An Island regained Paradise after Rodents were completely eradicated.

It was Bikar Atoll and Jemo Islet, remote uninhabited islands, which are part of the Marshall Islands in the North Pacific, are classic island paradises from above: white sand beaches, clear turquoise waters and lush forests. But over decades, even centuries, the remote uninhabited islands have been over occupied by rats.

Rats, which are invasive to the region, had destroyed native flora and fauna, preying on baby crabs, turtle hatchlings and seabird eggs. In 2024, Paul Jacques, project manager and his team from the non-profit, Island Conservation, visited in 2024, both islands were crawling with them. “They were running everywhere”, he told in his report. “Walking around at night with a torch, it was almost frightening the forest floor was moving with rats”.

The rodents, which are invasive to the Marshall Islands and likely arrived as stowaways on ships, have caused ecological chaos. They devour native vegetation and prey on turtle hatchlings, baby crabs; The islands, which were once havens for the likes of endangered green sea turtles and seabird colonies, observed those populations decimating. When the Spanish (explorers) first saw Jemo they called it ‘Los Pájaros’ (The Birds) because there were so many birds there, says Jacques. “When we went there last year, there weren’t many at all”. 

A year later, the scenario experienced a paradigm shift, with the tireless efforts with the aid of an eradication program undertaken by Island Conservation together with the Marshall Islands’ Marine Resources Authority and the Ministry of Natural Resources and Commerce.

Rat bait was dropped by drone in July 2024, around 25 kilograms per hectare (55 pounds per 2.5 acres) in lines across the islands, so that there were no gaps in coverage, explains Jacques. The bait, designed to target rats, has little effect on other species. It needed to be widespread so that each individual rodent could consume at least one pellet, he adds.

During the summer of 2025, the team went back to the Island, and was completely mesmerised. Upon looking for rats, they spotted innumerous birds, a clear sign that the mission was accomplished. Within an hour on Jemo and Bikar, Paul Jacques was confident that it had worked, and following intensive monitoring with trail cameras, rat traps, spotlight searches and thermal detection equipment, they confirmed that rodents had been successfully eradicated from the two islands.

Seabird populations were soaring: a breeding colony of 2,000 sooty terns had established themselves on Bikar, whereas the year before there had been none. Jacques saw greater crested terns and brown noddies nesting on the ground, a Christmas shearwater, a dark-brown seabird which he says has never been recorded on Bikar before, alongwith species of geckos and land crabs that were absent in 2024. Species those were undetectable before, suppressed by the rats, resurfaced again.

One of the most striking signs of success was the thousands of seedlings of the native Pisonia grandis trees that had sprung up across the forest floor. In 2024, they had counted zero. “To come back onto the island and immediately see a carpet of seedlings was a real early indication for me that something radical has changed here”, says Jacques.

The rebound of native flora and fauna helps to restore the entire ecosystem. Nutrients from the seabird guano (faeces) boost soil fertility; crabs release their larvae into the water, which provides a food source to other marine animals.

Historically, Jemo Islet was an important resource to the community living on Likiep, an atoll about 40 kilometres (25 miles) away. They travelled to the island to fish, hunt for crabs and harvest crops such as coconuts and pandan leaves, used for weaving. In recent years, the resources declined dramatically, but due to the restoration project, island communities, some of whom have been involved in the efforts of sustainable developments hope to adopt these traditions.

“Both Jemo and Bikar once held huge rookeries of seabirds and turtles. Now that rats have been removed, we look forward to the recovery of these colonies and the restoration of the vital natural processes that connect the deep ocean, the land and reef”, said Byrelson Jacklick, invasive species coordinator for the Marshall Islands Ministry of Natural Resources and Commerce, in a press release.

Since, Bikar is only visited nowadays by scientific expeditions that take careful biosecurity measures, and because of the community involvement and awareness of the rats’ dire impact, Jacklick expects the residents of Likiep to be equally cautious when visiting Jemo. There are no plans to reintroduce new species or to modify the habitat.

According to a 2023 report from the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES), 90% of all global extinctions on islands are mainly attributed to invasive alien species. But it noted that eradication programs are cost-effective and have a high success rate of 88%.

If a problematic invasive species can be removed, it’s a gift that keeps on giving. “If you give it 10 years, if you give it 30 years, the change is cumulative. Populations increase, animals reappear that you thought were locally extinct because they’re in such low numbers that they weren’t detectable”, says Jacques.

Team Maverick