Synanthropy, and ice cream for crow
BY Rupert Goodwins / 5 March 2008
My new favourite word is synanthropy – the study and practice of creating symbiotic relationships between people and animals. I came across it thanks to the ever-giving Metafilter group blog, a pretty fine palace of symbiosis n its own right. It pointed me at A Vending Machine For Crows, a project by polymath techie Joshua Klein that aims to put some of the hundreds of millions of dropped coins back in circulation. It does this by training crows to realise that if they find coins and take them to the machine, they’ll get food. Crows, and corvids in general, are my favourite birds; they’re impressively intelligent, communicative, fast to learn and innovative when problem solving. They also like shiny things: really, what’s not to love?
The benefits of this idea are manifold. Klein posits that if you can get a few crows trained, then the idea will spread naturally throughout the population – and that means that mostly, human intervention can be restricted to seeding the idea and then leaving enough machines around. That makes it very economical – especially if the crows remain unaware of the true market value of the coinage they find. Although I’m sure that economics will take over if the idea catches on; if it’s profitable for the machine operators, then rival devices will appear offering better deals and a wider range of treats – and I do hope crows really are partial to ice cream. Is it perhaps entirely smart to introduce intelligent non-humans into our economy?
Perhaps the most exciting long-term potential for the Crow Vending Machine is that humans will lose a bit more of that apartness when it comes to other animals, and learn to think in symbiotic terms. That can only be advantageous; currently, our attempts to game the world’s ecosystems are clumsy and full of ill thought out missteps. Co-option is better than control. Meanwhile, watch yourself when you’re counting out change for that lunchtime sandwich at the pavement cafe. If this catches on, avian mugging will spread from the seagulls in no time flat.
SMART ENOUGH TO LIVE
HALVED COCONUTS AS PORTABLE SHELTER
Scientists discover coconut-carrying octopus / Dec 15, 2009
Two scientists at the Melbourne Museum have recorded the first case of tool use in an invertebrate animal. The veined octopus, Amphioctopus marginatus, selects, stacks, transports and assembles coconut shells as portable armour. Many octopuses use available objects such as shells and rocks for shelter, but that is not considered tool use. Dr Mark Norman says what makes these animals so special is the the planned future use of the coconut shells. “It comes at a cost, carrying these shells in this awkward way and it’s a fantastic example of complex behaviours in what we consider the lower life forms,” he said. “I think these sorts of behaviours are everywhere in nature. There’s really complex behaviours that we write off because we think we’re the clever ones.”
He and colleague Dr Julian Finn spent more than 500 hours diving in remote waters off Indonesia to observe and film the animals. They watched the octopuses dig out coconut shells from the ocean floor and empty the shells of mud using jets of water. Dr Finn says it is not unusual for octopuses to live inside coconuts but it is how the veined octopus uses the shells that is unique. “It gathers them together, it stacks them like bowls, covers its whole body over bowls, lifts them up and then trundles along on its arm tips until a predator comes or there’s a threat,” he said. “Then it closes them over like a ball and hides inside.”
This series of actions are among the most complex ever recorded for octopuses. The veined octopus evolved this behaviour by first using clam shells as shelter. However once humans began discarding large numbers of coconut shells they found the perfect armour to protect themselves against fish attackers. The pair have written a scientific paper on the veined octopus which appears in the scientific journal Current Biology.
‘NEVER LAUGHED SO HARD UNDERWATER’ : RESEARCHER
Study reveals use of tools by octopuses / 2009-12-15
Researchers often see tool use as a mark of intelligence. Humans, birds, primates and other mammals are all known to use them, and now a report by British and Australian researchers published in the journal Current Biology says that octopuses, an invertebrate, can be added to the list. Until recently, science had perceived invertebrates as lacking the cognitive abilities to demonstrate tool use. While some have been observed using leaves or sand to collect and transport food, researchers have said that these behaviours are different to the tool use seen in mammals and birds.
