Waking to a clear blue sky and warm sunshine, I decide to visit Friston Gallops again. As those who have read my previous posts will know, I have become very worried about the population of Chalk Hill Blues at this site -- one of the best in Sussex over the past few years (possibly THE best).
When I first arrived at the sheltered NE corner (approx. TV554997), my fears seemed to be confirmed, with just a handful of Chalk Hills being seen. However, as I walked the areas with the shorter grass and clumps of wild thyme, I flushed up a few more males, maybe a dozen in total. I decided to climb up to the higher slopes, and disturbed several more Chalk Hills as I did so, including a couple of females (my first of the year). By this time, I had seen maybe 25 in total, and remember that this is a site where it was estimated that there were several hundred thousand a few years ago.
Feeling very disappointed and fearful, I eventually reached the upper area at the north end of the site (approx. TV552999). To my delight, here it was a different world. Swarms of male Chalk Hill Blues were chasing around in the sunshine, madly looking for females, fighting with each other and any other species that came too close. The females mainly kept their heads down, but each time I disturbed one, it was quickly pounced upon by a male or two, sometimes several. This was more like the Friston Gallops I knew of old!
The colony at this northern end covers approximately three 100x100 metre squares on the OS map, so that's 30,000 sq m. If we say there was one Chalk Hill every 10 sq m, (and from my observations today, I think that's a very conservative estimate) this means that there were 3,000 individuals. So, nothing like the numbers of recent years, but still a fair-sized colony.
In a large patch of thistles at the edge of the grassland, I also saw some Painted Ladies with that very fresh orange/salmon-pink colour, together with several Red Admirals, a Small Tortoiseshell and a Peacock.
I then walked south down the western margin of the gallops to the SW corner. The grass along most of this section is long and rank with Meadow Browns and little else, but along the path I did see several Wall Browns flitting along in front of me (about 20 in total). Marbled Whites were plentiful here a few weeks ago, but have now finished. On reaching the far SW corner (TV544991), the habitat is better and there is another small colony of Chalk Hill Blues, but nothing like the numbers in the northern area. However, I also saw some Common Blues and a couple of Brown Argus here, together with many second-generation Small Heaths.
So, to summarise what I actually saw (as opposed to extrapolated)
Chalk Hill Blue - let's say 300+ at the very least
Common Blue - 5
Brown Argus - 3
Meadow Brown - several hundred, but declining now
Gatekeeper - 50+
Small/Essex Skipper - 30+
Small Copper - 4
Painted Lady - 4
Small Tortoiseshell - 1
Peacock - 1
Red Admiral - 20
Brimstone - 4 (1 female)
Small Heath - 50+
Wall Brown - 20
I didn't get many good photos - the butterflies were too active in the heat, but here are a few record shots.

- Chalk Hill Blue (male)

- Chalk Hill Blue (female)

- Brown Argus

- Wall Brown (female)