It is incredible to think that every year in Britain butterflies manage to survive the harsh winter by hibernating but one of our most striking species, the peacock, does just that
In the weeks leading up to hibernation, peacock butterflies convert some of their blood sugar into glycerol to act as a kind of anti-freeze in anticipation of the forthcoming cold period. Then the peacock finds a safe place with relatively constant temperatures and shelter from the cold winds, such as a hole in a tree or inside a shed. Here the butterfly will fold its wings and sleep, its dull underside helping it to disappear in the darkness.
This strategy means that the peacock is always one of the first butterflies we see in the spring. During March, if we get a warm period of weather, the first peacocks will leave their hiding place to go in search of their first meal of the year.
The peacock butterfly is a gloriously vibrant addition to the spring scene. To us the colourful eye-spots on its upper-wings, obviously reminiscent of a peacock, are simply beautiful but to the butterfly they are its primary means of defence. If disturbed the peacock butterfly can rub its wings together to create a hissing sound; this combined with its large eye-spots will help to deter predators.
Over the next couple of months the peacock butterfly will lays its eggs, often about 500 at a time and several layers deep, on the underside of stinging nettle leaves. By laying them in layers they increase the chances that some will be protected from desiccation and birds looking for a meal.
In the ensuing weeks the adults, which have now lived for almost a year, die of old age and the caterpillars of the next generation hatch out and start fattening up on nettle leaves. In July they form chrysalides and emerge as adults in August and so the cycle goes on.