Heather Wright/The Independent

It seems counter intuitive to set fire to a protected wildlife habitat.

But that’s just what wildlife groups were doing over the past week. Jill Crosthwaite of the Nature Conservancy of Canada says setting fire to parts of the Karner Blue Sanctuary in Port Franks will bring wild flowers and other fauna to life on the forest floor.

The Karner Blue Sanctuary is a 37-acre oak-savannah forest – one of the most threatened habitats in North America. In 1988, Port Franks residents worked to buy the land which was one of the last known homes for Karner Blue Butterflies. Eventually a coalition of government and conservation groups, including the Nature Conservancy of Canada (NCC), came up with the money. At the time about 350 of the rare butterflies, which were already extinct in the rest of the country, were found there.

Despite the efforts of conservationists, by 1991, the Karner Blue Butterflies could no longer be found on the Port Franks property.

Some speculated collectors captured some of the rare species but the more likely cause of their extinction was a major drought which stifled the growth of wild Lupine necessary for the Karner Blues to flourish.

From 1994 until 2001, conservancy groups prepared plans to revive the oak-savanah habitat. The standard recommendation was a “succession of controlled burns” to revive the forest floor and bring the wild Lupines back in abundance. Some burns were completed, but recently Lambton Wildlife and the NCC mapped out burn areas within the 37 acres hoping to make controlled burns a yearly event. This year, about three acres of land was burned.

Employees of the NCC, Lambton Wildlife volunteers, firefighters from Walpole Island and Barney Burnett of Wildfire Specialists waited for two hours April 24 for the perfect conditions for a prescribed burn. Gust of wind over 20 kilometres-an-hour scuttled the operation. Wednesday, weather conditions were perfect and the burn went ahead.

Before a flame was lit, Burnett, firefighters and the NCC walked each plot of land, checking for wildlife, including snakes. In the two-acre plot to be burned, the workers were surprised to find a turkey vulture sitting on a nest. It flew away as the workers approached it. The nest, which contained 12 eggs, was in an area which was being sprayed so it wouldn’t burn. The firefighters added extra water around the nest to keep any flames at bay.

The walking path around the two-acre plot was sprayed with water. And then NCC staff carrying heavy torches walked behind ATVs spraying the trails again, igniting a circle of fire in the oak-savanah habitat. As the low flame moved across the landscape, the ground turned black.

Crosthwaite says it won’t be black for long.

“We’ll find quite quickly – especially because we’ve had this late winter and everything is ready to go – that ground, once it’s blackened, it heats up very quickly,” she says. “All of the leaf litter has been removed, so there’s sunlight hitting the ground, so all of those plants that are sitting there ready to go are going to pop up very quickly. I imagine – it’s hard to say for this site – but it may even be within a few days that you’re starting to get green reappearing.

“We’re really looking to improve habitat for wild Lupine so this one is going to be absolutely beautiful. It has spikes of purple flowers, and it will respond really, really well to fire. New Jersey Tea is another one, so it’s a little bit more of a shrub, and it will have white flowers later in the year. And there’s something called Golden Cocoon, which has really nice yellow flowers.”

Crosthwaite says some tall grass prairie species, like big blue stem and blue bells, may also spring up.

She’s hopeful this will improve the habitat needed for the Karner Blue butterfly. “There are patches of Lupine (in Port Franks), if you get the right time, you’d be able to find them, but they there’s a lot of leaf litter on top, so they are all wanting more sunlight than they’re getting.

“What we have found in other burns, in more kind of prairie situation, is that that first year after the burn, the Lupine is really, really happy,” Crosthwaite added.

But, she says, it would be very difficult, even with a revived habitat, to reintroduce the rare butterfly. “Right now there are no plans to reintroduce the Karner Blue Butterfly. There are no populations left in Canada so any reintroductions would have to come from across the border, which is an added complication. The US populations are also not doing well, and it is very sensitive to temperature and climate conditions,” she says adding there would be a lot of work needing to be done before the butterflies would be reintroduced.

“There are other rare butterflies that will benefit from the prescribed burn. Mottled Duskywing is a butterfly that was recently reintroduced at Pinery and, if populations get big enough, they may spread to Karner Blue Sanctuary as well.”

This year’s burn took a year-and-a-half to plan including consulting with neighbours and the Municipality of Lambton Shores. Lambton Wildlife and the NCC say the best long-term plan would be to continue the prescribe burns each year with the entire sanctuary completed over a 10-to-15 year period.