatest risk of this story is a loss of credibility for the scientists and environmental groups who tell it."

Why -1? I'm quoting exactly from the article mentioned above in the thread. Am I wrong in anything? Am I disrespectful? Please care to explain.

I didn't downvote you, I can't since you replied to me, but you are selectively quoting the article, which may have been the reason. The article also said the Elk population was reduced by the wolves, and that this impacted plant regrowth but not as much as widely believed, and yes some areas haven't been improved at all. It also said bear populations increased. It's a nuanced piece.

I've read a few papers on this in the past, after having originally seen the video. The ongoing research is indeed nuanced and complex, and as with a lot of ongoing scientific research, there's disagreements among scientists.

Different papers use different methods to estimate predation risk in various locations, for instance. Some base it on actual predation incidents, some on landscape factors (which may model risk perception as opposed to actual risk).

There's also discussion about the way active predators such as wolves impact an area, which is different from lie-in-wait predators. And there's an idea that a constant background threat comes to be ignored, as opposed to a sort of pulsing threat, where there are surges of predation.

Also worth noting that various studies take place in different areas of the park, and in different seasons. Not to mention there's three main varieties of trees under discussion (aspens, cottonwoods, willows), which have all seen different recovery rates in different areas.

It's not a simple question, and from what I've seen in my sort of casual reading on the topic, it's not at all settled.

I think that the summary of that story, though, is, "Actually, wolves hardly did anything." Yes, not literally nothing, but that for the most part, plant regrowth didn't happen at all. Where it did happen, it's far from clear that the wolves -> elk predation causality chain was a major factor.

Please resist the urge to question receiving a downvote. If it's unwarranted (and I think it was, in this case), someone will likely give you a corrective upvote.

The other common case is someone clicking the downvote button in error. Is there any way to undo a downvote, or is that a planned future feature?

No, there isn't. There probably should be (but it's debatable, perhaps like edits, they should be timed, with a hint in the UI that not only voting is done (arrows removed), but which vote was cast (eg: dim the arrow not pressed, highlight the one pressed.).

What really should be done, is change the hopelessly small arrows (which are annoying on desktop, unusable on mobile) to a pair of unicode up-down arrows/triangles side-by-side that are more or less full line-height/1em. Eg: ▲▼. It would mean a minimal change in layout (small increase in left margin) -- but greatly increase usability.

I'd probably stopped using hn (well interacting with the ui) a long time ago, if I wasn't using vimperator, and could just hit "f"[ollow links] and type a number for the arrow I wanted to hit, rather than hunting the tiny glyphs.


Why doesn't HN have a policy whereby the downvoter must explain the reason for it, much like a Wikipedia edit is strongly encouraged to have a written reason?

How can we teach people not to do something worthy of downvote if there is no visible feedback mechanism to help see why something downvoted was rightfully so?

If the current policy (of downvoting without a reason) is to avoid discussing the reason for the downvote, so that the conversation not be derailed further, then maybe we should focus on disincentivizing this specific behavior.

Not unexpectedly parent was downvoted too as will I most likely be. It seems to have become a trend lately.

To any newcomers with downvote privilege: There used to be that you had to say something wrong or unpopular to be downvoted, not just something that could have been avoided etc. That way HN came across as a friendly (although biased) community. I'd appreciate if we extended this to newcomers and tired ones today: If you have gained your downvote-privilege, use it carefully, don't assume stackoverflow-moderator-responsibility.

(Notice that this is my second account, I have lurked and participated here a few years and have another account that I sometimes log into when someone really needs my downvote or I want to be personally identified with my answers ; )

looks like someone downvoted a quote they don't like. It irks me when that happens here.

As I've pointed out before either there is a change in policy or we got some unusually active downvoters recently. I don't know and I don't have time to research it but I guess someone with admin access could do some kind of query on users with unusual amount of downvotes?

I habitually downvote discussions about downvoting as they pretty much always distract from the topic at hand and really aren't all that interesting in themselves.

