[HN Gopher] How a hawk learned to use traffic signals to hunt mo...
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How a hawk learned to use traffic signals to hunt more successfully
Author : layer8
Score : 308 points
Date : 2025-05-27 11:46 UTC (11 hours ago)
(HTM) web link (www.frontiersin.org)
(TXT) w3m dump (www.frontiersin.org)
| munchler wrote:
| Surely the author teaches at Rutgers University, not "Rudgers".
| c-linkage wrote:
| It's spelled like it sounds! :D
| troelsSteegin wrote:
| Local to south Jersey it's "ruckers".
| cameronh90 wrote:
| I'm from south Jersey and have never heard of this
| "ruckers". Is it near Ouaisne?
| layer8 wrote:
| It's an Albany expression.
| hughdbrown wrote:
| I was about to call fake on this -- Americans from south
| Jersey are largely unfamiliar with the present perfect
| and would not say "[I] have never heard of" but "[I]
| never heard of" instead.
|
| But it turns out this grammatical cue is an effective way
| to discover that the comment is not about an American
| south Jersey but a British one.
| panny wrote:
| I've watched karasu carefully wait for a yellow light to drop his
| walnut in an intersection. The last car passing cracked his nut,
| then he had time to gather the meat during the light change
| before other cars came along.
| Someone wrote:
| Some crows in Japan do something like that, dropping nuts
| on/near a pedestrian crossing, and waiting for a green
| pedestrian light. See
| https://youtu.be/BGPGknpq3e0?feature=shared
| Neywiny wrote:
| Looks like Karasu is the Japanese word for crow. So this is
| an interesting linguistics exchange
| fortran77 wrote:
| There's a better writeup of this here:
|
| https://www.theatlantic.com/science/archive/2025/05/hawk-new...
| bayindirh wrote:
| Or, the original paper:
|
| https://www.frontiersin.org/journals/ethology/articles/10.33...
| krisoft wrote:
| I have a similar story. I was taxiing a Cessna 152 at LHBS. It is
| a big grassy field. On that day there were a large flock of black
| birds sitting on the grass. I made the usual radio call to
| announce that I'm leaving the runway and taxiing to the tie-downs
| when the birds flitted away just between my airplane's nose and
| my destination. The birds outside of that "road" by roughly a
| wingspan distance remained on the ground and kept doing whatever
| they were doing. And the ones who took to the air settled back a
| short distance away from my future path.
|
| Now just to clarify I don't think the birds were listening on my
| radio call. The way I explained it to myself is that they were
| observing airplanes coming and going long enough that they
| learned that if an airplane hesitates at that point the next
| thing they will do is to turn towards the tie-down area. Or maybe
| it was just randomness. Or maybe as I was making the radio call I
| already started turning and they just got scarred away by my
| engine noise.
| Neywiny wrote:
| I'm not an ornithologist but I think birds integrate some
| onboard magnetic compass sensors. So, it would be interesting
| if they can pick up the magnetic part of an electromagnetic
| wave of the radio. Seems very low likelihood but would be cool.
|
| Edit to add
| https://www.sciencedaily.com/releases/2023/08/230828130356.h...
| . What frequency were you at? Seems they may actually be
| listening.
| IAmBroom wrote:
| "Picking up" and "discerning useful data" are very different.
|
| I'm not even talking about "deciphering". Even knowing that
| energy in a certain bandwidth means planes about to leave
| seems a large jump - and a radio tuned to a station is likely
| an order of magnitude more stringent than an animal's sensory
| abilities.
| PunchyHamster wrote:
| I'd imagine the fact they are high frequency rather than
| constant field would make it impossible
| throwanem wrote:
| I see pigeons and sparrows dodge cars by inches, too. For that
| matter I do the same myself! Sparrows hawk insects out of the
| air, and I believe starlings also. Predicting motion would need
| to be second nature, I think. Like skillfully catching a ball,
| but much more so and between your teeth...
| vikingerik wrote:
| Well, there is survivor bias there, of course; you don't see
| the ones that _didn 't_ learn to dodge...
| stanmancan wrote:
| We call that evolution
| hnlmorg wrote:
| Nit pick, but it's natural selection
|
| The cars aren't evolving the birds, but they are
| selecting the fittest.
| im3w1l wrote:
| But it makes you wonder why they cut it that close. What
| benefit they get from it. I can think of several plausible
| reasons but none that is self-evidently true.
| fullstop wrote:
| Perhaps for the same reason that people skydive or engage
| in other risky behavior.
