More than a dozen spotted dusk butterflies were seen in Pinery Provincial Park at Lake Huron this spring.

It is the first time the butterflies have been seen in southwestern Ontario in three decades, after being declared endangered in 2012.

Ryan Norris, from the Department of Biology at the University of Guelph, said, "About 80 percent of larvae fail in their first year." "So our success on the first try is really amazing."

The team said they have not saved the species yet, but described it as a promising first step. "Let’s see our work bear fruit and succeed in this way."

The Cambridge Butterfly Conservatory played a big role in the initial success of this program.

Over the past few years, the conservatory has been helping female butterflies survive before releasing them into the wild.

Adrian Brewster, Executive Director of the Cambridge Butterfly Conservatory, said, "What we do is really protect them from threats in the wild and increase their survival rate." The conservatory is now preparing to welcome another batch of females.

Brewster said, "Last year, we had about 25 females." "We hope this year to bring in up to 40 to support our program, and each one can lay between 200 and 300 eggs."

The next steps will be to continue counting and monitoring the butterflies in Pinery Park, allowing the team to learn more about what can be done to keep the species alive longer before releasing the next batch.