JUNEAU, Alaska (AP) — A resident on St. Paul Island, situated hundreds of miles from mainland Alaska, reported seeing what they believed was a rat. This unconfirmed sighting has garnered significant attention due to the potential environmental repercussions of a rat infestation on the island, which is renowned for its rich biodiversity and is part of the Pribilof Islands — often referred to as the “Galapagos of the north.”
Why the alarm? Because rats are known to quickly multiply and wreak havoc on remote islands by decimating local bird populations, consuming their eggs, chicks, and even adult birds, thus dramatically altering established ecosystems.
In response to the report received in June, wildlife officials conducted an extensive search around the resident’s apartment complex, examining nearby grass areas, the building’s exterior, and even under porches for any signs of the rat, including tracks, droppings, or chew marks. They set up traps baited with peanut butter and installed trail cameras, but as of now, no evidence of a rat has been discovered.
“We know from observing other locations across Alaska and the globe that rats can be devastating to seabird colonies,” noted Lauren Divine, director of the Aleut Community of St. Paul Island’s ecosystem conservation office. “Thus, the community takes any potential threat very seriously.”
The concern on St. Paul Island comes amidst longstanding efforts to maintain the exclusion of non-native rats from some of the world’s most ecologically significant yet remote islands. Successful rodent removal initiatives have been implemented on hundreds of islands globally, including what was once dubbed “Rat Island” in Alaska’s Aleutian chain, as reported by the U.S. Fish and Wildlife Service. These types of programs can be expensive and drawn out—sometimes taking years and costing millions—making prevention the most effective approach.
To bolster their defenses, officials have placed “chew blocks” around developed areas of St. Paul designed to detect rodent activity by capturing bite marks. Some blocks are infused with ultraviolet materials, enabling inspections with black lights to reveal any rat droppings that glow under specific conditions. Community members have been asked to remain vigilant for any rodent sightings while securing permission for the U.S. Department of Agriculture to bring a detection dog to the island, even though canines are typically prohibited in the Pribilofs to protect local fur seals.
While no signs of rats have been found since the summer report, the search will likely continue with heightened vigilance over the coming months. Divine likened the ongoing search effort to searching for a “needle in a haystack,” especially without certainty that any rat even exists on the island.
The small community, made up of around 350 residents situated on the southern tip of this treeless, storm-battered island, has long operated a rodent surveillance program. This includes strategically placed rat traps near the airport and at waterfront areas where boats frequently dock, all aimed at detecting and exterminating any potential rat arrivals.
Yet, the reality is that it took close to a year to capture the last known rat on St. Paul, which was believed to have arrived via a barge and was discovered dead in 2019 after eluding initial detection efforts. This history underscores the critical importance of addressing even unverified sightings with urgency, as stressed by Divine.
Looking to the larger picture, the U.S. Fish and Wildlife Service plans to conduct an environmental review to explore the possibility of eradicating rat populations from four uninhabited islands scattered throughout the distant Aleutian chain, which is home to over 10 million breeding seabirds from various species. The agency has observed that islands with established rat populations generally have notably lower numbers and diversity of nesting birds. For instance, remains of least auklets and crested auklets have been found within cached food stores of rats on Kiska Island, another site where rat footprints have been detected.
If the agency decides to proceed, it is estimated that the first of these eradication projects may take up to five years to initiate. Given the thorough planning, research, and testing required for each island, it could potentially take decades to complete all planned initiatives, pointed out Stacey Buckelew, an island invasive species biologist affiliated with the Alaska Maritime National Wildlife Refuge.
Nonetheless, these efforts are vital for the preservation of seabirds already facing pressures like climate change. The successful eradication on what was once called Rat Island serves as a testament to the effectiveness of such programs. Rats were believed to have first arrived on the island after a Japanese shipwreck in the late 18th century, with fur traders later introducing arctic foxes in the 19th century.
The fox population was eradicated in 1984, but it wasn’t until nearly 25 years later that conservationists successfully eliminated the rats through aerially dropping poison pellets. Those involved noted that the absence of nesting seabirds left the island startlingly silent compared to its previously bustling, rat-free counterparts.
Since the rat eradication, research teams have noted the resurgence of native bird species, including the return of tufted puffins, which are vulnerable to predation by rats and foxes. The island has since reclaimed its original name from the Unangan people of the Aleutians: Hawadax. During surveys conducted before the rats were eliminated, no song sparrows were heard, yet during a visit in 2013, their songs filled the air almost continuously, as Buckelew recounted.
Donald Lyons, director of conservation science with the National Audubon Society’s Seabird Institute, expressed his awe at the natural spectacle witnessed in the Pribilof Islands, highlighting the incredible abundance of wildlife as witnessed through the return of countless auklets to their colonies each evening—potentially millions of birds taking flight. He emphasized the importance of taking the reported rat sighting in St. Paul seriously, also recognizing the efforts of the largely Alaska Native communities dedicated to preventing the spread of invasive species.
“The Preble Islands remind us of the once abundant wildlife that previous generations have documented, much of which we seldom see in our modern times,” he remarked. “This is truly a place where one can still experience the wonder and spectacle of nature.”
