Head to head
Common Green Darner vs Blue Dasher
A common green darner and a blue dasher both patrol the same North American ponds and lakes, yet one spends its life on the move across generations while the other tends to stay close to a single favoured perch for its entire adult life.
| Common Green Darner | Blue Dasher | |
|---|---|---|
| Scientific name | Anax junius | Pachydiplax longipennis |
| Size | Among the largest North American dragonflies | Smaller, more compact |
| Migration | Multi-generational, thousands of km | Non-migratory |
| Signature behaviour | Fast, agile flight | Forward-angled perching posture |
| Mature male colour | Green thorax, blue abdomen | Powdery pale blue body |
| Eyesight | Nearly 360-degree compound eyes | Standard compound eyes |
| Habitat | Ponds, lakes, wetlands | Ponds, lakes, wetlands |
| Conservation status | Least Concern | Least Concern |
Common Green Darner vs Blue Dasher: common questions
Which of these two dragonflies migrates?
The common green darner is the migratory one, undertaking a genuine multi-generational journey in which descendants of autumn migrants complete the return trip north the following spring, while the blue dasher stays in the same general area year-round without a comparable migration.
Why does the blue dasher perch at such a distinctive angle?
A blue dasher perches with its wings angled forward and down at a distinctive tilt, a posture thought to help the dragonfly regulate its own body temperature by controlling how much direct sunlight reaches its body, a behaviour the common green darner does not rely on to the same degree given its more active, less perch-bound lifestyle.
Which of these two dragonflies is bigger?
The common green darner is considerably bigger, ranking among the largest and fastest-flying dragonfly species in North America, while the blue dasher is a smaller, more compact species, though still one of the most commonly encountered dragonflies around ponds and lakes.