Sixteen species of butterfly on the way down

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SEVENTEEN million butterflies have been counted so far. This took quarter of a million days though and half a million kilometres of walking by people like me, across the UK.

From Cape Wrath to the Lizard peninsula five thousand of us have trudged our little patch of downland, mountain, farmland, woodland, dune or heath in pursuit of these will o’ the wisps which are telling us how safe our world is for us.

My wife walked her same route every week for 30 years. I am still doing my four miles each week after 37 years. Her transect is in West Dean Woods where we live.

Mine is on the downland of Kingley Vale three miles north west of Chichester, with is famous yew forest of 30,000 yews.

These seventeen million insects are now all inside a computer on www.ukbms.org. About one hundred thousand of them are mine.

Another forty thousand logged by my wife. Much enjoyment all round. Healthy exercise too and a good excuse to be out in the fresh air.

But what has it all told us? A report has just been put about by Butterfly Conservation. Aided, you bet, by Defra, Forestry Commission, Natural England, Centre for Ecology and Hydrology, Joint Nature Conservation Committee, etc. etc.

Over the 2,000 sites on permanent scrutiny for 37 years twelve species are on an upward graph. Twenty six species are remaining on a straight line graph. But sixteen are on a slide down.

These losers include that once very common butterfly the small tortoiseshell, one of the prettiest. Another is that common companion of every country village of yore, the wall brown.

Rarities like the heath fritillary are now being joined by the once common family members pearl-bordered and small pearl-bordered fritillaries. All three require properly worked coppice woodland which has now become derelict in Sussex. After strenuous effort in the West Country, the large blue is now increasing. So is that Sussex favourite the adonis blue.

Others increasing are red admiral, swallowtail, comma, mountain ringlet, dark green fritillary, large heath, speckled wood and silver-spotted skipper. Some declining are green hairstreak, Lulworth skipper, wood white, white-letter hairstreak, Duke of Burgundy fritillary and grayling.

37 years is not long enough to tell us what is really happening because some insects may be on a century-long up or down swing depending on these very long but regular planet changes in climate.

What it does show is that targeting problems can find solutions for instance with the large blue and the swallowtail.

Farmers do it with food crops. Butterfly buffs are growing crops of butterflies instead. Here’s to the new season.

Richard Williamson