tag:theconversation.com,2011:/us/topics/corvids-36104/articlesCorvids – The Conversation2023-09-14T08:22:49Ztag:theconversation.com,2011:article/2129142023-09-14T08:22:49Z2023-09-14T08:22:49ZAre crows really that clever?<p>It’s no secret corvids are endowed with remarkable cognitive abilities.</p>
<p>Internet is awash <a href="https://www.youtube.com/watch?v=PZXmV0BfCWs">with videos of crows</a> imitating voices or solving complex brainteasers. But are these birds as intelligent as they are made out to be?</p>
<h2>The nutcracker puzzle</h2>
<p>One of the most quoted studies to back up the thesis of a superior intelligence in corvids is that of crows using cars as nutcrackers. In 1978, <a href="https://academic.oup.com/auk/article-abstract/95/4/760/5208772">researchers in California</a> noted that American crows would throw nuts on the road, wait for a car to crush them and then feast on the shattered fruit.</p>
<p>Despite being widely circulated by the media and even by other scientists, the study is a textbook example of how studying animal behaviour can lead us, often unintentionally, to anthropomorphise – i.e., assign animals abilities or thoughts similar to humans’, when their behaviour is actually explained by different processes.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/341665/original/file-20200614-153817-8rc66s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/341665/original/file-20200614-153817-8rc66s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/341665/original/file-20200614-153817-8rc66s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/341665/original/file-20200614-153817-8rc66s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/341665/original/file-20200614-153817-8rc66s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/341665/original/file-20200614-153817-8rc66s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/341665/original/file-20200614-153817-8rc66s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/341665/original/file-20200614-153817-8rc66s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">American crow calling.</span>
<span class="attribution"><a class="source" href="https://fr.wikipedia.org/wiki/Corneille_d%27Am%C3%A9rique#/media/Fichier:Corvus_brachyrhynchos_30157.JPG">Walter Siegmund/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>In 1997, <a href="https://sora.unm.edu/sites/default/files/journals/auk/v114n02/p0296-p0298.pdf">researchers at the University of California</a> took a closer look at the crows’ behaviour to check whether they did indeed use cars as nutcrackers. They hypothesised that if crows really understood that cars could pry nuts open, then the animals would place their nuts on the road and not remove them when a car approached.</p>
<p>However, the academics found that the crows did not throw their nuts onto the road when a car was approaching any more than when the road was empty. What’s more, out of the 200 cases studied, the researchers never saw a car crush a nut. This showed that the theory that crows were consciously using cars as nutcrackers was in fact false: crows drop their nuts on hard surfaces to crack them (such as roads) and a car sometimes crushes one. This is a happy coincidence for the crow, which does not, however, make the connection between the car and its meal.</p>
<h2>Proven cognitive abilities</h2>
<p>More recent research that was carried out with methods specifically designed to limit anthropomorphism is restoring corvids’ reputation for smarts. For example, it was long thought that only primates knew how to use tools. But since the 2000s, a host of studies has shown that several other species are capable of reproducing this feat, including <a href="https://www.pnas.org/content/102/25/8939.short">dolphins</a>, <a href="https://www.sciencedirect.com/science/article/pii/S0960982209019149">octopuses</a>, <a href="https://www.pourlascience.fr/sd/ethologie/lintelligence-des-grands-corbeaux-comparable-a-celles-des-grands-singes-et-des-enfants-12661.php">corvids</a> (crows included) and even <a href="https://www.sciencedirect.com/science/article/abs/pii/S1616504719300333?via%3Dihub">pigs</a>.</p>
<p>Corvids also appear to be highly sophisticated tool wielders thanks to their ability to <a href="https://psycnet.apa.org/record/2008-07027-001">choose and even manufacture tools of the right length and diameter</a> for the task they want to accomplish, such as twigs. For example, New Caledonian Crows have a track record of <a href="https://www.nature.com/articles/379249A0">producing hooks</a> by bending materials.</p>
<p>They also have an impressive memory for faces. <a href="https://www.sciencedirect.com/science/article/abs/pii/S0003347209005806">Researchers at the University of Washington, Seattle, tested this ability by donning a mask</a> to capture and then release American crows. Wild birds <a href="https://www.youtube.com/watch?v=bOkj7lJpeoc">would go on to aggressively scream every time they saw the masks</a>, more than two years after they were caught. Even crows that had not been captured learned to recognise and avoid this threatening figure by <a href="https://royalsocietypublishing.org/doi/full/10.1098/rspb.2011.0957">observing the behaviour of their companions</a>. This study is the first to show that wild, non-domesticated animals can recognise a human by their face and can remember it for several years, passing on this information to their fellow animals. The extent of this recognition is quite remarkable, both in temporal and social terms.</p>
<h2>Master Raven and self-control</h2>
<p>In <a href="https://link.springer.com/article/10.1007/s10071-019-01317-7">another experiment</a>, Rachael Miller and her colleagues at the University of Cambridge compared the self-control of Caledonian crows with that of children aged 3 to 5. Self-control is what enables us, for example, to reason with ourselves when we want to watch the last episode of a series so as not to be tired the next day. It’s an aspect of executive control, which enables us to make good decisions and plan for the future. Adults are generally able to use self-control without too much difficulty, but children only start to develop this ability between the ages of 3 and 5.</p>
<p>The experiment tested a specific aspect of self-control: delayed gratification, which occurs when you have to choose between a mediocre but immediate reward and a much better reward that is not immediately available. A typical example of delayed gratification is <a href="https://www.youtube.com/watch?v=QX_oy9614HQ">the marshmallow experiment</a>.</p>
<p>In Miller’s experiment, children and crows were presented with a slowly spinning tray containing two rewards (different stickers for the children, and sweets for the crows): one of the two rewards was more interesting to the subject, either because it was bigger or because it was of better quality. As it rotated, the tray made the less valuable reward accessible to the subjects, who could then grab it. If they succumbed, the tray then stopped spinning. However, if they waited for the first reward to pass, then the second, much more interesting one, became accessible to them.</p>
