Endangered butterfly found in only one spot in Alberta focus of new protection project

A partnership between Parks Canada and the Calgary Zoo seeks to better understand and revitalize the population of the half-moon hair streak butterfly.

In Alberta, the half-moon hairstreak butterfly is only found in the Waterton Lakes area

The half-moon hairstreak butterfly is no bigger than a quarter when its wings are spread. This photo was taken in Waterton Lakes National Park in 2019. (Submitted by Jill Hockaday/Calgary Zoo)

A new partnership between Parks Canada and the Calgary Zoo aims to protect and revitalize the population of a small, brown butterfly in Alberta's Waterton Lakes National Park.

The half-moon hairstreak, also known as the Satyrium semiluna, has been endangered in Alberta since 2016, according to the Species at Risk Act.

"There's an imminent need to make sure that we don't lose them," said Axel Moehrenschlager, director of conservation and science at the Calgary Zoo on The Homestretch.

In Alberta, the butterfly is known to live only in a grassland area along the roadway entrance to the Waterton Lakes National Park in the Blakiston Fan.

The entrance road to the park in a grassland area called the Blakiston Fan is the only spot the butterfly is known to inhabit in Alberta. (Submitted by Parks Canada)

"If it spreads its wings, it's no bigger than a quarter," Moehrenschlager said.

"These grasslands have beautiful flowers in the summer, such as silky lupine, silvery lupine, yellow buckwheat, Missouri goldenrod. And these plants are really essential for this tiny little butterfly."

The butterflies use these grassland for food, breeding and habitat, according to a release by Parks Canada.

The reason for their low population in the province is largely due to a loss of native plants in the area, said Moehrenschlager.

Much of the reason for this loss is due to invasive plants, the release said.

Another reason for their low numbers is the intense fluctuations in their ecosystem, said Moehrenschlager, such as the past fires in Waterton.

The insect relies on the grasslands and grassland flowers for food, breeding and to live. (Submitted by John Stoesser/Parks Canada)

It is hard to know how many of the butterflies there are across its habitats in Canada, Moehrenschlager said.

"One of the tricky things is that they really boom and bust between different years. And when they bust, they really do. And they've really come down in their numbers," he said.

The butterflies have habitats across Canada, nine in British Columbia and one in Waterton. 

In a three-year program, Parks Canada and the Calgary Zoo plan to revitalize the population of the butterfly through measures like long-term population monitoring and the collection of genetic material.

The organizations hope to better understand what the butterflies need in order to flourish — be it moving the butterflies to a similar, wild location nearby or bringing in more of the butterflies from other places.

The project also intends to restore some of the butterfly's natural habitat and remove invasive plants from its main habitat, the release said.

Parks Canada will pitch in $289,000 to the Calgary Zoo for the effort.

Moehrenschlager said of the several projects they are working with Parks Canada on for endangered species, this is the smallest.

"We want to treasure those spaces and those precious parks and the nature within them," said Moehrenschlager.


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