A short BBC clip narrated by David Attenborough showing crows in Japan using city traffic to crack nuts, dropping them at intersections and retrieving them when the light changes.
Why Hacker News points people here: HN uses it as the standard illustration of animal tool use and adaptive intelligence in crow threads.
“Here's a video (from Japan) about this phenomenon”HN comment, 2015
“crows in Japan, who have learned to crack nuts by leaving them in traffic at intersections, waiting for the cross signal, then retrieving them.”
Shows Japanese crows cracking nuts using traffic.
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Individuals of many species are capable of copying the behaviour of another individuals (usually of the same species) by observation. The other primates are the most well-known mimics ("monkey see, monkey do"), but most mammals and birds do this. We like to think we're special in this respect, but we're really not. Birds, for example, learn features of their songs from other songs they hear. Over time, these features accumulate in a bird's repertoire, and even develop into a dialect for an area. See link Another example in birds is the behaviour of crows in Japan, who have learned to crack nuts by leaving them in traffic at intersections, waiting for the cross signal, then retrieving them. See this video This is the first example I've heard of a "play" behaviour being learned, but what can I say? The life of a captive dolphin would be boring; a new way to pass the time would be a useful thing to know.
Cites itymseDec 2015
“Here's a video (from Japan) about this phenomenon”
Video of crows using traffic to crack nuts in Japan.
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Here's a video (from Japan) about this phenomenon: this video I wonder whether it was discovered independently, or if it has been communicated somehow. Or maybe they've "always" done this, except with horses before cars.
Cites itSomeoneJul 2016
“they place the nut on zebra crossings with traffic lights, and wait for the light to turn green”
Crows wait at crossings for the light before retrieving nuts.
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They're smarter nowadays; they place the nut on zebra crossings with traffic lights, and wait for the light to turn green (possible using 'pedestrians cross the road' as a clue) before hopping onto the road ( this video )
Cites itnneonneoSep 2016
“Video, narrated by David Attenborough”
Attenborough-narrated crows dropping nuts on crosswalks.
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Video, narrated by David Attenborough: this video The cleverest crows drop the nuts on the pedestrian crosswalk, so that there is a long safe duration to grab the cracked but.
Cites ityareallyJan 2017Full comment
> "Monkeys can be trained to do some pretty complex things in comparison to what a bird can do, it seems to me monkeys are smarter than birds." Crows are likely on par with chimps and dolphins for intelligence by creating their own tools in the wild and other intelligent behavior (language, facial recognition, passing on knowledge). Parrots such as African Greys and cockatoos are right up there too with problem solving abilities. I know cockatoos can be trained to "pick locks" and then pass on the knowledge to other cockatoos. linklinklinkthis videolinklinklinklink
Cites ityareallyJun 2018
“They'll use traffic to crack open nuts by dropping them in front of traffic lights.”
Crows drop nuts in front of cars at lights.
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Crows in Japan are definitely quite intelligent. They'll use traffic to crack open nuts by dropping them in front of traffic lights. After a car runs over them, they'll wait for the red light and then retrieve the now cracked open nut[1]. [1] this video
Cites itchongliNov 2019
“New Caledonian crows who have learned to use traffic to crack nuts”
Crows using traffic as example of general intelligence.
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We know a great deal more about biological general intelligence than we do about AGI. Many animals create their own goals and work to achieve them. We learn what works and what does not, and adapt our strategies to compensate. Humans do this (obviously) but a lot of other intelligent animals can do it as well. One of my favourite examples is the New Caledonian crows who have learned to use traffic to crack nuts [1]. Here, a crow had no pre-defined objective function apart from "eat food to stay alive" and has accomplished something remarkable. It found a food source that it had never had access to before, it developed a complex model of its urban environment, it combined its knowledge of the problem (the hard nut shell) with its knowledge of its environment (cars crush small objects), and it constructed a sophisticated for strategy for using cars to crack open the nuts and fetching the contents when the traffic lights indicated it was safe to do so. This is general intelligence! [1] this video
Cites itAnimatsMar 2022
“Crows have been seen using traffic to crack nuts.”
Crows use crosswalks to safely retrieve cracked nuts.
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Crows have been seen using traffic to crack nuts. Including using a crosswalk to get a chance to retrieve the cracked nuts.[1] [1] this video
Cites itSomeoneMay 2025
“Some crows in Japan do something like that, dropping nuts on/near a pedestrian crossing, and waiting for a green pedestrian light.”
Japanese crows wait for green pedestrian light.
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Some crows in Japan do something like that, dropping nuts on/near a pedestrian crossing, and waiting for a green pedestrian light. See this video
