Wednesday, November 11, 1998 Published at 19:24 GMT
The wheel truth about hamsters
The lab hamsters had to find food inside one of four cylinders
Hamsters are cleverer than you think. The popular pets might spend much of their time going nowhere in a spinning wheel but they actually have an excellent sense of direction, according to new research.
Swiss scientists have found that golden hamsters use a system of "dead reckoning" - similar to that used by mariners - to get from one place to another.
Without using any visual clues to guide them, they can compute their position from internal information such as how fast they have been travelling and for how long.
They use visual clues only to confirm what they already "know" about their current position. Visual and non-visual clues are also used to confirm when they have arrived at the place they want to get to.
The scientists set up an experimental apparatus in which the hamsters were presented with a symmetrical, circular arena containing four identical cylinders - only one of the cylinders had any food in it.
In a series of training runs, the hamsters were led to locations on the edge of the arena and then to the bait.
The hamsters then had to find the food themselves after being led to different positions on the edge of the arena.
The experiments were conducted in the light and in the dark. The arena and the nest where the animals originally started were also rotated to try to confuse the animals still further.
But it seems the hamsters were up to the task. On the majority of runs, they climbed into the right cylinder and filled their cheek pouches with food before returning to their nest.
In the "light" study the success rate for six individual animals varied from 67% to 100%. In the "dark" experiment, the researchers had some difficulty persuading the hamsters to complete the test - one refused altogether.
"This suggests that the animals anticipated the distance they had to cover in darkness and that the further they had to go to reach the goal, the more reluctant they were to leave the arena periphery," the researchers from the Universite de Geneve at Carouge wrote in the journal Nature.
Nevertheless, when the hamsters did go in search of the bait, they were usually successful.
"How did the animals plan their path to the goal cylinder in experiments Light and Dark?" the scientists posed. "By proceeding along two different routes to the goal site during the preliminary training trials, the animals could learn the location of the goal with respect to the nest exit, and store this information in long-term memory as a nest-to-goal vector.
"Furthermore, path integration [dead reckoning] informs the animal continuously on its current position within the arena during the hoarding trip."