| throwanem wrote:
| Why waste energy giving someone else a free shot at
| whatever you're finding it worth your time to stand in
| the street over? It isn't that someone else wants that
| dropped french fry or whatever. It's that _everyone_ else
| does.
| quinnirill wrote:
| This is quite common prey animal behavior. Larger
| predators have a harder time adapting to rapid turns made
| just as the jaws/claws are about to snap shut.
| harrall wrote:
| Not a bird but as a human, it's fun.
|
| Adrenaline is hell of a drug... and the best one.
| throwanem wrote:
| Correct. They would be visibly laminated to the pavement or
| smashed in the gutter. It does happen, but less often than
| ospreys drop fish in late summer.
| PunchyHamster wrote:
| You do, you can usually find those on your passenger seat
| blarg1 wrote:
| I once threw a tennis ball straight up, just as a bird
| happened to be flying past, it rolled right and dodged it by
| a cm.
| throwanem wrote:
| I don't really know what it's like to be a bird, of course,
| but I have to imagine their subjective experience of
| duration differs greatly from ours.
| dmd wrote:
| Search for "flicker fusion rate" to learn a lot more
| about this.
| throwanem wrote:
| That talks about the mechanics of visual perception. I'm
| discussing qualia, which I am far more confident crows
| share with me than does the particular subtype of Hacker
| News commenter who will with tiresome predictability and
| total lack of novelty turn up to press the footless
| insistence that crows could never.
| rzzzt wrote:
| Mine is 42 Hz according to a recent examination. Are high
| refresh rate monitors are wasted on this pair of eyes?
| throwanem wrote:
| I don't know. Have you tried one? That's neither the
| rhetorical nor the dismissive response it may seem...
| rzzzt wrote:
| The mouse is very snappy compared to a 60 Hz display.
| umbra07 wrote:
| Just do a basic double blind test. get someone else to
| switch the hz a couple of times for you, and see if you
| can tell the difference. i would be surprised if you got
| anything less than a 100% success rate.
| toss1 wrote:
| Our flicker fusion rate is different for the fovea and
| nearby central vision vs the peripheral vision.
|
| The central vision is slower-response, higher-resolution,
| and of course color vision.
|
| The peripheral vision is monochrome and has a much faster
| flicker-fusion, tuned to picking up motion in the
| periphery.
|
| So, the same flicker rate that you never notice on a
| small monitor may flicker annoyingly on a large monitor.
| To check that a setup will not flicker for you, set it up
| in a darkish room, focus around 70deg-100deg to one side
| of the monitor so it is in your peripheral vision, and
| both look at one place and notice your periphery, and
| also move your focus quickly from one place to another
| and notice if the screen blurs like bright stationary
| objects or looks like a discontinuous blur (really easy
| to get that effect with fluorescent lights). Do it both
| left & right and towards the ceiling. If flicker shows up
| in these tests, it will still eventually bug you when
| looking directly at the screen, even if it isn't as
| noticeable because your focus is in the center of your
| vision.
| HeyLaughingBoy wrote:
| Squirrels, OTOH...
| sodokuwizard wrote:
| If true, then this hawk has more pattern recognition than many
| humans I've encountered over the years.
| hoseja wrote:
| If you have nothing else to do and your lunch depends on it,
| many patterns can be gleaned even by birdbrains.
| throwanem wrote:
| The voice of experience.
| lloeki wrote:
| > Cooper's hawk is on a rather short list of bird of prey species
| that have successfully adapted to life in cities. A city is a
| difficult and very dangerous habitat for any bird, but
| particularly for a large raptor specializing in live prey: you
| have to avoid windows, cars, utility wires, and countless other
| dangers while catching something to eat every day.
|
| Peregrine falcons adapted quite well, and they're much more
| sizeable. That said, their size make them very apt to hunt
| pigeons, so this could be a less risky niche to hunt for; I mean,
| pigeons usually fly higher up than sparrows.
| Etheryte wrote:
| Plus pigeons are not exactly known for being incredibly smart
| or agile, so if you're big enough to take one down, you
| probably won't struggle too much for food.
| Modified3019 wrote:
| Pigeons are actually known for being very agile, and are able
| to do vertical takeoffs and evasive maneuvers like a backflip
| loop immediately after takeoff, which is precisely to evade
| predators like falcons.
|
| City pigeons just tend to become fat, lazy and used to
| suppressing their flee response around traffic and people.
