This report presents an analysis of butterfly sightings data for the month and identifies reports that are notable due to unusual timing, abundance, rare forms, behaviour or other aspect of interest.
The analysis presented on this page was produced by Claude, an AI assistant developed by Anthropic, as part of an exploratory exercise to surface interesting patterns and insights from our butterfly sighting records. The results are intended to demonstrate the potential of AI-assisted analysis in citizen science contexts.
AI-generated outputs can contain errors or misinterpretations and while the analysis has been sample checked by human reviewers, the Editor may not agree with all of the comments. The findings should not be treated as definitive scientific conclusions and are best understood as indicative insights. If you spot any errors please let us know at webmaster at sussex-butterflies.org.uk.
Species: Queen of Spain Fritillary (a scarce national migrant, very rarely recorded in Sussex)
What's Unusual: August brought an exceptional wave of Queen of Spain Fritillary sightings across the county. The first individuals were reported at Alfriston (Report #8399, seen 8 August) and West Dean Woods (Report #8278, seen 27 July but only confirmed and reported on 9 August), followed within days by records at Kingley Vale and Lancing Ring (10 August), Kithurst Meadow (11 August), Bevendean Down and Saddlescombe Farm (16 August), Greenway Bottom near Seaford (21 August, the observer's first ever sighting of the species), and further Greenway records on 28 and 29 August. Neil Hulme, who wrote an article on the timing of the influx into southern Britain (Report #8280), had personally seen around 20 individuals by the end of the month (Report #8392).
Context: The editor speculated there could be "10-20 individuals, in Sussex, right now" as reports multiplied through mid-August, and by the close of the month one regular observer felt this year had "surpassed all others" for the species. Several further probable sightings were submitted more cautiously to iRecord, since Queen of Spain Fritillary could be confused with Dark Green and Silver-washed Fritillary in flight. Locations ranged right across the South Downs, from Kingley Vale in the west to Seaford in the east.
Locations: South Downs, county-wide (Kingley Vale to Seaford)
Species: Long-tailed Blue
What's Unusual: A male Long-tailed Blue arrived in a Felpham garden on 8 August, settling on the everlasting pea for 20 minutes (Report #8263). Six days later a female was found egg-laying on the same plant (Report #8310). Further east at Whitehawk Hill, Brighton, individuals were logged on 11, 14, 18, 19 and 23 August (Reports #8294, #8314, #8342, #8345 & #8361), building to what one observer called "my best ever Long-tailed Blue day", with 17 sightings of an estimated six individuals in under an hour on 18 August, including three engaged in a dogfight (Report #8342). For one visiting couple, three Long-tailed Blues at the same site the following day made up their 60th British species (Report #8345). Egg-laying on sweet peas was also confirmed at Westham (Reports #8286 & #8326).
Context: Long-tailed Blue is normally a scarce, late-season immigrant in Sussex. This year's pattern, an early arrival, confirmed egg-laying at two separate sites, and sustained sightings for most of the month, points to a stronger and earlier immigration than usual, with a real chance of a home-grown generation appearing later in the autumn.
Locations: Felpham; Whitehawk Hill, Brighton; Westham
Species: Dingy Skipper, second brood
What's Unusual: By 24 August, second-brood Dingy Skippers had been reported from 32 different locations across Sussex, drawn from 38 separate posts (Report #8367). The editor described this as "extraordinary", noting that 2025's total of 15 locations was itself a new county record at the time, and that in 2023 just a single second-brood individual was recorded in the entire county. A crowd-sourced appeal for further records (Report #8385) pushed the confirmed total to around 38 locations by 29 August, with the editor expecting it to "comfortably exceed 40" once late reports were added (Report #8398).
Context: The editor was clear that the point of the exercise was not the record itself but what it reveals: "highlighting the effect of a warming climate on our native insects" (Report #8398). A warm, dry spring and a run of six heatwaves and a prolonged, three-month drought through the spring and summer of 2026 was repeatedly cited by contributors as the likely driver.
Location: County-wide (32+ separate sites)
Species: White Admiral, second brood
What's Unusual: A White Admiral came down to drink at a garden water dish in Sharpthorne on 9 August (Report #8275), just 36 days after the last sighting of the first brood on 4 July. The editor called it "quite ridiculous", noting that a second-brood individual would not normally be expected before mid-September. Remarkably, three further second-brood White Admirals followed before the month was out: at Kingley Vale on 25 August, described by the observer as "my first ever second brood" (Report #8377); at Ashcombe Bottom the same day, unexpected among a search for fritillaries (Report #8379); and at The Comp on 27 August, resting undisturbed beside a busy path (Report #8391).
