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Ravens parallel great apes in flexible planning for tool-use, bartering (2017) (science.sciencemag.org)
72 points by NoRagrets on June 27, 2019 | hide | past | favorite | 47 comments



I imagine that, in these experiments where the subject is offered a choice, one must take care that the experimenter does not subconsciously signal the 'smart' option, such as by the counter-party in a bartering exchange being unaware of the problem that the subject is being tested with, and by avoiding having decoy objects that are more similar to each other than they are to the tool.


Yes. This has been standard practice in animal experiments for many decades.


The most fascinating thing that birds have no six layered neocortex like mammals do. So birds do all the processing by other brain structures like allocortex and/or basal ganglia. It means that they could have a really different kind of intelligence.


Some ornithologists believe that raven and crows surpass even dolphins and apes in intelligence. While I agree that dolphins and apes are intelligent, from my own observations, I would agree with that bird expert. I've seen ravens and crows do some really amazing things. Scientists think apes, for example, are about as intelligent as toddlers. Ravens are something else entirely. Birds can see the earth's magnetic field and take advantage of it for navigation. Ravens can make tools, toys, and solve more complex problems than apes. All corvids can accurately judge weights by sight, and all of them can remember faces for years. This is why farmers who shoot crows find their house, barn, and family animals harassed from then on. Corvids harbor grudges that other animals do not. And apparently the grudge and memories are passed down to offspring.


They also teach their young if someone hurts them. In some parts of the world, a way to keep birds away from orchards is to kill a crow and hang it for the others to see..such a human thing to do. It always reminds me of how they hung Il Duce at the end of WW II and how undignified it was to do that a crow..a creature that is far superior in intelligence.

I have always imagined that we have alien intelligence amongst us..two off the top of my head..octopus and mycelium. I have waffled about corvids..is it learned intelligence or is it innate animal/avian intelligence? Which usually makes me wonder about ‘intelligence’. What is the true definition of intelligence? Etc.


Knowledge itself is really not much unless it's applied. Corvids apply their knowledge/intelligence. I'm sure some is innate and some is learned. My children do the same. My youngest son was brainy from day one. There is nothing he cannot solve given the time. My older son is very intelligent as well, but his mind is different. He's more physical in nature and lends his mind to physical pursuits like how to drive a ball farther, stance, wrestling moves, etc. They learn and apply knowledge differently.

I'm sure there are corvids for whom cracking nuts themselves is great fun/skill shown, whereas there are some who will use a passing car tire to do the work for them. Some people enjoy working on their own cars while others see it as useless and infuriating. Both types can do the work, one sees it better as simply paying for it. I appeal to Robert Heinlein here. Specialization is for insects. People should be able to do many things well. It just makes you stronger.

I remember once in the Corps when we were deploying. A young Marine was laying out all of his gear for inspection, required and permissible personal stuff he believed would aid him. The Gunny walked over and said, "Dude, you are going to kill yourself humping all of this extra crap. You don't need any of it. The more you know, the less you have to carry."


They also communicate knowledge across generations and across flocks. There is a particular mask that corvid researchers at University of Washington used for experiments. It hasn't been used for twenty years. If they bring it out, the flocks still recognize and respond to it, even though the birds who would have seen it are likely dead. Even wilder, birds miles away in the city also respond to it, so the information is being transmitted.


I think we humans don't fully understand just how intelligent animals are. The ability to relay information across town rapidly is but one aspect, and it's fascinating. And they could do this while we were still wearing animal skins and carrying spears.


Being fair, we could do the same thing, then.

I tend to think it's down to the artificial distinction between "Man" and "Nature" that's infested our ways of thinking about the world for the last, oh, several hundred years at least, I suppose. That distinction may not have been invented for the purpose of supporting a sense of superiority, but that's the effect it has had, and I think it's long past time we disposed of it for the useless and actively harmful distortion of perception that it is.


There is an Indian treatise in living called Brihat Samhita by Varahamihira. There is an entire chapter on crows and how to find omens from crow calls and determine weather from their flight path. I think humans have been observing crows/corvids for a very long time. I think they turn up in Norse mythology often too.


Judging by my own experience, they have enough theory of mind to understand apologies, at least to the extent of laying aside a grudge; I offended a family of crows one time, getting too close to a nest and upsetting a fledgling, and after several days of potato-chip offerings close but not too close to where I'd given offense, they stopped giving alarm calls and swooping at me any time I walked out the door of the office where I then worked.


The crows where I live are fond of Cheez-its. They also like peanuts and popcorn (unsalted), but I tend to not feed them too much junk food. I did this to show my children that crows are good birds and will protect the area from bad birds like Purple Martins and Blue Jays, both of which are highly destructive. I'll take the crows as neighbors any day.


Potato chips wouldn’t have been my first or even my tenth choice, but I only had a breakroom vending machine to work from. It was that or candy bars, really...


