Hugh Kemp didn't set out to establish a wildlife reserve, but wildlife simply kept imposing itself on his secluded farm. So, in the end, the wildlife became the focus of what he was doing.

"It's a truly wonderful testament to the power of nature over man," he reflects. It is over 40 years since Hugh and his wife, Jane, bought 100 acres of treeless, windswept hillside more than half-way up a quiet cul-de-sac of a valley which sneaks out of Wensleydale. The valley is called Snaizeholme, and the plan was to make a living by growing Christmas trees on their bleak tract of hillside. Perhaps it was somewhat ambitious in retrospect, given that they then lived among the flat fields of Kent and both were artists. However, the enterprise worked just fine, and it was later followed by other forestry plantations. But what the Kemps hadn't anticipated was that their trees would provide food and shelter not only for them and their two small sons, but also for a quite surprising range of birds and wild animals. Now semi-retired – Hugh is in his 82nd year – they find themselves running one of Yorkshire's few private wildlife reserves and welcoming a fairly steady stream of people who make the not-inconsiderable effort to come and see the star attraction, red squirrels.

"We never imagined this would happen," says Hugh. "I had lived in the South for many years, although I was born in York and my family were farmers in the area. I suppose the ties with Yorkshire were pretty strong, and in the early Sixties I decided to come back here to try and earn a living." At first, he searched for a suitable farm in the North York Moors but prices there seemed inflated by businessmen from Teesside snapping up almost everything that came on the market. So he switched his attention to the Yorkshire Dales and had country newspapers sent to him in order to keep an eye on properties for sale.

It was Jane who spotted the advert. With one of the papers spread out on the floor, she started chuckling and said: "With a name like this, we are bound to end up there." The farm's name was Mirk Pot, and it was described as being located on Cow Hill. The Kemps soon found themselves at Hawes, and when they drove out to see it, Hugh's first impression was "the sort of place where Edgar Allen Poe might have spent his winter holidays". The land rose to 1,200ft above sea level and the wind conditions were pretty fierce. Hugh was not sure he could grow the common-or-garden Christmas tree, the Norway spruce, in such conditions. Also, the only available living accommodation not only lacked electricity but its living space was waist-deep in manure. "It seemed hopeless," he says, "but we rather liked the place."

And so they rented a house in Hawes until there was somewhere habitable to live in Snaizeholme. One of the first things he did after planting his trees was to fence them off from sheep and cattle. Unexpectedly, the ground which had for years been nibbled away by livestock suddenly started to return to nature, and unplanted trees such as hawthorn, blackthorn, bird cherry, ash and rowan began to grow. This was followed by a dramatic increase in Snaizeholme's bird life. The young conifers were soon attracting species like goldcrests, siskins and crossbills. Chaffinches were so numerous that Jane started calling them "Snaizeholme sparrows".

And a number of interesting wild orchids were found to be growing in one of their fields, which led the Yorkshire Wildlife Trust to adopt it as one of their reserves for a number of years. Then there were roe deer attracted into a new plantation of sitka spruce, as well as a sighting of a water vole, while both Jane and Hugh started seeing the exceedingly shy pine marten. But most remarkable of all, one day a neighbour reported that a red squirrel was in their woods.

"I often get asked if we introduced the red squirrels to Mirk Pot and I answer rather facetiously that, no, we didn't buy them on eBay. They just appeared one afternoon. A neighbour rang up Jane and said, 'Oh, I've seen a red squirrel hop out of your woods and come to our bird feeder'."

The following day, Jane went down to the block of conifers where the squirrel had been sighted and saw it for herself. In fact, there was a whole colony of them, which Hugh believes spread out from the well-known Lake District population and reached Wensleydale via Mallerstang and Garsdale.

Quite how many there are, no-one yet knows, but Hugh thinks the figure is around 20. They may originally have been attracted by the abundant natural food on trees around Mirk Pot, but now they are provided each day with a special mixture of peanuts, pine nuts and sunflower seeds, dispensed from special feeders. One of the feeders is viewable from the kitchen window, and Jane has given the squirrels names inspired by the colour or markings on their tails – "Light Tail," "Stripey Tail," and so on.

"I've never tried to tame them," she says, "but they do communicate with me, and show their displeasure if I'm late putting out food for them. They make a strange nagging noise with their teeth and wave their tails about in anger like cats do when they're cross."

Skulls of dead sheep or deer are nailed to a tree for them, which the females chew for calcium when they are pregnant.

And their main threat – the grey squirrel, which carries a virus that
is deadly only to red squirrels – is kept under control by shooting and trapping. Greys can't even use the feeders, because the access point drops down under their heavier weight.

Further down the valley, Hugh has established a number of ponds which he hopes will attract otters. On the other side of Mirk Pot, holly and yew trees have been planted to make the woods even "cosier" for the red squirrels.

"Forty years ago," he reflects, "we were told repeatedly that trees would not grow in this part of the Dales. All we can say is that we have created an oasis in this harsh environment, and I am sure our sons will continue to look after the woods."

Visitors are welcome to see the red squirrels at Mirk Pot by prior arrangement. Organised parties can contact Hugh Kemp by email at kemp@mirk-pot.freeserve.co.uk or by telephone on 01969 667510.

Individuals can join a guided walk to Snaizeholme from the Yorkshire Dales National Park Centre at Hawes. Telephone 01969 666210 for details. Motorists visiting Snaizeholme are asked to leave their cars on the B6255 Hawes-Ingleton road, opposite the old Widdale Chapel and telephone kiosk, and walk up to Mirk Pot.

Hugh Kemp's autobiography, Trees and Wildlife in Wensleydale, is published by Arima Publishing, Bury St Edmunds, price £9.99. Obtainable locally from Mason Bros, Market Place, Hawes, North Yorkshire, DL8 3QX. Telephone 01969 667278.