On a windswept island in the Bering Sea, surrounded by tundra and miles away from mainland Alaska, a resident seated outside their home thought they spotted something startling—a rat. Such a sighting would not generally attract attention in many places around the globe, but on St. Paul Island, part of the ecologically rich Pribilof Islands, it caused a significant commotion.
Dubbed the “Galapagos of the north” for its biodiversity, St. Paul Island’s ecosystem could face catastrophic consequences if rats, known for stowing away on ships, manage to establish a presence. These rodents can swiftly overrun remote islands, devouring eggs, chicks, and even adult birds, and destabilizing vibrant ecosystems.
Following the resident’s report in June, wildlife officials descended upon the apartment complex. They combed through nearby grasses, inspected the building’s surroundings, and crawled under the porch in search of tracks, chew marks, or droppings. Peanut butter baited traps were set, and trail cameras arranged to confirm the rat’s existence—so far, no evidence has surfaced.
“We know—because we’ve seen this on other islands and in other locations in Alaska and across the world—that rats absolutely decimate seabird colonies, so the threat is never one that the community would take lightly,” remarked Lauren Divine, director of the Aleut Community of St. Paul Island’s ecosystem conservation office.
This episode adds another layer to the extensive efforts to prevent non-native rats from infiltrating and establishing populations on some of the world’s most remote and ecologically delicate islands, both in Alaska and globally. Successful eradication of rodents has occurred on hundreds of islands worldwide, including a former “Rat Island” in Alaska’s Aleutian chain, a notable achievement by the U.S. Fish and Wildlife Service. Given that such endeavors can span years and cost millions, prevention remains the most effective strategy.
In developed areas of St. Paul, officials deployed wax blocks known as “chew blocks,” which record the unique incisor marks left by rodents. Some blocks contain ultraviolet material, enabling inspectors to use black lights to detect glowing droppings. Residents have also been urged to report any rodent sightings, and authorities are considering bringing a dog, typically banned to protect fur seals, to aid in the search.
Despite no confirmed rat evidence since the summer sighting, the hunt continues. Divine compared the search to finding a needle in a haystack, “and not knowing if a needle even exists.”
Approximately 350 people reside on this treeless island with its rolling hills and storm-battered cliffs. The community has long maintained a rodent surveillance program, featuring rat traps near the airport and waterfront areas where vessels dock, aimed at detecting or eliminating any rats that arrive. The last known rat, presumably disembarked from a barge, was trapped after nearly a year of evasion by the community in 2019. This underscores why even an unconfirmed sighting is taken with utmost seriousness.
An environmental review by the U.S. Fish and Wildlife Service is underway to assess eradicating potentially tens of thousands of rats on four uninhabited islands in the Aleutian chain, hundreds of miles southwest of St. Paul. The Aleutians host over 10 million seabirds across various species.
Rats have noticeably affected the diversity and number of breeding birds on islands where they’ve established populations. Carcasses of least and crested auklets, known for their noisy nesting colonies, have been discovered in rat caches on Kiska Island, one of the studied locations where rat footprints were spotted on a sandy shoreline.
Should the agency proceed, the first projects might take five years to commence, requiring decades of planning, testing, and research to complete all efforts, according to Stacey Buckelew, an island invasive species biologist with Alaska Maritime National Wildlife Refuge. However, she emphasized that such initiatives are crucial to supporting seabirds already impacted by climate change.
The successful eradication of rats on what was once “Rat Island,” now called Hawadax, exemplifies the potential impact of such programs. Rats, believed to have arrived via a Japanese shipwreck in the late 18th century, wreaked havoc until wildlife teams, after eradicating arctic foxes introduced by fur traders in the 19th century, eliminated the rodents by dropping poison from helicopters in the early 21st century.
Since the eradication, native birds have rebounded, with species once thought extinct reappearing. The island’s environments improved dramatically, as did its soundscape, with song sparrows prevalent where they were once absent.
Donald Lyons, director of conservation science with the National Audubon Society’s Seabird Institute, described witnessing the dramatic evening return of auklets in the Pribilof Islands—“tens of thousands, hundreds of thousands, perhaps millions of birds in the air at a given time.” He affirmed the importance of the community’s efforts to prevent invasive species, highlighting that such wildlife abundance is a rare spectacle in the modern age.
“It’s the abundance of wildlife that we hear stories about or read in historical accounts, but really seldom see in our modern age,” he said. “It really is a place where I’ve felt the wonder, the spectacle of nature.”
