Where are butterflies in winter?

A few butterflies – including the Red Admiral and the Painted Lady – migrate south to warmer climes in late autumn. Most, however, overwinter as caterpillars close to their food plant, while others overwinter as pupae or eggs. Only a very few overwinter as adults.

Whatever the stage, the butterfly enters a dormant, hibernation-like state (diapause). At the same time glycerol forms in its body, which acts as antifreeze and helps it withstand temperatures well below freezing.

Unusually mild winter weather can create a so-called false spring that fools nature. It can make plants, animals and insects react as if spring has arrived – including the few adult butterflies that overwinter. If the butterfly wakes from its dormancy and the weather then turns to frost, the consequences can be serious. It may find it hard to return to its dormant state and therefore risks dying.

More photos

In late autumn the Painted Lady (left) and Red Admiral (right) migrate to warmer southern Europe and North Africa

Cabbage whites overwinter as pupae in dry places such as on buildings and under lean-to roofs. Photo: Large White

A batch of eggs laid by Lille Penselspinder (a tussock moth), which have overwintered and are ready to hatch – seen in April on the dike at Bøtø

Small Tortoiseshell – overwinters as an adult in houses, hollow trees and similar places.

Brimstone – overwinters as an adult in evergreen vegetation such as Holly and Ivy.

Peacock – overwinters as an adult in buildings, hollow trees and woodpiles

Comma – overwinters as an adult in hollow trees, among dead leaves or in dense vegetation.

Camberwell Beauty – overwinters in hollow trees, under bark and in woodpiles