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Endangered black swift numbers increasing in Banff's Johnston Canyon

“They are just such cool and intriguing birds,” said Banff National Park resource conservation officer Jennifer Reimer of endangered black swifts.

BANFF – Efforts to recover and save an endangered bird species in the tourist hotspot of Johnston Canyon may be paying off.

Five active black swift nests were confirmed in the busy Banff National Park canyon this year, up from three in 2020 and only one or two active nests each year between 2005 and 2019.

While the increase in nesting pairs to the highest level in 17 years is a positive sign, Parks Canada officials say it is still below historical numbers of about 12 active nests counted annually in the 1970s and early 1980s.

Jennifer Reimer, a Parks Canada resource conservation officer who heads up the black swift monitoring program in Banff, said five active nests is significant, particularly because black swifts only lay one egg a year.

“They were all active so this was very exciting,” she said.

“The eggs all hatched and by mid-September everybody had fledged and hopefully flew to South America.”

The black swift nesting colony in Johnston Canyon, about 38 kilometres west of the Banff townsite, was initially discovered in 1919 and was the first confirmed inland nesting site in North America.

The walls of the canyon are the perfect place for black swifts to build a home, given the species makes mossy nests in crevices on cliff faces, and often by waterfalls, in British Columbia and western Alberta.

Little is known about the biology of the black swift – a bird recognized by its black plumage, long and pointed wings and unique notched tail – but it’s believed the species mates for life and lives upwards of 16 years of age.

Black swifts also only lay one egg a season and have a lengthy seven-week rearing period, with chicks not fledging until near the end of September.

“They have a unique and fascinating life history,” said Reimer. “They are more like a sea bird that way.”

Black swifts also fly extremely high, having been recorded flying in Colorado as high as 4,300 metres.

Reimer said these birds spend 24 hours a day in the air when they are in the wintering grounds in South America.

“That’s only been discovered in the last few years – so that’s really exciting,” she said.

“They are exerting an enormous amount of energy, albeit they are very efficient fliers, but they’re spending most of their life in the air and they just come up here for those brief few months in their life history to rear one chick.”

The nesting duties are shared by the parents, with both the male and female trading off shifts during the incubation period.

“It’s a very cooperative nesting process and one of the other things that is unique about the black swift is they’re off the nest the majority of the time,” Reimer said.

“Once the egg is hatched, that chick gets left alone for long periods of time while both adults are out foraging for insects.”

Because they live in inaccessible places high on canyon walls or cliff faces, natural predators are few and far between.

“Because that’s one of their unique adaptations, they are pretty inaccessible to any terrestrial predator,” said Reimer, noting she is unaware of any records of small mammals accessing nests.

“There are occasional reports of a raven or another raptor that could potentially prey on the nest, but again, that’s rare.”

It wasn’t until 2012 that it was first discovered that black swifts fly to South America to winter.

Several birds from Colorado were tagged with tracking devices, which indicated their wintering grounds were in the Amazon rainforest of Brazil.

There was also a reported sighting of a black swift in Tambopata, Peru, in 2012.

However, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) indicates there is no information on whether black swifts that breed in Canada winter in the same region. Canada is home to about 80 per cent of the North American population.

“Indeed, the wintering area of birds from different breeding areas in North America remains to be determined,” according to COSEWIC’s status report on black swifts.

COSEWIC designated the black swift as endangered in 2015 and the species became federally protected under the Species At Risk Act in 2019 as populations plummeted by more than 50 per cent over the past 40 years.

The causes of the decline are not fully understood, but believed to be in part related to changes in food supply – like many other birds that specialize on a diet of flying insects – that may be occurring at one or more points in the black swift’s life cycle.

In addition, scientists say the black swift may be sensitive to climate change.

“This is because its waterfall nesting sites are likely to be impacted by decreased snowpack and glacial melt,” according to the black swift status report from COSEWIC.

To protect the known colony in Banff’s Johnston Canyon, Parks Canada implemented a seasonal May 1-Nov. 15 restriction in 2018 to prevent people from going off-trail and getting too close to the nesting birds.

During the COVID-19 pandemic, visitation numbers to the popular canyon were down compared to pre-pandemic numbers of close to one million in 2019 – anywhere between 3,000 and 8,000 people a day.

Reimer said it’s likely black swifts will return every year to the same nesting sites in the canyon, but only if they have the space and security to nest without disruption.

“I definitely think it’s helping reduce the level of disturbance on nesting birds,” she said of the seasonal restricted activity order.

“Because their nesting period is going for such a long period of time, there’s more opportunity for them to be disturbed or for people to influence the success of that nest,” she added.

“We’re trying to balance that visitation to Johnston Canyon as well as maintaining that buffer and creating space for the birds to nest.”

As part of its strategy to protect the endangered bird, Parks Canada also beefed up enforcement of the off-trail closure at Johnston Canyon. It is illegal to disturb black swifts and their occupied or unoccupied nests.

National park wardens laid 77 charges in 2019 and 22 charges in 2020. So far this year, 14 charges have been laid; however, Parks Canada notes the number is not a true reflection of overall compliance.

“We’re still seeing visitors going into the closed areas in Johnston Canyon, but it’s difficult to compare numbers this year from last year because of the changing environment with COVID restrictions and accessibility to Johnston Canyon,” said Reimer.

“Regardless, it only takes a few people going in there to create a disturbance, so we’re just trying to build that stewardship with the public to help us support the recovery of black swifts as much as we can.”

Conservation groups are pleased to hear of the increased nesting pairs in Johnston Canyon, praising Parks Canada for the effort put into educating visitors and enforcing the area's nesting closure.

Reg Bunyan, vice-president of Bow Valley Naturalists, said wildlife disturbances are often associated with motorized or industrial activity, but this is an excellent example of the subtleties of disturbance factors, where something as simple as human presence can potentially influence the reproductive success of a sensitive species.  

“Of course nesting success is only part of the battle,” he said. “Without improvements to southern wintering habitat and decreases in the use of pesticides, black swift populations will likely continue to struggle.  

Work on a recovery strategy, including identification of critical habitat continues, but Parks Canada began to boost monitoring efforts in Johnston Canyon in 2015 following the COSEWIC designation.

Monitoring tools include drones in winter once the birds have flown south, remote cameras and infrared cameras that use a no-glow for nighttime images.

The cameras have divulged previously unknown information in Johnston Canyon, including when the birds arrive in spring and when they leave for South America in the fall.

“This year we were able to get an exact date down to the hour of when the birds arrived and we’ve never had that information before,” Reimer said.

“That also plays into our overall knowledge and our active management strategy to support recovery of black swifts.”

The only other known black swift nesting site in Banff National Park was discovered last year in the backcountry in the Egypt Lake region.

Confirming nest sites can be challenging, particularly as adult birds often visit nest sites only late in the evening.

There are thought to be fewer nesting pairs this year in that location, with a maximum count of five last year and two this year, but Reimer stresses that is inconclusive.

“As a caveat, because they are so difficult to detect, it’s hard to confirm there was one nesting pair this year or two nesting pairs,” she said, noting there are too many variables.

“We’re still working on our best methodology to accurately detect the birds as they are leaving and coming into the nests.”

Reimer said she hopes people take time to learn about black swifts and the importance of protecting the endangered species.

“They are just such cool and intriguing birds,” she said.

To let Parks Canada know about any black swift nesting activity, or to report anyone disturbing a black swift or its nest, call Banff emergency dispatch at 403-762-1470 any time day or night.

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