|The silent disappearance of the Wall Brown from Nottinghamshire|
|Sometimes you don't realise that you have missed something until its gone, but this phrase it quite apt when referring to the Wall Brown as this was once one of our commonest butterflies.|
|Today this delightful
butterfly has had its name shortened, with the 'Brown'
being dropped, which is a shame as Wall Brown is a much
more delightful sounding name than just 'Wall'.
The original name was actually spot on and extremely descriptive, because this butterfly was common and widespread in Nottinghamshire and could be seen well within the limits of urban areas, including the very centre of Nottingham. Any sparsely vegetated strip of waste land would hold adults and we have even seen females egg laying on isolated coarse grasses growing against a wall.
In the early 1980's we used to breed the Wall Brown (Lasiommata megera) and Speckled Wood in captivity for fun, then later began to concentrate on some of the rarer butterflies. To be honest, back then, the Wall Brown population of suburban Nottingham never needed augmenting by the release of captive stock, but it was impossible then to see how the fortunes of two species would change so dramatically within the space of 20 or so years.
|Back in the early 1980's, you could not find a Speckled Wood (below left) for love nor money in Nottinghamshire, yet the range of the Speckled Wood has expanded beyond belief since. Nowdays, they probably grace most gardens and open spaces throughout Nottinghamshire at some time during the year, and are certainly not confined to the woodland rides and glades that they once were.|
|The Wall Brown has gone in completely the opposite direction however and very suddenly too. The butterfly's overall UK decline is estimated by some suthorities to be as much as 37%, but many 10km grid squares will have declines of considerably higher percentages and the Wall Brown is probably now extinct in many of the grid squares across Nottinghamshire. Today, the Wall Brown has generally contracted its range towards coastal areas.|
|Looking back at our butterfly records from Eakring (reproduced above), we have not recorded Wall Brown at Eakring (or anywhere else in Nottinghamshire) since 2006, but it was three years earlier that the sudden decline in numbers came. Reading the notes for 2002, the Wall Brown was increasing in numbers at Eakring on previous years (1998-2002), but seemed to reach a halt in 2003 despite numbers still being relatively high. This has never been a butterfly to be found in large numbers anywhere though, when compared to the sometimes large emergences of Nymphalid butterflies such as the Peacock and Small Tortoiseshell etc, but was usually always found in ones and twos. Now it seems to have gone completely and never gets a mention.|
|The Wall Brown's decline at Eakring and in Nottinghamshire, surely cannot be completely down to a change in climatic conditions, as they have disappeared so quickly. The suddeness of the decline, based on our small sample of records coming from a limited area, means that any particular reason is currently theoretic. The advent of permanent set-aside strips and no change in the amount of larger areas of suitable grassland habitat at Eakring, would mean we cannot blame habitat loss in this instance. Then again, this was a butterfly that could easily be found within city centres and suburbs, and was not dependant on large expanses of habitat.|
|UK distribution of the Wall Brown between 1980 and 2006.||UK distribution of the Wall Brown between 2006 and 2009.|
maps we have generated through the NBN Gateway, show the
dramatic decline of the Wall Brown over three periods
since 1980 and the butterfly's range contraction towards
the upland areas of the Pennines and coastal areas. The
Wall Brown seems to have suffered greatest losses from a
large area beginning just south of London, through up
into South Yorkshire, central Wales and Norfolk.
Declines and increases in many of our native butterfly populations are nothing new and their populations are ever-changing and ever likely to change in the future, no matter how much we try to help them.
Remember how the Comma began an enormous expansion in its UK range back in the 1940's, after being confined to areas near the Welsh border and other species such as the Speckled Wood, Gatekeeper, Brown Argus, Dingy Skipper and the Essex Skipper, have also increased.
These range expansions have all steadily taken place over a number of years and are, in these instances, most certainly in direct response to the recent changes in our climate and which has suited these butterflies.
|UK distribution of the Wall Brown between 2010 and 2012.|
Brown represents a classic example of how our common
insects can suddenly slip away, virtually unnoticed and
without warning. Perhaps more importantly, we should be
aware that all our insects are worthy of care and
protection, no matter how common a distribution map
indicates they are and that conservation bodies and
organisations, should not neccessarily create areas of
habitat to save a few species at the risk of others.
Common insects are often largely ignored by recorders, who can sometimes have a tendency to send in records that only they regard as being important. We were asked recently by someone, about who they should send their rare invertebrate records to. We replied that they should send all their records to the county recorder and to send everything and not to filter out what they think may be interesting or known to be rare, because we often know more about the rare species than we do the common. Its amazing how very common species often get neglected, as every single record is important in developing a much clearer picture of our fauna.
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|The UK distribution maps on eakringbirds.com are provided by the National Biodiversity Network (NBN Gateway) Each red square on the map indicates species present in 10km grid squares.|