GH and BG walked transect 22 on the morning of 31st August. The weather was mild with a mixture of sun and cloud.
As we’d anticipated, the 30-minute torrential cloudburst of three days earlier had a dramatic and detrimental effect on the number of butterflies still flying: last week’s total of 199 plummeted to only 48 for this week. It was the Meadow Browns who were hit hardest, with a reduction from 108 last week down to only 13. Small Heaths were also reduced, down to 21 from last week’s 51. Once again, there was a single Brown Hairstreak in the oak trees bordering Hill Wood Field but this time he/she settled long enough to be photographed. 
​It is the sixth week in succession that we’ve recorded Clouded Yellows. This is remarkable because in previous years we’ve thought ourselves lucky to have seen a single CY, yet so far this season we’ve counted a mighty 46.

​Count details:
​21 Small Heath
13 Meadow Brown
4 Clouded Yellow
4 Small Copper
3 Brown Argus
1 Brown Hairstreak
1 Common Blue
1 Small White

​Count summary:
48 butterflies from 8 species.

GH and BG walked transect 21 on the morning of Sunday 23rd August. The weather was fine for the first few sections but thereafter banks of cloud rolled in and reduced the sunshine.
​The Meadow Browns’ total count was 108 (very similar to last week’s number) but they were largely concentrated on Hither Field, where we recorded 79. Hither Field was also where we saw 11 of the 13 Common Blues recorded and 23 of 51 Small Heaths. 
The Clouded Yellows were still flying around in good numbers. In Hill Wood Field we had a close sighting of a single Brown Hairstreak, which sadly escaped being photographed.

Count details:
​108 Meadow Brown
51 Small Heath
13 Common Blue
9 Clouded Yellow
5 Small White
1 Brown Hairstreak
1 Chalkhill Blue
1 Large White
1 Small Copper

​Count summary:
190 butterflies from 9 species.

Transect 20 was carried out on Tuesday 18th August when not only the temperatures plummeted, but so did the butterfly numbers. 
It was only about 20°C and the whole transect took place under solid cloud with quite a breeze in places. 
We’re coming towards the end of the season for the Chalkhill Blues and Silver-spotted Skippers, but we had walked as far as Section 5 before we saw a Common Blue. This was disappointing, given the recent high numbers recorded for this species. 
As previously reported, the second section has been mown and has very little by way of nectar sources, so it wasn’t entirely surprising that here we saw just one butterfly: a Meadow Brown. Meadow Browns were seen in all but one section, albeit in lower numbers than in recent weeks. 
There were comparable numbers of Small Heaths to last week – they seem to fly in more windy conditions while the Meadow Browns prefer to hunker down in the grass. 
We spotted five Clouded Yellows across four sections, including two in Fames Rough where we’ve not seen them before.

Count details:
​119 Meadow Brown
53 Small Heath
9 Chalkhill Blue 
7 Common Blue
5 Clouded Yellow
2 Small White
2 Speckled Wood
1 Silver-spotted Skipper
1 Small Copper

Count total:
199 butterflies
from 9 species.

​If you would like to know more about any of the butterfly species mentioned, visit ​butterfly-conservation.org

Friday 7th August was chosen for Transect 19. It was another very warm one, under a virtually cloudless sky. After many weeks of heat and drought, all of the fields on our transect route are parched brown. Yet despite there being fewer flowers, the number of butterflies is at an all-time high for this time of the year.
This is due entirely to the super abundance of Meadow Browns, who have more than doubled their average count. The Common Blues, Chalkhill Blues and Small Heaths are also having a good year. 
Clouded Yellows are infrequent visitors but this is the third transect in succession when we’ve seen them in higher numbers than previously (Liz even spotted a rare ‘helice’ form, a paler variant of female CYs, see below).
A remarkable find and another reminder that even in our drought-stricken landscape, the butterfly season can still produce some unusual surprises.

