They 'd have to have remained undiscovered for a very long time. And bearing in mind that the NT holds training courses for entomologists there it would be remarkable if we'd missed them. It's not like it's not visited every day by the public. And yet the population has built up to a level where it turns up in nearby gardens and still no sign of them in the wood. That's pretty special pleading. If we were talking about private woodland with big keep out signs and their own security force I might believe it. But not in a public park. And not on the North Norfolk coast - which holds more naturalist per acre than anywhere else in the country.Jack Harrison wrote:HarassedDad has seenI am far from convinced that should automatically be considered suspicious......a photo of a Purple Emperor taken in a garden in Sheringham yesterday. To put this context, the nearest emperors are in Suffolk, we haven't had a proven record since the early 60's.
There is plenty of ancient woodland to the south of Sheringham (it could hardly be to the north). In my youth in the 1950s, Pearl-borderd and High Brown Fritillaries occurred in the Pretty Corner woods. With the well-known ability of the Purple Emperor to lurk undetected (Neil Hulme recently re-iterated this), surely PE could have easily remained un-discovered at a very low population level? PE is now seemingly doing much better in recent years so I would think it is possible that finally it has reached observational status in North Norfolk.
Jack
Bearing in mind that they're only in Suffolk because someone put them there. Otherwise the nearest colony would be over 100 miles away. And the ability to lurk undetected is a fascinating hypothesis, but by definition it's impossible to prove. All we know is that there weren't any PE's seen somewhere and then there were. Either they were there all the time but invisible, or they just arrived. What we do know is that people try all the time to introduce them - there's probably no more common illicit introduction species. And this case we have an email from a butterfly supply company saying they might have sent purple emperor in a box shook out 30 miles away, and the sighting is in a bungalow just 300m from the sea at a time when we know there's migrants coming in.
I would say the undiscovered colony theory is running a pretty poor third in the probability stakes.
The Holmes Dunes report was only a "possible" seen briefly and put out on the pagers. I have three other reports of that grade but they probably shouldn't be listed in the main summary - or should be noted as such at least.
But hopefully, not urgently 
Or choose to live another, lets say, three decades 
