4
Recording the Butterflies and Larger Moths of
Essex
When in 1984 you receive a new number of the
Essex Naturalist, giving distribution maps of
our macrolepidoptera, you may wonder where all
the dots came from. This will tell you.
I should make it clear from the start that Geoff
Pyman is in charge and will write the supporting
text: I am only one of the recorders and the
map maker. Accordingly, in 1981, when the
project was launched, I prepared distribution
maps showing all the records made by the Essex
Naturalists' Trust for their Guide, those held
by the Biological Records Centre at Monks Wood
and any others I could lay hands on. It became
at once apparent that most of the maps had a
common pattern corresponding with the distribution
of the recorders themselves and great chunks of
Essex were left almost completely blank. We
tried to put this right in 1982, adding over
7,000 new or updated dots, but the imbalance
remained. For example, in two adjacent 10 x 10
km. squares with equal potential, one had modern
records for over 500 species, whereas the other
had only 3.
So another year was devoted to recording . I
prepared a new set of updated maps for distribution
These showed clearly the gaps for each species
and the squares which were under-recorded. The
latter were as far as possible allocated to
individuals.
My assignment was north west and central northern
Essex, an area in which the number of species per
square ranged from 5 to 336: six of my squares
had fewer than 25 modern records. All now exceed
100 and I have added over 1,000 dots. This is
how it was done.