Count details:
​ 481 Meadow Brown
104 Common Blue
65 Small Heath
35 Chalkhill Blue
18 Small White
15 Clouded Yellow
9 Small Copper
5 Large White
3 Silver-spotted Skipper
3 Speckled Wood
2 Gatekeeper
2 Painted Lady
1 Brown Argus
1 Brown Hairstreak
Count Summary:
744 butterflies from 14 species.
If you would like to know more about any of the butterfly species mentioned, visit ​butterfly-conservation.org

After a couple of last-minute postponements, GH, LN and BG completed Transect 18 on the morning of Tuesday 4th August. The weather was pleasantly mild whenever the sun disappeared behind cloud, but temperatures climbed rapidly when the sunshine returned – ideal conditions for the butterflies.We started and finished our walk in Stagbury Field, an important site for two of our chalk grassland specialists. Here we recorded 45 Chalkhill Blues, thanks to a large patch of its larval food plant, horseshoe vetch. Stagbury Field is also the only place on our transect route where we see rare Silver-spotted Skippers, which lay their eggs on the sheep’s fescue grass – we recorded 6 SSKs on this transect. The total count was a few hundred down on last week’s but, at 674, the number is still high in comparison with previous week 18s. Once again, it was the Meadow Browns, Common Blues and Small Heaths (as well as the Chalkhill Blues) that boosted the total score. For the second week in succession we saw a few colourful and speedy Clouded Yellow butterflies.
​Although moths are not included in our survey, it's worth mentioning that over recent weeks we have regularly seen the spectacularly agile Humming-bird Hawk Moths flying around Hill Wood Field.

Count details:
407 Meadow Brown
104 Common Blue
55 Small Heath
45 Chalkhill Blue
14 Small White
12 Gatekeeper
7 Clouded Yellow
​7 Small Copper
6 Silver-spotted Skipper
5 Dingy Skipper
4 Brown Argus
3 Painted Lady
2 Speckled Wood
1 Holly Blue
1 Large White
1 Silver-washed Fritillary

​Count Summary:
674 butterflies from 16 species.

If you would like to know more about any of the butterfly species mentioned, visit ​butterfly-conservation.org

On Transect 17, walked on Saturday 25th July, GH, LZ and BG were joined for the second time by Luka Mehew, who proved very useful for the day's busy counting. 
The weather was hot and quite humid, just right for a further surge in butterfly numbers to our second-highest ever transect count of 1,153 butterflies from 22 species (beaten only by our remarkable Week 14 total of 1,207 butterflies in 2019).
Once again, it was the prolific Meadow Browns who, with a count of 659, more than doubled their previous (2019) high of 299. Equally impressive were the 193 Common Blues, which in other years have struggled to reach 3-figure totals.
The ‘specials' continued: there were 6 Clouded Yellows (our first sightings for 4 years), a rare sighting of a Small Tortoiseshell, and our first Silver-spotted Skipper of the year.
Record numbers and notable rarities made Transect 17 one of the highlights of our outstanding 2026 butterfly season.

Count details:
​659 Meadow Brown
193 Common Blue
136 Gatekeeper
56 Small Heath
39 Chalkhill Blue
12 Small Copper
11 Small White
10 Purple Hairstreak
9 Brown Argus
6 Clouded Yellow
5 Silver-washed Fritillary
3 Red Admiral
3 Small Blue
2 Comma
2 Large White
1 Brimstone
1 Dingy Skipper
1 Holly Blue
1 Painted Lady
1 Silver-spotted Skipper
1 Small Tortoiseshell
1 Speckled Wood
Count summary:
1,153 butterflies from 22 species.

We missed transect 15 to avoid the uncomfortable heat levels of that week and, as conditions had eased, GH, LN and BG ventured out for week 16’s transect on the morning of Saturday 18th July. 
We had continuous sunshine, with warm and occasionally hot temperatures. The fine conditions were perfect for butterflies and once again they nudged the day’s count up to a new high of 822 (from 21 species) for this 2026 season. Butterflies were seen in good numbers in all 12 sections of our transect route, a sure indication of being at the season’s height. 
This remarkable count was largely due to our recording a massive increase in Meadow Brown numbers, our highest ever count of 450, but  we also saw 211 Gatekeepers and 85 Common Blues (second brood).
A strong supporting cast featured butterflies from 17 other species, including our first Chalkhill Blues of the year (see below) and a single Brown Hairstreak, Britain's last regular butterfly to emerge each season.

Count details
450 Meadow Brown
211 Gatekeeper
85 Common Blue
14 Small Copper
14 Small Heath
7 Chalkhill Blue
7 Purple Hairstreak
6 Brown Argus
4 Speckled Wood
3 Dark Green Fritillary
3 Silver-washed Fritillary
3 Dingy Skipper
3 Marbled White
3 Small Blue
2 Large White
2 Small White
1 Brown Hairstreak
1 Large Skipper
1 Comma
1 Red Admiral
1 Small/Essex Skipper
Count summary
822 butterflies from 21 species.