The new report details a type of behaviour of the veined octopus called ‘stilt walking': the soft-bodied octopus spreads itself over stacked, upright coconut shells, makes its eight arms rigid, and raises the whole assembly to then amble across the seafloor. The octopus later uses the shells as a shelter, which the researchers say is different to a hermit crab using a discarded shell. ‘There is a fundamental difference between picking up a nearby object and putting it over your head,’ said Mark Norman of the Museum Victoria in Australia, who worked on the project and led the report, ‘versus collecting, arranging, transporting (awkwardly) and assembling portable armour as required.’ The researchers found that the veined octopus exhibits further tool abilities by assembling the coconuts. This confirms the behaviour as tool use, distinguishing it from other object manipulations by octopuses, such as using rocks to barricade a lair entrance.
To study the octopuses, researchers dove for nearly 500 hours between 1999 and 2008 off the coasts of Bali and northern Sulawesi in Indonesia. More than 20 octopuses were studied, and the discovery of the behaviour was a surprise. ‘I could tell that the octopus, busy manipulating coconut shells, was up to something, but I never expected it would pick up the stacked shells and run away,’ stated Julian Finn, also of the Museum Victoria. ‘It was an extremely comical sight – I have never laughed so hard underwater.’ The researchers believe that the behaviour is likely to have evolved using large empty bivalve shells prior to the relatively recent supply of clean and light coconut shell halves discarded by costal communities near the marine habitant of the octopuses. The report concludes: ‘Ultimately, the collection of use of objects by animals is likely to form a continuum stretching from insects to primates, with the definition of tools. However, the discovery of this octopus tiptoeing across the seafloor with its prized coconuts shells suggests that even marine invertebrates engage in behaviours that we once thought the preserve of humans.’
BRAINS WITH TENTACLES
How Smart Is the Octopus?
BY Carl Zimmer / June 23, 2008
Aristotle didn’t have a high opinion of the octopus. “The octopus is a stupid creature,” he wrote, “for it will approach a man’s hand if it be lowered in the water.” Twenty-four centuries later, this “stupid” creature is enjoying a much better reputation. YouTube is loaded with evidence of what some might call octopus intelligence. One does an uncanny impression of a flounder. Another mimics coral before darting away from a pushy camera. A third slips its arms around a jar, unscrews it, and dines on the crab inside. Scientific journals publish research papers on octopus learning, octopus personality, octopus memory. Now the octopus has even made it into the pages of the journal Consciousness and Cognition (along with its fellow cephalopods the squid and the cuttlefish). The title: “Cephalopod consciousness: behavioral evidence.”
So, is the octopus really all that smart? It depends on how you define intelligence. And if you’ve got a good definition, there are quite a few scientists who would love to hear it. Octopuses can learn, they can process complex information in their heads, and they can behave in equally complex ways. But it would be a mistake to try to give octopuses an IQ score. They are not intelligent in the way we are—not because they’re dumb but because their behavior is the product of hundreds of millions of years of evolution under radically different conditions than the ones under which our own brains evolved.
Grady Hendrix recommended that we avoid the giant squid at all costs. Daniel Engber explained why it’s so hard to find a giant squid and wondered if cats can really sense death. Seth Stevenson reviewed the history of celebratory sports gestures, including the venerable “octopus toss” of the Detroit Red Wings. You’d have to go back about 700 million years to find the moment in the history of life when humans and octopuses diverged. Our most recent common ancestor, scientists suspect, was a little wormlike creature with eyespots and little more. Since then, our lineage evolved bones; theirs evolved boneless bodies they control with water pressure. We’ve accumulated so many and such incredible differences over that time that 20th-century scientists were excited to discover a few deep similarities. In the 1950s, for example, biologists demonstrated for the first time that octopuses have massive brains.
Cephalopods belong to the same lineage that produced snails, clams, and other mollusks. A typical mollusk might have 20,000 neurons arranged in a diffuse net. The octopus has half a billion neurons.* The neurons in its head are massed into complex lobes, much the way our own brains are. In comparison with their body weight, octopuses have the biggest brains of all invertebrates. They’re even bigger than the brains of fish and amphibians, putting them on par with those of birds and mammals. In the late 1950s, Oxford biologist N.S. Sutherland decided to put the big brains of octopuses to the test. He would show them two shapes and reward them for touching one but not the other. They might learn to tell a rectangle in a horizontal position from the same rectangle rotated 90 degrees. And once they had figured out this test, the octopuses knew to select any horizontal rectangle they saw, no matter what its particular dimensions. They were learning what to learn. Over the years, octopuses have shown many more signs of intelligence. They proved to have an excellent memory. They were clever and unpredictable. Jennifer Mather, a Canadian biologist, has tossed toys into octopus tanks and watched as the octopuses inspect them and puff them around with jets of water.* They are playing, she argues. Clams do not play. Humans do.