<p>The experiment included two tests: one in which the two rewards were visible all the time, and another where they only came into view when the tray started to spin. In the second trickier test, the second most coveted reward was not visible while the first passed in front of the subjects, who then had to use their memory on top of self-control. In the first test, both the crows and the children were able to wait for the best reward. But in the second one, the children outperformed the crows, because the latter were unable to wait for a reward they could no longer see.</p>
<p>In fact, this experiment is one of the few that has attempted to directly compare animals and children in terms of cognitive ability, using the same task for both species. Such results are therefore very interesting and give us a better perspective on the intelligence of crows.</p>
<p>However, we must bear in mind that animals are often tested on abilities that we, as humans, find important and in which we excel. Our biased view of the abilities of other species leads us to believe that we are the most intelligent creatures on Earth. But if crows were to test us in areas where they are highly intelligent, such as visual memory, navigation in 3D space or perception of the Earth’s magnetic field, would we be able to compete?</p><img src="https://counter.theconversation.com/content/212914/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mélissa Berthet a reçu des financements du Fond National Suisse et de l'Université de Zürich. </span></em></p><p class="fine-print"><em><span>Sonya Kaiser ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son organisme de recherche.</span></em></p>Scientists pour over the existing literature on corvids’ smarts to debunk some myths, and uphold others.Mélissa Berthet, Docteur en biologie spécialisée en comportement animal, University of ZurichSonya Kaiser, Dual Masters in Brain and Mind Sciences, Sorbonne UniversitéLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1739542021-12-22T13:49:47Z2021-12-22T13:49:47ZSeagulls, songbirds and parrots: what new research tells us about their cognitive ability<p>As you can imagine, a human intelligence test doesn’t really cut it for birds. It isn’t that easy to assess how an animal perceives information from the environment, processes it and decides to act. But researchers have developed a range of clever experiments to find out more about their cognitive abilities. Do they recognise each other, for example, or understand causal relationships where one thing can lead to another?</p>
<p>A commonly used “intelligence test” for animals is the <a href="https://pubmed.ncbi.nlm.nih.gov/25984937/">string-pulling task </a>. In this set-up, a piece of food is attached to a string. The food is then positioned out of reach for the animal – although still visible – and if they understand the causal relationship between the string and the food, they will start to pull the string which then moves the food closer to them until they reach it. If an animal can solve the string-pulling task we assume that it understands the relationship between the string and the reward and can deliberately execute a series of actions to get access to the reward. </p>
<p>In a recent study, <a href="https://royalsocietypublishing.org/doi/10.1098/rsos.211343">ring-billed gulls were tested</a> using the string-pulling model. Ring-billed gulls inhabit Canada and northern USA, however individual birds regularly wander to western Europe and are nowadays regular visitors in Ireland and the UK. </p>
<p>Gulls from a colony in Canada were individually marked with a colour band. This allowed the researchers to identify individual birds, which is important when testing cognition – and is often an obstacle for research on wild animals. In the test, a transparent plastic box was presented to the gulls, and they needed to pull a string through an open slit to retrieve a piece of sausage placed in a petri dish from inside the box. Gulls are omnivores and their diet consists of insects, fish, grain, eggs, worms and rodents. So a piece of sausage was particularly appealing.</p>
<h2>Seabird skills</h2>
<p>This task was given to 138 individuals at least once and 104 individuals – 75% – of the gulls attempted to solve the task. Of these, 26 individuals – 25% of those who attempted the task at least once – successfully retrieved the food from the box by pulling the string. </p>
<p>That may not seem like a particularly large number of successful gulls, but in a comparable <a href="https://academic.oup.com/auk/article/112/4/994/5168328?login=true">experiment in common ravens</a>, 26% successfully solved a similar task, suggesting that ravens and gulls perform similarly well. So that one test, at least, seems to suggest that corvids might not necessarily always possess higher cognitive abilities compared to other groups of birds, as has been widely assumed.</p>
<figure class="align-center ">
<img alt="A rook carrying a takeaway box in its beak." src="https://images.theconversation.com/files/438829/original/file-20211222-23072-1itpe1r.jpeg?ixlib=rb-1.1.0&rect=0%2C0%2C3620%2C2408&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/438829/original/file-20211222-23072-1itpe1r.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/438829/original/file-20211222-23072-1itpe1r.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/438829/original/file-20211222-23072-1itpe1r.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/438829/original/file-20211222-23072-1itpe1r.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/438829/original/file-20211222-23072-1itpe1r.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/438829/original/file-20211222-23072-1itpe1r.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Rooks are known for their skills in collaboration.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Gulls also perform well in other recent cognitive tasks – for example, urban herring gulls <a href="https://royalsocietypublishing.org/doi/full/10.1098/rsos.191959">use human cues</a>, such as human handling of food or human behaviour, to make foraging decisions which exploit their city home and help them to locate hidden food for themselves.</p>
<p>Up until recently, groups of birds such as fowl, birds of prey or penguins were rarely subjected to cognitive tests, because they were widely considered “less clever” and therefore less interesting than the songbirds – corvids such as crows, ravens, magpies and jays – and <a href="https://brill.com/view/journals/beh/156/5-8/article-p391_1.xml">parrots</a> which have attracted the most interest from animal cognition experts due to what is thought to be their <a href="http://blogs.nwic.edu/briansblog/files/2013/02/feathered_apes.pdf">extraordinary cognitive abilities</a>.</p>
