[HN Gopher] Crows are capable of recursion, scientists claim
       ___________________________________________________________________
        
       Crows are capable of recursion, scientists claim
        
       Author : kposehn
       Score  : 99 points
       Date   : 2022-11-05 18:21 UTC (1 days ago)
        
 (HTM) web link (www.scientificamerican.com)
 (TXT) w3m dump (www.scientificamerican.com)
        
       | recuter wrote:
       | Well, this makes them more capable than some project managers.
        
       | frithsun wrote:
       | One more threat to javascript developers trying to make it in
       | today's economy.
        
         | mmplxx wrote:
         | Seems to me that more is at stake here for lisp developers.
        
         | youguyssuck wrote:
         | This actually proves that crows are smarter than JavaScript
         | developers
        
           | HideousKojima wrote:
           | Reminds me of the "game journalist vs. pigeon" video:
           | 
           | https://m.youtube.com/watch?v=vfIn9OqhZWo
        
             | tanseydavid wrote:
             | I struggled with the exact same move in Cuphead training. I
             | had the exact same reaction as the game journalist.
        
               | HideousKojima wrote:
               | Were you not able to read the instructions on the wall?
        
               | tanseydavid wrote:
               | My immense frustration was largely due to the fact that
               | yes (of course) I was able to read the short instructions
               | on the wall.
               | 
               | What I could not do (for more than 3 minutes straight,
               | iirc) was execute those instructions in the proper manner
               | to get Cuphead to do what I wanted.
               | 
               | disclaimer: I am old as hell and phased out of any
               | serious video gaming in the era of 2D, 2 button and an
               | 8-way joysticks
        
         | aulin wrote:
         | now they just need to learn memoization and they're ready to
         | master the FAANG interview
        
         | tengbretson wrote:
         | Meh. Until they can figure out a stack-safe trampoline, forget
         | about it.
        
       | harrykeightley wrote:
       | def caw():         print("Crow on the tower of Hanoi say...")
       | caw()            caw()
        
         | agumonkey wrote:
         | cawrecursive scheme
        
         | bbarnett wrote:
         | All that work, and with no rest(sleep)?
        
       | uranium wrote:
       | Why is this evidence of recursion rather that evidence of
       | recognition of symmetry? The sequences they show are all simple
       | symmetrical ones, e.g. {()}.
        
         | kragen wrote:
         | NSFW!
        
       | elcapitan wrote:
       | "Crows demonstrate that crows are capable of recursion"
        
       | yamrzou wrote:
       | https://archive.ph/zLgN0
        
       | perihelions wrote:
       | Other thread:
       | 
       | https://news.ycombinator.com/item?id=33454205 ( _" Crows found to
       | be smarter than we think"_)
        
       | JimBlackwood wrote:
       | Kind of ironic, but the picture used seems to be of a raven - not
       | a crow.
       | 
       | Feathers on the beak are quite far out, the shape of the head
       | isn't as "streamlined" and the top beak is more curved and
       | longer. Or am I mistaken here?
        
         | cercatrova wrote:
         | > _Here 's the thing. You said a "jackdaw is a crow."_
        
         | kzrdude wrote:
         | I didn't read the paper but it talks about "Corvids (jays,
         | jackdaws, crows and ravens)" first but it seems like they did
         | experiments using carrion crows (Corvus corone corone).
        
         | b3morales wrote:
         | I believe the extended overhanging curved tip is just the sign
         | of a captive crow that is, sadly, not taking good care of its
         | beak. Raven beaks are generally much broader.
        
         | [deleted]
        
       | hoosieree wrote:
       | Not surprising. Crows around here are always making a Racket.
        
       | tasuki wrote:
       | So are cauliflower and broccoli?
        
       | dtgriscom wrote:
       | Linguistic recursion, rather than algorithmic recursion (?)
        
         | adrian_b wrote:
         | Yes, it appears that they have taught the crows to write some
         | kind of LISP-like expressions with nested parentheses, which is
         | what is meant here by recursion.
        
       | vintermann wrote:
       | "They do not seem to possess anything similar to human language"
       | 
       | They definitively have ways of telling each other things. Just
       | how they do it and what the limits of it are, I guess we don't
       | know.
       | 
       | What I'd like to see is trying these tasks on a flock, rather
       | than individual birds.
        
       | zaidhaan wrote:
       | > Adapting the protocol used in the 2020 paper, the team trained
       | two crows to peck pairs of brackets in a center-embedded
       | recursive sequence.
       | 
       | > Two of the three monkeys in the experiment generated recursive
       | sequences more often than nonrecursive sequences ...
       | 
       | I'm no academic but aren't those extremely small sample sizes to
       | make any reasonable deductions from? This looks to be even
       | addressed in one of the papers cited...
       | 
       | > While a sample size of two is not enough to infer that any crow
       | in the population may generate center-embedded recursive
       | sequences, we present a "proof of existence" showing that this
       | cognitive capacity is, in principle, within the reach of carrion
       | crows.[0]
       | 
       | [0] https://www.science.org/doi/10.1126/sciadv.abq3356
        
         | zaidhaan wrote:
         | Not sure why I got downvoted. If my assumption is wrong then
         | I'd be really curious to hear from someone that knows better.
        
           | goto11 wrote:
           | It is unclear what your complaint is. As the second quote
           | states, you only need a sample size of one to prove that a
           | certain ability can exist. You just cant say much about how
           | widespread the ability is.
        
             | zaidhaan wrote:
             | Thanks for the clarification. That seems fair, I suppose
             | the title of the article gave me the impression that they
             | were claiming such an ability would be widespread in all
             | crows (despite the study being done on two carrion crows),
             | when in fact it seems the intention was to state that the
             | ability _can_ exist in any crow given that they proved it
             | exists for those two specific crows.
        
       | RcouF1uZ4gsC wrote:
       | > Some scientists remain skeptical. Arnaud Rey, a senior
       | researcher in psychology at the French National Center for
       | Scientific Research, says the findings can still be interpreted
       | from a simple associative learning standpoint--in which an animal
       | learns to link one symbol to the next, such as connecting an open
       | bracket with a closed one. A key reason, he explains, lies in a
       | feature of the study design: the researchers placed a border
       | around the closed brackets in their sets--which the authors note
       | was required to help the animals define the order of the
       | brackets. (The same bordered layout was used in the 2020 study.)
       | For Rey, this is a crucial limitation of the study because the
       | animals could have grasped that bordered symbols--which would
       | always end up toward the end of a recursive sequence--were the
       | ones rewarded, thus aiding them in simply learning the order in
       | which open and closed brackets were displayed.
       | 
       | Doing this seems to make this more of a linear problem than a
       | recursive problem. Place all the non-bordered symbols. Then place
       | all the bordered symbols in reverse order of the non-bordered
       | ones.
        
         | mannykannot wrote:
         | I thought what followed was equally thought-provoking:
         | 
         | "In Rey's view, the notion of "recursive processing" as a
         | unique form of cognition is in itself flawed. Even in humans,
         | he says, this capacity can most likely be explained simply
         | through associative learning mechanisms..."
         | 
         | AFAIK, this contrasts quite markedly with Chomsky's position
         | that recursion is central to his universal grammar.
        
           | jeffmcmahan wrote:
           | Yes, as usual, our pop science writer with a dim
           | understanding of the issue quotes critics of the Chomskyan
           | paradigm (the study aims to falsify Chomsky's suspicion that
           | a symbolic operation called "merge" gives humans a unique
           | capacity for deep recursion) and for balance quotes _other_
           | critics of the Chomskyan paradigm - and never do we hear from
           | the syntacticians (who study recursive grammatical structure
           | as a career).
        
       | hairofadog wrote:
       | I feed the crows cashews as I walk the dog, and I find their
       | behavior fascinating.
       | 
       | They "commute to work" each day. Crows all live in a community
       | that they go home to each night, and then each morning they all
       | come back to their specific areas, usually in pairs. If you're in
       | a place where you see crows every day, it's almost certainly the
       | same pair of crows you're seeing each day.
       | 
       | Each pair has a strict territory. I don't know how it works in
       | rural areas, but in my neighborhood the territories are
       | demarcated by streets and cover one or two neighborhood blocks.
       | 
       | They definitely recognize me and follow me for the peanuts.
       | Usually they'll follow me from one block to the next, and another
       | pair will come up and chase them off.
       | 
       | They do seem to set aside their territorial fighting when there's
       | a lot of food; a guy up the street from me throws ridiculous
       | amounts of food onto his front lawn, like whole loaves of bread,
       | to feed the birds (probably rats and coyotes too), and the crows
       | all gather peacefully there every morning before heading back to
       | their territories.
       | 
       | I would love to know how they determine who gets what territory.
       | I assume it's handed down; every year there's a month or so when
       | the adolescents come out (they're a little bit ganglier and
       | pester their parents for food all the time rather than foraging
       | for it themselves) so I think they're there to learn the ropes.
       | Are there crow dynasties that have owned certain city blocks for
       | generations? How long do they last?
       | 
       | Lots of interesting stuff to watch in the lives of crows.
        
         | onos wrote:
         | Which is it peanuts or cashews?
        
           | hairofadog wrote:
           | They prefer cashews but until the economy gets a little
           | better it's peanuts.
        
         | mannykannot wrote:
         | Around where I live (southern New York), the crows seem to
         | gather in groups of twenty or so as sunset approaches, and
         | appear to be socializing (and making quite a lot of noise in
         | the process.) There does not seem to be any fixed location
         | where this happens, and it seems different from when they are
         | mobbing a raptor, where the target of their ire can quickly be
         | seen from the way the crows are directing their attention
         | towards it.
         | 
         | I can't say whether it occurs only at certain times of the
         | year, and I have not paid any attention to where the birds go
         | afterwards.
        
           | hairofadog wrote:
           | It looks like there's a pod in Poughkeepsie, but it's an
           | annual gathering place rather than nightly?
           | 
           | https://www.scenichudson.org/viewfinder/poughkeepsies-
           | massiv...
           | 
           | Some other reporting about crows in your neck of the woods:
           | 
           | https://www.ithaca.com/news/seeing-spots-nope-those-are-
           | crow...
        
           | whatevertrevor wrote:
           | I've observed a daily rollcall at evenings in our
           | neighborhood. They don't necessarily gather together, but
           | they sit atop tall trees and then caw to tally everyone up in
           | a radius of a few blocks without fail at sunset.
        
         | geewee wrote:
         | How did you manage to get started? The crows close to me are so
         | skittish that if I try to throw a peanut at them they just fly
         | off and never come back. I've only managed to not have that
         | happen once.
        
           | carapace wrote:
           | Crows are companions-to-hunters (wolves and humans mostly.)
           | They interpret your behavior through that "lens".
           | 
           | If you set out food and then watch them that means (in crow)
           | that you are a hunter, and a lousy one, and you're trying to
           | hunt _them_.
           | 
           | Toss out some food and "forget" it and they'll think you're
           | such a successful hunter that you don't even need to every
           | scrap. Someone worth knowing.
           | 
           | In the old days, crows would go on the hunt with us and fly
           | over hidden game in the bush dipping a wing in a certain way
           | to let you know where it is, then you share the meat with
           | them. They still remember even if most of us have forgotten.
           | ;)
        
             | voidz wrote:
             | I love this. Can you earn their trust, as in, become pals
             | with them? Or is this more of a human desire. It's probably
             | mostly food based priorities to them.
        
               | nomel wrote:
               | I had a pair of crows that I was somewhat close to. I
               | could get within a couple feet of them, before they would
               | back away.
               | 
               | It definitely seemed food based. But, observing how they
               | interact with their (lifelong?) companion, I don't think
               | I'm able to perceive crow emotions.
        
               | carapace wrote:
               | > Can you earn their trust, as in, become pals with them?
               | 
               | It's a very human question.
               | 
               | All living things are friends (except sometimes at
               | mealtime) because we are all part of one singular
               | organism. The separateness and individuality of
               | multicellular organisms is a perceptual illusion.
               | 
               | (This sound metaphysical, and perhaps it is, but it's
               | very literal: all cells use the same chemical language,
               | the same bio-molecular machinery of thought. Cf. Michael
               | Levin's lab's work. Also "wood-wide web", etc. The way I
               | sometimes put it is "We are Solaris". but that only makes
               | sense if you've read the book or seen the movies...)
               | 
               | Anyway, all animals already trust each other. When you
               | can understand how that's true and share that trust then
               | you can "talk" with animals. Like Dr. Doolittle or some
               | fairy tale princess, they will come up and hang out with
               | you.
               | 
               | > It's probably mostly food based priorities to them.
               | 
               | Yeah, but that's the same for _everybody_? Don 't you and
               | your friends spend a lot of time discussing food? Cooking
               | and eating together? "Com-pan-ions" are literally those
               | who eat bread together: "com" is community, etc. and
               | "pan" is bread.
               | 
               | Live long and prosper.
        
               | [deleted]
        
               | Wistar wrote:
               | I have tried, and over a fairly long period of coaxing
               | with popcorn, and they remain extremely wary. Only once,
               | out of a group of 15-20 crows, did I earn the trust of a
               | single crow enough that he, or she, would come within 10
               | feet of me to pickup kernels I had strewn on the ground.
               | The rest stayed far away.
        
           | hairofadog wrote:
           | Hmm, if you're literally throwing it _at_ them, yeah, they
           | don't like that. You just kinda have to throw it where they
           | can see it, then walk away, and they'll come running over to
           | scoop them up. Do that for a week or two and they'll start
           | looking for you. Also, cashews are their favorite (based on
           | watching them pick the cashews out of trail mix and then come
           | back for the other stuff later).
           | 
           | They don't let me get close to them, but sometimes they do
           | fly up from behind and tap me on the back of the head to get
           | my attention.
           | 
           | Also, unlike the guy up the street, I only throw out a few at
           | a time so they have to sort of follow me to get anything.
           | 
           | My ultimate goal is to be able to point at someone and have
           | the crows attack them like in Bioshock. It'll be my thing for
           | when society collapses. So far, however, I think our
           | relationship is much more "let's get some peanuts off this
           | sucker" than "I'll loyally follow this peanut person into
           | battle".
        
             | lioeters wrote:
             | > point at someone and have the crows attack
             | 
             | I imagine this would be a conceptual leap for their
             | intelligence, to understand the meaning of "pointing" and
             | to make a connection to the target, what's being pointed
             | at. But then again, I suppose hunting dogs have achieved it
             | - they know what to attack - so it might be possible for
             | smart crows too.
             | 
             | Now that I think about it, there are cultures where people
             | train hawks for practical hunting purposes. So taming crows
             | may not be too far-fetched, though it might take a few
             | generations..
        
             | prox wrote:
             | I few times I made a pointing "forwards" gesture and then
             | went ahead to where I pointed, although they probably knew
             | my route already. But halfway there ;)
        
             | colechristensen wrote:
             | Crows really like Cheetos.
        
           | prox wrote:
           | Just place a few fav seeds where they can see it clearly,
           | soon they will figure it out. Once they start recognizing you
           | (which is very fast, few times tops) they will come. Don't
           | look or make sudden motions when they are near enough. They
           | don't like that.
           | 
           | In time some might become more interested in you, depending
           | on mood, and will come closer to you.
        
       | fullsend wrote:
       | I'm always amazed how low supposedly smart people's opinion of
       | animal consciousness is.
        
