Wetlands – Dragonfly Detectives

Common Green Darner
© Parks Canada

The wetlands of Prince Edward Island National Park are home to an amazing variety of plants, invertebrates, fish and birds.  Some of the most enchanting inhabitants are dragonflies and damselflies.  Sedge Sprites, Delicate Emeralds, Wandering Gliders and Ruby Meadowhawks are among the 42 species found in the park’s wetlands. 

With their bright, jewel-toned bodies and intricate wings, the adult forms of dragonflies and damselflies are instantly familiar.  Fascinatingly, these insects only become airborne at adulthood.  At younger life stages, they are aquatic and live entirely underwater. 

When dragonflies and damselflies make the transition from water to air, they leave behind their old larval cases.  These exoskeletons, or exuvia, are being collected from the vegetation growing around wetlands and shallow ponds as part of the park’s ecological monitoring program.  With careful study, exuvia can actually be used to identify the species of dragonfly or damselfly that left them behind. 

“By collecting and identifying the larval cases, we can gather important information about the abundance and diversity of dragonflies and damselflies within the park's wetlands,” says Paul Giroux, park monitoring ecologist. “This information is then used along with other measures to assess the ecological integrity of our wetlands.”

Dragonflies and damselflies are avid predators and capture other insects for food.  As such, they occupy a top position of the wetland food web and serve as good indicators of the overall health of wetland ecosystems.  By acting as detectives, tracking down the traces of these insects, park staff are working to monitor the state of these important habitats and ensure their protection into the future.