Purple Emperor strikes back at Sheringham Park

Purple emperor butterfly
Published : 31 Jul 2018

The rarely seen Purple Emperor butterfly has been spotted at Sheringham Park for a third year running, suggesting Norfolk now has its first breeding colony.

There have been a few sightings of the Purple Emperor at Sheringham Park in recent weeks. This species is rarely seen in Norfolk; instead it tends to occur in larger woodlands in southern England. 

An elusive butterfly

The Purple Emperor is Britain’s second-largest butterfly. Despite its size, it’s 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. 

A significant moment for Norfolk

Rob Coleman is the Learning Officer at Sheringham Park; '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.

'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.'

Purple Emperor (female)
Purple Emperor (female)
Purple Emperor (female)

Spotted in the tree canopy

Unlike other rare butterflies that can be found in great numbers when conditions are favourable, the Purple Emperor lives at a very low density.

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

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, as well as defend this area from intruders and potential rivals. 

If you are lucky enough to encounter one, you’ll notice the males of this beautiful butterfly have an iridescent purple or bluish sheen to the upper surface of the wings when viewed from a certain angle.

" At Sheringham Park the National Trust is looking after the sallows the butterfly favours. Recently, people have worked out how to look for this elusive giant, which is why it's been discovered at Sheringham. I'm delighted that Norfolk has declared itself well and truly Purple."
- Matthew Oates, specialist volunteer on butterflies