Context: Four second-brood White Admiral records in one month is unprecedented in the recording scheme's history. The editor linked the pattern directly to this year's exceptionally hot, dry conditions, remarking after the Ashcombe Bottom sighting that it was "yet another astonishing record for White Admiral, in the month of August".
Locations: Sharpthorne; Kingley Vale; Ashcombe Bottom; The Comp
Species: Brown Hairstreak
What's Unusual: A Brown Hairstreak turned up in an Etchingham garden on 13 August, some 25km from the nearest previously known colonies around Weir Wood Reservoir and Polegate/Hailsham (Report #8307). The editor called it "a mega record" and "an awesome record", and County Recorder Colin Pratt confirmed there were "no known 21st century Sussex records" east of a line drawn from Hartfield to Pevensey before this sighting, although the species had existed there historically in the 20th century (Report #8316). A second nearby record followed at Hurst Green a few days later.
Context: The Etchingham record capped a strong year for Brown Hairstreak's established range further south: by 13 August one observer had personally seen 9 individuals around Seaford, with another 10 reported by others, "an incredible number considering they only had one local record before last year" (Report #8318). The editor attributed the wider expansion to consecutive warm springs in 2025 and 2026, in contrast to the cold, wet springs of 2023 and 2024.
Locations: Etchingham; Hurst Green; Seaford area
4 August 2026
A volunteer work party surveying Stoke and Medley Bottoms for landowner Nyetimber counted 3,588 individual butterflies of 24 species in one day, dominated by 862 Chalk Hill Blue and 742 Meadow Brown. Neil Hulme called it "the best chalk grassland habitat in West Sussex".
9 August 2026
A seventh visit of the season in search of Grayling at Deep Dean again drew a blank. With the species already lost elsewhere in the country, the observer warned "we are witnessing a catastrophe", as this colony has nowhere left to disperse from if it disappears.
10 & 18 August 2026
Male Adonis Blue numbers at Anchor Bottom were reported to be doubling every three days, from 1,002 counted on 9 August to an estimated 8,000–10,000 individuals (males and females) flying across the whole site by 18 August, when a single transect alone recorded 2,148.
1 August 2026
A high-speed fly-past in a Pevensey garden was reported as a Monarch, prompting caution from the editor over whether any Sussex Monarch could be considered genuinely wild, versus an escape or release, as later suggested by a separate report of daily Monarch sightings near Plumpton College.
11 August 2026
A Swallowtail seen in an East Grinstead garden was confirmed by the editor as an immigrant from mainland Europe. Sussex Swallowtails are usually restricted to the coastal plain or South Downs hilltops, so a sighting north of the Downs is very uncommon.
12 August 2026
More than 30 Humming-bird Hawk-moths were counted along a 60-yard stretch of buddleia at Washington, described by the editor as "an extraordinary count and surely yet another Sussex record for this species, at one location, on the same day".
16–17 August 2026
Fresh third-brood Wall Brown were found at High and Over and Friston Forest in mid-August, which the editor described as "an astonishingly early date", attributing it to the summer's run of six heatwaves.
20 August 2026
A Small Blue at Horseshoe Plantation, Beachy Head, was described by the editor as a late record: since 2006, Small Blue has only been recorded beyond 20 August in four other years, and the Eastbourne area has a habit of producing late records for many species.
25 August 2026
A Storrington wildlife garden reached 30 individual Clouded Yellow sightings for the season, against an average year of just 2 to 3, in what the editor rated among the best 3–4 Clouded Yellow years in Sussex since the website began in 2006.
31 August 2026
A female Brown Argus at Knowlands Farm lacked the "figure of eight" marking on the leading edge of the hindwing underside, an identification feature so consistent that the editor called its absence "a very rare record".
August 2026 stands out as a landmark month for butterfly recording in Sussex, shaped by sustained hot, dry weather and characterised by:
Taken together, these records point to a summer of striking contrasts: unprecedented arrivals and record abundance for many species set against continued drought stress and real concern for others, with the Sussex recording community once again capturing it all in detail.
