Joshua Klein on the intelligence of crows

小さいことは気にすんなッ、主題と主張をつかもう！

自動販売機でカラスに餌を買ってもらう？

排除・駆除するのではなく、お互いに利益となるバランスある関係を模索する。すばらしい「発想の転換」だと感じると同時に、クレインさんの「基本姿勢」に敬意を表します。

【話題】 カラスと仲良くする方法

【時間】１０分４秒

【要約】

１．カラス研究のきっかけ

　カクテルパーティーでの会話

　10年に渡る研究

　絶滅危惧種には注目する反面、

　ヒトの生活圏で生きる生物には意外と無関心だ

　駆除するのではく新しい関係の模索

２．カラスは頭が良く、互いに学び合う生き物

　環境の変化に敏感・柔軟に適応する能力をもつ

　（例）

　　ニューカレドニアカラス

　　チンバンジーと同じ脳の比率

　　スウェーデンのカラス

　　ワシントン大学の研究

　　仙台のカラス

３．自動販売機のしくみ

　スキナー理論を用いた４つのステップ

　　①自動販売機を設置して周囲にコインとピーナッツを撒く

　　②更に慣れさせ、幸せを享受させる

　　③コインだけを与える

　　④何も与えない

　カラスは簡単には諦めず、いろいろと試す生き物
　一羽のカラスが、落ちているコインを拾って自販機に入れた
　これがリスはと違うところ

４．駆除するのではなく共生する

　自動販売機以外にもいろいろなやり方があるはず

　共に利益を得るバランスある関係をつくることが大切

【語彙】

Alfred Hitchcock film "The Birds" ：アルフレッド・ヒッチコック監督の映画「鳥」

eradicate ：根絶する

synanthropic species ：人間の生活圏で人間と何らかの関係を持ちながら生きる生物（ネズミ、ゴキブリ、カラスが典型）

parasitism ：寄生、パラサイト

thrive ：繁栄する

exponential ：指数的な

unprompted ：促すことなく

proportionate ：比例した

anecdotes ：逸話

bait ：餌

peers ：仲間

infidelity ：不倫？

Skinnerian ：行動心理学のスキナー理論

stymie ：追い詰める

crows

【transcripts】

How many of you have seen the Alfred Hitchcock film "The Birds"? Any of you get really freaked out by that? You might want to leave now. (Laughter) So, this is a vending machine for crows. And over the past few days, many of you have been asking me, "How did you come to this? How did you get started doing this?" And it started, as with many great ideas, or many ideas you can't get rid of anyway, at a cocktail party. About 10 years ago, I was at a cocktail party with a friend of mine, and we're sitting there, and he was complaining about the crows that he had seen that were all over his yard and making a big mess. And he was telling me that really, we ought to try and eradicate these things. We gotta kill them because they're making a mess. I said that was stupid, you know, maybe we should just train them to do something useful. And he said that was impossible.

And I'm sure I'm in good company in finding that tremendously annoying -- when someone tells you it's impossible. So, I spent the next 10 years reading about crows in my spare time. (Laughter) And after 10 years of this, my wife eventually said, "Look, you know, you gotta do this thing you've been talking about, and build the vending machine." So I did. But part of the reason that I found this interesting is that I started noticing that we are very aware of all the species that are going extinct on the planet as a result of human habitation expansion, and no one seems to be paying attention to all the species that are actually living -- that are surviving. And I'm talking specifically about synanthropic species, which are species that have adapted specifically for human ecologies, species like rats and cockroaches and crows.

And as I started looking at them, I was finding that they had hyper-adapted. They'd become extremely adept at living with us. And in return, we just tried to kill them all the time. And in doing so, we were breeding them for parasitism. We were giving them all sorts of reasons to adapt new ways. So, for example, rats are incredibly responsive breeders. And cockroaches, as anyone who's tried to get rid of them knows, have become really immune to the poisons that we're using. So, I thought, let's build something that's mutually beneficial. Well, then let's build something that we can both benefit from, and find some way to make a new relationship with these species. And so I built the vending machine.

But the story of the vending machine is a little more interesting if you know more about crows. It turns out that crows aren't just surviving with human beings -- they're actually really thriving. They're found everywhere on the planet except for the Arctic and the southern tip of South America. And in all that area, they're only rarely found breeding more than five kilometers away from human beings. So we may not think about them, but they're always around. And not surprisingly, given the human population growth, more than half of the human population is living in cities now. And out of those, nine-tenths of the human growth population is occurring in cities. We're seeing a population boom with crows. So bird counts are indicating that we might be seeing up to exponential growth in their numbers. So that's no great surprise.

But what was really interesting to me was to find out that the birds were adapting in a pretty unusual way. And I'll give you an example of that. So this is Betty. She's a New Caledonian crow. And these crows use sticks in the wild to get insects and whatnot out of pieces of wood. Here, she's trying to get a piece of meat out of a tube. But the researchers had a problem. They messed up and left just a stick of wire in there. And she hadn't had the opportunity to do this before. You see, it wasn't working very well. So she adapted.

