They defied all the odds - they are not supposed to be in the North-East, no one really expected them to nest and no one in their wildest dreams ever expected that they would produce young.

But today, history was made with the announcement that a pair of bee-eaters have become the first to breed in this country for almost 50 years.

The RSPB and Durham Wildlife Trust confirmed that the birds, one of Europe's most colourful species, have hatched chicks at Bishop Middleham Quarry nature reserve in the county.

Now there are hopes that the news could create a major boost for the local economy as thousands of visitors head for the area.

The bee-eaters, which would normally nest in southern Europe, arrived at the disused quarry at the start of June, creating great excitement among birdwatchers from all over the country.

Since their appearance at the reserve, which is managed by Durham Wildlife Trust in partnership with English Nature, thousands of visitors have flocked to see them and the birds have been guarded round-the-clock by wardens amid fears that illegal egg collectors may try to raid the nest.

The birds dug out the nest into a cliffside and yesterday it emerged that they are now delivering food regularly, leading observers to conclude that the chicks have hatched.

Bee-eaters, which eat a range of insects as well as wasps and bees, were last recorded breeding in the UK in 1955, when two pairs nesting in a sand-pit in Sussex raised seven young. Before that, the only other known nesting attempt was in Scotland in 1920. Normally they nest no closer than Paris.

The chicks will not leave their hidden nest until the middle of next month, so the number of young is still unknown although the birds tend to lay clutches of between four and nine eggs. The military-style 24-hour guard mounted by RSPB staff and Wildlife Trust volunteers will continue until the birds leave.

David Hirst, of the RSPB North of England Region, said: "Bee-eaters are stunning birds and to have a pair nesting again in the UK after nearly half a century is an amazing event. They have brought a brilliant splash of unexpected continental colour to northern England this year."

Richard Wood, Chief Executive of Durham Wildlife Trust, said: "Bishop Middleham Quarry is particularly important for its flora, including several species of orchid, but we are, of course, absolutely delighted that the bee-eaters have chosen to breed there. Their success shows just how good a habitat this is and how well it is managed."

Kevin Spindloe, Bee-eater warden at Bishop Middleham Quarry, added: "Now that the eggs have hatched, we expect that many people, and not just keen birdwatchers, will want to come and be part of this event. We hope that over the coming weeks many visitors will enjoy watching these beautiful birds."

* A Viewpoint has been set up on farmland near the village of Bishop Middleham, north-west of Sedgefield. Access is from the A1 and A177 and follow the signs to the bee-eaters. A local farmer has provided the viewing area and there is a small charge for car parking.

Bee-eaters feed, as their name suggests, mainly on bees and wasps but catch a wide variety of other flying insects as well. They are colourful birds with turquoise underparts and tail, bright yellow throat, chestnut head and back, green eye markings, and black eye stripe.

They lay their eggs in holes between 50 and 275 cm long, which they carve out of soft earth.

Bishop Middleham Quarry nature reserve, which is managed by Durham Wildlife Trust in partnership with English Nature, is a large abandoned magnesian limestone quarry which has has been recolonised by a wide variety of plants, including dark red helleborine, common spotted, northern marsh, pyramidal and fragrant orchids.

The quarry has been a Site of Special Scientific Interest since 1968 and is regarded as one of the country's best disused quarry wildlife habitats.