Mather is also the author of the new paper arguing for consciousness in octopuses. She does not claim that they have full-blown consciousness like we do but a simpler form known as primary consciousness. In other words, they can combine their perceptions with their memories to have a coherent feel for what’s happening to them at any moment. Mather bases her claim not just on how octopuses behave but also on how their brains work. For example, one sign of the complexity of the human brain is that we can be left-handed or right-handed. Our preference comes from one side of the brain dominating over the other—a sign of how the two sides of our brains are not identical. Instead, they divide up mental work and communicate with each other to create a unified sense of reality. Octopuses may not be left-handed (or left-armed), but Mather claims that they show similar kinds of specialization with their eyes. In a 2004 experiment, she and her colleagues found that when they looked out from their dens, some preferred to sit with their left eye facing out, others with their right.
But some octopus experts are skeptical of these bold claims. Many reports of weird octopus behavior come from casual observations in aquariums. Even some experiments have not held up to scrutiny. Last year, Jean Boal of Millersville University and her colleagues found fault with Mather’s experiments on left- and right-brained octopuses. The problem was that the scientists had looked at too few octopuses. It was impossible to rule out the possibility that octopuses might not have any preference at all for either eye. The results of the experiments might simply have been a matter of chance. After 50 years, in other words, we still don’t know that much about what’s going on in the heads of octopuses. Carefully designed experiments will be essential for finding out more, but so will a more octo-centric attitude. What we call intelligence is really just a set of behaviors and abilities that evolved in our ancestors as they adapted to a particular way of life. Octopuses evolved behaviors of their own, but they were adapting to a way of life that’s hard for us to imagine—they were naked mollusks in a world of fish.
The earliest cephalopods, which lived about a half-billion years ago, had shells. Over the next 250 million years, they evolved into giant predators. They shot bursts of water out of siphons to swim—a prehistoric form of jet propulsion.* But their glory was cut short by fish with jaws—our ancestors. Fish could swim faster by bending their bodies than cephalopods could move by jetting. Today, only a single shelled cephalopod survives—the nautilus, which spends most of its life lurking deep underwater. The other living cephalopods lost their shells. While they gave up a defense against predators, they were free to evolve new skills. Squids became fast swimmers. Octopuses instead moved to the sea floor, where they could use their shell-free bodies to explore cracks and crevices for prey. But in order to survive in this new niche, they had to become fast learners. Jean Boal and her colleagues have done some experiments that show how good octopuses are at learning geography. Boal put the octopuses in tanks with an assortment of landmarks, such as plastic jugs, plates of pebbles, and clumps of algae. It took only a few trials for the octopuses to find the quickest route to a hidden exit in the bottom of the tank. What made Boal’s results particularly impressive is that the octopuses were learning two completely different mazes at once. Boal would move them from one to the other after each trial. Somehow, the octopuses could keep track of two geographies concurrently. When octopuses are moving across new terrain, they can perhaps learn the best escape from predators.
Octopuses escape from predators not just by hiding quickly but by deceit. One of the most impressive examples of this deception is what marine biologist Roger Hanlon calls the moving-rock trick. An octopus morphs into the shape of a rock and then inches across an open space. Even though it’s in plain view, predators don’t attack it. They can’t detect its motion because the octopus matches its speed to the motion of the light in the surrounding water. For Hanlon, what makes this kind of behavior remarkable is that it’s a creative combination of lots of behaviors, used to address a new situation. Similarly, when an octopus escapes an attack, it may puff up its body and turn white to scare a predator, shoot off puffs of ink to distract it, zigzag through the water, and then suddenly switch its skin to match the surrounding coral.
