Rare butterfly spotted at National Trust site in Norfolk

Purple Emperor, male. Pictures: Matthew Oates (Image: Archant)

It suggests that Norfolk now has its first breeding colony.

Despite its size, Britain's second-largest butterfly is one of our most elusive insects.

It is rarely seen because it typically spends most of its time flying high in the tree canopy. At Sheringham Park, the viewing towers overlook the tree tops, giving rangers and visitors a fighting chance to spot one.

Rob Coleman, learning officer at Sheringham Park, said: 'I first spotted a Purple Emperor at Sheringham Park in 2016, which was a really significant moment for Norfolk, a county where this butterfly had not previously been seen for more than 40 years.

'The adults feed on honeydew produced by aphids and tree sap high in the canopy, rather than on flowers on the ground, which you'd typically associate as a food source for butterflies.

'Dedicated butterfly watchers were on the look-out last year and three further sightings were made over the course of the summer. Sightings of male and female emperors gave us the tantalising hope that there's a breeding colony somewhere in the park.

'Now, for a third year running a male Purple Emperor has been spotted at Sheringham Park. Sightings in similar locations over a three year period would indicate that a naturally colonised breeding colony is the most likely explanation. What makes this even more special is that it's the first one in Norfolk.'

Sheringham Park is the ideal habitat for this butterfly, as they need oak trees for courtship displays and mating, as well as sallow trees for egg-laying and there are plenty of both. It's the males that set up their territories and set off in pursuit of females high in the canopy. They also defend the area from intruders and potential rivals.