In 2024, Marshall Islands crews cleared rats from two remote islands: A year later, 2,000 sooty terns returned

Conservation teams spread rat bait across Bikar Atoll and Jemo Islet in the Marshall Islands using drones in July 2024. A year later, monitoring teams found a new colony of about 2,000 sooty terns on Bikar and thousands of native tree seedlings across the forest floor. Invasive rats had overrun the two remote islands for years. The rodents ate native vegetation, seabird eggs and young, turtle hatchlings and other wildlife. On Jemo, they also damaged resources traditionally collected by people from the nearby Likiep Atoll. The Marshall Islands government led the restoration effort, with technical support from Island Conservation. By 2025, monitoring indicated that the rats had been successfully removed from both islands.The rats had taken over the forest floorIsland Conservation project manager Paul Jacques visited Bikar and Jemo in 2024, when rats were widespread across both islands. He told CNN that the animals were running through the forest at night and had become a major pressure on native species. The problem was particularly serious for animals that nest or feed on the ground. Rats can eat eggs and young birds, while also consuming seeds and seedlings before they can develop into mature plants.CNN reported that the bait was dropped by drone in July 2024 at a rate of about 25 kilograms per hectare. The pellets were distributed in lines across the islands so that rats would have little opportunity to avoid them. The campaign was carried out with the Marshall Islands Marine Resources Authority and the Ministry of Natural Resources and Commerce. The goal was to remove the invasive predator and allow the existing ecosystem to recover.A new seabird colony appeared within a yearWhen conservationists returned in 2025, they found about 2,000 sooty terns breeding on Bikar. There had been no sooty terns recorded there during the previous year's monitoring. Conservationists also observed greater crested terns and brown noddies nesting on the ground. A Christmas shearwater was recorded on Bikar, while geckos and land crabs that had not been detected during the 2024 visit were also seen.Island Conservation's September 2025 report said the sooty tern colony was feeding hundreds of chicks. The organization described the findings as evidence that the 2024 rat-removal campaign had succeeded. The result is notable because sooty terns are vulnerable to predators when they nest on the ground. Removing rats does not automatically guarantee a population increase, but the new colony appeared during the first year after eradication. The monitoring team used trail cameras, traps, spotlight searches and thermal detection equipment to check whether rats remained on the islands. Those methods supported the conclusion that the rodents had been successfully eradicated.The forest floor changed just as quicklyConservationists found thousands of seedlings of the native Pisonia grandis tree on monitored plots across the islands. In 2024, none had been recorded in the 60 monitored plots. Pisonia grandis is important to island ecosystems because mature trees provide habitat used by seabirds. The sudden appearance of young plants therefore matters beyond the number of seedlings counted. The change also suggests that seeds were surviving after the rats were removed. Before the eradication, rats could consume seeds and young plants before they had a chance to establish themselves.Island Conservation reported that the recovery was documented by teams from the organization, the Marshall Islands Marine Resources Authority, the Ministry of Natural Resources and Commerce and community members from Utrik Atoll. The restoration also has a connection to the surrounding ocean. Seabirds carry nutrients from the sea onto islands through their guano, which adds nutrients to the soil, and those nutrients can support plant growth and eventually move back into nearby marine ecosystems. The Marshall Islands' Secretariat of the Pacific Regional Environment Programme said the 2024 rat-removal project was part of the Predator Free Pacific program, with Island Conservation providing technical expertise. The program involved both Bikar and Jemo and was led locally by Marshall Islands agencies.Jemo could become useful to nearby communities againJemo Islet lies about 40 kilometers from Likiep Atoll. CNN reported that people from Likiep have traditionally traveled to Jemo to fish, collect coconut crabs and gather plants such as coconuts and pandan leaves used for weaving. Those resources had declined as invasive rats became established, and the restoration project was therefore not limited to wildlife protection. Local communities also have an interest in keeping Jemo free of rats so that its natural resources can recover.Bikar is rarely visited outside scientific expeditions, while visitors to Jemo will need to avoid accidentally bringing rats or other invasive species back. There are also plans to assess whether similar work could be carried out elsewhere. Island Conservation said feasibility studies were underway for Bokak Atoll, another remote Marshall Islands ecosystem where invasive rats remain a problem.Catch the latest World News and Live updates. Download the TOI app.