There’s not much point in trying to pin this sort of behavior to some human-based scale of intelligence, because our behavior emerged as apes adapted to life spent on two legs, in groups, and using our hands to make tools. We’d fail pretty badly at an octopus-based test of intelligence, but surely we wouldn’t hold it against ourselves.
Tiny Crow Camera Spies On Clever Birds / Oct. 10, 2007
A new technique developed by Oxford University zoologists enables researchers to ‘hitch a ride’ with wild birds and witness their natural and undisturbed behaviour. The scientists developed miniaturised video cameras with integrated radio-tags that can be carried by wild, free-flying birds. Using this new ‘video-tracking’ technology, they spied on the behaviour of New Caledonian crows, a species renowned for its sophisticated use of tools, recording behaviours never seen before. Observing New Caledonian crows in the wild is extremely difficult because they are easily disturbed and live in densely forested, mountainous terrain. ‘Video-tracking’ enabled the Oxford scientists to obtain particularly intimate observations of crow behaviour. ‘Everyone thought that New Caledonian crows use tools mainly to probe into holes and cracks in rotting wood and tree crowns, but we now discovered that they use tools even on the ground,’ said Dr Christian Rutz, from the Behavioural Ecology Research Group at Oxford’s Department of Zoology.
One crow was seen probing leaf litter with grass-like stems – a mode of tool use, and a tool material, that decades of observation with conventional techniques had missed. ‘This discovery highlights the power of our new video-tracking technology’ said Dr Rutz, who leads the group’s field research. ‘This is the first time that wild birds have been tracked in this way, and it has already changed our understanding of New Caledonian crow behaviour.’ For the study, 18 crows were fitted with ‘tailcams’ with each unit weighing about 14 grams – only slightly heavier than a conventional radio-tag. The units were attached to two tail feathers with strips of adhesive tape, and were designed so that they did not adversely affect the bird’s movements, and could be removed by the crows themselves or would detach after a few weeks with the birds’ natural moulting process.
‘Observing wild birds this closely in their natural habitat has been one of the final frontiers of ornithological field research,’ said Dr Rutz. ‘Whilst video footage has been taken before using tame, trained birds, it is only now that we have been able to design cameras that are small and light enough to travel with wild birds and let them behave naturally. Potentially, this new video technology could help us to answer some long-standing questions about the ecology and behaviour of many other bird species that are otherwise difficult to study.’ A report of the research, entitled ‘Video Cameras on Wild Birds’ was published in Science Express on Thursday 4 October 2007. The research was undertaken by Dr Christian Rutz, Lucas Bluff, Dr Alex Weir and Professor Alex Kacelnik from the Behavioural Ecology Research Group at the Department of Zoology and was funded by the Biotechnology and Biological Sciences Research Council (BBSRC).
CROWS SHOW CULTURAL ADAPTATION
email : josh [at] wireless [dot] is
TEACHING CROWS (TO TEACH OTHER CROWS)
TO COLLECT TRASH, IN EXCHANGE FOR PEANUTS
BY Claire Trageser / December 12, 2008
In June, Josh Klein revealed his master’s-thesis project to a flock of crows at the Binghamton Zoo in south-central New York State. The New York University graduate student offered the birds coins and peanuts from a dish attached to a vending machine he’d created, then took the peanuts away. Klein designed the machine so that when the crows searched for the missing peanuts, they pushed the coins out of a dish into a slot, causing more peanuts to be released into the dish. The Binghamton crows quickly learned that dropping nickels and dimes into the slot produced peanuts, and the most resourceful members of the flock began looking for more coins. Within a month, Klein had a flock of crows scouring the ground for loose change. Now Klein is working with graduate students at Cornell University and Binghamton University to study how wild crows make use of his machine. Although his invention might conjure Hitchcock-worthy visions of crows stealing the loose change from pedestrians’ pockets and hands, Klein’s conception is more benign. To Klein, the machine demonstrates the value of cooperating with “synanthropes” — animals that have adapted seamlessly to human environments. “Rather than just killing off a species, why not see if they can do something useful for us, so we can all live in close proximity?” he said. To pursue his research, he founded the Synanthropy Foundation this year. Someday, he hopes, similar techniques may allow us to train rats to sort our garbage for us.
