4Bs Butterfly Count : Is it a great summer for butterflies or are we just returning to normal?

Early profusion of butterflies
A number of people commented in the 4Bs nature group that this is a good year for butterflies. The spring and early summer hot dry sunny weather brought out sightings of clouds of white butterflies in May and June. 

But butterfly sitings were less frequent in July as more unsettled, cooler, cloudy and wetter weather become the norm.

The early summer profusion is in stark contrast to the summer of 2024 the second worst for common butterflies since scientific records began in 1976. We won’t know whether it has been a good year for butterflies until the results from the Big Butterfly Count are published. But our small 4Bs sample will at least provide a pointer to the national picture.

 4Bs Butterfly Populations are Recovering in 2025

The annual Big Butterfly Count finished on August 10th. 78 counts were made within the 4Bs area and 910 butterflies were observed during the 15 minute counts. Very few counts observed no butterflies, although on cloudy cooler and windy days you would be hard pressed to find a butterfly in the air. On sunny days counts were typically in double figures with 3 to 5 species being spotted during a 15 minute period and the average of all counts in the 4Bs was 11.7 butterflies per count. This is similar to the overall national average of 10.3 and considerably higher than the all time low of 7 per  count in 2024, due to the poor spring weather. 

Our most abundant butterflies were 1) Large White 2) Meadow Brown  3) Small White 4) Gatekeeper 5) Common Blue. This compares to the national survey where the most abundant butterflies were 1) Large White 2) Small White 3) Gatekeeper 4) Red Admiral  5) Meadow Brown

Our Large and Smal White butterflies have done particularly well this year compared to last year where the Meadow Brown and Gatekeeper butterflies were the most abundant.

---

So has it been a good year for butterflies?
One thing is certain - its been a lot better than last year. While the average of 11 per count in 2025 is considerably higher than average of 7 per count in 2024 its broadly in line with the  average of 12 butterflies (including day-flying moths) per 15-minute count in 2023. So this year we might claim that our butterfly populations have recovered to 2023 levels.

Towards a sustained revovery?
For butterflies to really flourish we need a series of back-to-back,climatically favourable years Then flying insect numbers really boom. This happened in the late 1940s and again in 1974, 1975, 1976 as well as 1982, 1983, 1984 and, to a lesser extent, 1994, 1995, 1996.

This century, we’ve experienced scattered decent butterfly summers – 2003, 2006, 2009, 2013 and 2018 – but no consolidation of good years. The fluctuations of global heating will probably thwart a run of truly brilliant butterfly summers but here’s hoping 2025 is start of a series of good summers which will enable a more sustained rcovery.

Source                                                                                                                                      Butterfly watch: A very good summer for butterflies or a return to average Guardian News Paper Patrick Barkham

Norman Jackson is the 4Bs Biodiversity Initiative Team leader