The winter challenge

Three brimstones were the first butterflies I saw this year in March when I was gardening with my dad. And we were gardening again in this lovely high-pressure weather when a female brimstone flew into view.

In bright sunshine, it swooped into a thicket of ivy and vanished. Butterflies don’t usually avoid sunshine, so I took a look. There it sat, deep in the ivy, on the underside of a leaf, hidden from the sun – and rain, frost and snow to come.

A butterfly’s big challenge is how to survive a British winter. The brimstone is one of five native species to tackle it in its adult form, hibernating under evergreen leaves until March, but possessing enough energy to search for nectar on sunny days. This is why colourful small tortoiseshells, peacocks, commas and red admirals have such cryptic undersides, camouflaging them when they close their wings for winter.

If I were a butterfly, I’d follow the likes of the brown hairstreak and hibernate as a robust little egg, but surprisingly, most of our 59 species endure winter in that fleshy, vulnerable-looking form – the caterpillar. Some bury deep into leaf litter on the ground; others, such as the purple emperor caterpillar, change colour to stay perfectly camouflaged during their long winter vigil on bare branches.

I cut back my buddleias in April so they would flower late for our hibernators, but they’ve been bereft of butterflies. Further west and south, however, there have been lovely gatherings of red admirals and peacocks, and some thrilling rare visitors from overseas – a monarch in Wiltshire, a Camberwell beauty in Cheltenham, and long-tailed blues in Newhaven.