| KineticLensman wrote:
| Pigeons fly surprisingly fast and can outfly smaller raptors
| in a straight line. A stooping (diving) Peregrine will
| usually win. Its strike may decapitate the pigeon which tends
| to minimise the struggling
| morkalork wrote:
| Except for the part where pigeon racing is an entire sport
| that relies on both their speed and intelligence
| jfk13 wrote:
| Except that it's not clear whether the intelligence+ that
| underlies their homing ability is equally effective in
| helping them evade predators.
|
| +Is "intelligence" even the right word here? I don't know.
| Much depends on how you define it, I guess, combined with
| the unknowability of the pigeon's own mental processes.
| varispeed wrote:
| The other day when visited local city park (in South London) I
| spotted a Buzzard just chilling on the tree among pigeons.
|
| Small, but majestic nonetheless.
| eorthling wrote:
| Obligatory note that if you're from the US you are probably
| picturing a different bird than parent saw.
| happyopossum wrote:
| would you care to expound on that?
| sethhochberg wrote:
| In the US, buzzard is pretty much always slang for a
| turkey vulture. The common buzzard in Europe/Asia is a
| different bird entirely.
| lloeki wrote:
| > The common buzzard in Europe/Asia is a different bird
| entirely
|
| Funnily enough in France:
|
| - buzzard is "buse" (mostly - although not limited to -
| Buteo[1])
|
| - there's an unrelated yet identically pronounced
| "busard" (Circus[2]).
|
| - EDIT: oh, and "balbuzard" (Pandion[3] a.k.a ospreys)
|
| [1] https://en.wikipedia.org/wiki/Buteo
|
| [2] https://en.wikipedia.org/wiki/Circus_(bird)
|
| [3] https://en.wikipedia.org/wiki/Pandion_(bird)
| hshdhdhj4444 wrote:
| You have the story of Flacco the owl who lasted 1 year in
| Manhattan after having spent his entire life in captivity.
|
| https://en.m.wikipedia.org/wiki/Flaco_(owl)
|
| Even his death (due to a collision with a building) was likely
| less because of his ability to survive, since he managed to
| learn all the skills necessary, and more due to the fact that
| his primary food source, rats in and around the city, were
| laden with rat poison.
|
| We have consistently and regularly underestimated non human
| animals cognitive abilities which is frankly strange if you
| understand evolution since it would be strange for only humans
| to have a certain evolutionary feature such as intelligence and
| every other species to not have it at all.
| nashashmi wrote:
| > underestimated non human animals cognitive abilities
|
| I think humans have done precisely what humans do:
| misunderstand. Unlike other animals, humans don't have the
| ability to understand creatures they have not studied for
| long periods of time.
|
| We know animals are intelligent. But we don't know what
| intelligence means. Is it something we can use? no? then it
| is something we ignore. And it is most likely something we
| disrespect.
| skipkey wrote:
| In my neighborhood in the East Valley in Phoenix, I've seen
| Cooper's hawks, kestrels, peregrine falcons, zone tailed hawks,
| merlins, and one immature bald eagle. Along with the numerous
| turkey vultures and the occasional black vulture.
| pdabbadabba wrote:
| > Peregrine falcons adapted quite well, and they're much more
| sizeable.
|
| I'm not sure what you mean. As far as I am aware -- and
| according to every source I've looked at in the last few
| minutes -- Peregrine falcons and Cooper's hawks are about the
| same size (length and wingspan are within 1-2 inches).
| throwanem wrote:
| Peregrines are somewhat smaller and much more lightly built.
| I live in a nesting pair's territory which often sees
| transitory Cooper's; they're easy to distinguish both in
| flight and at rest. Male Cooper's are more peregrine-sized
| and hard to tell from sharp-shinned hawks sometimes, but that
| is an ordinary enough sexual dimorphism in birds.
|
| Interestingly, while peregrines and accipiters like Cooper's
| share a habit of taking passerines in flight, the response of
| potential prey seems to differ. I frequently see songbirds
| mob a Cooper's; I can't think offhand of a time I've seen
| them respond to a peregrine other than by crypsis.
| lloeki wrote:
| Sadly we don't have Cooper's around here so I have no
| experience with them, hence why I looked them up (see
| nearby comment) and according to that source found out they
| were on the smaller size and much smaller weight.
|
| Around here the only ones who would dare mob a peregrine
| would be crows.