Vending Machine for Crows / April 12, 2009
An article in the Year in Ideas issue on Dec. 14, 2008, reported on Josh Klein, whose master’s thesis for New York University’s Interactive Telecommunications Program proposed “a vending machine for crows” that would enable the birds to exchange coins for peanuts. The article reported that beginning in June 2008, Klein tested the machine at the Binghamton Zoo, that the crows learned how to use it and that after a month the crows were actually scouring the ground for loose change.
The Times has since learned that Klein was never at the Binghamton Zoo, and there were no crows on display there in June 2008. He performed these experiments with captive crows in a Brooklyn apartment; he told the reporter about the Brooklyn crows but implied that his work with them was preliminary to the work at the zoo. Asked to explain these discrepancies, Klein now says he and the reporter had a misunderstanding about the zoo.
The reporter never called the zoo in Binghamton to confirm. And while the fact-checker did discuss the details with Klein, he did not call the zoo, as required under The Times’s fact-checking standards. In addition, the article said that Klein was working with graduate students at Cornell University and Binghamton University to study how wild crows make use of his machine, which does exist. Klein did get a professor at Binghamton to help him try it out twice in Ithaca, with assistance from a Binghamton graduate student, and it was not a success. Corvid experts who have since been interviewed have said that Klein’s machine is unlikely to work as intended.
These discrepancies were pointed out to The Times by the Binghamton professor several weeks after the article was published; this editors’ note was delayed for additional reporting. These details should have been discovered during the reporting and editing process. Had that happened, the article would not have been published.
PREVIOUSLY ON SPECTRE : EFFORT TO CORRUPT BIRDS PAYS OFF
MEANWHILE : VOLUME DISPLACEMENT
Clever Crows Prove Aesop’s Fable Is More Than Fiction
BY Hadley Leggett / August 6, 2009
Aesop’s fables are full of talking frogs and mice who wear clothes, but it turns out at least one of the classic tales is scientifically accurate. Researchers presented four crows with a challenge from Aesop’s fable “The Crow and the Pitcher”: a container of water not quite full enough for the birds to reach with their beaks. Just like Aesop’s crow, all four birds figured out how to raise the water level by dropping stones into the glass. The crows also selectively chose large pebbles over small ones, and quickly realized that dropping rocks into a container of sawdust didn’t have the same effect. “The results of these experiments provide the first empirical evidence that a species of corvid is capable of the remarkable problem-solving ability described more than two thousand years ago by Aesop,” wrote the researchers in the paper published Thursday in Current Biology. “What was once thought to be a fictional account of the solution by a bird appears to have been based on a cognitive reality.”
The researchers took four adult rooks, a type of intelligent crow, and tempted them with a tasty worm floating on top of a glass of water, just out of reach. Then they placed a pile of small rocks next to the crows. After they assessed the height of the water from the top and sides of the glass, the crows dropped stones into the glass until the water level rose enough for them to grab their prize. Once they’d caught the worm, the birds didn’t keep putting stones in the glass, and they didn’t try to grab the worm until they’d dropped in a certain number of stones. “This number was strongly correlated to the number of stones needed to raise the water level to the correct height,” the researchers wrote, “suggesting that, having assessed the starting level of the water, rooks translated this into an estimate of the number of stones needed.”
Before this experiment, the birds had never been exposed to a glass with water in it, and they’d never used stones as tools. According to the researchers, the only other animal known to perform this kind of task is the orangutan, which has been recorded spitting into a tube to bring a peanut into reach. “Corvids are remarkably intelligent, and in many ways rival the great apes in their physical intelligence and ability to solve problems,” said biologist Christopher Bird of the University of Cambridge in a press release. “This is remarkable considering their brain is so different to the great apes’.” The antics of the four birds — Cook, Fry, Connelly and Monroe — can be seen in the videos below. Cook and Fry snagged the floating worm after just one try, while Connelly and Monroe succeeded after two attempts. Unfortunately, Fry had a bad reaction to one of the worms and gave up in the middle of the experiment.
