"Not my choice of meal, but..." - the observation of a passing walker when shown these massed male butterflies extracting soluble minerals and moisture from animal dung. A sentiment that the photographer shared, as he balanced in a precarious position, trying not to topple forwards towards this rather unpleasant by-product of dog food! Male Chalkhill Blue Butterflies Polyommatus coridon emerge in advance of the females, and this gathering of at least 41 males was the most impressive total that the photographer had seen. A genuinely rare sight these days, and such totals would have been far more likely in the past. An early (9th August) solitary second brood male Adonis Blue P. bellargus was also present - the film shows this butterfly with its wings opened, enabling a comparison to be made with the paler (and somewhat variable) lighter shades of blue on the uppersides of the slightly larger Chalkhill Blues. To put things in perspective, this film was recorded in summer 2023 at a site formerly renowned for its butterflies, but sadly in rapid decline (in common with so many other butterfly haunts), and taken during a spell of unusually hot weather, and following on from a record hot summer the previous year that must have killed off many larvae attempting to feed on desiccated food-plants. In the past, it would have been possible to have recorded up to about 23 species of butterflies during a day at this site in early-mid-July, and many more insects besides. Today, seeing 23 individual butterflies belonging to a much smaller range of species during a visit is more likely, and the biodiversity has been much reduced, both in variety and in population strength. Even on the day that this film was shot, the number of invertebrates seen (other than these Chalkhill Blues) was depressingly small. The habitat hasn't changed noticeably, and no damaging chemicals are being used to spray the crops on farms in the immediate vicinity, but this doesn't prevent substances including neonicotinoids (used for dusting seeds) from being distributed by the wind from further afield. Anthropogenic climate change is clearly having an impact too. Urgent action is required to protect vulnerable habitats if future generations are going to be able to see native butterflies in anything like their former numbers!
20 окт 2023