       | EGreg wrote:
       | Chomsky would be surprised
        
       | rojobuffalo wrote:
       | > ...the crows still had to figure out the center-embedded order
       | where open and closed brackets were paired from the outside
       | in...if the birds only learned that open brackets were at the
       | beginning of the sequence and closed ones were at the end, you
       | would expect an equal proportion of ( { ) } mismatched and
       | correct responses. But...the crows chose more of the latter than
       | the former, even with the more complex sequences of three pairs
       | of brackets.
       | 
       | I'm no expert but it seems like the birds are identifying visual
       | symmetry. Maybe they are remembering the mid-point of nested
       | symmetrical symbols, and that's still interesting, but is that
       | "understanding recursion"? Recursion is the idea of repeating an
       | algorithm or a function calling itself. Visual symmetry is a
       | little simpler than that.
       | 
       | If a crow peels an onion layer by layer that doesn't mean it
       | understands recursion. It's doing something recursive.
       | Understanding recursion, in my mind, involves being able to
       | describe a recursive function or make a prediction based on
       | understanding the function.
        
       | ispo wrote:
       | They have some skills better fitting that my younger self! Not an
       | exaggeration!
        
       | default-kramer wrote:
       | > To address this limitation, Liao and her colleagues extended
       | the sequences from two pairs to three pairs--such as { [ ( ) ] }
       | 
       | Three pairs of brackets still seems like setting the bar very
       | low... But even if they got great results with 10 pairs of
       | brackets, wouldn't that be more easily explained by
       | "understanding symmetry" rather than "understanding recursion"?
        
         | Oxidation wrote:
         | Presumably you could check that with non-symmetrical symbols
         | (so unrelated pairs like A/Y, or 1/W, etc)
         | 
         | But then, I'm not sure that many humans would figure that out.
        
       | mannykannot wrote:
       | I wonder is the result owes a lot to visual processing (a highly
       | developed trait in most birds.) Arguably, with the symbol-pairs
       | used here, each pair look a bit like a single but partially-
       | obscured convex object, with the inner ones lying on top of the
       | outer ones.
        
       | jamal-kumar wrote:
       | I suppose the next step is seeing if you can train bees to get
       | the concept. May seem farfetched but I was recently reading how
       | they can be taught to understand basic arithmetic and the concept
       | of zero. [1]
       | 
       | [1] https://www.quantamagazine.org/what-scarlett-howard-
       | learns-f...
        
       | syllablehq wrote:
       | Crow Recursion is the name of my new nerdcore death metal band
       | "Crows will claw your face if you mess with crows will claw your
       | face if you mess with crows will claw your face if you mess with
       | crows will claw your face if you mess with crows will claw your
       | face if you mess up the END CONDIIITTTTIIIIOOONNN!
        
       | prgammer wrote:
       | Was it tail recursion?
        
         | eckza wrote:
         | Tail-caw optimized.
        
       | shafyy wrote:
       | I also love how crows put a walnut on the road, wait until a car
       | drives over it and cracks it open, and then they go collect it.
       | Smort.
        
       | xkcd1963 wrote:
       | The recursion example in the article is not good because it is
       | language dependent. One could also say: "running mouse chased by
       | cat in the past" and you would get the same idea as in opposed to
       | "The mouse the cat chased ran". I believe other non-indoeuropean
       | languages like Chinese or Japanese work in some ways much
       | different from ours where you would pretty much derive to similar
       | sentences if you translate without considering grammatical rules
       | (not to say that they dont use recursion). Also one has to make a
       | distinction from recursion and recursion in language as opposed
       | to "if you cant recurse in communication you cant recurse in
       | general".
        
