Fireflies facing loss of local habitat as marshes dry up
German study has documented decline, but scientists have not identified a cause
When summer finally arrives in Edmonton, the firefly punctuates the warm nights like sequins on a veil.
A type of beetle, fireflies use a chemical reaction in their abdomen to create a flickering light. From late June to early July, areas with high humidity and moisture are lit up by its glow.
Ahead of Earth Day on Sunday, Postmedia spoke with Gerald Hilchie, undergraduate laboratory co-ordinator at the University of Alberta, and John Acorn, a naturalist with the U of A, about the challenges facing the little light bugs.
Fireflies, at least here in Edmonton, face a loss of habitat. While there is no data to indicate that fireflies in Edmonton are in peril, a German study has documented a decline in the flying insects over the years, without identifying a single cause, Hilchie said.
“The marshes are drying up quite fast — resulting in a loss of habitat — and putting a strain on these little guys,” he said.
Acorn believes that despite the replacement of traditional wetland habitats with urban stormwater ponds within the city, there is still a fairly healthy Alberta firefly population, especially where more traditional marshlands have been retained, such as in Lois Hole Centennial Provincial Park north of the city or in the Clifford E. Lee Nature Sanctuary near Devon.
“Fireflies in this part of the world, in Alberta, are found either in marshy situations, shallow wetlands with a lot of tall grasses and sedges, or in mature poplar forests, usually north of Edmonton,” said Acorn.
“They light up to attract mates,” he said.
“So the males will blink and the females will blink in response and that’s how they find each other at night.”
Not many people in Edmonton see fireflies.
“There is a slight problem with observing them lighting up in the wild because they do so in late June and early July,” Hilchie said. “It stays light to almost midnight (then).”
Alberta has at least seven species of fireflies, although a couple of them, such as Ellychnia corrusa, do not glow. Fireflies light up the map all the way to northeast of Fort Chipewyan, south through Fort McMurray, Edmonton, Calgary, Medicine Hat and Cypress Hills. They are even seen in the Northwest Territories in suitable habitats, Hilchie said.
To observe their lights in Edmonton, one would need to stay up until 1 a.m. or 2 a.m. in the right type of habitat, he said.
“This is usually a mosquitoinfested marsh area or similar wetland,” Hilchie said. “In my personal experience, most people avoid such areas in the middle of the night.”
Acorn suggests waiting until June and then travelling outside of the city.
“They’re mostly little predators feeding on other small creatures. They’re also very bad tasting,” he said, adding fireflies are one insect he has not personally tried eating.
“They have a distinctive look that protects them from being eaten by birds and so on, because they produce ridiculously obnoxious chemicals that make them bad tasting.”