Wednesday, June 29, 2011

Perplexed, or should that be purplexed

I bumped into Chris Dennis at Finemere Wood today when shortly after this male iris made an appearance. Chris had already seen three males all at the same time on the main track. Maybe the season is sparking to life.
We followed him for at least half an hour in which time he moved over a dozen times but never going far. He always returned to the path to continue taking up salts. Something very strange appeared to happen during this time. When he first arrived it was quite difficult to see the purple sheen, care had to be taken to get the correct angle to the sun for it to show at all. Even then the purple colour was quite subdued. However as time passed the purple colour appeared to become more and more intense. After half an hour the purple sheen was not only intense but could be seen from nearly any angle. During the sighting the sky filled in from broken clouds to overcast and rather grey. I also took a lot of photos during the sighting which when reviewed in sequence appear to confirm the colouring up phenomenon. I have no explanation for this apparent behaviour and wondered if anyone else had witnessed anything like it.


Jill said...

Hi Steve. I have a chance to visit Finemere woods next week and was wondering if it was indeed a good time to go looking for Purple Emperors I have visited once before but had no luck. I seem to remember a long main track Is this the most likely place to find them? Having never seen one before I would love to like everyone else who has never had the pleasure

All the best Jill

Alexander Henderson said...

Hi Steve, your observation of his majesty's purple sheen is an interesting one.

The tiny structures which refract and reflect light from the wings mean that seeing any purple sheen is dependent on the angle at which the light meets the wing.

On a bright sunny day, the Sun's light is not very diffuse, and most of what hits the emperor's wing will be over a narrow range of angles (not always the 'best' angles). On a cloudy day, the Sun's light which makes it down to earth is much more diffused - ie spread over many angles, and I would say must surely make seeing the sheen easier, as more light will be at the correct angle to show the sheen.

I have some more info if you are interested - message me on - my username is m_galathea.

Alexander Henderson

Steve Croxford said...

Hi Jill. This coming week should be good provided you can get some good weather. Anywhere along the main track up the hill from the entrance is good.Look for them Oak edging along the track or on the track itself.

Good luck.


Jill said...

Thanks Steve :o) Having had a good look around this site etc I've also identified that Oakley woods a good place too so I'll try both places Thanks so much for your help and I'm hoping the forecast thundery showers aren't too bad on Weds /Thurs

All the best, Jill