No worries. Chocolate is terrible for animals, particularly dogs and birds. I was shunned for a few weeks by some Marines when stationed in Japan for sticking up for some seagulls. Our barracks was situated along the coast (literally) and there was an elevated seawall that ran for about 5 miles around the base. Marines would purchase Alka-Seltzer tablets by the box and walk along the seawall tossing them into the air where the birds would catch them. About 20 seconds later, the bird would explode from the tablet. I rained verbal hell down on them and was told I was a pussy and all that, but I explained to them they are damaging an ecosystem that is balanced. Typical idiots with no care or knowledge of anything. I earned the name green weenie and tree hugger in the platoon even though I'm neither. I just believe in being a good steward of resources.


Wow..that’s messed up.

That’s the kind of classic behaviour clue in kids that would indicate that they’d likely be psychopaths or sadists when they grow up. And these were grown up and were marines as well..


Looked at in another way, it lends support to the functionalist viewpoint that intelligence is not dependent on a specific medium.


There is also an older study from February with similar results:

Romana Gruber, Martina Schiestl, Markus Boeckle, Anna Frohnwieser, Rachael Miller: New Caledonian Crows Use Mental Representations to Solve Metatool Problems. In: Current Biology. February 2019, doi:10.1016/j.cub.2019.01.008

One of its highlights:

- Crows can preplan three behaviors into the future while using tools

Evolution is fascinating. I wonder if there's another possible outcome where these intelligent birds evolve into a species that is capable of using technology like we are today. Perhaps after mankind wipes itself out?


There is a book, Children of Time, I caution that it isn't actually a good book, its a bit ridiculous, but it was fun to explore what an earth-like planet would be like if spiders became the sentient species.


Thanks for giving me an excuse to recommend "A Deepness in the Sky", by far my favorite science fiction book with a planet of sentient spiders. It's the second in a series, but the first two book can be read out of order. https://www.amazon.com/Deepness-Sky-Zones-Thought/dp/0812536... (The first book is good too; The third one was OK, but not as great as the first two.)


I second this recommendation. Really great book.


It's not that bad, it won an Arthur C Clarke award.

Though I similarly thought it a bit ridiculous, that was actually more from the human elements of the plot than the spiders or ants. Spiders who'd just launched their sputnik. Overall I thought it a pretty good attempt with an unusual take, and worth reading.


I don't know how either of you could consider Children of Time to be poorly written, I recall it being quite good.


Was I damning too much by feint praise? I thought I agreed it was pretty good. Just some of the human plot stretched a bit far to the ridiculous. The spider eye view of the world and technology, and their take on religion was fun, and well done.

Much better than a couple of books by far more acclaimed authors I've read recently, for instance.

I'm British, we're fed sarcasm and understatement from birth. :)


You need hands and thumbs to manipulate the environment. Or maybe it would work if you’re an octopus but I don’t think they live long enough. Birds would need to give up flight and have stronger bones.


Zygodactyl birds like parrots do quite well with a claw and their beak, both of which are opposable. Ravens and crows mostly just use their beak, which also works quite well based on watching them out my window.


I think the ability to transmit complex information, like talking, is more important than thumb. Other animals have the equivalent of thumbs and have not created technology.


Crows are passerine. If they perch on a branch..their feet automatically clamp making them ‘glued’ to the branch..I don’t know how that ties in..but I have always wondered why they evolved like that..


It's much more likely that mankind wipes ravens than itself.


There are several other intelligent and adaptable corvid species that would be a lot harder for man to wipe out: carrion crows, hooded crows, rooks, and jackdaws all thrive near human societies.


I've had an interest in crows and ravens for years. Most corvid researchers agree that ravens top the list in intelligence due to their larger brains. Crows tend to squabble over resources whilst ravens tend to be loners (mating pairs hang out for life). Magpies are also very high on the intelligence scale, as they are also corvids.

Ravens have shown extreme intelligence in solving issues on how to open containers, defeat barriers to a food source (greenhouses), windows, etc. Ravens have been observed "timing" windows opening/closing to source food behind glass.

Ravens make toys from pine cones, bottle caps, twigs, and play with them with other ravens. They also use ant piles to roll around in, allowing the formic acid from the ants to cover them, giving them a barrier to mites and other bad hosts (called "anting").


Two things I like that corvids do, demonstrating intelligence but most importantly demonstrating _our_ type of intelligence rather than the more alien intelligence of something like an octopus:

1. Messing about, e.g. young bird finds an object which slides on an ice-covered roof. Hops on, rides the object down, and then crucially, it picks the object up and flies to the top to do it again. What for? Not for anything, this is clearly fun to do.

2. Tormenting small dogs. Small "yappy" dogs are awful. I'd feel bad about tormenting one though. But crows don't feel bad, good for them. Dogs are often left on a lead tied to something, the lead has a specific length and a crow can see that this limits the dog's reach, so it will taunt the dog or even attack it, then fly just barely out of reach, knowing the lead will restrain the dog to its further annoyance.