       | perrygeo wrote:
       | We know that crows and many other animals use tools, which
       | represents at least one level of linguistic abstraction ("It's
       | not just a rock, it's a member of a more general category of
       | things capable of smashing open food").
       | 
       | I've always thought that recursion, specifically the ability to
       | apply abstraction to itself, was a unique human trait. We don't
       | just abstract one level, we keep going - building tools that help
       | us build tools, building social structures that facilitate the
       | production of these meta-tools, etc.
       | 
       | So while we see other animals using tools that they find in their
       | environment, I don't know of any evidence that they recurse on
       | that, i.e. they always use tools for their primary purpose but
       | never engage in systematic production of tools, or tools that
       | make other tools. But given this article, maybe it's not mental
       | capacity or linguistic recursion that limits tool making but
       | something more mechanical like simply dexterity?
        
         | bbarnett wrote:
         | One comment, re: tools to build tools. I've seen animals use
         | rocks, in videos, to debark sticks, to be used to perform
         | another task.
         | 
         | That's a tool to make a tool, and I bet there are other cases.
         | 
         | In fact, I recall a video of a monkey, using a sharpened stone,
         | to break the window of its habitat. To sharpen the stone, it
         | used something else (the video did not say anything other than
         | the monkey sharpened the stone).
         | 
         | So that is another case.
        
       | BirAdam wrote:
       | So, crows, cetaceans, octopuses, and elephants... let's just be
       | thankful that all of the other smart animals can't manipulate
       | their environments at scale.
        
         | vintermann wrote:
         | Elephants can rip up trees at a pretty impressive scale.
        
           | nkrisc wrote:
           | Environmental "engineering" by ancestors of elephants is a
           | possible factor that contributed to the environmental change
           | that likely lead to the extinction of Gigantopithicus, the
           | enormous, ancient ape.
        
             | bbarnett wrote:
             | So they warred on our cousins! Thus, we shall place them in
             | caged enivros, to be starred at by our young, pointed at,
             | fed token treats, their humiliation complete.
        
         | brnaftr361 wrote:
         | "Smart" is a... Bad category. It's just a big breeding ground
         | for reification.
         | 
         | We do have a term for animals that do manipulate the
         | environment: _ecosystem engineering_. Which includes a variety
         | of species, including trees. Which to that extent, it 's our
         | scale of engineering that pales in comparison.
         | 
         | I mean, cyanobacteria is implicated in an extinction event, and
         | the initiation of the great oxygenation event, and the rise of
         | complicated metabolic systems using oxygen as the terminal
         | electron acceptor. Very cleverly (intelligently, smartly?) they
         | evolved [by chance,] a metabolic niche that was totally vacant
         | which coincidentally could also positively amplify for some
         | extraordinarily long period.
        
         | ren_engineer wrote:
         | if you look at all those groups you can kind of see what each
         | lacks compared to humans to get runaway intelligence benefits
         | that basically create a continuous selective effect for more
         | intelligence.
         | 
         | humans have a solid combination of dexterity, life span, and
         | verbal communication. Dexterity allows for manipulation that
         | allows intelligence to be used to maximum effect in an
         | environment, life span allows for time to learn and share
         | knowledge, and verbal communication allows to share knowledge
         | effectively which allows group work and knowledge to pass
         | through generations.
         | 
         | crows and elephants seem to be the most limited by lack of
         | dexterity, crows actually try to use tools to get around the
         | limitation. If Elephants had some octopus style multi-trunk
         | tentacles that could be used like hands they'd be set I think
        
           | bmitc wrote:
           | I am not convinced dexterity has much to do with
           | intelligence. It is more an enabler of technology development
           | and not raw intelligence.
        
             | shmageggy wrote:
             | The idea is that the ability to create technology creates
             | an evolutionary gradient whereby increased intelligence
             | yields better tools yields increased survivability
        
         | j-bos wrote:
         | Reminds me of this speculative piece:https://twitter.com/CWingU
         | exkull/status/1554639440873652227?...
         | 
         | tldr is ancient elephants manipulating the environmemt at scale
         | and enslaving ancient humans. Short worthwhile read with fun
         | details to justify the narrative.
        
       ___________________________________________________________________
       (page generated 2022-11-06 23:01 UTC)