The best approach to being downvoted is not to woundedly post asking why you were downvoted, but to wait. If your post has genuine value, it will almost always be voted back up. This has happened to me more times than I can count.

If your post is not upvoted over time, perhaps you're wrong about its value. Certainly the community disagrees with you. That questioning should be directed inwardly. Perhaps sometimes the answer will be that you don't care if the community disagrees with you, you still feel your point was justified. That also happens to me.

I understand the emotional impulse to question what a poster feels to be an injustice, but all they're really doing is indulging their emotional impulse at the expense of actual on-topic and interesting discussion.

Please don't do that.

Sometimes, the way to improve your skill at communicating is getting feedback from the community.

Further, you can't assume that someone asking for such feedback is asking in a defensive way. Although that often happens, the written text is a poor way of judging that. Spoken tonality is more accurate. If you're interpreting a request for feedback as one coming out of being "wounded", that is more likely to be a projection of your own habits of communication and psyche than what is actually happening.

Thanks, seeing the discussion, for a moment I thought I'm the only one thinking this way.

Regarding people suggesting to "look into myself what I did wrong" - I was totally flabbergasted as to why I was downvoted, that's exactly why I wanted to ask and, hopefully, learn something. The only ideas I had were those I listed, but none seemed to match.

Now, from the comments I learned something, that the quotes I used were apparently seen by some as "selective" and/or not reflecting the message of the article. Now, this at least explains somewhat the reasons, and for this I'm grateful; although I actually still can't say I agree, given that: 1) I believe I'd personally rather comment instead of downvoting in such case; 2) quoting is always more or less selective, yet here the quotes are quite large, and I'd still stand by opinion they do reflect the contents of the article; 3) the movie is composed fully of assertive sentences, and the quote and the article do counter them explicitly (e.g. movie: wolves -> willows grow higher; article: willows don't grow higher) and references multiple scientifical studies for that IIUC; 4) actually one of most important reasons I admire HN is when people provide calm but strong counterarguments to anything with quotes and references to scientifical papers, so that's what I try to do too...

I see and I used to agree although I usually didn't care to do that myself. Lately I find a lot of the downvoting that has been going on has been so stupid that the stupid "why the downvotes?" question has seemed relevant.

My theory is that we're seeing the influx of Reddit members.

There's evidence even this thread, as in the children of this parent (https://news.ycombinator.com/item?id=8449500). Comments that add nothing meaningful, often contributing nothing other than snark or inane "Internet comedy".

There is much that is positive about Reddit, and much that is negative. Something HN doesn't need is the blatant downvoting because of mere differences in opinion.

Personally, I wish HN didn't have a downvote button at all, but that we could leave actual moderation to moderators.

I wonder if the big story is about a different predator species so apex that wolves are basically a hobby for it, and how changes in the behavior and priorities of that species can have dramatic impacts on the park.

Look around a bit and you'll see loads of articles and rebuttals to this video's thesis. I for one thought the video was really beautiful but it shouldn't stop researchers from attempting to be accurate, even when it isn't something we want to hear.

For those that can't watch the video, aka tldr, the deers in Yellowstone National Park were apparently very destructive, and the harm caused by them was lessened when wolves arrived. The wolves also reduced the coyote population. Forests recovered which lead to increases in population of other species including eagles, beavers and bears, and there was less soil erosion affecting the rivers themselves.


tl;dr: wolf good, deer bad

Back to reddit...

Reminds me about this TED talk http://youtu.be/vpTHi7O66pI where Allan Savory speaks about the behavior of herbivores with/without predators and the impact on flora.

Fascinating, really.

I hope the day will come when we understand the biosphere of this wonderful planet we live on.

