Out of the Shadows: Black Swifts, North America's Most Mysterious Birds

Out of the Shadows: Black Swifts, North America's Most Mysterious Birds

Whether exploring dark, wet caves in Colorado or crossing paths with Montana's grizzlies, a dedicated band of scientists and volunteers is determined to solve the mystery of one of the most elusive birds on earth. 

By Alisa Opar/Photography by Michael Lundgren
Published: September-October 2012

Then there's the enigma of their behavior in their wintering grounds. While the three birds from two sites in Colorado outfitted with geolocators all traveled to the same general area in Brazil, no one knows if it's the primary overwintering site for the global population, or just one of many. Other questions include what they eat down south and where they roost--or if they roost. "Common swifts from Europe fly all winter without roosting at all," says Beason, explaining that the birds rest in flight. "It's possible that black swifts could be doing that, or roosting every few days." 


The Colorado team is turning to technology to solve some of these riddles. They're putting geolocators--simple gadgets with a light sensor, a digital clock, and a tiny memory chip--on birds from other colonies to chart their migratory routes. The swifts carry them in a special harness Gunn designed and made. Geolocators provide enough information to determine the bird's location, but researchers must recapture the birds to retrieve the data. So far they've recovered four of eight geolocators they've deployed. 

"Geolocators don't pinpoint the exact spot the birds went to, but they do give the general area," says Beason, lead author of the study published in the Wilson Journal of Ornithology in March. "I was most surprised because I thought they'd go to a mountainous area, and it looks like it's lowland rainforests, though there are some waterfalls and cliffs." 

This past summer researchers planned to attach geolocators to swifts in New Mexico; next summer they'll outfit birds in Idaho and California. "We want to determine if other populations of black swifts are all wintering in the same area of Brazil or not," says Gunn. "If they are, and anything happened to that one spot, it could have huge implications for the breeding population of swifts in North America."  

Alarmingly, the Amazon is rapidly being cleared for agriculture. One computer model predicts that by 2050 up to 30 percent of the forest cover in the part of Brazil where the birds winter could be lost. Beason and his colleagues are talking with a researcher in South America, hoping that the recent findings will spur studies of black swifts there. Once conservationists know where the birds are going and how they're using the landscape, they'll have the ammunition they need to better protect them. For instance, if huge numbers of swifts congregate in one area in winter, conservationists could fight to protect that critical habitat.

The team is already making plans to equip the birds with satellite tags, which will reveal precise migration routes and wintering grounds (see "Unlocking Migration's Secrets"). Unfortunately, the current transmitters are too big for swifts, though the Colorado team expects smaller devices will be available in two or three years. They'll divulge not only the birds' path but also offer insight into the their behavior--where they stop during their three-week journey to the Amazon and how much time they spend aloft or roosting once they arrive.

Meanwhile, Gunn is spearheading cutting-edge genetic analysis that will give a clearer picture of the population size and diversity. Team members have already collected blood samples from three dozen swifts, and they gathered feathers from birds throughout the breeding range this year. DNA samples allow scientists to decipher how diverse the populations are. "If there's a lot of gene flow from colony to colony across North America, the birds would be experiencing great genetic diversity," says Gunn. "They'd have a larger gene pool to draw from and perhaps be more adaptable to risks, like climate change or disease."

She hopes the analysis will also provide a more accurate population estimate. "Banding and searching for new colonies to add to the count could take decades," says Gunn. "This should give us a much better population estimate, which directly relates to conservation."

While the Colorado team forges ahead on the technology front, groups in other states are scouring the wilderness for new nesting sites. In Montana, where three active swift sites are known, that means risking the occasional run-in with a deadly predator, as Daniel Casey discovered in 2004. 

That year Casey, an American Bird Conservancy biologist who lives south of Glacier National Park, spearheaded a statewide effort to visit 32 potential nesting sites--places where swifts had been spotted flying above waterfalls or areas that would seem to offer ideal habitat. (They're still at it; in addition to investigating a variety of potential sites in Glacier, this past summer Montana Audubon and Montana Fish, Wildlife & Parks scientists and volunteers sought out possible sites elsewhere in the state.) 

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Alisa Opar

Alisa Opar is the articles editor at Audubon magazine. Follow her on Twitter @alisaopar.

Type: Author | From: Audubon Magazine


this article

I found this article Fascinating! What a mystery bird this is! I know the Flat Tops and have climbed it in the past- very tall and precipitous it is, and beautiful. So is the lovely Bird!
Estella Leopold- Univ. of WAshington, Seattle

Black swifts

One of the most interesting bird articles I have read, fantastic.

Black Swifts

As the holder of M.A.s in Environmental Studies and Marine Biology, I am a staunch defender of our wildlife and its habitat.

I appreciate all that you are doing to help preserve our birds and their refuges.

Please keep up the good fight.

Best regards,

Joan Hunnicutt

Black Swifts

I winter in Puerto Rico and I believe I have seen this species in the western karst area of PR, at the Camuy River Caverns. They are possibly nesting there. If anyone is interested in documenting the presence of this species e-mail me. Dr. C. Skinner.

Chimney swifts?

I'm not aware of the different types of swifts, but I do know that one type inhabits chimneys and I heard them at my workplace just last year. I am concerned for them, because there was talk to do away w/them because of the "rattling" sound they made. Some thought snakes were inhabiting the chimney.

Black Swift Sighting in the state of Washington 18-years ago

On 7/6/1994 my wife and I saw a black swift while hiking northwest of Mt. Adams WA on the way to Council Bluff from the Council Lake campground. I recorded it in the notes of that hike. I am retired from the U.S. Fish & Wildlife Service and live in Portland Oregon

black swifts

WOW! Great article about a wonderfully elusive bird!

Black Swift article

This article explains the saga of the Black Swift beautifully. The article in Smithsonian misses the drama and excitement that this one projects.

What an amazing effort Rich, Kim, Carolyn, & Jason have poured into this on-going, live, detective story.

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