Clever Animals How and Why
Homing pigeons owe their name to the ability to return home from distant, unfamiliar release points — in some cases, even if they’ve been transported, anaesthetised and deprived of all information about the journey. They were used to carry messages in both ancient Greece and China, and by the 16th century were being used in formal postal services. In 1860, Paul Reuter employed a fleet of 45 to deliver news and stock prices between Brussels and Aachen. Only in 2002 did India’s police force retire its pigeon messenger service, when it was made redundant by e-mail. Homing pigeons have proved especially useful during times of war. One bird, “Cher Ami”, was awarded the French Croix de Guerre for his heroic service during the First World War in delivering 12 important messages, despite sustaining a bullet wound. Equally amazing, but for different reasons, is the unfortunate bird that set off from Pembrokeshire in June 1953. It returned, dead, in a box postmarked “Brazil”, 11 years later.
Viewers of Flipper do not need to be told that dolphins are cleverer than most inhabitants of the sea. Whether he was upholding the law, or embarking on a daring sea rescue, the iconic TV hero’s brainpower never failed to amaze. Even without television trickery, dolphins are smart. The latest evidence of intelligence came this week, when researchers published the results of a study in the Brazilian Amazon which showed male members of pods carrying “gifts” in the form of sticks, or, most endearingly, makeshift bouquets made from seaweed, to attract mates. DNA tests revealed that the males who carried the most gifts proved the most successful fathers. Research in Australia showed bottlenose dolphins use bits of marine sponge to protect their noses while they probe the seabed. Scientists say the behaviour is evidence that they show signs of culture learned from their forebears, rather than passed down in genes.
While they may not yet have developed the power of speech, as exhibited in the upcoming Jerry Seinfeld film, Bee Movie, and are all too easily snared by beer traps in summer, bees are unexpectedly clever insects. As early as 330BC, Aristotle described the remarkable “waggle dance” bees use to communicate with members of the hive. It was originally thought the dance was designed simply to attract attention, but in 1947, Karl von Frisch, who was later awarded a Nobel Prize for his work, deduced that the apparently random runs and turns of the dance, which bees perform in groups, correlates directly to the position of the sun in relation to the location of food. If a bee runs from the six to 12 o’clock positions, it means food is in the direction of the sun. The number of waggles dictates how far away the food lies.
Most dog owners will claim their pooch is the smartest in the park. But retrieving sticks or barking at postmen, while impressive when compared with the skills of, say, a jellyfish, is hardly rocket science. However, new research suggests mutts are capable of much more: in an experiment at the University of Vienna, two border collies, an Australian shepherd and a mongrel were presented with images on a touch screen. The pairs of photos offered the choice of a landscape or a dog. When the dogs used their nose to push against the dog image, they got a treat. If they plumped for the landscape, they were forced to wait a few seconds before the next round. The training stage complete, the dogs were shown landscape and dog photos, and continued to correctly pick out the dogs. In the final phase, the dogs were shown an unfamiliar dog superimposed on a landscape they had seen in training. Even then, the animals were able to pick out the dog. Scientists say the results show that dogs can use abstract concept, a skill which had been attributed only to birds and primates.
The 65 million-year-old leatherback turtle has witnessed the fall of the dinosaurs and the rise of humanity. But the giant sea creature is most extraordinary for its ability to travel huge distances, from the cold waters in which it feeds to the tropical and subtropical beaches where it hatches its eggs. Female turtles originally tagged in French Guiana off the coast of South America have been recaptured on the other side of the ocean in Morocco and Spain. In 2006, the so-called “Dingle turtle” made headlines after being tagged off the west coast of Ireland and embarking on an astonishing 5,000-mile journey to the Cape Verde islands, off West Africa. Leatherbacks are found from Alaska to New Zealand.
