Endangered Mottled Duskywing butterfly making comeback thanks to dedicated scientist team
Carmen Groleau | CBC News | Posted: August 14, 2021 12:00 PM | Last Updated: August 16, 2021
Thanks to recovery efforts, more than 700 butterflies were released this year at Pinery Provincial Park
A recovery team made up of researchers and organizations from across southern Ontario are working to save a type of butterfly they say was "dangerously close" to being extirpated from the province.
And for the first time in decades, over 700 of the endangered Mottled Duskywing butterflies were released at Pinery Provincial Park this summer.
"Both personally and professionally, it's really rewarding since I've been interested in working with the Mottled Duskywing since 2007," said Jessica Linton, senior biologist with Natural Resource Solutions Inc. in Waterloo.
Linton is chair of the Ontario Butterfly Species at Risk Recovery Team (OBSRRT), which was formed in 2017 and has dedicated the last four years to the recovery of the Duskywing butterfly.
Linton is also the author of a recovery strategy on the Mottled Duskywing butterfly for the province.
She said the team's focus to recover the Duskywing butterfly centres on it being one of the last species of butterfly that lives and thrives on what is a now rare habitat in North America called Oak Savanna.
"There use to be several rare butterflies associated with this Oak Savanna habitat ... there was four of them, the Duskywing being one of them, and the other three no longer occur here in Ontario," she said.
"We don't want to lose that last species."
Saving the Duskywing butterfly population, said Linton, also goes hand-in-hand with the recovery and preservation of the Oak Savanna habitat.
Why is the Duskywing endangered?
There are a few reasons behind the endangerment of the Duskywing butterfly, according to Linton, but it largely has to do with the loss of habitat.
The species has been extirpated, meaning it no longer exists, in Quebec, but few existing populations can be found in southern Ontario in areas like the Rice Lake Plains, Halton region and around Lake Simcoe, she said. The species can also be found in southern Manitoba.
"The initial loss of this species and fragmentation of its habitat would have possibly been due to larger scale habitat loss that occurred after European settlement and land was cleared for agriculture," Linton said.
That left pockets of habitat in southern Ontario that faced pressures through urban expansion, industrialized development, intensified agriculture and invasive species.
The Oak Savanna also relies on natural burning to maintain an open canopy, Linton added, which would have traditionally been done by Indigenous communities on the land.
"That doesn't really happen anymore," she said.
That's why the team landed on Pinery Provincial Park as the new home for the Duskywing butterfly. Linton said the park has gone to great lengths to recover and preserve the Oak Savanna.
Optimism on species' reintroduction
Members of the recovery team are monitoring the butterflies everyday. The butterflies were released in three different life stages, which will give researchers a better idea of when they should be released going forward, said Ryan Norris professor of integrated biology at the University of Guelph.
It's rigorous work, but Norris said based on what they've seen so far, he's hopeful that they will see the Duskywing butterfly next year.
"We've hit a couple of major milestones already with the release," he said.
He said the released adult butterflies have remained in their new habitat and saw the females of those released butterflies lay eggs in the area. Norris said they also noticed the butterflies that were released in their crystal form emerge from their pupa.
"All of these are really great signs," he said.
"You never know what's going to happen with these things. We're introducing a species to an area that they haven't been in 30 years, so anything could happen."
Adrienne Brewster, executive director and curator at the Cambridge Butterfly Conservatory, also shares that optimism.
The conservatory has been part of the recovery effort of the Duskywing butterfly for several years and were responsible for raising the butterflies in captivity, a process called captive rearing.
"Next year's monitoring, and monitoring in subsequent years, will really help us understand if this reintroduction took hold and I'm pretty optimistic about it because we had such great numbers for reintroduction," Brewster said.
The release at Pinery Provincial Park is the first of several releases the team will be conducting over the years.
Linton said the recovery team is now looking at other sites in southern Ontario that could be new homes for the Duskywing butterfly. They are looking at Norfolk County next.
"There are several properties that the Nature Conservancy of Canada has been doing an excellent job of restoring and they are in close proximity to locations where the butterfly use to occur as well," she said.
Listen to the full interview below with guest host Jackie Sharkey: