Val Bourne Wildlife
Val anticipates the joys of newly awakened butterflies
I’VE just started to see butterflies again in my Gloucestershire garden – such bringers of joy. However, if I lived further south, I might see red admirals flying on winter days, because these butterflies are now resident in warmer parts of Britain due to a warming climate. I didn’t realise this until I saw a handsome red admiral feeding on a snowdrop in a Somerset garden in midFebruary. That butterfly was able to fly and feed as and when, because red admirals do not enter a torpid state of dormancy or hibernation.
Most of the red admirals I see in my own garden are migrants, not residents, and they often come in three waves. The first migration in April is thought to come from North Africa and southern Europe. In May and June, butterflies arrive from Spain and Portugal, and then a larger third invasion from central Europe arrives in August. Many will end their visit by migrating southwards in October, and this strong-flying butterfly is known to fly at night – an unusual trait shared by another migrant, the painted lady.
Some butterflies do enter a proper period of dormancy, and the first to emerge here are normally peacocks and they generally appear in March. I sometimes find them in the garden shed, so I leave the shed door open on fine spring days so that these tatty individuals can make their escape. Occasionally I disentangle them from a spider’s web, unsure whether they’ll make it or not. Males are slightly smaller than females, although both have those distinctive eye spots. Once they breed, the females lay a cluster of up to 400 eggs on the common stinging nettle.
Female peacocks select nettles growing in sheltered, sunny sites. A ground-breaking recent book, entitled
Life Cycles of British and Irish Butterflies by Peter Eeles, has pictures of the tiny pale greenish-grey first instars. They shed their skin as they grow, and the fully grown fifth instars are a velvety black. Once ready to pupate, the caterpillars will travel several metres before spinning a silk pad. The pupating caterpillar hangs from a branch or leaf, forming a J shape. It’s apparently possible to see the wings through the case although, try as I might, I haven’t found a pupating peacock – yet! There are three more butterflies that overwinter in a torpid state: the comma, the small tortoiseshell and the brimstone. Male brimstones appear in April here, and they often head for our patch of native bluebells. The combination of acid-yellow butterfly and cobalt-blue bluebells is one of the sights of spring. In warmer places, the males can fly as early as February or March. The butter-coloured wings of the male brimstone may have given rise to the generic term of ‘butterfly’. The females are much paler and a little later in flight.
The brimstone is our longest living butterfly, and those you see in spring could be eight months or more, because they emerged the previous summer. There’s only one brood a year, but this butterfly can be seen from spring until late autumn. In summer, ours are very fond of our pink perennial pea (Lathyrus
latifolius). The brimstone always closes its wings when feeding, and Peter Eeles calls them “exquisitely scalloped”.
These exuberant butterflies fly through the garden at a fast pace, and several males will chase one female. They’re said to hide in bramble patches in winter, but they are almost impossible to find, because the folded wings look very leaf-shaped in profile. Comma butterflies also overwinter and will also fly early in the year in mild weather, but we normally see ours in July.
We are fortunate to see plenty of small tortoiseshells here most years. Peter Eeles tells us that this ubiquitous butterfly, which is found right across Britain, can wander several kilometres a day. It’s been parasitised by a tachinid fly,
Sturmia bella, and butterfly populations have fluctuated, sadly. Ours appreciate dandelion flowers in spring, while in August they are drawn to wild marjoram.
“First to emerge are normally peacocks”