Good-Bye Chalkhill Blues - Clearbury Down Wiltshire
Posted: Mon Aug 04, 2008 8:38 pm
I visited Clearbury Down in Wilts today and am prompted to share my thoughts...
Around ten years ago I began visiting Clearbury Down in Wiltshire to see the Chalkhill Blues. At peak season one could expect there to be an estimated 30,000 - 40,000 Chalkhills flying on any one day, on a relatively small piece of downland oasis in a sea of otherwise arable land.
During the first week of August the population would boil over like a pan of milk and hundreds of Chalkhills could be observed around the margins of neighbouring fields.
It's quite a walk to the down itself and as one drew closer by following neighbouring field edges it was a surreal experience to see increasing numbers of Chalkhill males patrolling the narrow field margins of golden cereal crops as one approached the site.
As one walked across the down the Chalkhills would rise in swirling clouds, and in excess of a hundred could be counted on individual clumps of marjoram, each butterfly jostling for position.
Clearbury Down used to throw up extreme aberrations too (law of averages when a colony reaches this sort of magnitude) - the beautiful fowleri (where the black margin of the male is replaced by white), radiata, alba and any number of more minor conditions. Indeed, in the early 2000's a specimen of the most extreme Chalkhill aberration (the aptly named) extrema was exhibited at a London event after having been captured that year on Clearbury Down. One of only a handful of this most remarkable form ever recorded in England.
In recent years the Down has deteriorated significantly. The vegetation in knee high, waist high in places and there are large areas of bramble. There is almost no Horseshoe Vetch and Chalkhill Blue numbers rarely exceed 100.
I am so saddened by the loss of this annual spectacle I felt compelled to put finger to keyboard.
So another prime Chalkhill site is lost, joining the ranks of Martin Down and Fontmell Down.
I don't know of any other site in England where the population of Chalkhills is anything like that of Clearbury Down up to a few years ago.
Felix.
Around ten years ago I began visiting Clearbury Down in Wiltshire to see the Chalkhill Blues. At peak season one could expect there to be an estimated 30,000 - 40,000 Chalkhills flying on any one day, on a relatively small piece of downland oasis in a sea of otherwise arable land.
During the first week of August the population would boil over like a pan of milk and hundreds of Chalkhills could be observed around the margins of neighbouring fields.
It's quite a walk to the down itself and as one drew closer by following neighbouring field edges it was a surreal experience to see increasing numbers of Chalkhill males patrolling the narrow field margins of golden cereal crops as one approached the site.
As one walked across the down the Chalkhills would rise in swirling clouds, and in excess of a hundred could be counted on individual clumps of marjoram, each butterfly jostling for position.
Clearbury Down used to throw up extreme aberrations too (law of averages when a colony reaches this sort of magnitude) - the beautiful fowleri (where the black margin of the male is replaced by white), radiata, alba and any number of more minor conditions. Indeed, in the early 2000's a specimen of the most extreme Chalkhill aberration (the aptly named) extrema was exhibited at a London event after having been captured that year on Clearbury Down. One of only a handful of this most remarkable form ever recorded in England.
In recent years the Down has deteriorated significantly. The vegetation in knee high, waist high in places and there are large areas of bramble. There is almost no Horseshoe Vetch and Chalkhill Blue numbers rarely exceed 100.
I am so saddened by the loss of this annual spectacle I felt compelled to put finger to keyboard.
So another prime Chalkhill site is lost, joining the ranks of Martin Down and Fontmell Down.
I don't know of any other site in England where the population of Chalkhills is anything like that of Clearbury Down up to a few years ago.
Felix.