A team of Canadian scientists, led by University of Guelph researcher Ryan Norris, is working to restore the frosted elfin butterfly to Ontario, more than three decades after the small, brown-hued insect was last seen in the province. The plan is to return the species to the northern shores of Lake Erie in Norfolk County, where it once lived.
The last confirmed sighting of the frosted elfin in Ontario was in 1988. Several surveys, including one in 2019, have found no sign of the non-migratory butterfly since then, according to the Committee on the Status of Endangered Wildlife in Canada. Scientists describe the species as extirpated in the province, meaning it has disappeared from a specific geographic area even though it survives elsewhere.
Norris, who teaches in the University of Guelph's department of integrative biology, said the team plans to import frosted elfin butterflies and their eggs from New York. The insects would be bred at the Cambridge Butterfly Conservatory and then released into the wild next spring in Port Rowan, southeast of London, Ontario. Before breeding begins, the team is making sure there are enough wild sundial lupins, the host plant the frosted elfin depends on.
Norris said the butterfly's disappearance was driven mainly by habitat loss from urban development and the expansion of farmland. He pointed to the scale of that loss in southern Ontario, where some habitat types now remain in very limited areas. Many of the sites the team is considering have been restored, including former tobacco fields that have developed into oak savanna habitat capable of supporting reintroduced species.
The frosted elfin project is part of a larger, cross-country effort involving universities, conservation organizations and government agencies. The work aims to protect three endangered butterfly species, which also include the mottled duskywing and the curiously isolated hairstreak. According to the University of Guelph, coordinating the recovery of all three at once will produce what researchers believe is Canada's first multi-species framework for insect conservation. The federal government has provided $2.4 million in funding for the project, the university said.
The effort already has one reported success. Five years ago, the mottled duskywing, a medium-sized butterfly that is dark grey and brown, was reintroduced at Pinery Provincial Park in Grand Bend, Ontario, and in other protected areas of Norfolk County. Norris said the results have been remarkable. The population has reached several hundred at the Pinery site and close to 100 at a second location, and the butterflies have been seen at sites the team is not monitoring. "They're spilling over into campsites," he said. "So, I think, with mottled duskywing, we're giving it a foothold and a chance for long-term persistence already in Ontario."
The project also aims to strengthen the population of the curiously isolated hairstreak, a rare butterfly that lives in Waterton Lakes National Park in southern Alberta. Norris said the species now exists at a single population, which the team is obligated to protect and understand better. Scientists are exploring whether the butterfly can be reintroduced elsewhere or whether its existing population can be supplemented.
Across all three species, restoring habitat is central to their survival. Experts warn that concentrating a species at one site leaves it vulnerable, since a natural disaster there could wipe it out. Norris said the hope is that by introducing butterflies into areas with suitable surrounding habitat, they will colonize those areas on their own, which he described as the route to long-term stability.
Norris noted that butterflies are important pollinators and a vital food source for other animals, making them a key part of a healthy ecosystem. Helping them return, he said, also restores habitats in Canada. "By us assisting them, we're restoring, rewilding places in Canada," he said. "I think that's quite symbolic."
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