Painted lady butterflies could be on their way
A colourful migratory butterfly that typically only travels up to Alberta every 10 to 15 years is back in the province for a second consecutive summer.
Painted lady butterflies are exceedingly rare in Canada, but occasionally, the species migrates in large numbers from deserts in northern Mexico and the southern United States all the way north into central Alberta and beyond. Rainy weather in southern environments drives the butterflies north.
The butterflies start their migration in spring. Now, Alberta-born painted ladies are emerging, multiple generations removed from the bugs that started the over-2,500-kilometre journey north.
According to University of Alberta biological sciences professor Felix Sperling, last year’s migration was expected to feature a high number of butterflies, but it “fizzled out” for unknown reasons.
This year, he says there’s already been more butterflies in the province than during last year’s migration.
While you may notice swarms of the insects during the summer, particularly around flowers and riverbank edges, the fast-flying creatures shouldn’t have a major environmental impact.
“Whatever impact they have on the ecosystem is quite small. Like all butterflies they contribute a little bit to pollination,” Sperling said. “The caterpillars eat thistles, which are actually considered a weed in the fields that farmers don’t much like.”
For Sperling, the painted lady migration is fascinating because of how it demonstrates a literal butterfly effect, where environmental changes on one part of the earth can affect ecosystems thousands of miles away.
“It shows us how interconnected everything is. Rains in Arizona and California are resulting, a couple of months later, in butterflies here that we don’t normally see,” he said.
Before last year, the last big painted lady migration took place in 2005.
This year, the butterflies should appear almost everywhere in the province south of Edmonton. Sperling says he’s personally spotted the species in Medicine Hat, Pigeon Lake and near Stettler.
Tom Taylor, who lives on a rural property in Leduc County, says he’s spotted quite a few painted ladies so far this season.
“I was out last night and I saw at least six fluttering around by one of my sheds,” said Taylor on Monday, adding that the butterflies were roosting — a migratory behaviour where butterflies take shelter together as a break in their journey.
“I don’t know if it’ll be quite as big of an invasion as 2005, but they’re certainly here this year.”
Sperling says he expects increasing painted lady numbers over the next four weeks.