I'm not convinced Monbiot is completely unbiased here. He still appears to be upset about how meat producers misrepresented his words [1] after he gave a favorable review to Simon Fairlie's _Meat: A benign extravagance_ [2], and it seems to be this position from which he attacks Savory. Savory's ideas are not terribly different from those of Joel Salatin, whose sustainable farming techniques are profiled in Michael Pollan's _The Omnivore's Dilemma_. Monbiot's arguments for why he recanted his review has more to do with the problems of currently prevalent meat production techniques than the techniques promoted by Savory, Fairlie, or Salatin. There is at least one rebuttal to Monbiot that cites several examples of Savory's techniques working in practice. [3]

[1] http://www.theguardian.com/commentisfree/2013/nov/27/al-gore...

[2] http://www.theguardian.com/commentisfree/2010/sep/06/meat-pr...

[3] http://www.theguardian.com/sustainable-business/2014/aug/19/...

Thank you. It looks like a well documented article. Makes me sad to find this out.

Also interesting is that the Guardian article is by the same person (George Monbiot) as the OP video. Not saying that's good or bad, just worth noting.

A message from Zimbabwe: regarding McPherson, Savory, Grasslands, Climate, Hope http://goo.gl/YQs5Nc ‪#‎defendingBeef‬

Indeed, so much non intuitive things to learn here. Brilliant

You can see something similar in economies too.

Amazon introducing AWS has radically changed Silicon Valley.

Other IaaS services and PaaS services also entered the market.

The huge variety of different SaaS businesses around now is probably directly related to the ease of leasing/running cloud servers.

Because start-ups need so little capital to get started these days, those start-ups engage with VCs and Angels not at the powerpoint stage of their business, but perhaps after the launch of their MVP ... or even after they have a solid running business.

That has changed the nature of the relationship between start-ups and investors, and the kinds of services the investors are expected to provide.

It has also made large-scale incubators like YC possible.

This concept of "rewilding" is very intriguing. I first heard about it through NPR's TED Radio Hour with a segment on George Monbiot. The show touches on interesting connections within nature.

Here is a link to the show - Everything Is Connected - http://www.npr.org/2013/09/27/216098121/everything-is-connec...

Also, link to The Rewilding Institute - http://rewilding.org/rewildit/

Happens to be part of the plot of Kim Stanley Robinson's Nebula Award winning "2312" as well.

Should I take away from the video that wolves are good for the environment or that rapid and substantial change in the relative populations of important species can have substantial impact throughout an ecosystem?

The idea that I take away from the video is less one of trophic cascade and more of the connectedness of things in biology.

The trophic cascade is a manifestation of the connectedness of all things biological.

I think this is just one example of how little we understand nature's systems. The food chain effect is well-documented in terms of numbers. For example, we already know that if you decrease the number of predators in an ecosystem, the species they normally prey on grow out of control. But the video shows that there's a massive amount of complexity under the surface of this model. For example, the wolves in Yellowstone changed not just the number of deer (their prey) but also their behaviors, which is one of the factors responsible for the cascade effect. Similarly, the increase in beaver numbers resulted in the creation of more niche ecosystems for other species.

If you are interested in this, it is definitely worth reading the second half of "Into the Cool" by Sagan and Schneider. The book is mostly about thermodynamics, but the second half of it applies the study of thermodynamic complexity (ala Prigogine etc.) to ecosystems. It gave me a different view of how the flow of energy through ecosystems results in the kind of ecological complexity in e.g. a rainforest. The effects of stressing an ecosystem and how removing energy or energy-gathering opportunities can result in a regression from a complex ecology to a simpler one (forest to gressland) are also explored.

> I think this is just one example of how little we understand nature's systems.

Oh, definitely. And it applies at a very broad sense of the word "nature." For instance, weight-loss. As a physics guy I have a minor aneurysm whenever someone, referencing the obesity epidemic, says something like "a calorie is not a calorie". What they're trying to say is very important, but I dislike the way that it's expressed, and it may be the reason why it's hard to get those views more accepted.

