- Lifespan
- 2–3 months as adults in the wild
- Size & Weight
- 32–39 mm in length; wingspan 50–58 mm
- Habitat
- Fast-flowing, well-oxygenated rivers and streams with abundant vegetation, typically in lowland areas with chalk or limestone geology.
- UK Distribution
- Found in southern and central England, particularly in chalk streams of Hampshire, Sussex, and the Midlands; absent from Scotland, Wales, and northern England. Present from May to September.
- Diet
- Small flying insects, particularly gnats, midges, and small flies caught in aerial pursuit.
- Prey
- Gnats, midges, small flies, and other small aerial insects
- Predators
- Dragonflies, robber flies, spiders, and insectivorous birds such as reed warblers and flycatchers
- Mating Season
- May to September, with peak activity June to August
- Breeding
- Females lay eggs singly into fast-flowing water; nymphs take 1–2 years to develop through multiple instars before emerging as adults
- Behaviour
- Males are highly territorial and perch conspicuously on bankside vegetation, displaying metallic blue wings to rivals and females. They are strong, agile fliers and perform elaborate courtship displays involving wing-fluttering. Females are more cryptic and greenish in colour.