12.25 - 13.25. Same route as on 25-v-18. Stopped counting AB after 20 mins! Huge concentration on steep chalk slope north of Juniper enclosure. Thinned out a bit where the grass is longer, but seen continuously on the hillside in very good numbers, and would easily have reached a count >1000. Lots of courtship and mating pairs. Some tired looking specimens but also what looked like newly emerged individuals still extending/drying their wings. Earlier (10am) was at Morgan's Hill and saw WB, AB, CB, DS, RA, SpW, SH, BA, MF, MB, GH, LS and LW in ones and twos - rather overcast, and I was mostly hunting orchids.