"Hares are remarkable animals. There's no other comparatively small animal that lives in the open, completely exposed to elements all year round," points out Liz Bradshaw. Now a research associate at Cambridge Zoology Department, she studied hares for her PhD and is a great admirer of their resilience. But says this is being put to severe test.
Britain has two species of hare, the mountain, or blue hare, Lepus timidus; and the brown, or European, Lepus europeus, a creature of arable farmland. Living in the open, they are relatively easily seen, and are at their most conspicuous during the "mad March" breeding season when the normally solitary creatures indulge in seemingly pointless chases (males driving off rivals) and "boxing" (females rebuffing over-amorous mates).
Hares are larger than rabbits, have much longer legs, and - except when running flat out - carry their ears upright. And while a rabbit's first instinct is to make for cover when threatened, a hare usually heads for open ground, relying on speed and stamina to out-distance its enemies. Close up, the distinction is even easier: hares are generally reddish- brown (rather than grey), and have black tips to their ears. Their large, bulbous eyes give them a slightly eerie appearance, perhaps explaining their mythical role as witches' familiars.
The fact that such superstitions can be traced back to the Celts, who worshipped the creature, suggests that brown hares - unlike rabbits - are indigenous. Yet recent research points to their introduction between 500BC and 500AD; the animal of Celtic myth was probably the mountain hare.
Whatever their origins, brown hares slowly increased in numbers as land came under cultivation. Experts believe they probably peaked around the turn of this century, at about 4 million, then declined during the Twenties and Thirties. After the Second World War agricultural improvements led to a rise in numbers, but the population fell sharply during the Seventies and Eighties.
The decline is now thought to have levelled off, but an accurate census is difficult. The greatest numbers are generally found in arable areas, yet even here populations fluctuate widely. One survey puts the mid- winter population at between 1.3 and 1.9 million; another estimates it at 820,000. Extrapolating numbers from shooting returns, the Game Conservancy Trust puts the population at just 1 million. This has triggered sufficient alarm for the hare to be given its own biodiversity action plan, and now a working group, headed by the Game Conservancy and the Mammal Society, is looking for ways of doubling hare numbers by the year 2010.
Agricultural intensification is thought to be one of the major problems. This has shifted food production away from traditional mixed farming to autumn-sown, single-crop farms with larger fields. The result, according to Steve Gibson, species advisor for the Joint Nature Conservancy Committee, is a dearth of food at critical times of the year: "There are plenty of tender shoots in the winter and spring," he says, "but little in summer as the crops ripen."
This does not give the whole picture, however, because hares remain numerous in intensively farmed areas such as East Anglia, while falling in numbers in the smaller, "mixed" farms of the West Country. Here a shift from haymaking to silage may explain the decrease, as the young - leverets - which are born and suckled in the open, are vulnerable to the mowing machines.
Increased predation is another factor. Apart from man, foxes are the main enemy and numbers have increased as traditional gamekeepering has declined. Research on a Leicestershire farm suggests that culling foxes can reverse the downward trend: "When the Game Conservancy took the 700- acre farm over in 1992 there were only half-a-dozen hares," says Stephen Tapper, director of research at the Game Conservancy. "We began fox control and now there are between 100 and 200 hares." Even so, he says, predation is worsened by modern agriculture, which forces inexperienced leverets out of ripening crops to forage around field edges where they are easily ambushed.
Mr Tapper believes that if the action plan is to achieve its objective of doubling numbers by 2010, there will have to be a general change in farming practices: "The key is going to be getting agri-environment schemes working in arable and pastoral areas," he says. "That probably means incorporating more grassland and a wider range of crops in arable areas, and patches of longer grass in pastoral ones." He admits, however, that in the long term the future of the brown hare is likely to be more closely linked to Common Agricultural Policy reform than to mere good intentions.
For a free fact sheet about the brown hare, send an SAE to The Mammal Society, 15 Cloisters House, 8 Battersea Park Road, London SW8 4BG