Monday, July 31, 2006
Elephants don't do stairs - or even gentle slopes, apparently. According to the results of a major new survey, released today, the giants of the savannah shun higher ground because the job of hauling themselves upwards is just too hard. Before we go dismissing Dumbo as a lazybones, however, it's worth thinking about the logistics of mountaineering, elephant-style. To generate enough energy, the four tonne vegetarians need to eat about 42kg (90lbs) of food a day. As a result they spend up to 18 out of every 24 hours foraging for fruit, grass and tree bark.
The co-author of the study, Iain Douglas-Hamilton reckons an elephant needs an extra 25,000 calories of energy for every vertical metre climbed - about 2,500% the cost of level walking. Finding enough food to fuel such activity is not easy. "Climbing is something that an elephant should not do lightly," he said. Even if an elephant does climb a mountain, getting back down again is almost as much effort. "Actually climbing down also requires quite a bit of energy for braking," Dr Douglas-Hamilton told the BBC nature website.
Douglas-Hamilton and his fellow researchers used GPS devices to track the movements of thousands of elephants in northern Kenya. They found the elephants confined their movements to around three quarters of their habitat, sticking to specific corridors that helped them avoid hilly terrain. "At an incline of five degrees, there were approximately half the number of [elephants] recorded per sq km as there were at a zero-degree incline," said Douglas-Hamilton, a chief executive of the charity Save The Elephants.
Some elephants do take the risk. They are great lovers of salt and there are instances of elephants climbing hundreds of feet to get access to salt mines. And famously an African elephant, nicknamed Icy Mike, lived and died on Mount Kenya, 4.4km (14,000 feet) above sea level. Scientists have yet to successfully explain why Mike did this. The results of the Kenyan survey are published in the new edition of the journal Current Biology.
Posted by nn9 at 9:28 am
Wednesday, July 26, 2006
The homing instincts of the humble bumblebee are a lot more powerful than anyone thought. A new UK study has revealed that the bomb-shaped insect can navigate its way home from as far away as eight miles (13 kilometres). The study, by the University of Newcastle and reported today by the BBC, tagged 20,000 bees with ID numbers then dropped them at various points around the countryside, leaving them to make their way home.
Some bees made it back from a drop off eight miles away - much further than the three miles (5 kilometres) it had been assumed was the limit of their range. Research into how bees navigate is developing all the time. It's believed they use a variety of information, including odour-based "maps".
Posted by nn9 at 10:43 am
Wednesday, July 19, 2006
"Who's a clever boy then?" Parrots can do much more than raise a laugh by mimicking their human masters. The results of a massive, 30 year study of African grey parrots revealed that the birds are up there with chimps and dolphins in terms of intelligence, with abilities similar to those of small children. “Their communication skills are similar to those of a two-year-old child, but their adding and ability with colours and shapes are more like a five or six-year-old,” the scientist in charge of the study, Irene Pepperberg, associate professor of psychology at Brandeis University in Waltham, Massachusetts told The Sunday Times
Pepperberg's star parrot, called Alex, displayed an astonishing range of mathematical abilities. He was able to name seven colours and five shapes and count or add up to six. He was also able to identify, request and refuse about 100 different objects. In one experiment, he was given collections of four, five and six blocks of three different colours. As individual blocks were pointed out to him, Alex was able to identify them by saying, for instance, "four blue". He performed a similar feat with groups of items, correctly picking out "four corks" for instance. During the course of these lengthy tests, Alex got it right eight times out of ten, Pepperberg concluded.
While other birds, such as crows, have displayed high levels of intelligence in making tools, for instance, Pepperberg believes that for parrots, the sky is the limit, so to speak. The most intriguing result in her tests came when Alex was asked which of two equal objects was the bigger.He confidently replied "none". This suggests birds are capable of much more complex pieces of logal thinking. The phrase "learning parrot fashion" may soon have a completely different meaning. There's much more about Alex at Pepperberg's website, The Alex Foundation. The results of her studies are also soon to be published in the journal Applied Animal Behaviour Science.
Photograph: Irene Pepperberg tests one of her gray parrots
Credit: Rick Friedman/Corbis
Posted by nn9 at 10:59 am
Friday, July 14, 2006
We aren't the only species who spend time teaching our children how to eat properly, it seems. A new study, published in today's Science, reveals that meerkats go to great lengths to educate their young how to feed themselves. Researchers at Cambridge discovered that adults select dead animals for their youngest pups to eat at mealtimes. As the pups get older, however, the adults bring live prey along, disabling them before serving them up if they are dangerous creatures, such as scorpions. Eventually, however, they encourage the young meerkats to hunt and prepare their food under their own steam. Much of the teaching is done by specific "helpers". "Helpers will gradually introduce pups to live prey," scientist Alex Thornton told the BBC. "So when pups are very little they get brought dead prey, like scorpions, lizards, and spiders; as they start to get older, helpers will bring them prey that's been disabled, so if it's a scorpion the helper might bite the sting off before giving it to the pup. Then finally when the pups are approaching independence, the adults will give them live food that the pups have to deal with on their own," explained Dr Thornton. This is only the second example of teaching behaviour discovered in animals. Earlier this year scientists revealed that ants teach each other to locate food supplies.
Posted by nn9 at 9:53 am
Thursday, July 06, 2006
They say a friend in need is a friend indeed. Well this frog was a friend in a million to a tiny mouse when it got caught in raging floodwaters in the Indian city of Lucknow. In a scene straight out of a Disney movie, the amphibian ushered the mouse to hop on its back then ferried it safely to dry land The picture and story is reproduced in full at the National Geographic's excellent animal news site.
(Photograph from Reuters/Pawan Kumar (India)
Posted by nn9 at 6:35 pm