This Peacock Butterfly is warming up on a log with its wings fully open.
Nature on our doorsteps: Solar panel wings
Rosaleen Dwyer is the County Heritage Officer at South Dublin County Council – every week she gives us an insight into the natural heritage around us and the beautiful biodiversity of the plants and creatures.
THE recent sunny weather has been very beneficial for butterflies.
Butterflies are cold-blooded creatures. Their bodies cannot generate internal heat like mammals can. Butterflies need to absorb heat from elsewhere before they can function.
The sun is their most important source of heat.
A butterfly’s wings are like solar panels.
These absorb heat from the sun and distribute the energy to the rest of its body.
The wings can also be angled to manage the degrees of heat that the butterfly needs throughout the day.
On a cool morning, the butterfly first begins to warm up by vibrating the muscles on its chest.
These need to be warm before the wings can operate properly.
When these muscles are ready, the butterfly can find a sunnier spot to fully warm up.
It will bask on leaves or flowers with its wings held flat against the surface it is resting on.
When warm enough, this Peacock Butterfly closed its wings to stop absorbing heat
This allows the wings to absorb as much of the sun’s warming rays as possible.
Butterflies often bask on sunny walls and stony footpaths, or on patches of dried, brown grass.
These substrates warm up and retain heat from the sun.
This also allows the undersides of the butterfly’s body and wings to benefit from the warmth rising up from underneath.
Throughout the day, depending on how warm the conditions become, the butterfly will change the angle of its solar panel wings to manage the heat it needs.
When it is comfortably warm, it raises its wings to a halfway point above its body.
This angle decreases the area of the wings exposed to the sun, and thus reduces the light it wishes to absorb.
It also allows cooling air to circulate around its body.
If it gets too hot, the butterfly closes its wings completely up above its body.
This temporarily shuts off the light reaching its heat-generating wings. It can then cool down before it needs to fly again.
The constant sunshine of recent weeks has allowed butterflies to be very active in our gardens and parks.
