There was good news and bad when recorder Andrew Wood reported on the changing status of Hertfordshire's butterflies at the Society's Autumn Meeting on Saturday 16 November.
Reviewing records for the decade since survey work took place for his book Butterflies of Hertfordshire and Middlesex (2017) he noted several species that had been seen in the county after years of absence or had recovered from a decline in numbers. These included the Brown Hairstreak whose eggs were found in south Herts last winter for the first time this century.
Britain's smallest butterfly, the Small Blue, was extending its distribution across chalky areas, aided by sowings of wildflower mixtures containing Kidney Vetch, while the Small Heath had recovered in numbers and was extending its range. The nationally rare Duke of Burgundy butterfly was seen at Aldbury Nowers four times in 2021 More controversially, a small colony of Adonis Blue established itself on Therfield Heath, attributed to a likely 'unauthorised release' of this attractive species at a site where it formerly bred.
Conference photos ©Tim Hill
On the negative side, Small Tortoiseshell – formerly an abundant butterfly – had become increasingly hard to find. The reasons were unclear although earlier hibernation resulting in reduced fat reserves for survival was one suggestion being advanced. Other species in decline were Common Blue, Grizzled Skipper and White Admiral, which had seemingly disappeared from some woods in central Herts. Numbers of another emblematic Herfordshire species, the Chalkhill Blue, fell following what now appeared to be a peak around the time of the survey.
Visit the HNHS YouTube page to watch the whole of Andrew Wood's presentation.
The Autumn Meeting also received a report on progress creating a Local Nature Recovery Strategy (LNRS) for Hertfordshire, intended to identify priority species and habitats as well as action needed to protect them and enable them to thrive. Marc Wilcox of Hertfordshire County Council, who manages the project, explained that the strategy – due to be drafted by March 2025 – was a statutory requirement for English counties under the Environment Act 2021.
Local authorities were working in partnership with landowners, the Herts and Middlesex Wildlife Trust and other relevant groups to map the most important wildlife locations in Hertfordshire. These included existing Sites of Special Scientific Interest and Local Nature Reserves, but also 'opportunity' areas with potential to become significant for their biodiversity.
Priority species were, meanwhile, being identified with the help of county recorders. Those recommended were being divided between 'flagship' species representative of their wider habitat and 'bespoke' species that would require intervention to help them to thrive.
Marc suggested the strategy would provide a tool for local government, the private and voluntary sectors and individuals to decide how best to take action. As a next stage, it was hoped central government would make funding available to 'seed' investment in nature recovery projects.
Marc Warren's presentation can be viewed on the HNHS YouTube site.
The Society is, once again, grateful to Affinity Water for hosting the Autumn Meeting and AGM at their offices in Hatfield.
At the start of the conference, Alister Leggatt, the company's Integrated Catchment Manager reported on the water situation in Hertfordshire after an unusually wet year. his presentation can also be viewed on the HNHS YouTube site.
