They prefer slow-flowing streams and rivers and occasionally canals and ponds. Populations are localised, and found only in southern England and a few sites in Wales. Over a stretch of about 1km, we found at least 20 of them, along with what was likely double that number of Blue-tailed Damselflies (Ischnura elegans). I’d hoped to see maybe a handful so 20+ was fantastic.
Broadly speaking, the males are a pale blue. The females a pale creamy white when immature, becoming a pale green later. For more detailed info see here.
I watched this male fly up from his perch, snatch a fly from the air and then settle back to eat it - not something I'd ever seen a damselfly do before.
As a bonus, I found my first Dingy Footman (Eilema griseola), dressed for the part in its elegant greys and beiges.