Alaskan Island Is On the Hunt for a Solitary Rat

On an island of windswept tundra in the Bering Sea, hundreds of miles from mainland Alaska, a resident sitting outside their home saw—well, did they see it? They were pretty sure they saw it. A rat. The purported sighting wouldn’t have gotten attention in many places around the world, but it caused a stir on St. Paul Island, a community of about 350 people that’s part of the Pribilof Islands, a birding haven sometimes called the “Galapagos of the north” for its diversity of life, per the AP. That’s because rats that stow away on vessels can quickly populate and overrun remote islands, devastating bird populations by eating eggs, chicks, or even adults and upending once-vibrant ecosystems. It took nearly a year to catch the last known rat on St. Paul, which was believed to have hopped off a barge. It was found dead in 2019 after it evaded the community’s initial defenses.

Shortly after receiving the resident’s report in June, wildlife officials arrived at the apartment complex in question and crawled through nearby grasses and under the porch, looking for tracks, chew marks, or droppings. They baited traps with peanut butter and set up cameras to capture any confirmation of the rat’s existence—but so far have found no evidence. “We know … that rats absolutely decimate seabird colonies, so the threat is never one that the community would take lightly,” said Lauren Divine of St. Paul Island’s Ecosystem Conservation Office. The anxiety on St. Paul Island is the latest development amid long-standing efforts to get or keep non-native rats off some of the most remote but ecologically diverse islands in Alaska and around the world.

Rodents have been removed successfully from hundreds of islands worldwide—including one in Alaska’s Aleutian chain formerly known as “Rat Island,” per the US Fish and Wildlife Service. But such efforts can take years and cost millions, so prevention is considered the best defense. Around St. Paul’s developed areas, officials have set out blocks of wax—”chew blocks”—designed to record incisor bites. Some of the blocks are made with UV material, which allows inspectors armed with black lights to search for glowing droppings. They’ve also asked locals to look out for any rodents. There have been no traces of any rats since the reported sighting this summer, but the hunt and heightened state of vigilance is likely to persist for months. Divine’s take? The search is like trying to find a needle in a haystack “and not knowing if a needle even exists.”

(More rats stories.)