A mid-summer butterfly boom

Transect 14 took place on the morning of Friday 3rd July in ideal butterfly spotting conditions – warm, sunny and with very little wind. It was a very busy session, and fortunately there were four of us (GH, LN, DJ and BG) to process the high number of sightings. 
The day’s total count was 779 butterflies (our 3rd highest ever count) from 22 species (exceeding last week’s record). The strong July sun brought out butterflies in good numbers across all 12 sections of the transect.
 We recorded a surge in the numbers of Meadow Browns and Small/Essex Skippers and a small increase in Marbled Whites. The Gatekeepers’ count also shot up from 1 last week to 57 this week. Purple Hairstreaks also increased from 2 a week ago to 30 – over the previous 10 years we had never reached double figures! On the minus side, the usually numerous  Common Blues are virtually absent so far this year. 
We hadn’t seen any Small Blues for 5 weeks but the sharp-eyed Duncan spotted one approaching and saw it land on Hither Field’s kidney vetch patch. It was a female and we witnessed her settle on the flower heads and lay eggs. That was nice to see and confirmation that this nationally scarce butterfly is continuing to breed on a site where years of habitat creation and kidney vetch planting are paying off.

Count details:
280 Meadow Brown
223 Marbled White
96 Small/Essex Skipper (inc. 17 Small and 4 Essex confirmed identifications)
57 Gatekeeper
30 Purple Hairstreak
20 Small Copper
8 Large Skipper
7 Silver-washed Fritillary
6 Dark Green Fritillary
6 Small Heath
6 Speckled Wood
5 Brimstone
5 Small White
4 Red Admiral
3 Large White
2 Peacock
1 Common Blue
1 Holly Blue
1 Painted Lady
1 Small Blue
Count summary:
779 butterflies from 22 species.
​

Butterflies of the week

Small Skipper (Thymelicus sylvestris) – pictured at top.

• Despite its tiny size, the Small Skipper is a fast, darting flyer, often zipping between grasses and wildflowers on sunny days.
• It is easily confused with the Essex Skipper, but the Small Skipper has orange-tipped antennae, whereas the Essex Skipper's antennae are black-tipped.
• Its caterpillars spend the winter tucked inside rolled grass leaves, emerging in spring to feed before pupating.
• When to see them in the UK: Typically June – August, with peak numbers usually occurring in July.

Female Small Blue, Hither Field

Kidney Vetch on Hither Field

Large Skipper

Purple Hairstreak, Hill Wood Field

If you would like to know more about any of the butterfly species mentioned, visit 
​butterfly-conservation.org

This week's survey by Graham Harris, Brian Gardner, Liz North and Duncan Jennings submitted to 
​Butterfly Conservation (UKBMS).
​Report by GK, BG & AI. Photos by Brian Gardner.