Now this is completely unprompted. She had never seen this done before. No one taught her to bend this into a hook, had shown her how it could happen. But she did it all on her own. So keep in mind that she's never seen this done. Right. (Laughter) Yeah. All right. (Applause) That's the part where the researchers freak out. (Laughter)

So, it turns out we've been finding more and more that crows are really, really intelligent. Their brains are proportionate, in the same proportion as chimpanzee brains are. There are all kinds of anecdotes for different kinds of intelligence they have. For example, in Sweden, crows will wait for fishermen to drop lines through holes in the ice. And when the fishermen move off, the crows fly down, reel up the lines, and eat the fish or the bait. It's pretty annoying for the fishermen.

On an entirely different tack, at University of Washington, they, a few years ago, were doing an experiment where they captured some crows on campus. Some students went out and netted some crows, brought them in, and were -- weighed them, and measured them and whatnot, and then let them back out again. And were entertained to discover that for the rest of the week, these crows, whenever these particular students walked around campus, these crows would caw at them, and run around and make their life kind of miserable.

They were significantly less entertained when this went on for the next week. And the next month. And after summer break. Until they finally graduated and left campus, and -- glad to get away, I'm sure -- came back sometime later, and found the crows still remembered them. So -- the moral being, don't piss off crows. So now, students at the University of Washington that are studying these crows do so with a giant wig and a big mask. (Laughter) It's fairly interesting.

So we know that these crows are really smart, but the more I dug into this, the more I found that they actually have an even more significant adaptation.

Video: Crows have become highly skilled at making a living in these new urban environments. In this Japanese city, they have devised a way of eating a food that normally they can't manage: drop it among the traffic. The problem now is collecting the bits, without getting run over. Wait for the light to stop the traffic. Then, collect your cracked nut in safety.

(Laughter) (Applause) Joshua Klein: Yeah, yeah. Pretty interesting. So what's significant about this isn't that crows are using cars to crack nuts. In fact, that's old hat for crows. This happened about 10 years ago in a place called Sendai City, at a driving school in the suburbs of Tokyo. And since that time, all of the crows in the neighborhood are picking up this behavior. And now, every crow within five kilometers is standing by a sidewalk, waiting to collect its lunch.

So, they're learning from each other. And research bears this out. Parents seem to be teaching their young. They've learned from their peers. They've learned from their enemies. If I have a little extra time, I'll tell you about a case of crow infidelity that illustrates that nicely. The point being that they've developed cultural adaptation. And as we heard yesterday, that's the Pandora's box that's getting human beings in trouble, and we're starting to see it with them. They're able to very quickly and very flexibly adapt to new challenges and new resources in their environment, which is really useful if you live in a city.

So we know that there's lots of crows. We found out they're really smart, and we found out that they can teach each other. And when all this became clear to me, I realized the only obvious thing to do is build a vending machine. So that's what we did. This is a vending machine for crows. And it uses Skinnerian training to shape their behavior over four stages. It's pretty simple.

Basically, what happens is that we put this out in a field, or someplace where there's lots of crows, and we put coins and peanuts all around the base of the machine. And crows eventually come by, and eat the peanuts and get used to the machine being there. And eventually, they eat up all the peanuts. And then they see that there are peanuts here on the feeder tray, and they hop up and help themselves. And then they leave, and the machine spits up more coins and peanuts, and life is really dandy, if you're a crow. Then you can come back anytime and get yourself a peanut.

So, when they get really used to that, we move on to the crows coming back. Now, they're used to the sound of the machine, and they keep coming back, and digging out these peanuts from amongst the pile of coins that's there. And when they get really happy about this, we go ahead and stymie them.

And we move to the third stage, where we only give them a coin. Now, like most of us who have gotten used to a good thing, this really pisses them off. So, they do what they do in nature when they're looking for something -- they sweep things out of the way with their beak. And they do that here, and that knocks the coins down the slot, and when that happens, they get a peanut. And so this goes on for some time. The crows learn that all they have to do is show up, wait for the coin to come out, put the coin in the slot, and then they get their peanut.

And when they're really good and comfortable with that, we move to the final stage, in which they show up and nothing happens. And this is where we see the difference between crows and other animals. Squirrels, for example, would show up, look for the peanut, go away. Come back, look for the peanut, go away. They do this maybe half a dozen times before they get bored, and then they go off and play in traffic.

Crows, on the other hand, show up, and they try and figure it out. They know that this machine's been messing with them, through three different stages of behavior. (Laughter) They figure it's gotta have more to it. So, they poke at it and peck at it and whatnot. And eventually some crow gets a bright idea that, "Hey, there's lots of coins lying around from the first stage, lying around on the ground," hops down, picks it up, drops it in the slot. And then, we're off to the races. That crow enjoys a temporary monopoly on peanuts, until his friends figure out how to do it, and then there we go.

So, what's significant about this to me isn't that we can train crows to pick up peanuts. Mind you, there's 216 million dollars' worth of change lost every year, but I'm not sure I can depend on that ROI from crows. Instead, I think we should look a little bit larger. I think that crows can be trained to do other things. For example, why not train them to pick up garbage after stadium events? Or find expensive components from discarded electronics? Or maybe do search and rescue? The main thing, the main point of all this for me is that we can find mutually beneficial systems for these species. We can find ways to interact with these other species that doesn't involve exterminating them, but involves finding an equilibrium with them that's a useful balance. Thanks very much. (Applause)

ジョシュア・クレイン「カラス用自動販売機」