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Read more:
<a href="https://theconversation.com/birds-that-play-with-others-have-the-biggest-brains-and-the-same-may-go-for-humans-151079">Birds that play with others have the biggest brains - and the same may go for humans</a>
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<p>But the recent studies on gulls – and a number of other waterfowl species – have shone a light on their previously undiscovered skills. Greylag geese can <a href="https://www.researchgate.net/profile/Isabella-Scheiber/publication/230811059_Long-term_memory_of_hierarchical_relationships_in_free-living_greylag_geese/links/552ccc770cf2e089a3acee56/Long-term-memory-of-hierarchical-relationships-in-free-living-greylag-geese.pdf">memorise social relationships</a> for at least six months, probably longer. And domestic chickens can <a href="https://royalsocietypublishing.org/doi/10.1098/rsos.210504">learn to differentiate</a> between a rewarded and unrewarded colour as quickly as carrion crows.</p>
<figure class="align-center ">
<img alt="Greylag goose landing on the water" src="https://images.theconversation.com/files/438755/original/file-20211221-19-1u5daf2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/438755/original/file-20211221-19-1u5daf2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=415&fit=crop&dpr=1 600w, https://images.theconversation.com/files/438755/original/file-20211221-19-1u5daf2.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=415&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/438755/original/file-20211221-19-1u5daf2.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=415&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/438755/original/file-20211221-19-1u5daf2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=522&fit=crop&dpr=1 754w, https://images.theconversation.com/files/438755/original/file-20211221-19-1u5daf2.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=522&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/438755/original/file-20211221-19-1u5daf2.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=522&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Greylag geese remember their social relationships.</span>
<span class="attribution"><span class="source">Claudia Wascher</span>, <span class="license">Author provided</span></span>
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<h2>Corvids and parrots still impress</h2>
<p>So it seems that corvids and parrots are not the only birds who show evidence of their brain power, and perhaps we should reconsider the use of the insult “bird brain”. But none of that detracts from the marvellous feats we witness in some of those more famous bird families. Earlier this year in Sydney, wild urban-dwelling sulphur-crested cockatoos not only learned to <a href="https://www.science.org/doi/10.1126/science.abe7808">open wheelie bins</a> and get food from them, but individuals also learned to do this from each other – it became a cultural innovation.</p>
<p>Other recent studies have shown that New Caledonian and Hawaiian crow are among only a handful animal species who can <a href="https://www.nature.com/articles/nature19103">make and use tools</a>. And, in a food hoarding experiment, scrub-jays demonstrated <a href="https://www.sciencedirect.com/science/article/pii/S2352154617300025?casa_token=QPSQSIaRQWwAAAAA:cuo8OCdrycb7MqvbqGl2D_gzTR44KypUp2xXHx4YCGRWyiezCi8TiRmuTP7b0Jw2Bzxcg9vF4A">what-where-when memory</a>: they seemed to remember what type of food they had hoarded at specific locations, and when they had done it. In the more barren winter months, this helps them to remember where they have hidden food which they have gathered and stored for later consumption.</p>
<p><a href="https://www.sciencedirect.com/science/article/abs/pii/S0003347214000414?casa_token=5AMokS7bPuIAAAAA:hFXpGkQ6hEMg_friH66T0T8Y6ML8gT4BDxfXStoF-pOBi4YCsExKSFd3RB_SyPJYM6zeI4JSNA">Crows, ravens</a> and <a href="https://royalsocietypublishing.org/doi/pdf/10.1098/rsbl.2012.1092">goffin cockatoos</a> dislike when they are treated unfairly and have been observed to wait for several minutes to receive a better food reward. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2602707/">Rooks</a>, meanwhile, and <a href="https://onlinelibrary.wiley.com/doi/pdf/10.1111/eth.12973">blue‐throated macaws</a> can cooperate with other individuals to together solve a string-pulling task. </p>
<p>It’s clear that cognitive abilities are important for animals to cope with all sorts of challenges in their environment. Therefore, understanding how they think can bring many valuable benefits. If we know how animals learn about predators, for example, it can help us to design more effective re-introduction programmes to conserve biodiversity. </p>
<p>And if we can assess whether an animal in a zoo, farm or kennel is feeling well or suffering, we can work to improve their living conditions and perhaps even control unwanted behaviour, such as those displayed by pets or in human-wildlife conflicts.</p><img src="https://counter.theconversation.com/content/173954/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Claudia Wascher does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Corvids and parrots might be the superstars of the bird world - but other species like gulls, geese and even chicken have shown some impressive skills too.Claudia Wascher, Associate Professor in Behavioural Biology, Anglia Ruskin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1617722021-06-02T14:12:26Z2021-06-02T14:12:26ZWe performed magic tricks on birds to see how they perceive the world<figure><img src="https://images.theconversation.com/files/403781/original/file-20210601-396-1qlk4j5.jpg?ixlib=rb-1.1.0&rect=605%2C258%2C3512%2C2427&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/eurasian-jay-garrulus-glandarius-759117964">Shutterstock/Piotr Krzeslak</a></span></figcaption></figure><p>Magic tricks can teach us about how the brain works. Magic capitalises on very specific blind spots in <a href="https://mitpress.mit.edu/books/experiencing-impossible">people’s attention and perception</a> so the techniques that magicians use to trick audiences are particularly interesting to psychologists like me. </p>
<p>Misdirection, for example, relies on the control of the audience’s attention to fool them. A magician will divert the audience’s attention away from things that show how the trick is done, towards the effect they want them to see. This and other magic techniques can reveal important characteristics of <a href="https://www.frontiersin.org/articles/10.3389/fpsyg.2014.01508/full">how our minds work</a>. </p>
