The last week of September 2019 marked the end of our fourth butterfly transect season. Each 26-week season is counted from the 1st April. Despite the cold blast of the ‘Beast from the East’ in the early spring, followed by the summer’s record high temperatures, we were out spotting and recording our butterflies and then reporting our findings on to the Butterfly Conservation Trust on 24 of those weeks.
The total count for 2019 is 5,763 butterflies from 30 species. Last year’s figures were 5,758 (a mere 5 less than this year) from 33 species – in 2019 we saw no Silver Spotted Skippers, Clouded Yellows or Brown Hairstreaks.
Compared with last year, our Skippers had a very good season; we saw more Brimstones and Orange Tips but fewer Large/Small Whites; there was a huge fall-off of Common Blue numbers and there were fewer Chalkhill and Holly Blues but a slight increase in Brown Arguses; it was a poor season for all of our Hairstreak species and for Speckled Woods, Silver-washed Fritillaries and Ringlets; while the Brown species (apart from the Ringlets) plus the Peacocks and Dark Green Fritillaries were seen in greater numbers. Once again, the Meadow Browns topped the table.
Throughout the season, we have been interested in observing the benefits or otherwise of our efforts to improve the habitats for Small and Chalkhill Blues. Our Kidney Vetch (the Small Blues’ food plant) seems to be doing quite well in various sites across our ‘manor’ and yielding a modest increase of one more Small Blue than the two we counted last year. We have increased planting and seeding Kidney Vetch this year, including the surrounds of the Lagoon. In spring we cut back an area of the coarse brachypodium grass in Stagbury Field that was threatening to smother the Horseshoe Vetch, food plant for our Chalkhill Blues and, as these butterflies are not seen anywhere else on our patch, reducing the coarse grass was essential. Perhaps the Vetch hadn’t quite recovered from the ‘rescue’, because over the season we saw fewer CBs than last year (138 as opposed to 180). Cutting the grass earlier may help numbers next year.
Full figures can be found here.
Info by Brian G. Posted by Graham K.