Wall brown - has suffered severe decline on a national scale (not seen in Surrey since c1998) but it can still be found on the warmer southern English coast. This decline may be linked to climate change.
Grizzled skipper - may have disappeared as a result of the annual summer cattle grazing on the Central and Bayfield Plains, where it was last recorded in 1997. Grazing at the appropriate stocking rate and period is usually beneficial to this species, at least on chalk downland locations.
However, fewer butterfly enthusiasts visit the common during May, when the grizzled skipper is on the wing, so it may still be surviving, albeit in a very small population. If you visit next May and see this butterfly, please e-mail the rangers.
White-letter hairstreak - is very rare and is a possible loss. Its decline is linked to Dutch Elm disease.
Ken Willmott FRES, Volunteer and Butterfly Conservation Surrey/SW London branch Conservation Adviser