Endangered seabirds return to Pacific island after century-long absence

Small seabirds skim the open ocean at night, patting their legs on the surface as they hunt for small fish. Now, for the first time in more than 100 years, endangered Polynesian storm petrels (Nesofregetta fuliginosa) have returned to a far-flung island in French Polynesia.

These rare birds began exploring Kamaka Island just three weeks after conservationists set up special equipment to attract them back, according to Coral Wolf, conservation science program manager at Island Conservation, the U.S.-based NGO overseeing the project.

“This remarkable progress brings hope for the future, as the Polynesian storm petrels reclaim their island home,” Tehotu Reasin, landowner of Kamaka Island, said in a statement. “These seabirds bring critical nutrients from the ocean to the island, which cascades down into the surrounding marine environment, benefiting fish and corals. The entire ecosystem can once again thrive.”

Researchers estimate that numbers of storm petrels were once quite high on Kamaka Island, as a relatively large number of individuals were recovered from an archeological site on the island. However none have been seen on the island since 1922. Now, o

Getting the birds to return required solving a serious problem: invasive rats that had driven the ground-nesting birds to local extinction by preying on their eggs, chicks and even adult birds.

“A majority of extinctions occur on islands with invasive species, rats as a primary cause,” Sally Esposito, strategic communications director at Island Conservation, told Mongabay.

Kamaka Island measures only 0.5 square kilometers (0.2 square miles), about the size of the Vatican City, and is uninhabited by humans. However, attempts to remove rats from the island failed in 2015, largely due to its steep and challenging terrain.

In 2022, Island Conservation worked with ENVICO, an Aotearoa New Zealand-based drone company, to conduct more than 600 flights to spread rat poison across the island. As far as the team can tell from extensive surveying, the rats have been eradicated.

Kamaka was an ideal location for this type of intervention, says Island Conservation, because it has very few land birds and no other small mammals that could be affected by the rodenticide. “No native species were harmed during the removal of invasive rats from Kamaka Island,” Esposito said.

The conservation team also studied the birds’ preferred habitat on Manui Island and used this knowledge to create optimal nesting conditions on Kamaka. The team installed solar-powered speakers playing recorded bird calls from the Manui colony and built “luxury burrows” equipped with cameras to monitor birds’ activities.

“We’re looking for ridge lines where they could access the site, and then we’re also looking for certain vegetation characteristics,” Wolf told Mongabay. “You want enough trees that are creating [ground] burrowing habitat, but at the same time making sure that there aren’t too many trees that they can’t access those sites.”

The team also collected and planted native sedges and grasses while removing invasive trees to enhance nesting conditions.

Their monitoring equipment documented a gradual increase in storm petrel activity throughout this year. Initial sightings in April and May led to consistent visits a few months later, with the birds showing particular interest in the artificial nesting sites and areas near the acoustic equipment.

“The results of our social attraction efforts were quickly apparent,” Thomas Ghestemme from the Ornithological Society of Polynesia (SOP MANU), a local organization that helped with the restoration efforts, said in a statement. “Polynesian storm-petrels began visiting at the start of the nesting season and became regular visitors, while also spending time in the nest boxes.”

However, actual nesting hasn’t yet been confirmed. “Right now, based on our review of all the camera trap data, we can’t say how many individuals we had visiting the site. We can say how frequent they were coming,” Wolf said. “Right now, we’ve only seen one at a time, so we know that they’re coming relatively regularly during the breeding season.”

Community involvement proved crucial to the project’s success. “We are committed to working with the island communities that provide in-depth knowledge of these environments,” Richard Griffiths, head of operations for the South and West Pacific at Island Conservation, said in a statement. “We simply could not have completed the Kamaka project without their time, skills, expertise, and relentless energy.”

The project is part of the Island–Ocean Connection Challenge, which aims to restore 40 island ecosystems by 2030.

Preventing extinctions has larger ecosystem benefits, Esposito said. “The return of nutrients from seabirds benefits the soil, which runs off to the marine environment and builds climate resilience, secures livelihoods, and human health.”

This article by Liz Kimbrough was first published by Mongabay.com on 14 December 2024. Lead Image: Polynesian storm petrels (Nesofregetta fuliginosa) near Rapa Iti Island, French Polynesia by Hadoram Shiriai.

Being publicly-funded gives us a greater chance to continue providing you with high-quality content.