Butterflies on the Edge

Something a bit different.  Comments from Mike over at https://alittlebitoutoffocus.com/?wref=bif on my last post made me realise that many readers may not understand that in the UK several species of butterfly are or were in great danger of becoming extinct.  I thought in this post I would try and explain why but not in minute detail.  I am not an ecologist so these are views purely of a layman, though many years ago I was heavily involved in angling conservation and river habitat restoration.

Why are butterflies in danger?  Each species has it’s own special requirements but it’s all down to habitat.  The UK is a (relatively) small but heavily populated island(s) so there is great pressure on land use.  More people want more houses, places to work, better transport.  Farmers are being asked to produce more food to feed the growing nation.  Nature has very often taken second place to these needs.  Britain has been shaped by man’s activities for millennia and because of this many butterflies have adapted to the man-made environment.  Now as our needs change many of the old practices are stopped and the butterflies are struggling with the effects.

Pearl Bordered Fritillary (Boloria euphrosyne) Bentley Wood, Hampshire 2018

Into the Woods.  It was said that thousands of years ago the British Isles were covered in woodland.  People have always exploited this natural resource and over time the ‘wildwood’ disappeared and in it’s place came commercial forest.  Certain trees were grown for various purposes, for instance Oaks for naval shipbuilding.  In the 1920’s huge areas were planted with quick growing non-native conifers with little benefit to wildlife.  One ancient practice was that of coppicing.  This is where sections of wood are cut down to generate new growth and was done on a rotational basis.  In these coppices some species of butterfly thrived as their caterpillar food plant grew in the newly opened areas.  These included the Heath, Pearl-bordered, Small Pearl-bordered and High Brown Fritillaries.  When the coppicing no longer became commercially viable the woods grew back, blocking light and the under-storey choking out those plants the butterflies needed, the Violets and Common Cow-wheat.  Populations crashed to the brink of extinction.  The High Brown Fritillary can now only be found on a few limestone hills around Morecambe Bay in Cumbria and some valleys on Exmoor.

High Brown Fritillary (Argynnis adippe), Latterbarrow Cumbria 2018

Green, green grass.  It is not just woodland that has suffered change.  Many areas of open grasslands are no longer grazed in the traditional way as this became unprofitable.  The effects were the same.  Plants that require certain conditions could not flourish and those species that rely on them collapsed.  The situation was made worse when the rabbit population, that helped keep the coarse grasses short, suffered the deadly disease myxomatosis which was introduced by man.  One species hit hard was the beautiful Adonis Blue of the warm southern chalk downs.

Adonis Blue (Polyommatus bellargus) Yoesden Bank, Buckinghamshire 2017

Queen of the Broads.  In my home County of Norfolk we have a butterfly that is just hanging on.  The Swallowtail is unlike it’s close Continental cousin in that it is totally reliant on Milk Parsley, a plant that grows in the reedbeds of the wetlands of the Broads.  If these reedbeds are not maintained this plant and the Swallowtail will die out.  It has lost the ability to wander far in search of a new home.

Swallowtail (Papilo machon ssp britannicus), Hickling, Norfolk 2018

What is the future?  These are just a few examples to show how butterflies have adapted to the way we managed the countryside.  It is that sudden change of use that has put them in peril.  We have moved quickly in land management but they have not had time to evolve.  Add in the consequences of global warming and things look dire.  It is not all doom and gloom.  More people are acutely aware of the problems and are acting quickly to address the situation.  Conservation groups are working on habitat restoration under the guidance of the scientists.  There have been massive success stories like that of the Large Blue (Phengaris arion). This has been reintroduced to it’s former areas after becoming extinct in 1978 when it was discovered what it needed to survive.  For people like myself who delight in seeing such wildlife we owe a debt of gratitude to these conservationists and must support them however possible.

Duke of Burgundy (Hamearis lucina), Totternhoe, Bedfordshire 2018. Hanging on but hopefully with conservation work will still be around for future generations to admire

TO DO NOTHING IS NOT AN OPTION     WHEN THEY ARE GONE THEY ARE GONE