The World’s Oldest Known Osprey Is an Online Sensation—and a Living Indicator of Watershed Health
At 29, Iris the Osprey has outlived the odds to become a cherished internet star whose brood of offspring is helping track river health in Montana.
Wings weary after a 2,000-mile journey, but still carrying her typical illustrious air, the matriarch of the Hellgate Valley landed in the escaping evening light. Feathers ruffled, spattered in fish blood, she touched down on her perch on April 7. Expectant fans from all over the globe rejoiced: Iris, who is the oldest known Osprey alive today, had returned to her home nest in Montana right on schedule.
Researchers have tracked Iris, named for the unique inflections in her eye, since she started nesting along Missoula’s Clark Fork River in 1999. Because Ospreys start breeding around 3 years, experts who monitor her estimate that she is an extraordinary 28 or 29 years old—far outlasting the average Osprey lifespan of about 15 to 20 years.
Over those decades, Iris has become a global avian sensation. Thanks to a camera installed on her nest in 2010, a wide audience has tuned in to watch this beloved bird’s trials and tribulations broadcast live online. Her fame has earned her thousands of committed followers who track her on social media and send her hundreds of annual letters from places as far as Japan and Ukraine. This year, one dedicated admirer even celebrated their 29th birthday alongside Iris in the parking lot below her Montana perch.
But Iris’s influence goes beyond her stardom. Because of her longevity and breeding productivity—she’s raised more than 20 offspring and now has many grandkids soaring around the area—researchers say she is “worth her weight in gold” in driving the success of the local population. Like raptors across much of the United States, the Ospreys in this region were formerly devastated by the use of DDT, but have rebounded since the ban of the pesticide in the 1970s.
Along with other Ospreys in the area, Iris and her descendants also demonstrate the importance of the species as sentinels for watershed health. For nearly two decades, the fish-eating predators have helped scientists trace the toxic industrial legacy along this stretch of Montana's rivers. “The amount of information we have been able to portray through Iris has been incredible,” says raptor biologist Rob Domenech, director of Missoula’s Raptor View Research Institute. “She is one helluva bird.”
Over the course of the 20th century, mines and paper mills along the Clark Fork River polluted the watershed with heavy metals—including arsenic, cadmium, lead, mercury, and antimony—that can hamper Ospreys’ reproductive success. The Environmental Protection Agency (EPA) and Montana Department of Justice have estimated that restoring the river, which remains lined with 185 miles of contaminated soil, will cost around $1 billion—making it one of the largest and most expensive Superfund sites in the country.
Scientists have tracked this pollution by sampling blood and feathers from hundreds of local Osprey chicks.
Since 2006, as part of the Montana Osprey Project, scientists from the University of Montana (UM) and the Raptor View Research Institute have tracked this pollution by sampling blood and feathers from hundreds of local Osprey chicks—including many of Iris’s offspring, as her nest was part of the initial study group. Before chicks fledge, their parents feed them fish from waters close to their nest, so their diets reveal which contaminants are present in the river. “They are our window into aquatic ecosystems,” Domenech says. The birds also offer insights into possible human health impacts, since Ospreys are at a similar level of the food chain to people.
Scientists have used the results from the project to fill in a detailed map of contamination levels throughout the Clark Fork River basin, helping to understand how the pollution affects wildlife and to guide continued restoration efforts. “Osprey nests along rivers are like beads on a necklace, each one a concentrated site to help us track the movement of toxins through the watershed,” says UM chemist Heiko Langner. The monitoring, for example, has revealed that the Clark Fork and its tributaries contain high concentrations of mercury—even though the potent pollutant wasn’t part of the original river cleanup plan.
Though scientists no longer sample chicks from Iris’s nest, her webcam has continued to give a window into a raptor’s daily life. Researchers use the vantage point to better understand the birds they sample and catch occasional glimpses of the more than 400 Ospreys they’ve color-banded to date. “The nest camera helps to understand their day in, day out,” Domenech says.
These days, the Iris show is broadcast through the Cornell Lab of Ornithology’s Bird Cam project, which manages around a dozen livestreams for different species around the world. According to the lab’s project leader Charles Eldermire, Iris has built a following not matched by many other avian broadcasts they host. Her legions of supporters have watched Iris struggle through hailstorms that destroyed eggs, owl attacks, and five years where she failed to raise chicks without a committed mate to help her protect the nest. “Iris has survived so much,” Eldermire says. “But there are also little stories that happen every day. The beauty of the live cam is that it gives people the opportunity to experience her narrative in a personal way.”
Sharonleigh Miles, a superfan from South Carolina who has watched Iris since 2014, says she draws inspiration from the bird’s perseverance, maternal instincts, and charisma. “Iris is a force to be reckoned with,” Miles says. “She has been my teacher in the ways of the Osprey, and it has been a true joy to learn from her.” Over the years, Miles has volunteered along with others to help manage Iris’s accounts on Facebook and Twitter, and has kept a detailed timeline of all the major events in the bird’s life.
That includes the rotating cast of other Ospreys who periodically show up as guest stars, propelling a plot that can feel like a soap opera. Take Louis, Iris’s former mate who left her to partner up with another female Osprey named Star. Louis still visits Iris occasionally, but less since Finnegan, Iris’s strapping younger mate, entered the picture last year. After Iris had several seasons without offspring, she and Finnegan successfully raised two chicks, Antali and Sum-eh, whose Séliš names honor the Indigenous tribes of the Hellgate Valley. “There have been good years and there have been bad years. But Iris goes on, and so we go on,” Miles says. “When Iris accepted a new mate, I knew that it was a fresh beginning.”
“There have been good years and there have been bad years. But Iris goes on, and so we go on.”
Now, as Iris settles in for her summer in Missoula, the season’s drama is already heating up. Finnegan hasn’t been spotted, but Iris has laid three eggs after Louis dropped by the nest—all of which were quickly snatched by ravens. Meanwhile, a spry and doting Osprey, temporarily dubbed “New Guy 2,” is courting her in the typical fashion of a raptor, bringing fish much like flowers. If they mate and she lays another set of eggs, it could be a successful summer.
No matter what comes next, the winged matriarch of the Hellgate Valley has already created a legacy that will last long beyond her 29 years. “Iris, this Osprey, has brought people together that would’ve never met or collaborated,” says UM professor emeritus Erick Greene, who has helped lead the Montana Osprey Project since the beginning. “She resonates with people from all over the world, and she has brought together scientific efforts that might not have happened without her. That is what makes this bird special.”