BUTTERFLY populations in Oxfordshire are 'sadly typical' of the worrying nationwide decline, local scientists have said.

Despite the county's numerous nature reserves, species which are disappearing from the English countryside have not fared any better here.

Scientists at Wallingford's Centre for Ecology and Hydrology (CEH) published an annual report this week which revealed that two declining UK butterflies – the grayling and the grizzled skipper – have suffered their lowest numbers in the 42 years the study has been going.

Among the 2,693 survey sites used were Oxford's ancient Wytham Woods, farmland at Little Wittenham and Aston Upthorpe nature reserve near Didcot.

Now one of the lead researchers at CEH, who helps conduct counts in and around Wallingford, has said Oxfordshire is as bad as anywhere.

Entomologist Marc Botham said: "Sadly I think Oxfordshire is quite typical: we've lost quite a few nature reserves in recent years.

"In Buckinghamshire there is a lot of good work going on where they're doing conservation management for the Duke of Burgundy so hopefully that will make a difference.

"We do have conservation work going on at Aston Upthorpe, but even if you have the right habitat and the right place you still have the weather to contend with."

In the latest report on the UK Butterfly Monitoring Scheme (UKBMS), Dr Botham and his colleagues concluded that fragile species had been hit hard by a chilly snap last spring and a 'gloomy, wet summer'.

Although butterfly numbers last year were actually up on 2016, they were still 'way below average' the researchers said, with 2017 being the seventh worst year overall in the UKBMS record.

The grayling and grizzled skipper both suffered their worst year since the records began, but the difficult weather conditions also caused problems for many more species.

The threatened dingy skipper saw numbers fall by 22 per cent compared to 2016 and the rare marsh fritillary declined 12 per cent.

Even the Large White, one of the UK’s most well-known and widespread butterflies, saw numbers tumble by 19 per cent. This common butterfly is now also in a state of long-term decline.

At the beginning of 2017 there had been hopes for a good butterfly year as many spring species emerged earlier than usual following a warm start.

Butterflies need warm, dry weather during their flight periods in order to feed and mate.

However a cold snap at the end of April saw spring species such as the grizzled skipper and Duke of Burgundy struggle.

The second half of the summer was cloudier and wetter than average which caused further problems for species already struggling from a combination of habitat loss and climate change.

Dr Botham said: "The weather can have a serious impact on individual species’ numbers each year as results from counts in 2017 show.

"However, populations can and do bounce back providing suitable habitat is available, and it is the long-term trends, particularly the declines of a number of common and widespread species, which are of great concern."

In a glimmer of hope, some species do seem to be on the up, including the beloved red admiral.

Dr Botham said: "Definitely in Oxfordshire red admirals and commas were absolutely everywhere last year.

"Because we had a warm winter people were spotting admirals out on January 1."

National admiral number in 2017 were up 78 per cent compared to 2016 and comma numbers rose 91 per cent.

However a major challenge still remains to get a better understanding of the factors affecting populations so conservation work can be targeted more.