| throwanem wrote:
| Sure. I'm just talking about the impression they give in
| life. But I suppose in that sense the other birds must
| find a peregrine much more striking, and it very
| belatedly occurs to me that peregrines no doubt look
| smaller and more gracile to me for the higher altitudes
| their stooping hunting habit would require. When I do
| occasionally see them on approach to their nearby nest,
| I'm struck by their relative size. So yeah, between that
| and reviewing my Sibley's the error here is mine, though
| - for that matter, likely also because - I do find all
| falcons rather streamlined and compact in impression
| compared with accipiters or buteos.
| lloeki wrote:
| > according to every source I've looked at in the last few
| minutes
|
| I may be mistaken but that's what I found:
|
| https://en.wikipedia.org/wiki/Peregrine_falcon
|
| > The peregrine falcon has a body length of 34 to 58 cm
| (13-23 in) and a wingspan from 74 to 120 cm (29-47 in)
|
| > Males weigh 330 to 1,000 g (12-35 oz) and the noticeably
| larger females weigh 700 to 1,500 g (25-53 oz)
|
| https://en.wikipedia.org/wiki/Cooper%27s_hawk
|
| > Total length of full-grown birds can vary from 35 to 46 cm
| (14 to 18 in) in males and 42 to 50 cm (17 to 20 in) in
| females. Wingspan may range from 62 to 99 cm (24 to 39 in),
| with an average of around 84 cm (33 in)
|
| > In northern Florida, males averaged 288 g (10.2 oz) and
| females averaged 523 g (1.153 lb). In general, males may
| weigh anywhere from 215 to 390 g (7.6 to 13.8 oz) and females
| anywhere from 305.8 to 701 g (0.674 to 1.545 lb), the
| lightest hawks generally being juveniles recorded from the
| Goshutes of Nevada, the heaviest known being adults from
| Wisconsin
|
| (not putting the full regional rundown, just the biggest
| entry)
| hackeraccount wrote:
| There are Peregrine falcons in my city. I remember walking
| downtown one time and seeing one on the sidewalk with a pigeon
| in its talons. All the commuters and I just walked around it.
| Really weird somehow.
| lloeki wrote:
| Interesting, around here raptors hunt high, and if prey falls
| to the ground they abandon it; too dangerous to go down in
| the streets.
| glxxyz wrote:
| I almost ran one over turning in a car park in Edmonton.
| Backed up and it was still standing on the pigeon glaring
| at me. I drove around.
| IAmBroom wrote:
| That's a hawk vs falcon hunting difference, not a city vs
| countryside one.
|
| Quail won't take off if a falcon's shadow passes over them;
| they'll burst if a hawk's does.
| vidarh wrote:
| London apparently has a high density of them (but high
| density still only means something like 40 breeding pairs),
| and some people are all excited about the prospect that they
| can do something about the rapidly rising wild parakeet
| population...
| morkalork wrote:
| I'm having a hard time squaring away the image of grey
| gloomy London also being overrun with colourful tropical
| looking birds, I had to google it and see.
| throwup238 wrote:
| They're surprisingly well adapted to a large range of
| temperatures because of the species found in temperate
| rainforests at higher altitudes. They frequently enough
| escape from pet stores and zoos that there are many
| sizable populations spread out around the world. The one
| nearest me is the infamous Pasadena parrots [1] which is
| made up of thousands of birds likely built up over
| decades of escapes. There are populations in Chicago, New
| York, Rome, Tokyo, and plenty of other cities in the
| world.
|
| [1] https://www.lafieldguide.com/p/the-pasadena-parrots
| guerby wrote:
| There's a couple of peregrine falcons with a live streaming
| webcam on top of Cathedrale Sainte-Cecile in Albi, south of
| France
|
| https://albi.fr/environnement/les-faucons-pelerins
|
| https://en.wikipedia.org/wiki/Albi_Cathedral
| twic wrote:
| The Black Redstart evolved to live in holes in cliffs and the
| like, and never used to be widespread in the UK. After the
| second world war, cities all over the south were bombed out,
| and they moved into the deserted, derelict bombed areas in
| great numbers. As the bomb sites were cleared and the cities
| redeveloped, their habitat was eroded. But at the same time,
| Britain was de-industrialising, and they moved into the
| abandoned factories in the North. As those now get redeveloped,
| they are losing their habitat again.
| johngossman wrote:
| If you are interested in these birds and live in the Seattle
| area, the Urban Raptor Conservancy has a wealth of information:
|
| https://urbanraptor.org/research/seattle-coopers-hawk-projec...
|
| There are over a hundred nesting pairs in Seattle.
| nosmokewhereiam wrote:
| Japanese _crow-dactles would put candy in wrappers into
| crosswalks and let cars run over them. They may have used the
| sounds of the crosswalk. I have no sources, just anecdotal.
