Sexes alike. Glistening steel-blue above; chestnut cap; unmarked, pure white underbody distinctive; two long, wire-like projections (tail-wires) from outer tail feathers diagnostic. Solitary or small parties; almost always seen around water, either perched on overhead wires or hawking insects in graceful, acrobatic flight, swooping and banking; often flies very low, drinking from the surface; roosts in reed beds and other vegetation, often with warblers and wagtails.