In the Brevia section of the 9 August 2002 issue of Science, Weir et al. report a remarkable observation: The toolmaking behavior of New Caledonian crows. In the experiments, a captive female crow, confronted with a task that required a curved tool (retrieving a food-containing bucket from a vertical pipe), spontaneously bent a piece of straight wire into a hooked shape — and then repeated the behavior in nine out of ten subsequent trials. Though these crows are known to employ tools in the wild using natural materials, this bird had no prior training with the use of pliant materials such as wire — a fact that makes its apparently spontaneous, highly specific problem-solving all the more interesting, and raises intriguing questions about the evolutionary preconditions for complex cognition. The crow’s behavior was captured on video.
THE MOST FAMOUS CROW (ACCORDING TO HUMANS)
Our experiments on tool selectivity did not examine whether the crows understood how their tools worked. To do this, we gave our subjects a very unnatural material – garden wire – and an unusual problem: some meat in a small bucket, at the bottom of a transparent ‘well’. In the first experiment, the crows were given a choice between a hooked and a straight piece of wire, and could only get the bucket if they used the hook.
As so often in scientific research, the experiment took an unexpected turn. On the fifth trial of the experiment, one of our subjects (“Abel”) removed the hooked wire, leaving the other subject (“Betty”) with only the straight piece. After trying to use this unsuccessfully, she wedged one end of it under a piece of sticky tape and pulled the other end with her beak – creating a hook! – which she then used to retrieve the bucket. When tested with only straight wire, she repeatedly bent it into hooks, using a variety of techniques, indicating that this was not something she just did accidentally on that one occasion (Weir et al. 2002).
These observations were particularly remarkable because it is the first time any animal has been seen to make a new tool for a specific task, without an extended period of trial-and-error learning. It seems that Betty understood that she needed a hook to get the bucket and that she could then figure out how to make a hook from a novel material. We have recently tested her with a different kind of material – flat strips of aluminium – and found that she quickly learned how to modify these as necessary, either to make a hook, or to make them longer or narrower (Weir & Kacelnik 2006). We are currently investigating whether other individuals have the same abilities.
email : alex.kacelnik [at] zoo.ox.ac [dot] uk
email : rd.gray [at] auckland.ac [dot] nz
email : grhunt10 [at] hotmail [dot] com
“In the past, people thought birds were stupid,” laments the aptly named scientist Christopher Bird. But in fact, some of our feathered friends are far cleverer than we might think. And one group in particular – the corvids – has astonished scientists with extraordinary feats of memory, an ability to employ complex social reasoning and, perhaps most strikingly, a remarkable aptitude for crafting and using tools. Mr Bird, who is based at the department of zoology at Cambridge University and is supervised by Dr Nathan Emery, says: “I would rate corvids as being as intelligent as primates in many ways.”
The corvids – a group that includes crows, ravens, rooks, jackdaws, jays and magpies – contain some of the most social species of birds. And some of their intelligence is played out against the backdrop of living with others, where being intelligent enough to recognize individuals, to form alliances and foster relationships is key. However, group living can also lead to deceptive behaviour – and western scrub jays (Aphelocoma californica) can be the sneakiest of the bird-bunch. Many corvids will hide stores of food for later consumption, especially during the cold winter months when resources are scarce, but western scrub jays take this one step further. Mr Bird says: “If they are being watched, they will hide their food, but they will do some ‘fake hides’ as well – so they’ll put their beak in the ground, but not place the food. It’s a bit like a confusion strategy. “Sometimes, if they are being watched, then they’ll even go back and hide the food again.”
Corvids’ cognisance of other birds has led scientists to ponder whether they are also aware of themselves. And to test this, scientists use the Gallup mark test, where an animal is marked on a part of its body that it cannot normally see and is then shown its reflection in a mirror. If it notices this mark and tries to remove it, then it suggests that the animal knows it is looking at itself and could possess some kind of self-awareness. So far, only some species of primates have consistently passed this self-recognition test, although more recent studies suggest elephants and dolphins may also respond. But last year, a German team revealed that magpies, marked with a coloured sticker under their beaks, tried to remove it when presented with a mirror – the first time a bird had been seen to pass this test. Professor Onur Gunturkun, from Ruhr-University Bochum, one of the authors of the Plos paper, says: “It throws out the assumption that only higher mammals were capable of self-recognition.”
