As It Happens

Banff scientists hope to unlock the secrets of elusive black swifts by studying their poop

Biologists at Banff National Park are studying the endangered black swift birds that nest near Johnston Canyon, hoping to find clues to their population decline -- in their droppings.

'What we'd like to know is what exactly are those birds eating,' biologist says of the endangered birds

An adult black swift bird rests on its nest in Johnston Canyon in Banff National Park. (Banff Media)

Story Transcript

Not much is known about the endangered and elusive black swifts, except that they have an uncanny ability to survive where few other animals can, in small crevices within caverns and cliffs. 

Researchers at Banff National Park are hoping to change that, by studying a critical nesting area along Johnston Canyon. And while it is quite rare and difficult to catch even a glimpse of the speedy swifts, the researchers are looking for clues inside the birds' remains — i.e. their poop.

"What we'd like to know is what exactly are those birds eating," wildlife biologist Barb Johnston told As It Happens guest host Dave Seglins. 

"If we can compare that to what they were eating about 40 years ago ... we can see if perhaps the diet has changed over time, and [if] that's one of the reasons for the decline."

'A real rare treat'

For most people, the black swift looks like a medium-sized dark bird. But to birders, it's most distinguished by its all-black colour.

"It's pretty hard to see it. Pretty cryptic when it's sitting on the ground or on a rock face, which is where it would normally roost," Johnston said. "But it's most commonly seen flying up high, so it would be a silhouette of a long-winged blackbird."

Barb Johnston is a wildlife biologist at Banff National Park. (Banff Media)

It's Johnston's job to try and catch a glimpse of the swifts, which have at least two nests within Banff National Park. It's been no easy feat.

Black swifts spend their winters in the Amazon and then return north in the spring when they make their nests. Those nests are often located in places that are hard for predators — and people — to reach.

When the biologist lays eyes on them, she says it's "a real rare treat."

"It's pretty exciting," she said. "They are a really unusual bird and they're extremely fast."

Five active black swift nests were discovered in Johnston Canyon in 2021. (David Gray/CBC)

Johnston and her team observed five breeding pairs of black swifts in Johnston Canyon in 2021, which is more than previous years. There is also another area within the national park where they saw two or three more nesting pairs.

Over the last 40 years, she said, there has been a dramatic decline in the black swift's population by about 50 per cent.

Canada designated black swifts an endangered species in 2019 under the Species at Risk Act.

Maintaining biodiversity

Black swifts are known to eat flying insects such as wasps, flies, beetles and spiders. Sometimes, they even chow down swarms of ants or termites. 

The biologist and her team plan to collect the birds' poop from the nests and analyze it to determine the exact species of insects they feed on — and whether they've been tainted with aerial pollutants.

"If you think of all the chemicals that have gone into the environment over the last several decades, it appears that that is causing an overall decline in insect populations," Johnston said. 

Researchers at Banff National Park are using thermal imaging cameras to locate and monitor black swift bird nests. Remote camera images, like this one, capture the birds' activity patterns and temperature, which help in understanding their micro-climate needs. (Banff Media)

They will compare their findings with the results of a very similar study by Canadian Wildlife Service research scientists on the diet of black swifts about 40 years ago. They have partnered with retired research scientist Jeff Horrow, who still has the vials of droppings he once collected.

The biologists have a lot of hope in this new study, as there seem to be few options left to help protect the endangered species. Unlike many other birds, black swifts only lay one egg a year, which gives them little chance to recover from a population decline.

To Johnston, it would be "a tragedy" to lose the black swifts.

"It's a really unique species and has lots of characteristics that make it really different from other birds," she said. "Maintaining biodiversity, in general, is really important for us at Parks Canada and for many people across the country."

Written by Mehek Mazhar. Interview with Barb Johnston produced by Kate Swoger.