Will the hare follow the corncrake?

There is a shabby look to the hillside at this vacant point in the year, neither finished with winter nor entirely sure about spring. In the corner of rough sheep-pasture outside my window, each big hummock of moor-grass is rounded away from the wind and rimmed with a pale, dead halo of last year's growth. Edging between them, to nibble whatever new blades it can find, a hunched-up mountain hare exactly mimics their form.

Only once, and that fleetingly, have I seen the "mad" behaviour associated with hares in March - that is, a female repelling an over-eager male by rearing up and giving him a left and right with her forepaws: the so-called boxing-match. Last spring, finding half-a-dozen hares grazing together in a rushy field above the shore, I stood hopefully (and very still) for half-an-hour, waiting for some action, but nibble was all they did.

Six hares at once would at least seem a reassurance about numbers. And it might be if I did not know what has happened to the uplands, the more usual half of the animals' habitat. The Irish hare, Lepus timidus hibernicus, is a subspecies which, unlike the Scottish mountain hare, is found right down to sea level. That is just as well at the moment, for great tracts of the hills are little better than brown desert, with not enough grass, let alone heather, to hold the shape of a hare lying in its form.

And no, this has not been changed by waving a wand of remedial schemes to take sheep off the hills and undo the gross ecological scandal of Ireland's over-grazing. A beginning has been made, in some corners of the west, on the winter withdrawal of some 700,000 ewes, but the final management plans to relieve the mountain commonages are still being worked out.

Even when the great burden of grazing is, in fact, lifted, it will take many years for the upland vegetation to recover its vigour and diversity. Meanwhile, there are stories of hares seen with sheep at hillside silage troughs, reduced to nibbling this rank pickle on land that once grew heather.

These stories may not be true: the hare is a fastidious creature which likes variety in its diet. What is certainly true is that the Irish hare is declining in Northern Ireland, which offers the very model of an intensively farmed landscape. A three-year study has found the hare is suffering from just the same kinds of change that have brought the corncrake so close to extinction. The North's population may now be down to as few as 8,250 animals.

The work was carried out from Queen's University by Dr Karina Dingerkus, who went to the game-bag records of big estates to see what hare numbers were like 150 years ago. On the Crom Estate, Co Fermanagh, in the most striking example, hare densities may have been as high as 138 to the square kilometre. Today the hare is still widespread across the north, but its numbers have drastically thinned, especially in the motorway heartland of rolling rye-grass swards and tight, Presbyterian boundary-hedges.

Dr Dingerkus based her survey on 150 one-kilometre squares, sorted for land-class, from the mountains down to the grassy drumlins. With research colleague Ian Montgomery, she walked them twice in winter and autumn, when vegetation was short, flushing the hares or searching for their droppings. More than one-third of the squares had no hares and one in three landowners spoke of a decline over the past 10 to 20 years (some even of a local extinction). And while there were hares in almost 90 per cent of the upland squares, this density fell away to half the squares in the intensive farmland of the lowlands.

No more than seven hares were seen in any one square, and most of the sightings were of one or two hares, flushed from the tall rushes and hedges of "semi-improved" farmland, still with sizeable areas of semi-natural grassland. Predictably, the hares sat tight longest in the rushy pastures and took fright at a much longer distance in the fields with less cover.

The estimate of 8,250 hares in Northern Ireland is a minimum extrapolation. The maximum would be 21,000, but even this, says Dr Dingerkus, would be a relatively low total. Her survey draws no hard and fast conclusions on causes of decline, but some possibilities seem fairly obvious, and are significant for the island as a whole.

She made a special study of hares' droppings at three separate sites and found up to 14 species of grass in the pellets. Upland hares were especially fond of Anthoxanthum odoratum, the coumarin-rich grass that gives old-fashioned haymaking its inimitable, sweet smell. Over more and more of our farmland, the early-maturing perennial rye-grass is the only species on offer.

Silage-making is itself a hazard to hares. Unlike baby rabbits, leverets are born above ground in nest-like forms in the grass. It's believed many are killed in the summer mowing - just like the corncrakes and their chicks. Hares and corncrakes both need cover, the first thing to go as fields are drained, reseeded and enlarged.

So, both in the hills and on farmland, the Irish hare's habitat has been degraded by modern agriculture to a quite dramatic degree. In Britain, where the lowland countryside is occupied by the brown hare, Lepus europaeus, numbers have also fallen drastically, even in the west of the island. Intensive farming has a way of isolating wildlife into "islands" of population, prone to quite sudden extinction.

Hares are a protected species under the Wildlife Act, and may not be hunted except by special licence. The one statutory hare reserve in the Republic is at Wexford, where the entire North Slob, including the nearby woodland of the Raven, offers sanctuary from hunting and shooting, or trapping for coursing. Their numbers here stand at about 40 to a square kilometre, compared with the half-dozen suggested for ordinary Irish farmland in a study in 1985.

The hare was reassuringly judged to be "widespread and common" from sightings during the nationwide Badger and Habitat Survey carried out between 1989 and 1993. On the strength of the Northern Ireland survey, we may need to look again, and more closely. Karina Dingerkus, meanwhile, is hoping to write a book on hares and would welcome records, strange observations - even folklore. She's also interested in local survivals of the brown hare, introduced to estates originally to boost stocks for shooting. Her address is 39, Beechgrove Avenue, Belfast BT6 0ND.