Flying visitor takes winter refuge

IT would seem a small thing to be concerned about, with the country in the state it’s in, but a beautiful butterfly which has been peacefully sleeping in my workroom for two months has suddenly woken up and now, on this bright, frosty morning, is beating its wings against my window, wanting to get out.

If it does so, it will certainly perish unless it can return to this refuge or find a new one.

A combination of a rise in temperature –I switched on the radiator earlier – and the brilliant winter light signalled that spring has arrived and it should be off mating and laying eggs to produce another generation with wings as gloriously patterned as its own.

Since its arrival in September, I have regularly taken a peek to confirm that it was still perched, wings folded, in the dark corner where it had chosen to hibernate. Small tortoiseshells survive over the winter by finding their way into houses and roosting behind curtains, pictures or cupboards. They have certainly been around much longer than mankind – fossils confirm that they were flitting about the primeval swamps 130 million years ago, whereas it is only 4m since the first hominoids appeared.

This is one reason, perhaps, to respect them, insects though they are. Another reason is their awesome beauty. Our best artists could never reproduce such colours in their vibrancy, the velvety wings, patterned in deep russet, white and black and edged with turquoise blue, while to create the creature itself, capable of reproduction and flight, would be quite beyond our ingenuity.

My concern about the future of my resident small tortoiseshell arises because in 2009 I counted no more than half a dozen in the entire summer. If there were none to lay eggs in 2009, would we have any tortoiseshells in 2010? Its cousin, the large tortoiseshell, once widespread, is now extinct in Ireland and Britain. Could the same fate befall this, one of the two butterfly species that overwinters with us (the other is the peacock) and whose reappearance in June, like that of the swallows, heralds the spring.

I need not have worried; populations vary widely year to year. The summer of 2010 brought a major hatch. I saw the first few flying on Sherkin Island, in Roaring Water Bay in west Cork, on June 16, and others later in the month. These would have been the progeny of a pair that had overwintered. Then there were none until mid-August when, suddenly, there were as many as 30 present in our garden at a time, swarming over the verbena and buddleia. On September 11, I noted a dozen ‘very fresh’ tortoiseshells on the verbena, their resplendent and pristine wings indicating that they had been newly hatched.

At around that time, two came indoors, one to a room not much used, the other to my workroom, where it has been ever since. But, now, this sleeping partner – companion in my solitary station where day upon day I punch the lonely keys (enjoying it immensely, I might say) – has awoken and wants to fly forth to almost certain extinction in the sharp, bright air. What should I do?

For now, I am playing God. I have drawn the curtains on the lovely day, pulled down the blinds. I have donned a jacket and turned off the radiator. Meanwhile, my florid friend has retreated to a secret corner somewhere. I hope I do not see him/her again until June when I will open the window and let him/her out into the open air.

Then, he/she will mate and, if female, will lay eggs. These will hatch into caterpillars that will spin silken nests amongst the growing leaves of nettles, the species’ food plant. After fattening, they will seek secluded places in which to transform into chrysalises from which, if not harvested by blue tits to feed their chicks, they will emerge in June as approximate clones of their parents (wing patterns vary) which will, by then, have expired.

Having fed on nectar and enhanced our gardens in midsummer, these adults will lay in July and then expire. The final generation will hatch in August and September and then seek human habitations wherein to sleep away the winter, to fly again, resplendent, in the spring.