Second nesting site for endangered black swift discovered in Banff

Birders in Banff National Park have discovered a second nesting site belonging to an endangered bird species.

Black swifts are small birds characterized by long, pointed wings, dark plumage and very particular preferences as to where they raise their chicks.

They like to nest on wet, cold rock faces, and Johnston Canyon was thought to be the only place in the park they inhabited.

But according to Jennifer Reimer, a resource management officer for Banff National Park who has led the black swift monitoring program since 2015, a second nesting site was discovered last summer. It happened during a habitat assessment in a remote area of the park near Egypt Lake.

And it's especially good news because in Canada, the population of black swifts has been on the decline for decades.

"Lo and behold, we happened to observe an adult black swift clinging to a rock face right beside a waterfall. So that was a good clue that there were likely active black swifts in the area," Reimer told the Calgary Eyeopener on Friday.

"We came back the following week … so we could confirm its activity, and we counted a total of five birds leaving the canyon."

Population on the decline

Prior to the discovery of the second nesting site near Egypt Lake, black swifts were thought to only have one Banff nesting site, which was discovered in Johnston Canyon in 1919, Reimer said.

Almost 100 years later, in 2018, an official order was implemented in the canyon to keep hikers from wandering off the trails, which was partly to protect the black swift.

Last July, Daniella Rubeling, the visitor experience manager for the Banff field unit, told CBC News that the population of black swifts in Johnston Canyon had increased from one nesting pair to three. 

It was a particularly exciting for Banff birders because in Canada the black swift population diminished by more than 50 per cent between 1973 and 2012.

"That's more nesting activity than we've actually had in the last 16 years," Rubeling said at the time.

On Friday, Reimer said the black swift's struggle to flourish has been linked to prey availability — or lack thereof.

Black swifts are aerial insectivores — they eat flying insects — which have also been in decline because of factors such as pesticides.

"They rely on those large insect plumes. And as a lot of people are familiar with, those aerial insectivores have been hit pretty hard over the last several decades," Reimer said.

New nesting site does not mean recovery

Reimer said that while it's incredible that they have found a second nesting site, it does not necessarily signal their population is recovering.

"That is difficult, to make any sort of conclusion about only one additional nesting site," Reimer said.

"I suspect that has been there for a while, so I wouldn't make that conclusion that, you know, that there is an increase in the population, based on what we're seeing."

Still, Reimer said, the discovery is good news, and significant.

Park officials now have two black swift colonies they can monitor — and with one relatively accessible in Johnston Canyon, and the newly discovered site near Egypt Lake more remote, researchers will be able to observe differences in how they fare.

And though the park had fewer visitors in 2020, Reimer said staff are hopeful the visitors they did have were more aware and respectful of the wildlife.

"We had a decrease in people violating that off-trail restriction, so those numbers decreased," Reimer said.

"It's difficult to make a direct comparison, you know, because we had so many fewer visitors at Johnston Canyon. But from that increased monitoring and the signage, it does appear that people are complying more … and we hope to build on that next season for sure."

With files from the Calgary Eyeopener.