Sunday, December 23, 2007

Dumb animals - we don't think so!

The BBC Natural History Unit's search for Britain's cleverest performing wild animal reveals some unexpected talents.

Words: Mike Beynon
Images: Richard Taylor

Bright badgers
I've made many films about badgers and have always found them to be delightful but dim. I would never have associated their bumbling antics with the word 'clever' - until I heard about Don Hunford's badgers.

Don, a respected expert, was impressed when a badger he was caring for managed to climb out of its underground shelter by ingenious means. The only way out of the shelter was through a hatch 3-4 feet above floor level. Pushing with its shoulder, the badger managed to shunt a handy box into position beneath the hatch and stand on it to escape.

Don decided to see if wild badgers could learn to use a similar strategy to obtain a food reward. He built a feeding platform on a tree just out of the badgers' reach, and provided a cube of wood nearby. The badgers figured out that by pushing the wood over to the tree, and climbing on top of it they could reach the treats.

Meet Betty
Cows, donkeys, otters, woodpeckers, foxes, rats and grey squirrels, they're all here. But the programmes we've made about animal intelligence are invariably dominated by examples of avian acumen. It was among the corvids that we found the star of this show. Betty is a female Caledonian crow and long-time resident at Oxford University.

When you see Betty in the flesh, you really get a sense of her remarkable intelligence. The inquisitiveness, the fascination with anything new, the way she cocks her head to study a novel object, the impression that she's working things out in her head before going into action.

Her ability to figure things out is demonstrated by the tasks she performs. Food is placed at the bottom of a tube too deep for her to reach with her beak, inside a tiny basket with a little hoop on top. Betty is given a thin wire, about 7cm long. She picks up the wire in her beak and sticks it into the tube. She can reach the food but can't raise it to the top. Then, extraordinarily, Betty carries the wire over to the wall, pokes its end into a little hole in the plaster, then pulls upwards with her beak to fashion a primitive hook. Betty flies back to the tube, inserts the wire down the shaft and through the hoop on the basket. She pulls the wire, and up comes the basket. Triumphantly, Betty eats her reward.

According to experts, this feat may make Betty the first animal, other than a human, to fashion a tool for a specific task using novel materials not found in the wild. Clever, or what?

A service stop with a difference
Driving down the M4 in heavy traffic on a hot day is not a pleasant experience. And taking a break at Membury Services is never going to be one of the great culinary experiences of your life. But for local residents, Membury has a lot to offer. They fly around the carpark, watching fractious children and fraught parents picnic beside their cars and then tip the scraps into one of the many wastebins. This information is observed, noted and filed away for future reference.

Rooks may not be one of Britain's most charismatic birds, but they are one of our cleverest. All corvids (in Britain, this includes rooks, crows, jackdaws, ravens and choughs) have large brains relative to their body size and remarkable memories, combined with an almost aggressive inquisitiveness. Their impressive capabilities are admirably demonstrated at Membury.

Located all round the carpark are wastebins, full of tempting rubbish. The trouble is, the staff at Membury are too efficient - before the bins even start to fill to a level at which the rooks can reach the titbits, the cleaners race to empty them. As a result, the rooks can only gaze longingly at food that is just out of beak-reach.

Thinking it out
Or they used to. The rooks have learned to perch on the rims of bins, reach in with their beaks, grab folds of the black plastic bin liners and haul them up and over the edge. This action would, in itself, be useless. Let go, and the weight of the rubbish will pull the bin liner - and the food - back down. So, to avoid this happening, the rooks have figured out that they have to stand on the fold of bin liner they've just pulled up before reaching back down to grab another beakful.

Inch by inch, the rubbish rises higher. It's a slow process, requiring immense patience - a hungry rook will have to pull out up to 20 or so folds of black plastic before it can reach its prize. By this stage, it's standing on a veritable hill of scrunched-up bin liner. Distractions are all around, but the rook is dedicated to its task and finally achieves its goal - the food is within easy reach.

Decisions, decisions
The bird now faces another dilemma. Does it take just one beakful of food and fly off, allowing the rest to slide back to the bottom of the bin? Surely then the effort required would outweigh the reward? Instead, the rook reaches in and tosses the scraps over its shoulder, repeating the action again and again, until a pile of food litters the pavement behind it.

Now the rook can relax and gorge itself on its well-deserved prize. If it can get a look in - an entourage of small birds is already busy helping themselves to a free lunch, courtesy of the rook's labours.