The one species of butterfly that most UK enthusiasts look forward to seeing each year is the mighty Purple Emperor (Apatura iris). Once this was a mythical beast that lurked deep in ancient woodland and was rarely seen. When I was a child I never dreamed I would see an Emperor, that was a long time ago, now with the internet and my car it is (relatively) easy. The most famous woodland for seeing Iris on the ground is Fermyn, part of the ancient forest of Rockingham near Corby in Northamptonshire.
On the 26th I set off early. It was very misty when I arrived at 7am. Parked opposite the glider club and waited for a friend to arrive from Hertfordshire. The mist did not clear until 10.30 then it went from cool to very hot in minutes, not great for seeing Emperors on the ground. At about 1.30pm they did however start to land in partial shade and become very approachable. What they are doing is extracting minerals, they don’t nectar on flowers like most butterflies but will feast on dead animals, excrement and other delicacies!
The beautiful purple/blue sheen on the upperwings is only seen at certain angles when the light catches it right, the females lack this. The Emperor is a large butterfly with a wingspan between 70-92mm (3-3 3/4 inches). The eggs are laid on the caterpillar’s food plant sallow. Males will congregate around the tallest, sheltered trees in the woods. Here they will watch out for passing females and joust with rival males. Their battles are quite vicious and they will even attack passing birds the size of pigeons!
In all I saw probably twelve different individuals. The most fantastic sighting sadly was not caught on camera, it was aberration iole where the wings lack the white markings. This is the ‘holy grail’ of Emperors, the rarest of the rare, unfortunately as it came to land it got involved in a skirmish with two Ringlet butterflies and glided off, not to be seen again, sigh!
I left Fermyn at 3.30pm, it was 84f. I had another target the White Letter Hairstreak (Satyrium w-album). This small butterfly lives most of it’s life high up in elm trees feeding on aphid honeydew. It will occasionally come down to nectar on bramble. I saw several at Fermyn but none descended, but a visit to Bedford Purlieus near Peterborough and I struck lucky. This is a species I have never photographed before, a lovely ending to the day.
And also https://apaturairis.blogspot.com/