When butterflies turned black

After a disappointing October for butterflies, the flight season for autumn species largely came to an end around October 10, although with a straggle of red admirals still heading south at Spurn till the end of the month.

Usually mid-October sees a lot of butterflies in this area, but this year it was exceptionally cold with night frosts and the first snow of the winter.

Europe has cooled down very quickly this autumn bringing larger than usual numbers of winter birds, like bramblings and waxwings, to our shores.

So now, as voluntary county butterfly recorder for Butterfly Conservation and the Yorkshire Naturalists' Union (YNU) my thoughts turn to producing the annual butterfly and moth report. We get about 40,000 butterfly records and 100,000 moth records every year and we have a team of some 30 people to share the effort.

There was once someone who did do the job on his own.

George Taylor Porritt was born in Huddersfield in 1848, son of a wool merchant. He became fascinated by moths at an early age and credited his nursemaid for setting the seeds of a lifetime passion when she encouraged him to rear a woolly bear caterpillar and see it turn into a resplendent garden tiger moth.

In the 19th century, collecting and mounting of collections of butterflies and moths was a national pastime.

Porritt collected to better understand the science of variation. His life spanned that time when the Industrial Revolution hit West Yorkshire and with it came smoke and air pollution. It also caused many species of moth to become darker. In fact, some very pale species became almost black. (See the light and dark specimens of the peppered moth on the Porritt's Lists cover, courtesy of Kirklees Museums and Galleries.)

George Porritt charted the changes and kept dated specimens to show those changes. Fortunately for us, his collections still exist in the Tolson Memorial Museum in Huddersfield, and provide important evidence of a change which has since reversed.

By the time Porritt was about 30 he saw the need to assess the distributions of butterflies and moths throughout the county, something which had never been done before.

Working through the Yorkshire Naturalists' Union he involved many enthusiasts spread across the region and drew up the county's first List of Yorkshire Lepidoptera, a detailed account of where to find species and on what plants they lived. This was published in parts between 1883 and 1886 in one of the YNU journals. The first of several updates was added as a Supplement in 1904.

Over the last five years, a small group of YNU and Butterfly Conservation members have been working on a reprint. We have taken his Lists apart and put them together in the modern scientific order we use today, adding additional information as well as a biography. Thanks to Kirklees Museums and Galleries, we have also been able to use colour pictures of the actual specimens Porritt refers to.

It amounts to a history of the county's butterflies and moths from the late 1700s until the early 1900s.

The book will be published in a limited edition in late January next year, to celebrate the Yorkshire Naturalists' Union 150th birthday. A pre-publication offer saving 8 is available for orders placed before December 31 this year: 25 inclusive of postage, payable to Butterfly Conservation c/o 10 Chellsway, Withernsea, HU19 2EN.

CW 20/11/10