I have had many fascinating experiences with corvids at the farm: 1. Walnuts..they leave it on the road and wait for my vehicle to crush it. They know timing. Like they know who enters and exits the farm gate and the path of the vehicles.

2. They have bought me gifts.(like little toy cars..some kind of plastic parts etc) They steal snake heads from raptor nests and clean them out. I found it interesting that raptors won’t eat snake heads but corvids do.

3. They have bought their young to visit me. Maybe I am imagining that they recognize me. The littles have no clue and will fly right into the window. They mostly recover.

4. They know my voice. Again, there is no way to prove this..I leave out food for them ..have been for 9 years now and they know when it’s me and when it’s someone else filling in on chores for me. I always call out to them by cawing. Could be because of that..they also come to the other side of my home and knock on the window if I am late or if I had overslept.

(it’s a cultural practice to leave food for crows before eating in the morning..as they represent ancestors because they can pierce the veil between land of living and the dead. It’s a habit and I don’t want to question it.)

5. They like cat food. They scoop kibble in their beaks and drop it in the bird bath to wet it and then take it away..likely to their nest. I have only ever seen raccoons do this ..washing of food ..before.

6. I have seen crows mob a raptor when it goes after s finch or a smaller bird. They will swoop down in great numbers to scare the raptor away.

7. Once a blue heron got caught in the farm’s drip tape..it tried to fly away but the tape was holding it back. A young Harris hawk came down to circle the heron...I don’t know why..because the heron is bigger than the hawk. But it was circling the heron..and trying to peck near its feet. Maybe it thought the drip tape was a snake?

8-10 crows swooped down and chased the young hawk away..and kept pulling the drip tape until the heron was able to shake its leg off and get away.


The dynamics between squirrels and crows is interesting.

Usually they both turn up at the same time. Squirrels are scrappy and messy and really noisy. Crows sit back and wait for them to finish. Very dignified. Squirrels ..otoh..can be grabby.

Once I had a batch of hazelnuts I couldn’t sell. And I was leaving it out for the squirrels. The crows hung around the squirrels as they cracked it open..and as usual in their ADHD state, they’d eat barely a third of it before picking another nut. Crows would go after the half opened nuts and peck on the meat still in it. It’s like ‘follow the crumbs’..they just had to stalk the squirrels who were like the can openers for the crows.


I watched a bunch of crows surrounding a swan. Whenever the swan went after one of them, another crow would pick the swan in the butt. Swan would turn around and another crow would pick at the swan from behind. This went on for a few minutes and then the crowd left. My only explanation was that they enjoyed messing with the swan for fun.


I watched a similar scene, but with magpies escorting the local cat out of the park. One magpie walking right behind the cat, pecking at the tail, and some others running interference in front of it. The cat made no attempt to catch the birds and instead tried to keep up the pretense of leaving on his own accord.


Swans are mean! They likely see the swan as vulnerable(can’t fly) but also strong(they hiss and have powerful neck muscles and honestly..it’s scary to be near a swan upclose..they have Darth Vader breath).

Crows really like to challenge those that are bigger and stronger than they are..swans, raptors(altho they likely go after raptors because as scavengers, they pick up the leftovers of raptor’s kill/food).

They like to protect smaller birds and those that are vulnerable. They likely see cats as predators even though cats hunt smaller birds.


"Swans are mean! "

Agreed! When I was a kid we used to go swimming at a lake and there was a one-legged swan that terrorized the whole lake every summer. The other swans were bad too but this one was especially mean.


Can't fly?


For many birds, including crows, take off is almost instant. Flap wings, lift exceeds gravity, up you go. Swans don't do that, I presume because they can't. They need a considerable run-up - call it 50 metres on land. If harried it may be impossible for the swan to fly away.


Sorry. My bad.

I guess..I meant..a bird in the water is vulnerable and ‘grounded’ to one that can swoop down and fly away and attack as a mob.


It's hard to tell. There's the danger of creating a supervirus that kills all humans, for one.


It would have to be specifically designed to have months or even years-long incubation period and maybe synchronized to start killing at once all over the world.

Otherwise some people would just isolate and survive, gain immunity, or find a cure.


mankind has been trying it since 500 years. So far... nope, more crows than ever.


but how many ravens?


Around 2.5 millions of common ravens in Europe + USA combined. Around 25 millions of crows only in Europe


Corvids can be found everywhere in the world. Cold places like the Himalayas..Scandinavian frozen wastelands..as well as the tropics, near the ocean..they have adapted to every clime and environment.


Its pretty great that so many branches of life, at least currently, seem to be developing intelligence (mammals, birds, octopus, even some fish). I'd really be curious to know how intelligent multi-cellular species from the past were. In my mind this suggests that there is some serious selection pressure for intelligence in evolution, at least here on Earth. If pressures were similar on other planets, mammalian-level intelligence might be fairly common among multi-cellular life on other worlds.




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