<p>But magic tricks might also be a good tool to investigate the non-human animal mind. The study of how animals perceive magic effects that fool and surprise humans can help us understand how their minds experience the world around them, and whether such experiences are <a href="https://doi.org/10.1126/science.abc6805">in some way like ours</a>. </p>
<p>That’s why, in <a href="https://www.pnas.org/content/118/24/e2026106118">a recent study</a>, my colleagues and I tried to perform magic tricks to birds. We tested sleight of hand on Eurasian jays, and found they were fooled by some tricks and not by others.</p>
<p>Misdirection is not totally new to some birds. Corvids – large-brained birds in the crow family including jays, ravens and magpies – hide food they can retrieve later, a behaviour known as caching. But if <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1560201/">another corvid is watching</a> them hide the food, they run the risk of <a href="https://doi.org/10.1098/rstb.2006.1992">their cache being stolen</a>.</p>
<p>To get around this, this clever family of birds use intricate and highly elaborate protection tactics that are comparable to the misdirection used by magicians. For example, corvids can hide food discreetly in one spot while pretending to hide it in many other places, making it difficult for the observer to <a href="https://psycnet.apa.org/record/2014-09971-001">spot the real cache</a>.</p>
<h2>Three tricks</h2>
<p>In our study, we performed three different sleight of hand tricks to six Eurasian jays and 80 human participants. Known as palming, French drop and fast pass, they are all used in magic routines to make objects appear and disappear. </p>
<p><a href="https://en.wikipedia.org/wiki/Palming">Palming</a> involves hiding an object in your palm while pretending the hand is empty. <a href="https://en.wikipedia.org/wiki/French_drop">The French drop</a> – shown in the gif below – involves pretending to pass something from one palm to the other, without actually moving the object. Finally, the fast pass involves moving an object between your hands so quickly it’s not seen by the audience.</p>
<p>They all involve misleading the observer into thinking an object has or hasn’t been transferred from one hand to the other. </p>
<p>For the first two of these tricks – palming and French drop – to succeed in misleading the average audience member, the observer needs some inherent understanding of what a typical transfer of objects entails. It’s this knowledge that certain movements usually produce particular outcomes that leads a spectator into assuming there was no foul play. </p>
<figure> <img src="https://cdn.theconversation.com/static_files/files/1595/French_Drop.gif?1622547306"><figcaption>The French drop.</figcaption></figure>
<p>Little is known about corvids’ preconceptions of human hand motions or whether they have similar expectations as us when observing transfers of objects between hands. Birds don’t have hands, so we wanted to find out whether they understand what hand movements should mean. </p>
<p>The third sleight of hand effect we used doesn’t rely on such expectations. Fast pass is based on the magician’s ability to performed very fast motions, which aren’t usually perceived by the observer. </p>
<p>Birds have <a href="https://link.springer.com/content/pdf/10.1007/s10336-007-0213-6.pdf">different visual perception</a> than people, with a much wider <a href="https://doi.org/10.1007/s10336-011-0769-z">field of view</a>. If our jays fell for similar sleight of hand techniques that magicians use to deceive humans, it might mean that they had similar blind spots.</p>
<h2>Clever jays</h2>
<p>Unlike our human sample, which was significantly fooled by all three of the magic effects we performed, Eurasian jays didn’t seem to be fooled by the first two tricks. This could be because jays lack the expectations about hand mechanics that makes us humans liable to these techniques of deception. </p>
<p>But our sample of jays was significantly fooled by the third technique – as shown in the gif below – suggesting that their visual system can be exploited with similar methodologies as the ones used in humans. </p>
<figure> <img src="https://cdn.theconversation.com/static_files/files/1594/Fast_pass.gif?1622546870"><figcaption>The fast pass.</figcaption></figure>
<p>It is possible that the effect might be exploiting different blind spots in attention and perception to those in people. Further research should be conducted to fully investigate the blind spots, and whether these are similar to our perceptive failures or explained by something else.</p><img src="https://counter.theconversation.com/content/161772/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Elias Garcia-Pelegrin does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Testing whether the birds react to sleight of hand helps us understand if they see the world like we do.Elias Garcia-Pelegrin, Researcher in Comparative Cognition and Evolutionary Psychology, University of CambridgeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1257132019-12-25T21:46:57Z2019-12-25T21:46:57ZCurious Kids: how do magpies detect worms and other food underground?<figure><img src="https://images.theconversation.com/files/306031/original/file-20191210-95130-1x643vf.jpg?ixlib=rb-1.1.0&rect=0%2C12%2C1697%2C1185&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Magpies have a few clever tricks to help them find food. </span> <span class="attribution"><span class="source">Gisela Kaplan</span>, <span class="license">Author provided</span></span></figcaption></figure><hr>
<blockquote>
<p><strong>How do magpies detect worms and other food sources underground? I often see them look or listen, then rapidly hop across the ground and start digging with their beak and extract a worm or bug from the earth – Catherine, age 10, Perth.</strong></p>
</blockquote>
<hr>
<p><a href="https://theconversation.com/au/topics/curious-kids-36782"><img src="https://images.theconversation.com/files/291898/original/file-20190911-190031-enlxbk.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=90&fit=crop&dpr=1" width="100%"></a></p>
<hr>
<p>You have posed a very good question. </p>
