With temperatures rising above the 30 degree mark, yesterday's transect was an exceptionally hot one. This unusual late season heat has encouraged the flowers on which the butterflies feed to carry on producing nectar and correspondingly our butterflies are still around in reasonable numbers (albeit in fewer species), especially the Meadow Browns, Common Blues and Brown Arguses and Small Heaths.
We recorded a total of 249 butterflies across 9 species. For the equivalent week's transect in 2016 our count was 165 from 11 species, in 2017 it was139 from 12, and last year it was 60 from 9. There's quite a difference between 2018 and this year.
This week's variable weather gave us a small window of opportunity in which to do our transect on Thursday, and for most of our walk around the sky was virtually clear, providing excellent conditions. Upon starting out in Section 1 (Hither Field) we saw straight away that the field had been mowed, clearing the grass and with it most of the wildflowers. We were relieved to see that some of our nurtured Kidney Vetch, being a low-level plant, had escaped the mower blades so there is still some hope that the patch will have seeded next year's plants.
Butterfly numbers are declining by the week but Meadow Browns are still seen in reasonable numbers; the Chalkhill and Common Blue numbers are holding steady despite having a poor season and Brown Argus even showed a slight increase over last week's figure.
Yesterday was the last warm fine weather (with intermittent cloud cover) before the forecast summer storm hit overnight. The late season decline in numbers is becoming quite noticeable now. The Marbled Whites and Small/Essex Skippers were absent today; Gatekeepers and Meadow Browns are still around but in fewer numbers and the number of Chalkhills was probably at its peak. The long-predicted horde of Painted Ladies (the butterflies, of course) has still not reached our patch yet but we recorded and photographed one individual in Section 1.