The black grouse's strange mating ritual could be coming to a field near you

The rain is blowing horizontally in Teesdale, Yorkshire, above a scrub-felted valley floor. Here, a dozen or so people take shelter within a convoy of cars, variously with scopes, binoculars and telephoto lenses fanning out of their windows. Perhaps the only thing more ridiculous than this cavalcade is the bizarre mating ritual those in it are here to observe.

Several hundred metres away from the group, a team of 35 male black grouse are indulging in one of the wackier products of natural selection. In an attempt to impress watching females, the birds are conducting a rather peculiar mating ritual. They are brandishing their bottoms.

This happens every dawn. The male birds assemble on this "lek" – their display ground – to show off the bright white feathers on their derrières. The aim? To attract watching females. They combine their primitive salsa with displays of strength, which females can associate with the strongest mate. These include jumping up and down and "squaring up" to each other. Completing the picture is their strange, loud, "bubbling" sound. Those that are judged to do it best by the females get the most mates – black male grouse being polygamous. See anything familiar in these sexual histrionics? Visit an inner-city nightclub.

"When you first see the lek it just gets you," says Philip Warren, a local black grouse expert. "You don't expect to see or hear something like this in the British countryside – the sight of these birds singing first thing in the morning – so even now when I go up to the moor and see this, it still amazes me."

This peculiar trip has been organised by an alliance of charities. The Game and Wildlife Conservation Trust, working with the Royal Society for the Protection of Birds, has seen a huge success in a project aimed at extending the range of the animal across the North Pennines.

The partnership has allied itself with landowners, farmers, grouse moor managers and gamekeepers to promote the grouse's favoured habitats, including providing suitable nesting and feeding sites, as well as trapping predators. As a result, the animals are now more abundant than ever – and lekking away happily.

Which is great news, because, unbeknown to most of the population (who might know the bird more for its association with whisky) black grouse are one of the nation's most magnificent creatures. They have a special place in the hearts of twitchers and shooters. You can see why when you size them up in the field. The male's bobbing, glossy dark plumage is crowned with a bright red eye-comb. And there are its black lyre-shaped tail feathers, above its blanched bum.

Their tale was not always so magnificent. Indeed, black grouse populations have varied considerably over the past hundred years. Up to 1900, they could be seen in every British county, but their numbers then dwindled. They were a favourite bird with the Victorians – when stuffed and mounted in glass cases. More recently, a slew of factors has contributed to their demise. They have been killed off by maturing forests, which, by blocking light to the forest floor, have destroyed the grasses and heather the birds require for their nests. They are also hit by poor land management in the form of over-grazing by sheep and red deer, which reduces the vegetation harbouring the caterpillars grouse chicks need to thrive. The numbers of male birds fell by 70 per cent between 1990 and 2002, with the bird becoming extinct in many UK regions. In 1998, there were only 773 males in England.

Watch footage of the male black grouse 'lekking'

But now, thankfully, their distinctive silhouettes are seen all over the place. For here is the happy news: the work of The Game and Wildlife Conservation Trust and RSPB lifted the number of UK black grouse to 1,200 last year. Two thirds of English black grouse are in the North Pennines; where the lekking in question is taking place, in the region's best known dale.

"The males' aim is to be the best man within the lek," explains Warren. "That's his only role: to take a central position in that lek. This position is associated with the strongest male, because he can retain the territory. The male that occupies the best, or central position in the lek gets to mate with the most females."

Lekking also has an important part to play in English folklore. Lek is Norse for "play" and in Yorkshire dialect you often hear talk of "lekking about", or playing around.

"When you see these birds first thing in the morning you can see why it has become associated with a game," says Warren.

Grouse experts such as Warren working in the scheme have targeted predators such as foxes, stoats and crows, along with promoting the preferred vegetation for their habitats. Warren adds: "In the Yorkshire Dales, black grouse have responded fantastically well to management... it is important to build on this success and recolonise former haunts on the southern fringe of their range. We are hoping to enlist the support of more than 50 land managers."

All of which is something of a coup for conservationists and gamekeepers, who are normally associated with helping people to blast the animals from the sky. Selena Masson, news editor of Shooting Times, explains: "Contrary to what the general public might think, gamekeepers are some of the country's most important conservationists. It is not just ecologists who take an interest in the countryside; gamekeepers have the specialist knowledge and practical experience to surpass any amount of theory. Without them, black grouse populations would have sunk to nothing.

"The recovering populations are testimony to the beneficial work that gamekeepers do." Indeed, strict restrictions surround the shooting of black grouse; their numbers have to be shown to be be above a certain level before they can be killed.

Warren agrees: "I wasn't surprised by the [success of the] project because it shows what happens if people work together. The thing about black grouse is that everyone can associate with them; they are a very well known bird in the uplands. This is in part because they stay with us all year. They don't just visit in the summer."

As the rain continues its torrent, it is just possible to make out a few of the birds continuing their dizzy display. The rain ceases and they come out in their droves; a beautiful demonstration of the survival of the fittest that cannot be dampened by even the most overcast of skies. Long may it continue.

Watch footage of black grouse hens feeding

Black grouse and where to spot them

* If you're on the look out as a nature lover, best scout out black grouse on farmland or moorland with nearby forest or scattered trees. The bird is now mostly confined to parts of the Scottish uplands, with a few surviving strongholds in areas of Wales and the North of England.

* The adult birds are primarily vegetarian. The tiny bits of animals that they ingest are principally wolfed down with plant matter by mistake. Their diet varies between regions and throughout the year, but generally includes buds, needles and cones of pines, catkins and other parts of birch, various dwarf shrubs, grasses and berries. Heather and bilberry are of particular importance.

* Around April, between half a dozen and a dozen eggs are laid. The females incubate them for up to four weeks, the young hatch together and leave the nest as soon as their down is dry.

* The female feeds the young on their first day, but from the second day onwards they are capable of feeding themselves. The young are capable of flight already at 10 to 14 days old. Broods remain together well into the autumn, and several families often join together to form small flocks.

* The cocks compete with each other for best display sites within the lek, which reaches its peak in the late spring. There is no pair bond between the two sexes, and males have no part in the nesting process or rearing of young.

* The best sites for shooting game birds are in upland areas of Scotland. The close season for shooting is 11 December to 19 August. "Trophy shooting" of males from leks has been reported from both private and public land. This illegal during the close season, and the disturbance may affect breeding success at the site.

Tom Bradley