Brimstones not so ready to risk early appearance

Brimstone butterfly feeding on primroses, Williamson's Weekly SUS-140904-090626001
Brimstone butterfly feeding on primroses, Williamson's Weekly SUS-140904-090626001

March came in like a lamb and and went out like one too so spring was sprung early enough for all the peacock and small tortoiseshell butterflies to come out of hibernation in mid March.

Here in West Dean Woods, small tortoiseshells were already laying their eggs on nettles in my garden before the month was out. By April 1 most of the peacocks seemed to have settled their breeding requirements too. The same went for the comma butterflies.

But brimstones were not so ready to risk all with early emergence, though most came out on All Fools’ Day. That was a warm sunny day despite air pollution from the Sahara and Europe. We counted 14 male brimstones flying around this nature reserve.

One female was among them. They were all searching for her but she kept herself to herself drinking nectar from violets and wild daffodils which were growing deep under scattered blackthorn bushes.

The male brimstones were more active on more obvious flowers such as cowslips and primroses. Here is a male in my photograph showing how much more yellow it is compared to the female brimstone which is almost white, what you might call snowberry white, the colour of old Morris Travellers.

What is unusual about all these brimstones flying around the nature reserve that surrounds my home is that there is no purging buckthorn tree in the near vicinity on which the brimstone caterpillars feed all their waking life.

It seems that brimstones have a partial migration in summer back to the tree where they were crèched last summer and which may be miles away. It seems that they then hibernate for the winter in a different area where there is a lot of ivy growing on old trees. We do have that in the nature reserve.

Thick ivy on old trees is essential for this most attractive butterfly – the one that was called “the butter-coloured fly” giving rise to the word butterfly. I have been telling landowners and forest managers not to speak of gardeners that ivy is vital to wildlife, till I am blue in the face.

It is of course sometimes necessary to remove ivy off some trees but it can often be safely left. Simply to cut it because it is ivy is not helpful to the ecosystem. A lot of birds feed on ivy berries in late winter. Blackbirds, mistle thrushes and wood pigeons are kept alive by ivy in the woods in March.

If all continues well with the weather Easter time will see many other butterflies to enjoy on the Downs such as dingy and grizzled skipper, common blue and small copper. Even if the weather turns into a roaring lion after the early promise, this will bring forth the wild orchids and the cushions of wild thyme, birdsfoot trefoil and rock rose which give such a brilliant colour to the hills for the holiday.

Happy Easter.