<p>Foraging for food can involve sight, hearing and even smell. In almost all cases learning is involved. Magpies are ground foragers, setting one foot before the other looking for food while walking, called <a href="http://www.publish.csiro.au/book/7677/" title="Biology and Behaviour of an Unusual Songbird">walk-foraging</a>. It looks like this: </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/299577/original/file-20191030-162164-vx8jyb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/299577/original/file-20191030-162164-vx8jyb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/299577/original/file-20191030-162164-vx8jyb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=485&fit=crop&dpr=1 600w, https://images.theconversation.com/files/299577/original/file-20191030-162164-vx8jyb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=485&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/299577/original/file-20191030-162164-vx8jyb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=485&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/299577/original/file-20191030-162164-vx8jyb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=610&fit=crop&dpr=1 754w, https://images.theconversation.com/files/299577/original/file-20191030-162164-vx8jyb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=610&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/299577/original/file-20191030-162164-vx8jyb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=610&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This is called walk-foraging.</span>
<span class="attribution"><span class="source">Gisela Kaplan</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Finding food on the ground, such as beetles and other insects, is not as easy as it may sound. The ground can be uneven and covered with leaves, grasses and rocks. Insects may be hiding, camouflaged, or staying so still it is hard for a magpie to notice them.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-is-a-magpies-poo-black-and-white-104920">Curious Kids: why is a magpie's poo black and white?</a>
</strong>
</em>
</p>
<hr>
<p>Detecting a small object on the ground requires keen vision and experience, to discriminate between the parts that are important and those that are not. </p>
<p>Magpie eyes, as for most birds, are on the side of the head (humans and other birds of prey, by contrast, have eyes that face forward).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/305806/original/file-20191209-90592-eed4d5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/305806/original/file-20191209-90592-eed4d5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/305806/original/file-20191209-90592-eed4d5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=171&fit=crop&dpr=1 600w, https://images.theconversation.com/files/305806/original/file-20191209-90592-eed4d5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=171&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/305806/original/file-20191209-90592-eed4d5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=171&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/305806/original/file-20191209-90592-eed4d5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=215&fit=crop&dpr=1 754w, https://images.theconversation.com/files/305806/original/file-20191209-90592-eed4d5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=215&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/305806/original/file-20191209-90592-eed4d5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=215&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A magpie’s eyes are at the side of its head and it can only see something with both eyes if that is straight in front of the bird.</span>
<span class="attribution"><span class="source">Shutterstock/Webb Photography</span></span>
</figcaption>
</figure>
<p>To see a small area in front of them, close to the ground, birds use both eyes together (scientists call this binocular vision). But birds mostly see via the eyes looking out to the side (which is called monocular vision).</p>
<p>This picture gives you an idea of what a magpie can see with its left eye, what it can see with its right eye and what area it can see with both eyes working together (binocular vision).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/299580/original/file-20191030-17868-ggvcnr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/299580/original/file-20191030-17868-ggvcnr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/299580/original/file-20191030-17868-ggvcnr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=599&fit=crop&dpr=1 600w, https://images.theconversation.com/files/299580/original/file-20191030-17868-ggvcnr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=599&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/299580/original/file-20191030-17868-ggvcnr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=599&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/299580/original/file-20191030-17868-ggvcnr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=753&fit=crop&dpr=1 754w, https://images.theconversation.com/files/299580/original/file-20191030-17868-ggvcnr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=753&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/299580/original/file-20191030-17868-ggvcnr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=753&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Here’s how a magpie’s field of vision works.</span>
<span class="attribution"><span class="source">Gisela Kaplan</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>You asked about underground foraging. Some of that foraging can also be done by sight. Worms, for instance, may leave a small mound (called a cast) on the surface and, to the experienced bird, this indicates that a worm is just below. </p>
<p>Magpies can also go a huge step further. They can identify big scarab larvae underground without any visual help at all. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/299581/original/file-20191030-17893-ljwvwg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/299581/original/file-20191030-17893-ljwvwg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/299581/original/file-20191030-17893-ljwvwg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=632&fit=crop&dpr=1 600w, https://images.theconversation.com/files/299581/original/file-20191030-17893-ljwvwg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=632&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/299581/original/file-20191030-17893-ljwvwg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=632&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/299581/original/file-20191030-17893-ljwvwg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=794&fit=crop&dpr=1 754w, https://images.theconversation.com/files/299581/original/file-20191030-17893-ljwvwg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=794&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/299581/original/file-20191030-17893-ljwvwg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=794&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Here is a scarab larva.</span>
<span class="attribution"><span class="source">Gisela Kaplan</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Scarab larvae look like grubs. They munch on grassroots and can kill entire grazing fields. Once they transform into beetles (commonly called Christmas beetles) they can do even more damage by eating all the leaves off eucalyptus trees.</p>
<p>Here is the secret: magpies have such good hearing, they can hear the very faint sound of grass roots being chewed.</p>
