• A black swift's "backpack" is held in place with strips of Teflon above and below where the wings join the body. The geolocator, with its light-sensor, is attached to the backpack. The trackers use light to record the length of days from sunrise to sunset.

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  • Click on image to enlarge



For more than half a century, a migratory mystery has confounded the bird world: Where do black swifts go when they leave their cliffside nests in Colorado?

A trio of Colorado bird researchers now has the first answer to that question. Their surprising finding got a drumroll unveiling Friday in Denver. The details are being published in an important ornithology journal next week.

And the answer to the mystery? Brazil.

Don’t yawn, nonbirders. Stick with the story because this is an avian yarn that involves dicey climbs behind waterfalls and pitch-black, ladder-toting hikes to remote caves. It has interesting elements such as itsy-bitsy bird backpacks on what look like flying cigars. It is underscored with a dying man’s devotion to “the coolest bird.”

“It’s all terribly exciting, to say the least,” said renowned black swift researcher Charles Collins of California State University in summing up the news.

Tracking black swifts to a remote rain forest in western Brazil is a big deal in the birding world, not just because it fills an unusual modern-day knowledge gap about a strange species. It also places a bird in a country where its existence had never been documented.

“To think that using technology in Colorado and never leaving the state, you can document a new species for a country in South America,” marveled Jason Beason of the Rocky Mountain Bird Observatory. He is a member of the trio that cracked the black swift conundrum.

There are plenty of reasons why black swifts merit such attention.

Of the four species of swifts in the U.S. and the 89 others around the world, black swifts are one of the most colorful in the figurative sense. They also are a species considered to be at risk from climate change.

Black swifts breed near waterfalls, on sea cliffs and in moist caves where they build their mud-and-moss nests in high crevices that usually can’t be seen from the ground. They have weak little legs, so they aren’t found walking on the ground or even landing on tree branches or wires. They are best at clinging to sheer cliff walls.

A later migration than most

Their scythe-like wings are longer than their cigar-shaped bodies, which makes them awesome aerialists. Swift chicks waste no time on fluttering flight practice. They zoom straight into migration from the nest. Swifts also migrate later than many other birds: They’ve been known to stick around Colorado until as late as Oct. 9. That’s why climate change could affect them more than it does other birds.

Much black swift study has been concentrated in Colorado because it is home to about half of all the known breeding sites in the country.

One of the first organized studies of black swifts was undertaken by the Denver Museum of Natural History in the 1940s. The museum sent scientist Owen Knorr to the remote town of Silverton in the San Juan Mountains to try to find black swift nests and fill in some gaps in knowledge about the species.

Knorr and his colleagues did their work in boulder-choked gulches. They used railroad spikes as makeshift pitons and roped themselves to walls to inch to nests tucked high in slick caverns.

The researchers determined a lot about the birds’ lives in Colorado. But they could only speculate about where they went when they flew south each September or early October and returned in late May or early June.

Fast forward to 1998, when Rich Levad, the late coordinator of the Rocky Mountain Bird Observatory, became obsessed with black swifts. He coined “the coolest bird” name for them, and he infected other bird researchers with the bug to know more about them.

Levad studied black swifts in the field until he was diagnosed with Lou Gehrig’s disease in 2004 and could no longer make difficult field trips. Then he began to write a book about them. “The Coolest Bird: A Natural History of the Black Swift and Those Who Have Pursued It” took Levad four years to finish. His widow, Karen, wrote in a foreword to the book that he was refining the text until the day he died in 2008.

Kim Potter, another member of the black swift trio, said she has no trouble understanding Levad’s obsession with black swifts.

“I’m unbelievably hooked on these birds. They have so many different characteristics from other birds. They are always surprising us,” said Potter, a Rifle-based wildlife technician for the U.S. Forest Service.

Because Levad was bothered that black swifts were the only species that breeds in the U.S. and Canada for which there was no migratory history pinpointed, Potter felt a need to carry on that part of the research.

Ladders, nets and ropes

So did Beason, who took Levad’s place at the Bird Observatory. Carolyn Gunn, a Dolores veterinarian and fish pathologist for Colorado Parks and Wildlife, rounds out the team.

The three birders followed in the footsteps of long-ago researchers with some precarious bird trapping that involved ladders, nets and ropes in remote caves and waterfall gulches. They jury-rigged fishing nets to scoop birds out of the air. They hiked cross country in wilderness at midnight using reflective-tape bits on brush to find their way.

While they studied the birds, they also spent several years puzzling over how to track the birds in their migration. Because of the black swifts’ short legs, geotrackers — affixed to leg bands — that have been used to track other birds wouldn’t work. Other geolocators and satellite devices were too large for birds that weigh no more than 10 nickels.

The researchers got a break when a new smaller version of a geolocator that had been used in the Antarctic was developed. They raised enough money to buy the devices, and then they had to figure out how to affix them to black swifts.

During one night of tossing and turning in her tent while on a black swift study trip, Gunn dreamed up the teensy backpack — held in place with strips of Teflon above and below where the wings join the body. The geolocator, with its light-sensor, was attached to the backpack.

In 2009, Beason and his team were able to capture and outfit four birds in a cave in a wilderness area north of Rifle and in the Box Canyon Falls, near Ouray.

The hard part came in 2010 when they had to capture the same four birds after they returned from their winter sojourns so they could retrieve information from the geolocators. Luckily, black swifts like to nest in the same locations year after year.

They captured three of the four birds, downloaded the information and spent months analyzing it. The trackers had used light to record the length of days from sunrise to sunset. From that, it was possible to calculate latitude and longitude.

Species unknown in Brazil

Tabulations showed the birds had traveled about 4,300 miles. They had flown about 244 miles a day on the trip to Brazil and about 211 miles each day on the return.

The surprise was not just that they had gone to Brazil, where their kind was unknown. Beason said he expected that the birds would be wintering in a mountainous area with waterfalls — something similar to Colorado. Instead, they headed to lowland rain forest.

“We’ve been in touch with bird field-trip leaders there, and they think they might have seen these swifts, but they aren’t sure,” Beason said.

With the answer now unveiled and the results set to appear in the Wilson Journal of Ornithology, the intrepid bird trio doesn’t plan to rest on its laurels.

There are other black swift questions still to answer.

Do the rest of the black swifts in North America also go to Brazil?

Do they do what is called aerial roosting, which is essentially flying on autopilot with no rests?

“Every time we ask a question about black swifts and we get an answer,” Potter said, “we turn around and there is another question.”

Nancy Lofholm: 970-256-1957 or

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