McDONALD CREEK — “We have ducks just below Heaven’s Peak,” crackles the radio in Lisa Bate’s hand.
“One female and two chicks and she’s very, very skittish. They’re headed upstream.”
Standing just off the busy main thoroughfare in Glacier National Park last week, the park biologist and a portion of her crew of dedicated volunteers are studying the waters of McDonald Creek for a glimpse of the trio of harlequin ducks swimming in their direction.
Cars start to slow as tourists scan the scene in hopes of spotting a bear or maybe even a moose. Some ease to a stop and hurry to the embankment’s edge with their binoculars hanging around their neck.
“What do you see? What is it?”
Just then, the three tiny brown ducks swim up around the corner. Bates takes a few moments to point them out to the visitors and offer a brief explanation about their plans to capture and band the rare sea-going ducks that migrate here every spring to breed and raise their broods on the very same waters where they were born.
This year has produced a bumper crop of harlequin chicks in Upper McDonald Creek despite the fact this spring’s unusually high runoff that came in pulses likely washed away the nests of at least 12 females.
Nesting is a precarious proposition for harlequin ducks.
Most place their nests just a few feet from water’s edge of the fast-moving streams filled with the frothing ice-cold water that pours out of the surrounding mountains. That works fine as long as water levels don’t suddenly rise.
There is no room for failure in the world of harlequin duck nesting.
The males stay around just long enough for the females to gorge and lay eggs. Once that’s completed — usually sometime in June — the brightly colored males fly back to the coast, where they molt and later travel to their wintering grounds where they meet back up with their mates.
So, unlike other species of waterfowl that might have a chance at a second try should a nest fail, harlequins are one and done.
“Harlequins are considered a boom-or-bust species,” Bate said. “They can go for years without successfully producing any chicks.”
In 2010, researchers were unable to find any chicks on McDonald Creek between Lake McDonald and Logan Creek. In 2014, they found five. In 2015 and this year, they’ve counted 19.
The Upper McDonald Creek drainage is considered one the strongholds of the rare species.
In other places across their range, harlequin numbers have been in decline. In Banff, harlequin pair numbers have dropped from 90 to 25 since 1995. On the coast, the male ducks no longer molt along the border of Washington state and British Columbia.
No one is certain what’s behind the decline. Theories range from increased recreational activities in sensitive nesting areas, to growing numbers of bald eagles that prey on harlequins, to changes in climate.
But in Glacier, harlequins appear to be holding their own.
Glacier National Park boasts the highest breeding pair density of harlequin ducks in the lower 48 states on Upper McDonald Creek and its tributaries.
The national park is also one of the few places that has monitoring data that reaches back into the 1970s after a graduate student named Craig Kuchel wrote his master’s thesis on his efforts to document their range in Glacier. In the 1990s, John Ashley sought to replicate Kuchel’s study and gathered his own rich set of data.
“That experience with harlequins really kind of took over my life,” Ashley said. “They are fascinating. They almost never go on land. Water is where they find safety. … Their strategy for survival is an environment that doesn’t change rapidly.
“I’ve been working on learning more about them for 26 years, or about half my life,” he said. “I can really never get enough.”
In the spring he teaches a class to interested adults. He tells them that harlequin ducks are more rare than grizzly bears in the national park.
On this day, Bate, Ashley and other volunteers are spending hours walking through smoke-shrouded air along a creek that’s hardly 30 feet across. A long hot and dry summer has brought fire, smoke and drought to the national park.
It’s the kind of change in climate that worries anyone who cares about the ducks that thrive in the cold waters and have been documented to live as long as 18 years.
Bate and her crew have been performing spring and fall surveys, as well as banding chicks, since 2008. Another graduate student, Warren Hansen, spent three years starting in 2011 to add to understanding on how the ducks were using the park.
“Even, with all that, there is a lot we don’t know about harlequin ducks,” Bate said.
With a project partially funded by the Glacier National Park Conservancy, Bate started last year implanting a tiny transmitter in male birds that provide a real-time look at where the birds live during the year.
“With the help of veterinarian Dan Savage, we’re taking this to a whole new level,” she said. “We still have a lot more questions than answers.”
All four of the male ducks implanted with the transmitters this past year went to different areas to molt. One ended up just south of Juneau, Alaska. Another traveled to Port Angeles, Washington. The other two went to the coastal waters of British Columbia.
From there, they all traveled to the Strait of Georgia between Vancouver Island and British Columbia to winter.
The hope is next year Bate and her team will implant another six males with transmitters and attach tiny geo-transmitters to collars on female ducks to gain even more insights on where the birds live out their lives.
Glacier Park isn’t alone in its effort to learn about the rare waterfowl.
Bate is working with a team of state and federal biologists from three states and two Canadian providences that hopes to learn where the ducks breed, molt and winter. Her team inside the park is also expanding its efforts to locate the ducks nesting habitat inside the park.
She estimates that 25 percent of all the harlequin chicks that are produced in Montana come from the McDonald Creek drainage, which extends far beyond the mainstream waters that are so visible from the main road. This year, a new nest was found two miles up a small tributary called Mineral Creek a couple hundred meters away from the water.
That nest would never have been found without the new efforts at monitoring tributaries that started this year, Bate said. She hopes there will be more.
Last week, Bate and her crew of volunteers successfully concluded their harlequin duck monitoring efforts after capturing and banding seven chicks from two different broods.
After the birds were located, they were driven into an 8-foot-tall net where they became ensnared.
After being carefully pulled from the net’s webbing, Bate took measurements before placing a stainless steel band that can survive the harsh conditions found in their saltwater winter home on one leg. On the other, she placed a plastic blue band that researchers could easily read from a distance.
So far, they have banded more than 200 harlequin ducks using that method, without a single casualty.
“Research like this is critical to sustain Glacier National Park’s precious habitat,” said Doug Mitchell, Glacier National Park Conservancy executive director. “Donations to the Glacier Conservancy ensure that important work like this will continue to preserve and protect the park for future generations.”