<p>We know this from <a href="https://www.sciencedirect.com/science/article/pii/S0003347281801121" title="Localization of soil dwelling scarab larvae by the black-backed magpie, Gymnorhina tibicen (Latham)">experiments</a> using small speakers under the soil playing back recorded sounds of scarab beetle larvae. Magpies located the speaker every time and dug it up. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/305294/original/file-20191205-70116-zd2m70.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/305294/original/file-20191205-70116-zd2m70.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/305294/original/file-20191205-70116-zd2m70.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/305294/original/file-20191205-70116-zd2m70.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/305294/original/file-20191205-70116-zd2m70.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/305294/original/file-20191205-70116-zd2m70.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/305294/original/file-20191205-70116-zd2m70.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/305294/original/file-20191205-70116-zd2m70.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An Australian magpie digging for food in a lawn.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/degilbo_on_flickr/3790117753/">Flickr/Lance</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>So how do they do it? Several movements are involved.</p>
<p>To make certain that a jab with its beak will hit the exact spot where the juicy grub is, the magpie first walks slowly and scans the ground. It then stops and looks closely at the ground – seemingly with both eyes working together.</p>
<p>Then, holding absolutely still, the magpie turns its head so the left side of the head and ear is close to the ground for a final confirming <a href="https://www.researchgate.net/publication/318003665_Audition_and_Hemispheric_Specialization_in_Songbirds_and_New_Evidence_from_Australian_Magpies">listen</a>. </p>
<p>Finally, the bird straightens up, then executes a powerful jab into the ground before retrieving the grub.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/305292/original/file-20191205-70133-1fvy04l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/305292/original/file-20191205-70133-1fvy04l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/305292/original/file-20191205-70133-1fvy04l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/305292/original/file-20191205-70133-1fvy04l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/305292/original/file-20191205-70133-1fvy04l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/305292/original/file-20191205-70133-1fvy04l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=532&fit=crop&dpr=1 754w, https://images.theconversation.com/files/305292/original/file-20191205-70133-1fvy04l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=532&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/305292/original/file-20191205-70133-1fvy04l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=532&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An Australian magpie digging for food gets a grub.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/File:Australian_Magpie_Digging_Grub.jpg">Wikimedia/Toby Hudson</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>That is very clever of the magpies. Very few animals can extract food they can’t see. Only great apes and humans were thought to have this ability. Clever magpies indeed. And farmers love them for <a href="https://www.sciencedirect.com/science/article/pii/S0003347281801121" title="Localization of soil dwelling scarab larvae by the black-backed magpie, Gymnorhina tibicen (Latham)">keeping a major pest under control</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-do-birds-sing-98381">Curious Kids: Why do birds sing?</a>
</strong>
</em>
</p>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to <a href="mailto:curiouskids@theconversation.edu.au">curiouskids@theconversation.edu.au</a></em></p><img src="https://counter.theconversation.com/content/125713/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gisela Kaplan does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Magpies have such good hearing, they can hear the very faint sound of grass roots being chewed.Gisela Kaplan, Emeritus Professor in Animal Behaviour, University of New EnglandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1237592019-09-18T20:36:34Z2019-09-18T20:36:34ZCable ties probably won’t stop magpie attacks – here are a few things to try instead<figure><img src="https://images.theconversation.com/files/292936/original/file-20190918-148974-1cc8uzz.JPG?ixlib=rb-1.1.0&rect=11%2C109%2C1553%2C1447&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Stylish? No. Effective? Probably not.</span> <span class="attribution"><span class="source">Tony Wills/Wikimedia Commons</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Every spring in Australia is heralded by reports of magpies swooping at people. While it is of little comfort to those at the receiving end of a surprise attack, such events are actually quite rare when one considers the number of magpies across Australia, and the fact that they love to share our urban habitat with us. </p>
<p>According to <a href="https://www.tandfonline.com/doi/abs/10.1071/MU99011">one estimate</a>, fewer than 10% of magpies swoop, and even fewer of these do so consistently. It is almost always males that swoop, and they only do so when they have <a href="https://www.jstor.org/stable/3783916?seq=1#metadata_info_tab_contents">chicks in the nest</a>. Once the chicks are out the males seem to calm down; presumably they perceive nest-bound chicks as most vulnerable. </p>
<p>Swooping behaviour also seems to vary across Australia – at least according to <a href="https://www.magpiealert.com/">Magpie Alert!</a>, a website on which the public can report magpie attacks. Many more swoops have been reported in the eastern states than in Western Australia, and fewest of all in Tasmania.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/bird-brained-and-brilliant-australias-avians-are-smarter-than-you-think-51475">Bird-brained and brilliant: Australia's avians are smarter than you think</a>
</strong>
</em>
</p>
<hr>
<p>But regardless of their relative rarity, being the target of a swooping attack by a magpie can be frightening. It has resulted in <a href="https://7news.com.au/lifestyle/health-wellbeing/swooping-magpie-blinds-little-boy-family-pleads-for-awareness-c-436878">injuries</a> and, tragically this week, the <a href="https://www.illawarramercury.com.au/story/6386661/cyclist-dies-after-avoiding-swooping-magpie-in-woonona/?cs=12">death of a 76-year-old cyclist in Wollongong</a>. </p>
