As you will have seen I popped out in a rare spell of good weather to see WLH with Philzoid.
As it turned out it was quite successful and we saw at least 14 individuals with several coming down to thistles to be photographed..
The nice thing about this site is that the suckering elms that the butterflies use are only 12-20 feet tall and there is an embankment that you can sit on and watch them – virtually at eye level.
This allows them to be observed at a distance of fifteen feet or so in their ‘normal’ behaviour mode on sprigs of elm. Most other locations where I have seen them they are considerably higher and it is difficult to observe them actually on the Elm leaves.
I have observed them for a couple of hours or so recently and their behaviour is quite interesting. They are very combative and will challenge any similar sized object that flies by, quickly returning to the same or a nearby leaf if it turns out not to be a competitor. If it is another HS they spiral up perhaps 100’ or so in close combat eventually splitting and mostly disappearing into the distance. I am sure that if there is a strong wind then this may be one way that they disperse – if they find suitable elms on landing.
The other interesting point is that when the sun is out, as they warm up they tilt their folded wings until they are almost flat against the leaf. It is quite strange because the body appears to be in an almost normal upright position.
Quite why they should choose this seemingly uncomfortable position rather than just face the sun and reduce the area of wing exposed to almost zero I am unsure? My theory would be that in this position they look like a damaged section of leaf whereas if they are upright they might appear more obvious to a potential predator.
Also, another thought – with a nice dark upper surface to the wing why do they not simply open their wings [like Brown Hairstreaks] to absorb warmth – if that is what they are doing? This would effectively double the amount of wing that is exposed and achieve the desired effect much more quickly
