Butterflies: Experts worried over November garden sightings - with butterflies 'meant to be hibernating'

Some Brits are still spotting butterflies in their gardens in mid-November, but wildlife experts say the sightings are “very worrying”.

Butterflies normally start to hibernate in late summer or early autumn, and then wake up around the start of March. But the recent sightings suggest milder weather could be delaying their instinct to hibernate in the first place. This comes after the 2023 Big Butterfly Count survey found climate change was having an impact on garden butterflies, with more red admirals seen than ever before - likely due to the warmer weather meaning more of the insects were skipping winter migration.

Gill Marchant, 73, told SWNS she was "amazed" when she saw four red admiral butterflies on her dahlia plants. Three days later, she was shocked to find another butterfly in her Cambridgeshire garden. "I was really surprised because we had a couple of nights before where we had a slight frost," she said.

"We've also had torrential rain - which butterflies don't tend to cope with terribly well. I then saw another one in my garden and I was just amazed because we had another cold night."

Ms Marchant feared that the reason they were there was because of global warming - and she worried about their odds of survival this late in the year. "The problem is that there is very little food for the butterflies and that's going to impact their survival," she continued. "They won't survive hibernation or flying to a warmer country.

Buglife - a UK-based invertebrate conservation charity - agrees that the sightings are a concern. Fundraising director Paul Hetherington said it was "very unusual" to see butterflies at this time of year. "It's all basically down to the fact it's not got cold enough for them to start hibernating, which is what they would normally do," he said.

"You would normally find them in sheds or garages this time of year, or some people even find them in their wardrobe... I haven't seen butterflies in November ever." Mr Hetherington agreed that climate change may be behind the errant insects.

"It seems to be getting caused by climate change - we are getting warmer and wetter winters then what we used to have. There's far less snow and ice about now," he said. "That's really worrying because the extra moisture we tend to get in the winter, is really bad for things like mould growth. If you get mould growth on you when you're a hibernating insect, then it's likely to prove fatal."

Although it is rare to see butterflies at this time of year, Mr Hetherington said: "there's not really anything you can do" to help them if you do see one in your garden. "If it's not cold enough for them to hibernate then they won't hibernate... But if you find them hibernating, then don't disturb them or put them back outside because that's going to be bad for them.

"They are hibernating for a reason, because it's got to a cold temperature," he continued. "They use up far less energy when they are hibernating."