Population crash of the Small Skipper at Eakring | ||
............... | ||
The Small Skipper
suffered a tremendous population crash in 1999. This
occurred after I had noted the species "as being
abundant in areas of long grass" during 1998,
when all suitable areas held typically large counts. These were checked frequently during 1999 when just one adult was found. It has yet to make any sort of comeback and is interesting to note that no changes in Small Skipper populations have been noted elsewhere. The cause remains a mystery. The fact that the species has technically been wiped out from this area alone seems to indicate some contributing local factor and would certainly rule out the weather as a cause, although periods of heavy rain can cause some annual flooding during the Winter months at Eakring Meadows, whilst other areas remain much drier. |
||
............... | ||
Pesticidal
use seems unlikely. Even allowing for spray drift in
windy conditions, at Eakring Meadows (the main stronghold
for the Small Skipper in 1998) protection is given from
even severe spray drift by well established trees and
hedgerows. The fact that there are no reported changes
within Small Skipper populations elsewhere, also tends to
rule out the use of pesticides. Over-grazing can also be ruled out, as even roadside colonies have disappeared and others situated within small permanently uncultivated sites. Maybe the cause will reveal itself in time and the Small Skipper will re-establish itself to former numbers over the next few years. I consider that the most likely explanation could be a severe case of localised parasitation by members of either the Tachinidae, Braconidae or Ichneumonoidae groups. |