<p>What can we do to avoid ending up on the receiving end? Is any of the advice meted out each year on avoiding attacks actually worthwhile, or backed by evidence? As with just about everything involving biology, the answer is “it depends”. </p>
<p>Some magpies never attack pedestrians but go for cyclists; others do the opposite. And some hold a deep animus against posties on bikes, and reserve their fury solely for them. Even more astonishingly, some magpies seem to really have it in for <a href="http://www.publish.csiro.au/WR/WR01108">particular people</a>, and will preferentially attack them. </p>
<p>Although Australian magpies are not related to true crows, they do share similar levels of intelligence. <a href="https://royalsocietypublishing.org/doi/full/10.1098/rspb.2011.0957">US researchers have shown</a> that <a href="https://www.audubon.org/field-guide/bird/american-crow">American crows</a> recognise people who have trapped them to band them, give alarm calls when they next see them, and even pass on that information to untrapped birds who also sound the alarm when they see trappers. </p>
<p>It seems likely that Australian magpies do the same, effectively holding a grudge against particular people. Unfortunate posties, travelling the same route each day and meeting the same magpies, seem to end up on the naughty list through no fault of their own.</p>
<p>Cyclists do seem to invoke more extreme reactions than pedestrians, judging by the fact that magpies appear to pursue cyclists farther. It therefore stands to reason that the best response to a swooping attack while cycling would be to get off and push your bike. </p>
<p>You will <a href="https://theconversation.com/dont-be-fooled-keeping-bike-helmets-is-best-for-health-661">of course</a> be wearing a bike helmet, and as magpies swoop from behind, this will offer protection against its sharp beak. </p>
<p>Sadly it seems that the classic tactic of attaching cable ties to your helmet <a href="https://www.magpiealert.com/Magpie-Story.php?story_id=10">does little to deter a determined magpie</a>, beyond the fact that some strategic placing can help keep them away from your ears. Ditto the idea of painting eyes on the back of your helmet or hat.</p>
<p>More reassuringly, however, magpies really only swoop in the vicinity of their nest, so once you have moved away you should be safe. If you become aware of swooping attacks in a certain area the best thing is to avoid it – even just crossing the road should be sufficient.</p>
<p>If you can’t do that, at least wear a hat and sunglasses; these will help reduce the chance of a determined magpie pecking a sensitive area. Turning to face magpies may also help – many birds do not appreciate being <a href="https://zslpublications.onlinelibrary.wiley.com/doi/full/10.1111/j.1469-7998.2011.00846.x">stared</a> <a href="https://royalsocietypublishing.org/doi/full/10.1098/rsbl.2019.0405">at</a>, and as magpies prefer to swoop from behind, this may be a good tactic if you find yourself cornered in a park.</p>
<p>If you have magpies in your garden, perhaps the most appealing way of avoiding attacks is to become their best friend. Given that magpies have long memories, a few judicious offerings of mince or similar tidbits throughout the year can help you <a href="https://theconversation.com/magpies-can-form-friendships-with-people-heres-how-83950">befriend</a> them, making them much more amenable to your presence come spring. </p>
<p>But don’t overfeed them – it’s just a friendly bribe, not a full-blown dependency.</p>
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Read more:
<a href="https://theconversation.com/magpies-can-form-friendships-with-people-heres-how-83950">Magpies can form friendships with people – here's how</a>
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<p>If all else fails, simply console yourself with the fact that swooping season only lasts a few weeks. For the rest of the year magpies are peaceful urban nighbours who delight us with their distinctive song. </p>
<p>Bear that in mind, and we can hopefully reach a détente with our feathered (and occasionally flustered) friends. In the meantime, if you are unlucky enough to be swooped, remember to help others avoid the same fate by posting the details to <a href="https://www.magpiealert.com/">Magpie Alert!</a>.</p><img src="https://counter.theconversation.com/content/123759/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bill Bateman does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Magpie attacks aren’t as common as you (and the media) might think. But here are a few tricks to get you through swooping season unscathed - and a few classic tactics that don’t work.Bill Bateman, Associate professor, Curtin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/731522017-02-21T14:46:26Z2017-02-21T14:46:26ZAnimals know when they are being treated unfairly (and they don’t like it)<figure><img src="https://images.theconversation.com/files/157697/original/image-20170221-18627-wc2aiz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption"></span> <span class="attribution"><span class="source">Claudia Wascher</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Humans beings appear to be <a href="https://academic.oup.com/qje/article/114/3/817/1848113/A-Theory-of-Fairness-Competition-and-Cooperation">hardwired to have a sense of fairness</a>. This is puzzling from an evolutionary perspective, which you would have thought would mean we were predisposed to seek advantage for ourselves and our families wherever possible. But in fact a sense of fairness is important for humans to be able to help each other. Human cooperation is based on reciprocal altruism – we help people because they’ve either helped us in the past or they may help us in the future. </p>
<p>This form of cooperation is only possible when individuals are able to keep track of other individuals’ efforts and payoffs – and a sense of fairness helps with this. But what about non-human animals? Is sense of fairness unique in differentiating humans from other animals or has it evolved in other non-human animals too?</p>
<p>There’s a way of testing for this in animals using an “<a href="http://journal.frontiersin.org/article/10.3389/fpsyg.2017.00270/full">inequity aversion task</a>”. One test subject receives a reward for completing a task, while an experimental partner gets a “booby prize” – something they don’t particularly like. You’d imagine that individual animals that have a strong sense of fair play would either stop taking part in the experiment or refuse the treat.</p>