What I'd say is: the physics of weight loss is extremely well understood, but the psychology of weight loss is not at all. I can tell you about thermodynamics but that doesn't really tell you, at the level you want, why everyone and everything is becoming obese. For a personal example, once I came from the Netherlands to the US Midwest, I rapidly gained a lot of weight, going from "skinny for my height" to having trouble with some Men's X-Large T-shirts. Is it because the portion sizes are in general much larger? Or is it because there's more fat or sugar or chemical additives here? Or is it because I'm not bicycling to work every day because distances are greater here? Or is it because in the Netherlands I was expected to "have a sport" (in my case ultimate frisbee) and I'm no longer able to maintain that time commitment in my new phase of life? Or is it because of a shift in my religious and personal priorities which made it harder to fast once or twice a week? Hey, maybe it's none of these! Maybe it's just that I'm now in a relationship with a teacher and her late-night grading causes me to get less sleep, but because I work a programming job and solve cognitively-complex problems, I have to spike my blood sugar constantly to maintain the same functioning. But maybe it's something else, like the fact that satiety signals only get sent from the stomach to the brain after 20 minutes, and here I just tend to eat more in that 20 minutes than there.

All I can really tell you as a physicist is that my body will naturally find some equilibrium where energy in = energy out, at which point weight will become mostly stationary -- and I can in theory point to the idea that I can change this by changing the situations that I'm in. In addition with a little bit of knowledge about hormones like leptin & ghrelin, I can tell you that when my fat cells eventually start to die, their equilibrium will signal hunger to my brain, making it hard to work off this weight without a lot of discipline about my food urges. (Another potential cause! I now have a refrigerator so food is "always around".) But even the littlest things, perhaps even getting an hour more sleep every night, could throw that whole psychological set of triggers completely in a different direction.

Some things, especially seen in the outside world, just have ridiculously complicated causal graphs. It's true of weather, ecosystems, biologies -- and even when those graphs are generated by some really simple rules like energy-exchange, their interactions can easily spiral out of control for how we see them.

Software is the same way. If each line has a chance of interacting with one other, that's going to be an O(n^2) causal complexity created by O(n) lines; good modules and interfaces only reduce the multiplicative constants but don't change the scaling. When you get to the 50+ million lines of Windows it's hardly remarkable that it has some bugs in it.

On "a calorie is a calorie", a suspicion is that there can be two diets equal in calories per day but very different in how they make the person feel, say, in energy level, and, thus, how many calories they burn or how much weight they gain or lose.

In my own efforts at dieting and weight loss, I'm not sure I've seen any such effect for the range of diet variations I've tried. Still, there are suspicions that some such effect might be true, somewhat common in reality, and significant.

This reminded me of a NATURE episode I saw, where it was all about one Fig Tree, and all of the species that live on it, nurture it, depend on it. It was fantastic.

What attributes make a species eligible for this type of ecosystem redefining introduction? Do they have to have been there before (i.e. reintroduction)? Because I just spent four months in Florida and I can tell you down there the populace pretty much holds the exact opposite excitement level for the introduction of pythons to their native habitats.

While getting my advanced open diver licence, I did a dive with grey nurse sharks. There I learn't how important sharks were. Where there are sharks, there are more reefs, more other species. When the sharks are killed, the over-feeding begins and over time the reef is depleted.

Must watch anime: Wolf Children (Ookami Kodomo no Ame to Yuki)

It's about a man that is also a wolf who meets a woman and they have kids, and about their struggle to grow up and live with their human and wolf personalities.

Ah, the amazing possibilities of a multi-variable predator-prey model, say, a system of several ordinary differential equations!

Hmm - how well controlled is this as an experiment?

It's ecology in a really large national park. You don't get to do much controlling there.

I'm sure he meant his comment with a little tongue and cheek. I believe the point is, don't assume that the conclusions drawn in this article are accurate. Do a little cursory "googling" and you'll find quite a few articles warning caution or full rebuttals of the thesis in this video. Here's one link http://elyfieldnaturalists.wordpress.com/2014/02/27/do-wolve...

great video ever...never saw anything like this

I never would have guessed the Imp knows so much about wildlife :)

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