Butterflies mating unseasonably early, in Peterborough!

February 2007. Red Admiral butterflies have been sighted mating in Peterborough, months ahead of normal. Butterfly expert Richard Donoyou was amazed to see the two pairs of frisky Red Admirals as he was washing his car.

‘This sort of thing just doesn't normally happen in Peterborough at this time of year,’ said Richard. ‘I couldn’t believe it. I had to get a stepladder to have a closer look.’

It has been an amazing winter for butterflies in general and the Red Admiral in particular. Many places in England and Wales had butterflies flying in late December and early January. New Year’s Day was marked by sightings of Red Admirals in no less than 12 counties. First sightings of several other butterfly species were much earlier this year, just as the final sightings of many species in 2006 were much later.

It has been widely acknowledged that these highly unusual sightings are indications of global warming.

Now the Government too is signing up to the concept that the presence or absence of butterflies tells us a lot about what is going on. It has officially accepted butterflies as indicators, not just of climate change but also all sorts of environmental change. The move has been welcomed by the charity Butterfly Conservation, whose President, Sir David Attenborough, says: ‘Butterflies are indicators of the health of the natural world.’

Dr Tom Brereton, Head of Monitoring with Butterfly Conservation, is an expert on what butterflies can tell us about the climate and the environment. He confirms that butterfly data, collected by hundreds of UK recorders, definitely points to climate change, with several species extending their geographic range northwards.

Referring to the Peterborough Red Admirals, he says this species does not normally do not start mating in the UK until at the end of April. ‘This butterfly is now beginning to behave as if it were in Spain, where Red Admirals are active through the winter on warm days.’

Dr Brereton, writing in the latest issue of the charity's magazine Butterfly, warns that although climate change currently appears favorable to butterflies, this is unlikely to be the case in the long term. ‘Predictions suggest that climate change will become a significant cause of butterfly decline this century,’ he says There is particular concern for species such as the Mountain Ringlet, which is being forced to find habitats at ever-higher altitudes to survive.

Butterflies can also indicate good news, especially when it comes to measuring the success of projects to halt and reverse the decline in biodiversity. The UK and other EU governments are committed to halting biodiversity loss by 2010.

The conversion to meadows of 50 hectares of previously intensively cultivated arable land at Bunkers Park, near Hemel Hempstead in Hertfordshire, was followed a six-fold increase in the number of Common Blues. Their presence reflected that this grassland had once again become rich in both flowers and other insects.

Similarly, monitoring data also shows the success of measure to save threatened species like the High Brown Fritillary, which is thriving on nature reserves around Morecambe Bay.

Read more about Butterfly Conservation.