Surrey Wildlife Trust - Butterflies
Above: The stunning peacock butterfly (Photo by Rachel O'Hara)
In the summer, over 40 species of butterfly can be seen in Surrey – if you know where to look for them. But as temperatures drop, they need strategies for surviving the winter. The main way they cope is by shutting down their metabolism: many do so as eggs until they hatch in the spring; some as caterpillars waiting to feed on new vegetation; others as a chrysalis before they emerge as a new adult. All are waiting for the conditions to be right to get on with the next generation.
However, five of Surrey’s butterfly species actually spend the winter in the adult form. Having gathered enough food to survive the colder months, they will then create the next generation the following spring. Some of these are readily seen in the winter whilst others are more secretive. What is true of them all is that they now can be seen earlier in the New Year due to the effect of global warming.
Species to look out for... One of our most striking butterflies, the peacock emerges at the end of July to feed up before disappearing for the winter. It escapes the cold by retreating to out-buildings and garden sheds (a tactic also adopted by the small tortoiseshell), upturned flower pots and gaps in garden or woodland log piles. A few years ago, groups were found hibernating in the World War II pill boxes on Surrey’s North Downs!
The brimstone has a different tactic and usually tucks itself into undergrowth, such as a bramble patch, emerging to fly around only if disturbed or when the temperature rises in spring. The male is a distinctive pale yellow colour and can be seen on a warm day from February onwards.
The comma, meanwhile, is well camouflaged and often hibernates on tree trunks. Careful monitoring over the years shows that the spring emergence is getting earlier as our winters get warmer.
The red admiral is a special case. Until recently, this common species was not a resident but an annual migrant into Surrey (from France, Spain and as far away as North Africa) that did not survive our winter. Due to climate warming, it is now becoming a resident (as far north as Yorkshire and the Isle of Man) and in Surrey can be seen on any warm day up until the New Year and beyond. They hibernate, often briefly, in trees within clumps of foliage such as ivy.
The dangers in winter... Besides being vulnerable to predation, especially by spiders, we too can pose a threat to hibernating butterflies. If you’re planning to sort out the loft, garage or shed this winter, or tidy up unruly undergrowth, be careful not to disturb these beautiful creatures. Leave some patches of dead vegetation and make sure the loft hatch is closed properly to prevent warming of the attic space. If you do uncover a hibernating butterfly, put it back where you found it or somewhere cool but sheltered.
If you’d like to know more or get tips on identification, visit
www.butterfly-conservation.org For your information Surrey Wildlife Trust, School Lane, Pirbright, Woking, GU24 0JN.
Tel: 01483 795440
Website:
www.surreywildlifetrust.org Email:
info@surreywt.org.uk