While the birds’ social intelligence has continued to impress, it is perhaps their physical intelligence, and in particular their tool use, that has stirred the most interest. Recent studies reveal that corvids’ tool-use may at least rival, and even surpass, that of primates, such as chimpanzees. And one species in particular possesses an extraordinary ability – the New Caledonian crow (Corvus moneduloides), which is found on the Pacific island of New Caledonia. Russell Gray and his colleagues from the department of psychology at the University of Auckland have studied this species extensively, and were the first to discover that the birds were crafting tools in the wild. Professor Gray tells BBC News: “They do some really complex looking things. “We have seen that they take a whole branch, chop off the side branches and hone away at the end to create a hook, which they use to get grubs.” Other experiments carried out at field stations have even shown that the birds will use a number of different tools to reach a tasty snack.
Inside the laboratory, captive New Caledonian crows are also helping scientists to better understand tool use and corvid intelligence. And one bird in particular seemed to posses a remarkable ability when it came to solving problems using tools – Betty. Alex Kacelnik, who leads the behavioural ecology group at Oxford University, said: “Betty was captured as a juvenile from the field, and she must have been one-and-a-half years old when she came to us. And we didn’t have any reason to suspect that she was an unusual animal.” However the team discovered, by chance, that Betty was able to perform some remarkable feats that had never been seen before in any other animals. The researchers were testing how New Caledonian crows selected tools by presenting them with a small bucket filled with some food, which was placed in a well, and pieces of wire, some straight and some with a hook at the end. The aim was to see whether the crows would select the bent wire to retrieve the treat-laden bucket. But Betty astonished researchers when she selected a straight piece of wire and then used her beak to bend it into a hook so she could pull up the bucket of food. When she was later tested with just the straight wire, Betty repeatedly bent it into hooks – and other experiments with aluminium strips revealed how she would bend, shorten and lengthen the material to get to her food. This was the first time that any animal had been seen to make a new tool for a specific task, without an extended period of trial-and-error learning.
As scientists discover ever-more intelligent behaviour in corvids, they are now trying to understand why this group has developed these special abilities. And New Caledonian crows’ tool-use is a key focus. Professor Gray explains: “What has led to just this one species in this one little island in the Pacific being able to make these complex tools? It’s an ongoing mystery.” Professor Kacelnik agrees: “This really is the million dollar question. We know that this is heritable – we have demonstrated that if you raise New Caledonian crows, without exposure to any social input, they still would want to use tools to solve problems.” Researchers are also looking at the cognitive processes that underpin this behaviour. Mr Bird says: “The interesting thing is that they can do so many of these clever things that primates can do – sometimes they can do them even better. But their brain is completely different from the mammalian brain. “They don’t have the area of the mammalian brain that is thought to be the area of intelligent cognition – the neocortex. Interestingly, they have another area, the nidopallium, that might do the same job.”
As scientists try to understand this, the research is also driving forward some more fundamental questions about intelligence. Christian Rutz, who also works for Oxford’s behavioural ecology group, says: “There are such enormous semantic issues. How do you define intelligence? How do you define what it means to understand something?” We have to be careful with ascribing intelligence to seemingly impressive behaviours, he says. He explains: “Not everything that looks smart to the human observer is actually smart. “For example, take orb web spiders. These animals build sophisticated structures for foraging, but would we call this behaviour ‘intelligent’? Probably not. He says to understand what the birds are doing and whether this sets them apart in any way, the same experiments need to be carried out, multiple times, on many different species, to properly compare results. Dr Rutz adds: “People tend to think corvid cognition research is now incredibly advanced and we’ve answered most of the questions – I don’t think so, I think it is at the very beginning.”
MUTUALLY BENEFICIAL SYNANTHROPY IN PRACTICE : SNIFFER RATS
Unexploded Landmines? Call for The Herorats
BY R J Evans / December 12, 2009
Unexploded landmines still remain a huge problem the world over. What is more, landmine clearance is an expensive business. One man has found a potential solution, however. It may seem like an unlikely combination. Giant pouched rats are not what spring to mind immediately when conversation turns to the global issue of unexploded landmines. However, Bart Weegens, from Belgium has found a low-technology answer to the continuing issue of unexploded mines. A childhood interest in the animals came to mind when he was musing over possible solutions and this led to an extraordinary development.
