Butterflies are one of the key indicators for biodiversity and environmental health.
Julian has kept records from his butterfly surveys since 2001 giving a clear picture of the butterfly situation within Carymoor over the past years. The results are also transferred to UKBMS, to help with the bigger picture within the UK, which I will continue to do.
This year has compared fairly with the conclusion from the UKBMS 2025 big count report, however there are one or two surprises within, both good and bad, with winners and losers too.
With so much data, so many numbers to analyse, it is difficult to make some sense of it all and can be confusing, therefor missing what is important, which species are improving, which are remaining static and those that are declining.
This can determine how well the environment is being managed at Carymoor or to see if there are any areas that could be improved to help, however there are also external factors other than environmental issues at play to take into consideration, such as climate change etc.
From this data recorded over the past 25 years, I am able to determine the expected, average total for each species, which indicates a target of performance for that species.
Similar to a traffic light system, highlighting green indicates an above average performance (the winners). Yellow indicates within a range of an average performance (stable) and red indicates a below than average performance (the losers).
The yearly total are a combination of both transects, Carymoor Environmental Centre and Upper Dauncy Field.
Average target number for:
Speckled wood 160. Small white 200. Large white 100. Small copper 30. Clouded yellow 25.
Meadow brown 550. Brimstone 55. Small tortoiseshell 125. Green-veined white 60. Holly blue 4.
The surprise from the winners is the speckled wood. The last brood of the year proved to produce an abundant of numbers for this unassuming beauty and was still being recorded on the last transect survey for the year. Though falling second in the highest recorded total, it has outperformed all increasing the expected average by a whopping 136. The actual total 296, Expected average total 160.
The small and large whites are no surprise that they did so well, during the end of July, through August and the beginning of September, the fields and gardens appeared to be full of them wherever you looked, such a wonderful sight.
The surprise or should I say disappointment within the losers is the meadow brown, falling by 50% of their expected total, whilst the gatekeeper remained with the range of their expected total and scoring the highest total count for the year.
Also the Brimstone, having it’s third worst year in the past 10 years, 2023 being it’s record, bumper year at Carymoor and performing even below last years performance is a sad indication of decline, the past recorded data since 2001 does indicate erratic and unstable numbers over the years.
Good news: Second consecutive year of spotting the Marsh fritillary on site.
Special moment. Spotting the elusive brown hairstreak, who likes to spend most of the day in amongst the leaves of trees.
The outlook for next year.
If Mother Nature delivers another fair year of weather for the butterflies, I hope and would expect most numbers to improve further.
I am forever optimistic for the butterflies at Carymoor, I just wish I could be as optimistic for the UK and the planet too.
Happy butterfly spotting.
Adrian Lanfear