Everyone knows man’s closest living relative is the sharpest tool in the animal box. After all, what other animal can brew up a cup of PG Tips while wearing a bowler hat? This week, however, the publication Current Biology has shed new light on the brain power of chimpanzees, revealing them to have photographic memories far superior to our own. Until now, it was not thought chimps could match humans in mental tests. But researchers in Kyoto discovered that chimps could recall a sequence of numbers displayed to them (for a fraction of a second), outperforming students who took the same test. The research suggests that short-term memory may have been more important to earlier humans, possibly because of our modern reliance on language-based memory skills.
Whale song, which is associated in particular with the humpback, is something of a mystery to scientists. Male humpbacks sing mainly during the mating season, but it is not known whether the song is used to attract females or to ward off other males. The song itself is complex. At any one moment, all the males in a population sing the same song. Over time the song slowly evolves into something new, with all the whales making exactly the same changes to their pattern of singing. Studies suggest that, once a population of whales has moved on from a particular pattern, it will never again return. Other whales such as the sperm and beluga also make songs but none are as complex as that of the humpback.
The old adage that elephants never forget was proved to have a basis in scientific fact in 2001, when research showed that matriarchs, who lead the herd, have an uncanny ability to remember faces. This enables them to know when alert their brood to menacing interlopers. Now, scientists at the University of St Andrews have shown that pachyderms are even smarter than that: a study of 36 family groups in Kenya suggests that elephants can build a mental map of where herd members are by combining their memory with a keen sense of smell. Researchers lay urine samples from wild elephants in the path of a herd. When the leader encountered the scent, it reacted with surprise because its memory told it the animal was walking behind, and could not have been able to lay its scent ahead.
The Arctic tern
Even more prone to wander than the leatherback turtle, the Arctic tern takes the longest regular migration of any known animal, from its Arctic breeding grounds to the Antarctic and back again every year. On this journey of about 22,000 miles, the seabird enjoys two summers and more daylight than any other creature on the planet. One chick demonstrated its flying ability by setting out from Labrador, Canada, in July 1928 to arrive in South Africa four months later. Another unfledged chick tagged on the Farne Islands, off the coast of Northumberland, in 1982 flew 14,000 miles to Melbourne, Australia, in just three months. Over its life, the Arctic tern will travel about 500,000 miles.
They might be famous for their brawn — ants can carry up to 20 times their body weight, the equivalent of a woman strapping a hippo to her back — but ants are not renowned for brains. When it comes to delegation, however, they’re smart. Males cannot claim much credit for this — they spend their days wandering around accepting food until they mate, when they promptly die — but worker ants, who are generally sterile females, are clever. They perform tasks such as foraging, defending, preparing food, construction and attending to the queen. The most dangerous task is foraging, so older, more expendable ants are given the job, while the younger ones wait on the queen.
New Caledonian Crows
The ability to fashion tools has always been held as uniquely primate, distinguishing us from (apparently) less intelligent creatures. But humans and apes are not alone in having tool-making skills. Crows amazed the science community in October when footage — recorded using tiny “crow-cams” on the tails of New Caledonian crows — showed the birds creating advanced implements. One crow was observed whittling twigs and leaves with its beak to fashion grabbers designed to retrieve grubs from the ground. The New Caledonian crows are the only known non-primate to create and use new tools.
Chimps might be able to outwit Japanese university students in a test of photographic memory, and are traditionally considered to be second only to humans in the intelligence stakes, but research published earlier this year suggested that orang-utans were the smartest swingers in the ape world. Scientists from Harvard University studied orang-utans in Borneo and found them capable of tasks that chimps could only dream of, such as using leaves to make waterproof hats and roofs. They also gathered evidence that the orange-haired apes have developed a culture in which adults teach the young how to make tools. Viewers of David Attenborough’s documentaries will remember the astonishing film of an orang-utan climbing into a canoe and using a paddle.
Animals Do the Cleverest Things
By Steve Connor, Independent UK
Posted on December 8, 2007, Printed on December 9, 2007