The back-edge of today's cold front might make for some interesting viewing - especially in those favoured spots where its passage coincides with sunset?
Four peacocks, a red admiral, a small blue, several cabbage whites and a 'brown thing', on the buddleias yesterday. Sadly, my interest in butterflies never really extended as far as brown ones.
Not too sure that this actually counts as research (Monckton apparently does!) Anyway: http://pesn.com/2011/04/17/9501811_James_Kwoks_Hidro_Tech_Floating_to_the_Top/