animals
edyong | April 2, 2008Did our ancestors exterminate the woolly mammoth? Well, sort of. According to a new study, humans only delivered a killing blow to a species that had already been driven to the brink of extinction by changing climates. Corralled into a tiny range by habitat loss, the diminished mammoth population became particularly vulnerable to the spears of hunters. We just kicked them while they were down.
The woolly mammoth first walked the earth about 300,000 years ago during the Pleistocene period. They were well adapted to survive in the dry and cold habitat known as the 'steppe-tundra'. Despite the…
edyong | March 31, 2008You might not be that impressed to receive a clump of grass or branches on a first date, but a boto dolphin might think differently. A new study suggests that these Amazonian dolphins wave bits of flotsam to attract mates.
The boto is a freshwater river dolphin that swims through the currents of the Amazon and the Orinoco. They are elusive creatures that are difficult to study, so very little is known about their social lives.
Tony Martin from the University of St Andrews spent three years in the Amazonian Mamiraua reserve studying the behaviour of botos. During this time, he spotted over…
grrlscientist | March 29, 2008tags: American bison, Bos bison, mammals, animals, photography, image of the day
American bison bull.
Image: Dave Rintoul, KSU [wallpaper size].
edyong | March 27, 2008
Imagine that you hand is made of jelly and you have to carve a roast using a knife that has no handle. The bare metal blade would rip through your hypothetical hand as easily as it would through the meat. It's clearly no easy task and yet, squid have to cope with a very similar challenge every time they eat a meal.
The bodies of squid, like those of their relatives the cuttlefish and octopus, are mainly soft and pliant, with one major exception. In the centre of their web of tentacles lies a hard, sharp and murderous beak that resembles that of a parrot. The beak is a tool for killing…
awild | March 27, 2008Jo-anne's father Keith sends these lovely photos of a swamp wallaby that frequently visits their house outside Melbourne:
voltagegate | March 27, 2008
The black caiman is just one of the endangered species that inhabits the Guiana Shield.
Back in November, the president of Guyana, one of the poorest countries in Latin America, offered the entirety of his country's rainforest to a British-led international body in return for help with development. Jagdeo was searching for alternatives to an obvious, but morally objectionable solution.
"Maybe we should just cut down the trees. Then someone would recognize the problem," said Mr Jagdeo. "But I want to think we can fulfill our people's aspirations without cutting down the trees."
British…
edyong | March 27, 2008My first ever feature article has just been published in this week's issue of New Scientist. It's about the ways in which songbirds are coping with the noisy din of cities. Low-frequency urban noises mask the calls that they use to attract mates, defend territories and compete with rivals. The race to adapt to this new soundscape has already seen some losers being forced out and some winners developing some intriguing strategies to cope with the clamour.
Robins have started to sing at night when it's quieter, while nightingales just belt out their tunes more loudly (breaking noise safety…
edyong | March 26, 2008Would you gamble on a safe bet for the promise of something more? Would you risk losing everything for the possibility of greater rewards? In psychological experiments, humans tend to play it safe when we stand to gain something - we're more likely to choose a certain reward over a larger but riskier one. Now, we're starting to understand how our two closest relatives deal with risk - bonobos, like us, tend to be risk-averse while chimpanzees usually play the odds.
Sarah Heilbronner from Harvard University studied the attitudes of five chimps and five bonobos to risky decisions. All the…
edyong | March 25, 2008We've all seen the images of receding glaciers and stranded polar bears that accompany talks of climate change. But rising carbon dioxide levels also have subtler and less familiar effects, and may prove to be a boon for many animal groups. Plant-eating insects, for example, have much to gain in a high -CO2 future as rising concentrations of the gas can compromise the defences of the plants they feed on.
Plants and herbivorous insects are engaged in a silent war that we are rarely privy too, where chemicals act as both weapons and messengers. Munching mandibles trigger the production of…
edyong | March 24, 2008Bdelloid rotifers are one of the strangest of all animals. Uniquely, these small, freshwater invertebrates reproduce entirely asexually and have avoided sex for some 80 million years. At any point of their life cycle, they can be completely dried out and live happily in a dormant state before being rehydrated again.
This last ability has allowed them to colonise a number of treacherous habitats such as freshwater pools and the surfaces of mosses and lichens, where water is plentiful but can easily evaporate away. The bdelloids (pronounced with a silent 'b') have evolved a suite of…
edyong | March 21, 2008Eagles may be famous for their vision, but the most incredible eyes of any animal belong to the mantis shrimp. Neither mantises nor shrimps, these small, pugilistic invertebrates are already renowned for their amazingly complex vision.
