RECENT warm spring weather, capped by the UK’s sunniest May since records began, has led to the early emergence of many butterfly species.

For the first time this century in an unprecedented influx, by the end of last month 53 of the UK’s 59 resident and regular migrant butterfly species had already been spotted.

Dr Richard Fox, associate director of recording and research at the charity Butterfly Conservation, who compiled the figures, said: “Over the past 20 years, we’ve typically received reports of 39 species by the end of May, so 53 this year is amazing.

“Last year, for example, only 43 butterflies had put in an appearance by this point and the only other year to come close to the current total was in 2011, when 50 species had started to emerge by May 31.”

The sightings, made by members of the public and displayed on Butterfly Conservation’s First Sightings web page, shows some extremely early dates for particular species this spring.

For example, the first Ringlet butterfly, was reported on May 24, but would not normally be seen before June 8, while the White-letter Hairstreak spotted on May 29 typically doesn’t appear until June 11. Silver-washed Fritillary and White Admiral, classic butterflies of summer woodland in southern Britain, were both seen on May 30, two weeks earlier than usual.

The rare Large Blue, successfully reintroduced to Britain in the 1980s, also made its earliest ever appearance this year.

These unusually early emergences aren’t necessarily a worry for these butterfly populations. Dr Fox explains: “Butterflies are able to adjust their emergence dates to suit the vagaries of the UK weather, indeed they need to do so to remain in sync with the plants that their caterpillars need to feed on.

“However, the trend towards earlier emergence of butterflies and moths in Britain over recent decades in response to climate change isn’t necessarily beneficial.”

More concerning is the impact that severe drought can have on butterfly numbers as plants die back leaving caterpillars to starve. Despite the record-breaking February rainfall, many parts of the UK had received little rain until this week and vegetation was starting to look parched.

This news comes ahead of Butterfly Conservation’s Big Butterfly Count, the largest citizen science project in the UK, which last year saw over 113,000 people take part.

Running between July 17 and August 9, The Big Butterfly Count is the UK’s biggest citizen science event. See