<p>One of the first species that was tested for inequity aversion were <a href="http://www.sciencedirect.com/science/article/pii/S0003347215000767">brown capuchin monkeys</a>. In a task where the monkeys had to exchange a token for a treat, one individual was given a piece of cucumber in exchange for a token, whereas a model individual – another monkey not the focus of the experiment – in an adjacent cage got a grape for the same action. Capuchin monkeys prefer grapes to cucumbers – and the individual receiving the cucumber soon started to “protest” by throwing the unloved vegetable back at the experimenter. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/157674/original/image-20170221-18630-1d2swgu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/157674/original/image-20170221-18630-1d2swgu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=423&fit=crop&dpr=1 600w, https://images.theconversation.com/files/157674/original/image-20170221-18630-1d2swgu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=423&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/157674/original/image-20170221-18630-1d2swgu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=423&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/157674/original/image-20170221-18630-1d2swgu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=532&fit=crop&dpr=1 754w, https://images.theconversation.com/files/157674/original/image-20170221-18630-1d2swgu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=532&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/157674/original/image-20170221-18630-1d2swgu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=532&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Capuchin monkeys also showed an awareness of what’s fair.</span>
<span class="attribution"><span class="source">orangecrush, Shutterstock</span></span>
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</figure>
<p>The capuchin monkeys were also well aware of unfairness in the amount of effort they had to expend to receive a reward. When they had to “work” for a reward – and could see that their experimental partner received the reward as a “gift”, they stopped participating. </p>
<p>A number of other primate species, including <a href="http://link.springer.com/article/10.1007%2Fs10071-014-0765-9">chimpanzees</a>, <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0153799#">rhesus macaques</a> and <a href="http://onlinelibrary.wiley.com/doi/10.1002/ajp.21014/abstract;jsessionid=8DB6E658D6026F091E6DEBC751314062.f04t02">long-tailed macaques</a>, have been shown to express some form of behavioural responses to inequity. Apart from primates, two further highly social mammalian species, <a href="http://www.sciencedirect.com/science/article/pii/S0168159109001865">dogs</a> and <a href="http://www.psychologie.hhu.de/fileadmin/redaktion/Fakultaeten/Mathematisch-Naturwissenschaftliche_Fakultaet/Psychologie/CompPsy/Papers/Oberliessen_et_al_2016.pdf">rats</a>, have also been shown to be sensitive to unfairness. </p>
<h2>Bird brains</h2>
<p>But what about non mammalian species? In recent years, the family of corvids has become one of the prime models when it comes to studying cognition in birds. Corvids are a large family of more than 120 species – including ravens, crows, magpies and jays. Corvids are <a href="http://www.sciencedirect.com/science/article/pii/S0960982207014947">highly social and have flexible social systems</a>. Adult ravens for example live in territorial pairs, whereas jackdaws live in large community groups. In some species, such as the carrion crow, sociability depends on the environment – they might breed in male-female pairs in some environments as well as cooperative groups in others. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/157698/original/image-20170221-18654-el8v0v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/157698/original/image-20170221-18654-el8v0v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/157698/original/image-20170221-18654-el8v0v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/157698/original/image-20170221-18654-el8v0v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/157698/original/image-20170221-18654-el8v0v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/157698/original/image-20170221-18654-el8v0v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/157698/original/image-20170221-18654-el8v0v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Er… excuse me?</span>
<span class="attribution"><span class="source">Claudia Wascher</span>, <span class="license">Author provided</span></span>
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</figure>
<p>Various forms of naturally occurring cooperation can be observed in different corvid species. They help each other in aggressive encounters and share resources such as food or information about predators. So, given the extent to which corvids have been seen to cooperate in the wild, we expected them to have a sense of fairness and unfairness. </p>
<p>We decided to put them to the <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0056885">same test as the primates</a>. The test subjects were four common ravens and six carrion crows. The birds received a piece of cheese as their reward (they like cheese) and a piece of grape as the booby prize. In one experiment, both individuals received the same food reward for exchanging a token with a human experimenter, while in another, one bird received only grapes for exchanging, whereas the other was given cheese. We also tried what’s called an “effort control” experiment in which the test subject had to exchange its token either for a piece of cheese or a piece of grape while the other bird was given the same reward, but got it as a gift and did not have to exchange for it. </p>
<p>In the “inequity” condition the subject crow – the bird that was being unfairly treated – stopped taking the lesser reward. In the “effort control” they stopped exchanging their token for the reward when they saw the other bird getting its reward for no effort. In both cases they could see how they were being treated unfairly and decided not to cooperate.</p>
<p>So in this respect, corvids are like some mammals – and a high complexity and flexibility in cooperation may have driven the evolution of this awareness of what is fair and what isn’t. The fact that inequity aversion is present not only in a number of primate species but also corvids suggests that this idea of fairness and cooperation is something that cooperative species have got in common which has enabled them to evolve sociability.</p>
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<p><em>Claudia Wascher will be giving a talk: Unfairness ruffles crows’ feathers as part of the <a href="http://www.sciencefestival.cam.ac.uk/">Cambridge Science Festival</a> from March 13 to 26.</em></p><img src="https://counter.theconversation.com/content/73152/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Claudia Wascher received funding from 'L'oreal women in science' scholarship. </span></em></p>Like humans, some animals have evolved a highly developed sense of fairness.Claudia Wascher, Lecturer in Animal and Environmental Biology, Anglia Ruskin UniversityLicensed as Creative Commons – attribution, no derivatives.