Winter Butterflies

While filling up my bird feeders, I glanced up and saw a Small Tortoiseshell butterfly in the roof of the shed. As I looked around, I found about fifteen more, wings neatly folded, just hanging around, waiting for spring to arrive. The old brick shed has a door that fits where it touches, but that’s exactly what these butterflies need, tucked up between the roof beams, out of the wind, but nice cool temperatures that don’t vary too much. The gaps around the door will allow them safe passage into a bright, spring morning where they will warm up and continue their journey, later in the year.

Image by Deb Depledge

Butterflies technically don’t hibernate, as insects they go into a dormant state when they overwinter. Many butterflies go into this dormant period as an egg, pupa or caterpillar, but some survive the winter months as adults. Red Admiral, Peacock, Small Tortoiseshell, Comma and Brimstone all go through the winter, waiting for the spring when they can breed. You can sometimes see Red Admirals on warm, sunny winter days as they don’t tend go into full dormancy, as the others do.

I did find another Small Tortoiseshell alive and well on the living room window sill, basking in the sunshine, which was keeping it from staying in this dormant state, which it should have been doing. Butterflies rely mainly on an external heat source to warm up or shivering (flapping their wings when stationary to use their flight muscles to generate heat) and the winter sun can fool them into thinking it’s time to wake up. It was quite dopey, but having previously found its cousins, I carefully used the glass and paper technique to gather it up and place it out in the shed, as it was a relatively warm day, where it should be happily doing nothing now.

Central heating can also cause butterflies to come out of this dormant state early, with the temperature increase. This can cause problems as what to do with the butterfly when you find it in the depths of winter. I was lucky enough to be shown (by the other butterflies) that my shed is an ideal place for to see out the winter months. The sunny day allowed me to move the butterfly when the ambient temperate in the shed was raised so it wouldn’t be a shock for the butterfly. Don’t forget to check on your butterfly as the spring arrives (early February and into March), to see if it’s active and needs to be let out, if your shed door fits better than mine!

If you find a butterfly in your house, which isn’t moving, it’s best left where it is to see out the winter. However, if your butterfly is awake, try to find somewhere safe outside in a shed or garage, where it can safely see out the winter months. If it’s cold outside, it’s not recommended that you put the butterfly outside, as the temperature change may kill it. So, keep it somewhere cool in your house (porch or conservatory) until it wakes in early spring.