Williamson's Weekly Nature Notes

They have been recorded flying in England every month of the year. I even saw one on Christmas Day 1958.

Yes, we had global warming half a century ago. Then came global cooling with those severe winters of the early 1960s.

My picture taken in the garden shows a male brimstone giving one of my narcissi a great big kiss.

What else can you call it? It was a lingering one as well, lasting a good half minute. Had to be for me to get a picture.

I am still in the Dark Ages with my old Pentax having to be got out of its case, hung round my neck, set for speed and aperture, then focused. Usually everything has flown away by then.

Male brimstones, which are yellow, can be easily told from the females, which are ivory- white like the old Morris Travellers.

Females stay in bed safely tucked up in an ivy bower until it's warm enough to get up. The males patrol when the temperature rises to about 12C (54F) and wander about looking for the females.

Our ancestors called them the butter-coloured flies, which easily became butterflies.

After about a week of warm weather the females get up and wander about, minding their own business. They do not need to seek the males because the males have sharpened up their appetites for a liaison.

They will pounce on a female, or even any white butterfly which comes their way. If the scent is right, he will try to mate there and then.

Wanting the strongest, she will fly high. Last year I watched a couple going up almost out of sight.

I suppose they were about 50 yards high, risking everything with the predators about ranging from chaffinches to hobby falcons.

He followed her every move then as she flew fairly straight and level. To avoid this exhausting battle, the male will often overpower and push her to the ground when she may escape by creeping down into the long grasses or just keeping dead still and upside down.

If she likes him, she will soon be laying her eggs, which you can see glued to the underside of buckthorn leaves.

These shrubs are not all that common and are easily overlooked, but the wonderful sweet smell of tiny, non-descript, greeny-yellow flowers will tell you where it is in May.

And there will usually be a butter- or yoghurt-coloured fly around it as well, both male and female brimstones, that is.

This feature first appeared in the West Sussex Gazette May 21 2008