Invertebrates
Twelve-Spotted Skimmer
Libellula pulchella · also called twelve-spotted skimmers
Perched prominently at the edge of a pond, a mature male twelve-spotted skimmer flashes a wing pattern of alternating dark and white spots, darting out abruptly to chase away a rival before returning to the exact same favoured perch a moment later.
Overview
The twelve-spotted skimmer, Libellula pulchella, is a large, boldly patterned dragonfly native to ponds, lakes, and slow streams across most of the United States and southern Canada. Its precisely countable twelve-spot wing pattern, robust size, and strongly territorial pond-edge behaviour make it one of the more conspicuous and easily identified dragonflies in North America.
A pattern you can count
Unlike many dragonflies that require careful comparison of subtle markings to identify, the twelve-spotted skimmer offers a genuinely countable feature, exactly three dark spots on each of its four wings, that turns identification into a simple, reliable exercise.
Status
Least Concern — widespread and abundant across suitable freshwater wetland habitat throughout most of the United States and southern Canada.
Twelve-Spotted Skimmer: common questions
How can you identify a twelve-spotted skimmer?
Count the dark spots across its four wings; this species always shows exactly three dark spots per wing, twelve in total, a precise and reliably countable pattern that makes it one of the easier dragonflies in North America to identify confidently from a distance.
How do you tell an adult male twelve-spotted skimmer from a female?
Mature males develop additional white spots between the dark spots on each wing as they age, a feature entirely absent in females and younger males, so a dragonfly showing both white and dark wing spots is reliably an older adult male.
How long does a twelve-spotted skimmer spend as a larva?
This species spends its larval stage underwater as a predatory aquatic nymph for a period that can last close to a year, hunting other small aquatic organisms before eventually emerging from the water and transforming into its adult flying form.
Why do twelve-spotted skimmers chase each other at ponds?
Adult males often perch prominently at the edges of ponds and defend a territory against rival males, darting out aggressively to chase away any intruder before returning to the same favoured perch, a behaviour aimed at securing the best spot for encountering females.