The return of an 'extinct' UK butterfly

The BBC’s security correspondent, Frank Gardner, is well-known here in the UK  for covering topics of huge global significance. But we’ve invited him onto the programme to tell us about his other passion - which is documenting wildlife. And he was part of a group that found something remarkable.

Frank - Yeah, this is pretty exciting actually. Along with a small number of other nature enthusiasts, specifically butterfly enthusiasts, we have seen the first wild living examples of a black veined white butterfly flying around in Britain since it was thought to be extinct in Britain in 1925, or to be used, the exact word, extirpated. They were first seen in Britain, or first registered in Britain, in 1667 in King Charles II. They disappeared from the British in 1925. They're quite common on the continent, but they disappeared from southeast England. That was their last stronghold. And then some friends of mine reported that they had seen them in southeast London about two weeks ago. And I thought this was pretty interesting. I was working all week in Ukraine, but as soon as I got a chance of the weekend, I went down, joined up with them, and they very generously gave their time to help me find them and photographed them. And I took those photographs, and they kind of went viral. Actually, it was extraordinary. I put one on Twitter on my Twitter account, which is Frank R. Gardner, and it got 470,000 views, nearly half a million views. I know I sound like a teenager, but it just shows the interest and popularity in these things. It's a very beautiful insect. I mean, if you imagine the kind of your bog standard boring communal garden white butterfly that flutters around and you know, is frankly a bit of a nuisance, nibbling away at things. It's like that, but perhaps nearly twice as large with these very lovely, delicate black veins running through it. And they like hawthorn trees and blackthorn, and there is a chance that they could actually reestablish themselves. So amidst all the really grim climate related environmental news about so many species disappearing in all parts of the animal kingdom, it's great to get a once a rare bit of good news here.

Chris - Was it the loss of hedgerows, which is what happened wholesale in the time window that you referred to their disappearance? Was it that in the southeast of England that led to their disappearance? Was it loss of environment and is it the fact that we have had some change of regulation, we have had incentivisation of farmers to concentrate on what's around the edges of their fields and replant hedges and so on. Is it that that's bringing them back?

Frank - The habitat is hawthorn and blackthorn and they need to have these undisturbed and yes, those habitats have shrunk. Believe it or not, Winston Churchill tried to reintroduce them along with the swallowtail. They were his favorite butterflies. And he actually got some caterpillars and got them reintroduced to his garden in Chartwell in Kent. But his gardener saw these nests in the hawthorn trees and cut them down. So that didn't go well. But I think the reason, I mean, it's a bit of a mystery why and how they have appeared. Butterfly conservation, the charity which monitors butterfly numbers in the UK, was very quick to say although it's lovely for people to see them, let's not get carried away, it's very unlikely that they're going to reestablish themselves here subsequently. It now looks as if rather than it being a casual and unofficial reintroduction by somebody, you know, rather irresponsibly chucking caterpillars around the place instead. Local experts are telling me they think that it was from a female that came across the continent last year. They're quite common on the continent, as I say, and laid eggs. And these have hatched, and it's a brood quite possibly from last year which makes me think they're in decent enough numbers. We could even see them next summer, in which case they'll reestablish themselves.