Butterfly numbers across Norfolk take 24% hit due to last year’s continued rain

Have you noticed a lack of butterflies recently? Well, you’re not alone, as an environmentalist body has discovered a significant decline in our fluttery friends.

Butterfly Conservation’s Norfolk branch had been asked by many people in the county, ‘Where have all of our butterflies gone?’, so the team crunched last year’s numbers in a bid to answer the question.

Figures revealed that there has been a 24% decrease in the insects in the county, with numbers dropping from 53,595 in 2023 to 40,698 in 2024.

Some of the most common butterflies were among the hardest hit, with Peacock numbers down 59% and Red Admiral down 49% even at “high-value” nature sites.

The data was taken from the UK Butterfly Monitoring Scheme (UKBMS) - where sightings are recorded from 26 weekly transects (a line across a habitat) conducted on high-value nature sites - and the Wider Countryside Butterfly Scheme (WCBS), which gathers information from monthly walks over the peak season in the wider countryside.

So why has there been such a big decline?

County butterfly recorder David Prince said: “Many factors will have contributed to these figures, but the most noticeable one was the weather.

“Butterflies are extremely reliant on the good weather - unfortunately, we had rain and lots of it.”

He explained that the rain continued above average for almost every month right up to the beginning of July, which resulted in many of the pupae failing to hatch, leading to low numbers of emerging adults.

The organisation has declared a national ‘butterfly emergency’ off the back of the results of last summer’s Big Butterfly Count, which was the worst ever recorded in its 14-year history.

However, there is still hope as numbers fluctuate annually and have been known to recover.

For example, Dark Green Fritillary and Green Hairstreak numbers are bouncing back from a poor 2023, and numbers for Swallowtail - a species found only in Norfolk - have remained stable.

The long-term trend is one of decline, with changing weather patterns being challenging for many insects, but nationally and locally, it has been shown that where conservation action is carefully targeted and sustained, in the long term, it has a real impact.

Butterfly Conservation is continuing to work in partnership with other organisations, communities and landowners on many projects that are halting declines and turning butterfly numbers around across the country.

Those wanting to volunteer to take on sites for future surveys can find full details here.