The black-tailed skimmer is a medium-sized dragonfly with a tapering abdomen. Adult males have a blue abdomen darkening to the rear. Adult females are yellow with dark ladder pattern on the abdomen.
The black-tailed skimmer prefers lakes, ponds, slow rivers and marshes, with exposed mud, stones or bare patches where the male can perch.
The main flight period is June and July. Males characteristically perch horizontally on exposed surfaces. They fly swift and low, skimming the water surface, while defending their territories. Mating can occur in flight or on land.