Old Castle Down is alive with larger fritillaries at the moment, with estimates of 100 to 500 seen in our Members' Day afternoon on Sunday. Most at present are at the southern end of Old Castle Down, just above Coed y Bwl reserve. They are starting to nectar more now, but on Sunday were on constant activity a few inches above the habitat, in and out of the bracken. Both Dark Green & High Brown Fritillary occur together here but the proportion of High Browns is already high and will probably increase as season progresses. First Silver-washed Fritillary of the year was also encountered on Sunday.