The idea occurred to Weegens as he realized that rats were both easy to train and had an excellent sense of smell. Combining these two would, he considered, provide a cheap way to detect unexploded mines and – what is more – with limited danger to human life. He founded APOPO, which is a non-profit organization, the aim of which is to train up African Giant Pouched Rats and to deploy them in the field. Not only would the rats be a cheaper alternative to mine clearance methods already in use – he figured that they would be considerably more efficient as well. An army of sniffer rats, would, it seemed save hundreds if not thousands of human lives. Not bad, considering that rats do not generally have a great press with a lot of people.
Having said that, the Giant Pouched Rats used in this project are only a distant relative of the common rat we hold in such great esteem. It is an intelligent species and easy to train – with many new recruits easy to breed. The female of the species can produce up to ten litters a year. Although this is a scary fact, only one to five arrive with each litter, despite the mother having eight nipples. In many African countries they are kept as pets but also are predominantly used as a food source. Perhaps the mine field is a better option than the casserole dish after all.
Initial funding for APOPO was in Belgium. This was given by the Belgian Directorate for International Co-operation. When the rats proved successful in terms of their training it was decided to switch the whole operation to Tanzania in East Africa. There they could be trained in near-to-real conditions and so the team is now based in Sokoine University of Agriculture in Tanzania. The training there proved successful and it was while this was happening that Bart thought of another use for the HeroRATS as they were now called. It had been discovered that the rats could detect tuberculosis in human sputum (the stuff you cough up when you have a cold). Research began on this in 2004.
So, how do the rats do their detection work? There are two methods, direct detection and REST. What happens is that they are trained from young to associate the smell of explosives with a treat – such as a banana or peanut. This reward is vital to the rat doing its work as, akin to our own species – individuals do not like to do something for nothing, after all. The rats move up and down an area the size of a squash court and when they locate a mine they usually sit still and scratch themselves. After that the mines can be detonated by their human helpers.
Why these rats though? As well as having the highly developed sense of smell important in this work they are, as we have seen, easy to tame, breed and train. The cheapness of breeding and maintaining them is further helped by their ability to adapt to a number of environments. Once they are trained the rats seem to actively enjoy performing repetitive tasks and they do not get stressed if their trainers are changed in the way that dogs will. Plus of course – one serious advantage over dogs – they are too light to detonate a mine by themselves if they step on it. A living rat is better than a canine cadaver.
Training is a little time consuming – it can take up to a year. They are trained according to pavlovian principles. A food reward is initially associated with a clicking sound – their favorites being bananas or peanuts. It takes a while for them to learn that a click means food but once they do then the real training can begin. The teaching goes that when they find TNT, indicating it by scratching, then they will hear a click and get their food reward. They are initially trained in cages and once they have learned that indicating a positive sample of TNT means food then they are ready to work in a field of mines.
The REST method of detecting does not involve visiting a minefield at all. REST stands for Remote Explosive Scent Tracing and this is when scent is brought from the mines to the rats. The rats can find explosives present in these samples and it helps to determine the actual boundaries of minefields. This means that more land can be cleared at a quicker rate. Direct detection involves harnessing the rats and proceeding with a systematic search of the minefield. The rat is connected, via a search string, to two trainers and this is how the rat is directed. When TNT is detected the rat will give itself a good scratch and safe detonation can then proceed. In order to ensure that all mines have been detected two or three rats will each search the same area. It is important though, to reward the rat whenever it performs its function.
The HeroRATS are currently deployed in Mozambique where they have enabled over one thousand families to reclaim their land. They have also helped with clearing areas so that power lines can be passed through – so bringing electricity which would not otherwise have been possible to over ten thousand local citizens. It is hoped that they will soon be deployed to Zambia, Congo and Angola as well, but negotiations are still underway. APOPO is actively looking for demining partnerships globally, not just in Africa.