After weeks of cold, wet weather we managed our first butterfly survey of the year today. The data we collect is a contribution to the UK Butterfly Monitoring Scheme managed by Butterfly Conservation. We saw 3 species - Brimstone, Peacock and Speckled Wood. Brimstone were by far the most numerous, they do well on the reserve because we have lots of Alder Buckthorn which is their caterpillar's foodplant. Female Brimstones were busy laying eggs on the Alder Buckthorn. The females are a pale yellow and can be confused with White butterfly species. The sulphur-yellow male is unmistakable. It's thought their yellow colour may have given rise to the term butterfly because they are butter-coloured and fly. A number of Garden Warblers were in full song. Their song can be difficult to distinguish from that of the Blackcap, but it has more liquid notes and someone once told me that a Garden Warbler was like a Blackcap singing under water and that's helped me identify them.
I should also mention that a couple of Hobbies have been seen flying over the heathland. They are small falcons that migrate south for the winter and when they return in the earlier part of the year they hunt dragonflies and damselflies. Later in the year their prey tends to be young Swallows/Swifts and they follow these birds south on migration.
Wealden Reserves Office Manager