Another Life: It is sometimes the duty of science to confirm the blindingly obvious, writes Michael Viney.
That sheep do, indeed, keep track of their lambs by the distinctive note of their baa (as researchers in France have now confirmed) will surprise no one on our hillside, where the April clamour of lambs cues constant fond reunions: the firm plugging in to the udder, the ecstatic wagging of tails.
It is bleat recognition that prompts ewes to quite heroic leaps and wriggles to reach offspring that have somehow squeezed through the fence.
Visual recognition, it seems, has to wait a bit, but more research (this time in Britain) suggests that sheep can be taught to have elephantine memories for faces. Trained to associate portrait images of fellow flock members with food, they could still pick the right picture out of pairs presented to them up to 800 days later. They went for the one associated with food. The researchers also measured brain-cell activity in the sheep and found that they could recall familiar faces, both ovine and human after year-long separation.
I much prefer the sheep in Yorkshire that have learned, all on their own, to cross a three-metre cattle grid by lying down and rolling across it (this on the witness of a Conservative councillor, no less). Or even the octopuses recently filmed on video as they walked backwards across the seabed on two tentacles, the rest bunched up, cleverly pretending to be a coconut or a clump of seaweed.
This bipedal disguise, described in last month's Science, reminded me of my youthful astonishment as a small octopus scampered away from me across the hot stones of a Greek jetty and dived back into the water from which I had just taken it. But this was mere locomotory skill: the well-established intelligence of octopuses is suggested by the female in the US national zoo that learned to twist the cap off a jar to get at the shrimps inside.
Most of the research on the resourcefulness and tool using of animals and birds centres on the drive for food. One of the oldest examples, in Ireland as elsewhere, was observed nine centuries ago by Giraldus Cambrensis, who notes how hooded crows will drop shellfish from a height on to rocks, to smash them open.
In a recent essay on the theme, the Smithsonian's David Challinor went back to Aesop's Fables for the story of the thirsty crow confronted with a narrow-necked jug in which the water was just out of its reach. It dropped pebbles into the jug until the water level rose. Considering some of the recent revelations, Challinor was compelled to wonder if this was really a fable, or an actual observation. It matches the conduct of ravens in an aviary that, challenged by pieces of meat on dangling strings, learned to pull the strings up in stages with their beaks while trapping each loop beneath their claws.
The current revelations are those from the Behavioural Ecology Research Centre at Oxford University, where Alex Kacelnik and his team have been working with crows from the south Pacific island of New Caledonia. These are the most advanced avian tool-users yet discovered. One captive bird, faced with recovering food from a vertical tube, bent a straight piece of wire (a material it had never encountered) into a hook - behaviour it repeated successfully on nine out of 10 occasions.
But is such aptitude a culturally acquired behaviour, learned from other birds, or is it an inherited instinct? In an elegant experiment which has startled the scientific world, four of the crows were hatched and reared without sight of an adult bird. Two of them were raised separately and shown how to use twigs to dig out food from holes and
crevices; the other two were left "naive" and uninstructed. But all four began to use twigs in this way at about the same time, demonstrating the instinctual basis for the behaviour.
The brains of crows are as big in relation to body size as those of chimpanzees, but their rather different structure had led scientists to suppose they had room only for instinct. Current research is showing that intelligence, as expressed by solving problems in novel situations, has evolved in an almost equal brain power in both creatures.
Meanwhile, what of the grid-rolling sheep? I discover that they have been at it in south Wales since the 1970s, one generation teaching the next.
And in the New Forest, in 1997, there were "reports" of a variation on the theme: one sheep would lie down on a grid and let its fellows march over its fleece. No doubt I shall be told of Irish solutions to the problem.