Which reminds me, one of the plants that EH want to encourage on Silbury is the foodplant of the Chalk Hill Blue.... ambitions to return to the old days maybe?
Trouble is, the British Chalk Hill Blues are extinct, kaput, no more - all they'll get there is some damn Dutch introduced ones what aren't the same as what used to be there.
So the buggers even cock up Silbury's butterflies... ;)