|
| _ They were big birds. Intimidating wingspans, if hit by cars on
| their highways: they damaged cars, etc.
| pfdietz wrote:
| Now I just need to learn to tell Coopers from Sharp-shinned. The
| eternal struggle.
| quercusa wrote:
| If only they'd perch side-by-side!
| devoutsalsa wrote:
| I once wrote a personal's ad in SQL on Craigslist, back when they
| had that section. A DBA replied and asked if I wanted hawking.
| She had a Cooper's hawk. I met her at a commercial park in a
| Saturday morning. She was driving a Honda CRV, the hawk was in
| the front passenger seat, and I hopped into the back seat.
|
| She started driving and spotted some crows. The hawk saw them as
| well. Wearing a "don't kill me either your claws" glove, she
| moved her hand to the hawk, who gleefully jumped on. She rolled
| down her window, stuck the hawk outside, and it was basically a
| drive by shooting with a bird bullet. This happened three times.
|
| My most vivid memory of this was her ripping the crows apart into
| pieces and putting the then into a bucket, like it was sushi
| you'd order from KFC.
| dmd wrote:
| And you didn't get married!?
| throwanem wrote:
| Not OP, but I'm friends with crows. Imagine having to try to
| explain _that_...
| srean wrote:
| Very intelligent birds.
| IAmBroom wrote:
| "Baby, those body parts mean nothing to me! I love crows!"
|
| Don't hate the player, baby.
| throwanem wrote:
| They have a much stronger sense of propriety than most
| humans. So really do most animals other than us and
| perhaps some close relatives. I'm not actually sure that
| says anything in our favor.
| qingcharles wrote:
| This is peak HN.
| senkora wrote:
| I bet she was a very good database administrator.
| layer8 wrote:
| Probably the hawkish type.
| 3cats-in-a-coat wrote:
| And this, kids, is a Markov chain.
| cs02rm0 wrote:
| _I once wrote a personal's ad in SQL on Craigslist, back when
| they had that section. A DBA replied and asked if I wanted
| hawking._
|
| I feel I have to reply, but I have no idea what to say.
| deadbabe wrote:
| For starters he could post what the hell his SQL query was.
| tsss wrote:
| That's really horrible. Crows can feel pain too, you know.
| patrick41638265 wrote:
| Reading the first paragraph of this made me think how LLMs must
| feel when someone tries prompt injection on them
| speakfreely wrote:
| I've reread this a few times and I still can't figure out if
| there's something wrong with me or something wrong with this
| post.
| cryptonector wrote:
| https://news.ycombinator.com/item?id=44109901
| isatty wrote:
| Whatever this is, write more.
| plank wrote:
| The point the story tries to make is that the Hawk learned
| traffic signals. That is not necessarily the case. It could be
| that the hawk just sees that the cars are blocking the sight of
| the prey.
|
| Still an intelligent action, only does not mean the hawk
| understands the signal itself.
| happyopossum wrote:
| the story as told outlines that the hawk will stage itself when
| it hears the sound of the crosswalk, in anticipation of the
| line of traffic getting long enough for it to use as
| concealment.
| hatthew wrote:
| The suggestion is that the hawk hears the signal and knows that
| the line of cars is about to be unusually long in a minute, so
| it prepares by flying into position.
| p3rls wrote:
| I once saw racoon prints descend from the rafters in a barn,
| complete with little muddy handprints on the doorknob into the
| feedroom, like some sorta sylvan-bandit tom cruise.
|
| When food is on the line, animals can figure all sorts of things
| out.
| hughdbrown wrote:
| 'Racoon', variant of 'raccoon'.
|
| Of course, I prefer the double-c variant because of the
| orthographic anomaly of the person who tends to the raccoons'
| area at the zoo, the raccoon-nook-keeper.
| AStonesThrow wrote:
| Coincidentally, American pedestrians are using HAWK signals to
| navigate road traffic successfully.
|
| https://en.wikipedia.org/wiki/HAWK_beacon
| louky wrote:
| >> As of 2025, he also teaches mathematics at Rudgers University.
|
| In the second sentence.
|
| Not even run through an AI grammar-checker?
| xandrius wrote:
| What's wrong with that?
| Philpax wrote:
| I believe it's Rutgers, not Rudgers.
| cryptonector wrote:
| Spelling, not grammar. Perhaps OP meant that the comma is
| unnecessary?
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(page generated 2025-05-27 23:00 UTC)