The future of an endangered species at a Norfolk nature reserve looks more promising after two red squirrels are believed to have successfully mated.

Pensthorpe Nature Reserve, near Fakenham, runs the Red Squirrel Breeding Programme, which was inspired by David Stapleford, of Hempton, also near Fakenham.

The main breeding pair at the nature reserve, which was the home of BBC's Springwatch programme, is Tortoiseshell, a female, and Tweedledum.

It is believed they have successfully mated and are tending to their summer litter in addition to the 38 kittens they have produced since 2008.

Tortoiseshell's granddaughter April has also recently been introduced to a new male and is nursing kittens.

These should start emerging from their box within the next two weeks.

Chrissie Kelley, head of species management for Pensthorpe's Conservation Trust, said: 'This is an exciting time for us at Pensthorpe. Having two breeding pairs is incredibly significant as it gives us real promise for the future of the species.

'Tortoiseshell's spring litter, which is now in the nursery enclosure, has recently been sexed and we have two females and two males, which is really encouraging news as the number of male species was far more prevalent last year.

'We will be swapping our male kittens for two unrelated males in the hope of our new females pairing up with them. Having good numbers of both will be even more encouraging.'

The Pensthorpe Conservation Trust is a key member of the East Anglian Red Squirrel Group.

Red squirrels survive in the wild in only a handful of locations across Britain.

Mr Stapleford received the Red Squirrel Survival Trust's (RSST) top honour in March at Pensthorpe.

He was awarded after guiding the breeding programme at the nature reserve, which helped save the mammals from extinction.

Mr Stapleford received a bronze sculpture of the endangered animal and a hand-signed letter and flowers from the RSST's patron, the Prince of Wales. He fell in love with the creatures as a schoolboy in wartime Hampshire when he saw an 'incredibly beautiful' dead squirrel, but did not see a living example until he visited Thetford Forest in 1963.

Mr Stapleford started mating pairs in his back garden.

Despite the effort being 'like breeding pandas', and the first 'couple' turning out to be females, he became an expert on their behaviour and feeding habits.

Norfolk still had pockets of wild reds when he moved to Hempton, near Fakenham, in 1979 to become Fakenham Junior School headteacher, but they had disappeared by the early 1980s.

They have been hit by competition from grey squirrels, introduced to England in the 1800s, and the squirrel pox they carry.

Now Pensthorpe, which Mr Stapleford visits almost daily, is breeding reds to introduce to grey-free areas such as Anglesey.

Visit www.pensthorpe.com or call 01328 851465.

sophie.wyllie@archant.co.uk