Transect 14 took place on the morning of Friday 3rd July in ideal butterfly spotting conditions – warm, sunny and with very little wind. It was a very busy session, and fortunately there were four of us (GH, LN, DJ and BG) to process the high number of sightings. 
The day’s total count was 779 butterflies (our 3rd highest ever count) from 22 species (exceeding last week’s record). The strong July sun brought out butterflies in good numbers across all 12 sections of the transect.
 We recorded a surge in the numbers of Meadow Browns and Small/Essex Skippers and a small increase in Marbled Whites. The Gatekeepers’ count also shot up from 1 last week to 57 this week. Purple Hairstreaks also increased from 2 a week ago to 30 – over the previous 10 years we had never reached double figures! On the minus side, the usually numerous  Common Blues are virtually absent so far this year. 
We hadn’t seen any Small Blues for 5 weeks but the sharp-eyed Duncan spotted one approaching and saw it land on Hither Field’s kidney vetch patch. It was a female and we witnessed her settle on the flower heads and lay eggs. That was nice to see and confirmation that this nationally scarce butterfly is continuing to breed on a site where years of habitat creation and kidney vetch planting are paying off.

Count details:
280 Meadow Brown
223 Marbled White
96 Small/Essex Skipper (inc. 17 Small and 4 Essex confirmed identifications)
57 Gatekeeper
30 Purple Hairstreak
20 Small Copper
8 Large Skipper
7 Silver-washed Fritillary
6 Dark Green Fritillary
6 Small Heath
6 Speckled Wood
5 Brimstone
5 Small White
4 Red Admiral
3 Large White
2 Peacock
1 Common Blue
1 Holly Blue
1 Painted Lady
1 Small Blue
Count summary:
779 butterflies from 22 species.
​

The high temperatures of the previous week had slackened off to a much more comfortably sunny 23 degrees, giving GH and BG a pleasant walk around on Monday morning. We’re now at the halfway point of the 26-week transect season and butterfly numbers are approaching their high-summer peak. 
This week’s count of 486 was the highest of this year and will probably be exceeded over the coming few weeks, depending on weather conditions.  It’s still the Marbled Whites and Meadow Browns plus a surge in the numbers of Ringlets that are responsible for the high count, but whereas at this time of year we normally record around 14 species, on this transect we counted an exceptional 18. Furthermore … new arrivals included the season’s first Purple Hairstreaks and a Gatekeeper. In short, our list of butterfly species showed a much wider range than normal.

Count details:
204 Marbled White
161 Meadow Brown
45 Ringlet
33 Small/Essex Skipper
​(including 1 confirmed Small Skipper)
8 Large White
6 Small Heath
4 Small Copper
3 Brimstone
3 Dark Green Fritillary
3 Red Admiral
3 Small White
3 Speckled Wood
2 Comma
2 Painted Lady
2 Purple Hairstreak
2 Silver-washed Fritillary
1 Gatekeeper
1 Holly Blue
Count summary:
486 butterflies from 18 species.

Saturday was forecast to be the coolest day in the midst of an early season heatwave and so GH and BG chose it as the most suitable for transect 12. The day proved to be pleasantly warm with a mainly cloudy sky, but the butterflies seemed to approve and were out in reasonable numbers. They gave us our highest count of the year so far as we approached the halfway point of the transect season.
When we reached Fames Rough we saw that the lower path, forming our transect Section 3, was fenced off down its length for conservation grazing. To compensate, we walked the upper path (section 4), counting butterflies on both our outward and return walk. We reasoned that the sheep currently on Coneyboro Hill (pictured below) may soon be moved into the fenced area of Fames Rough. Last week the count was low but numbers for this transect shot up to 430 butterflies, our best result of 2026 to date – beaten only by the week totals of 517 (2020) and 435 (2017). The rise in numbers was due mainly to the surge in Marbled Whites, Meadow Browns, Ringlets and Small/Essex Skippers.

Count details:
​188 Marbled White
157 Meadow Brown
32 Small/Essex Skipper (3 confirmed as Small Skipper)
30 Ringlet
8 Small Heath
4 Large Skipper
4 Painted Lady
1 Common Blue
1 Dark Green Fritillary
1 Red Admiral
1 Speckled Wood
Count summary:
430 butterflies from 12 species.