Most weeks between September and December, Stacie Evans drives up the Haines highway, counting bald eagles through a high-powered scope.
Her drives are part of a longstanding annual survey that aims to provide insight into the valley’s annual gathering of eagles, which is one of the world’s largest. Last week, she saw more than 1,400.
“It's the highest count that's been documented since the year 2000,” said Evans, who is the science director of the Takshanuk Watershed Council, a local conservation nonprofit.
The annual gathering in the Alaska Chilkat Bald Eagle Preserve is central to the area’s identity – and it serves as an economic boost for the town of Haines at the start of the winter.
Evans emphasized that the road surveys do not amount to a comprehensive population count, so there’s no way to say for certain how many raptors are actually in the area each year.
But they do provide a snapshot of what’s happening, particularly within sight of the highway. The large number of eagles counted this year marks a departure from recent survey data, which has captured significantly fewer eagles compared to decades past.
“We can say that there has been a decline,” Evans said. “I mean, it’s pretty obvious from when the survey started in 1988.”
Between 1988 and 2000, for instance, surveyors counted well over 1,000 eagles every year but one. But in road surveys conducted since 2011, peak counts only surpassed 1,000 four times, including this year.
Some locals say they’ve seen a decline with their own eyes. Craig Loomis has lived in Haines since the 1960’s. He recalls driving up the highway and seeing far more eagles than he does today.
“I mean there were eagles all over the place,” Loomis said. “And that didn’t count the ones away from the river that we couldn’t see.”
A big year for salmon – and eagles
The road survey entails counting eagles at the same pullouts, and along the same sections of road, as many weeks as possible from mid-September through mid-December. That protocol has remained consistent over the years.
At each stop along the way along Evans’ drive last month, eagles were perched in the cottonwoods and scattered across the riverflats both alone and in larger groups.
The valley has a resident bald eagle population that sticks around all year. But each fall, more arrive from as far away as Washington state to take advantage of a unique hydrological feature – and fishing opportunity.
“A lot of the water that's coming from the Tsirku into the Chilkat is subsurface, so it's not exposed to air temperature,” Evans said. “Which means in the winter time, it is relatively warm, and so it keeps the Chilkat River from freezing.”
That facilitates prime access to a particularly late run of chum salmon heading into the coldest months of the year.
“It is a really unique thing. There’s not a lot of fish available at that time of year,” said Steve Lewis, a raptor biologist with the U.S. Fish and Wildlife Service. “It probably gets them through the winter.”
The high count in November likely correlates with an especially strong chum run. Alaska Fish and Game area management biologist Nicole Zeiser said this year’s peak chum count – recorded via aerial surveys – surpassed 20,000 fish.
In an email, she said that’s a “strong number given that surveys capture only a fraction of the total fish present in the drainage.”
In 2020, the run was incredibly weak – and the eagle count was, too. The peak count that year was under 300 birds. Zeiser did not respond to questions about the long-term stability of the Chilkat chum run.
Weather is the other factor that can impact the eagles and where they feed. Warmer falls can result in more open water. Lewis said that allows the eagles to feed in different areas of the valley that are farther from the road, making them harder to spot.
“If it's really, really cold, and lots of places are frozen, then the eagles are really condensed. If it's not that cold, and they can be spread out, then they'll be spread out,” Lewis said.
That could happen more frequently with climate change. In Southeast Alaska, average temperatures between September and January are about four degrees higher today than they were in 1988, according to data from the National Oceanic and Atmospheric Administration.
“Any anecdote that says it is warmer than it used to be is almost certainly correct,” NOAA Senior Scientist Brian Brettchneider said in an email.
The annual Bald Eagle Festival typically happens in mid-November. But Kathy Benner, of the Haines-based American Bald Eagle Foundation, said event organizers are considering delaying the event to increase the odds that it will overlap with cold temperatures – and lots of eagles feeding within eyeshot.
“I personally think it probably would be a great idea to try to move it a little bit closer to when the temperatures are colder,” she said.
‘No means for counting’
The Chilkat Valley gathering is often described as the world’s largest, but experts say the Harrison River in British Columbia — considered Canada’s only “salmon stronghold” river — likely deserves that title.
The area can draw as many as 15,000 eagles in November and December, said Myles Lamont, a wildlife biologist with TerraFauna, a Canadian wildlife consulting group.
The gathering in the Chilkat Valley, meanwhile, is often put at somewhere between 3,000 and 4,000 eagles.
Fish and Wildlife biologists used to fly over the Chilkat Bald Eagle Preserve to do a more comprehensive survey. But that hasn’t happened for at least 20 years, Lewis said, and it probably isn’t in the cards any time soon.
“We don't have tons of funding no matter what,” he said. “And I don't have a lot of funding to support that kind of specific area survey for this one population.”
Lewis said that’s unfortunate, given that he regularly hears from people in Haines who are interested in learning more about what is happening in the eagle preserve each year.
Evans, of Takshanuk, said the organization would be interested in aerial surveys, but they also lack the necessary funding. Benner, of the Bald Eagle Foundation, said the same.
“We have no means for counting at this time,” Benner said in a phone interview.
That leaves the road survey data. It’s not a perfect system; the surveys have been conducted by different people over the years, and there are a smattering of years with no data. Plus, there’s no way to see the entire valley from the road.
“It doesn’t necessarily always give you the most unbiased look at what the numbers are doing,” Lewis said. “But obviously, if there's lots of eagles in the valley, you're probably gonna have a higher count. If there's not as many, you'll probably have a lower count.”
Evans emphasized that bald eagle populations as a whole are doing quite well. So even if the Haines congregation is shifting in some way, over time, that doesn’t mean the raptors are in danger. It could just mean they’re elsewhere.
“This is not a population survey at all,” Evans said. “There's no indication that eagle populations are diminishing.”
Lewis echoed that point. Ultimately, he said, “I’m not sure what the eagles are doing in the valley.”