Now, a group of scientists have found that they use a visual system that's never been seen before in another animal, and it allows them to exchange secret messages.
Mantis shrimps are no stranger to world records. They are famous for their powerful forearms, which can throw the fastest punch on the planet. The arm can accelerate through water at up to 10,000…
edyong | March 17, 2008
Geckos are nature's champion climbers. With remarkable ease, they can scamper across ceilings and up smooth vertical surfaces, and they do so at speed. A vertically running gecko can cover 15 times the length of its body in a single second. So far, scientists have focused their attention on the gecko's amazingly adhesive feet but a new study demonstrates the importance of a neglected piece of their climbing gear - their tails. Geckos use their tails to stop themselves from falling, and to land safely if they do.
A gecko's foot is a marvel of biological engineering. Rather than relying on…
omnibrain | March 14, 2008Here's a pretty cool African Grey doing crazy sound effects.
Another video after the fold.
Here's one of the most pointless - poorly drawn - boring you tube videos I've ever seen! I love it!
It's a girl drawing a neuron and all its parts :)
edyong | March 14, 2008Crocodiles and alligators are the epitome of stealth. They can wait motionlessly for prey on the surface of the water, dive to the bottom, or roll around the length of their bodies, all without creating a single ripple.
This sneaky manoeuvrability is all the more impressive for the fact that a crocodilian can pull it off without moving its legs or tail. It's particularly difficult because a waiting crocodilian has to move slowly and methodically, and must make do without the helpful forces of lift and drag that accompany faster movements.
Now, for the first time, we know how they do it. They…
edyong | March 13, 2008
Many animals have cunning ways of hiding from predators. But the larva of the sand dollar takes that to an extreme - it avoids being spotted by splitting itself into two identical clones.
Sand dollars are members of a group of animals called echinoderms, that include sea urchins and starfish. An adult sand dollar (Dendraster excentricus) is a flat, round disc that lives a sedate life on the sea floor. Its larva, also known as a pluteus, is very different, a small, six-armed creature that floats freely among the ocean's plankton.
A pluteus can't swim quickly, so there is no escape for one…
edyong | March 11, 2008
Some of us have enough trouble finding the food we want among the ordered aisles of a supermarket. Now imagine that the supermarket itself is in the middle of a vast, featureless wasteland and is constantly on the move, and you begin to appreciate the challenges faced by animals in the open ocean.
Thriving habitats like coral reefs may present the photogenic face of the sea, but most of the world's oceans are wide expanses of emptiness. In these aquatic deserts, all life faces the same challenge: how to find enough food. Now, a couple of interesting studies have shed new light on the…
edyong | March 10, 2008
The story of evolution is filled with antagonists, be they predators and prey, hosts and parasites, or males and females. These conflicts of interest provide the fuel for 'evolutionary arms races' - cycles of adaptation and counter-adaptation where any advantage gained by one side is rapidly neutralised by a counter-measure from the other. As the Red Queen of Lewis Carroll's Through the Looking Glass said to Alice, "It takes all the running you can do, to keep in the same place."
The Red Queen analogy paints a picture of natural foes, wielding perfectly balanced armaments and caught in a…
omnibrain | March 10, 2008This is photoshopped right?!
Gosh I hope so! I'd be too embarrassed to take this little bugger for a walk! You need a cute dog to pick up girls at the park.
-via funnyjunk.com-
edyong | March 4, 2008The transformation from caterpillar to butterfly or moth is one of the most beguiling in the animal world. Both larva and adult are just stages in the life of a single animal, but are nonetheless completely separated in appearance, habitat and behaviour. The imagery associated with such change is inescapably beautiful, and as entrancing to a poet as it is to a biologist.
According to popular belief, within the pupa, the caterpillar's body is completely overhauled, broken down into a form of soup and rebuilt into a winged adult. Richard Buckmister Fuller once said that "there is nothing in a…
retrospectacle | March 4, 2008 Looking outside my window, across the snow-cover vista otherwise known as Ann Arbor, it amazes me that anything can live (or, even thrive) in such a frozen environment. Since I was a kid I was fascinated with animals, such as the snowshoe hare, that can change the color of their fur from brown in the summer to white in the winter. The process occurs over about 10 weeks, with the white fur appearing first on the ears and feet and gradually moves towards the body. During the spring, brown fur replaces the white fur in the reverse process.
Certainly this increased camouflage provides the hare…