For the first time in decades, Peruvian diving petrels, small seabirds known locally as “yuncos,” have returned to nest on Pajaros Uno Island. These birds, which feed in the offshore waters off the coasts of Peru and Chile, had abandoned the island more than 40 years ago due to invasive rats which were eating their eggs and chicks. The birds recently returned to Pajaros Uno Island after the success of Island Conservation’s multi-year rat eradication and implementing tools to bring the birds back. 

Island Conservation is an international organization dedicated to restoring islands for both nature and people. They lead island-marine ecosystem projects that aim to improve community livelihoods, enhance climate resiliency, manage invasive species, and reestablish native animals and plants. Their work to eliminate invasive rats on Pajaros Uno Island began in August 2020. Rats are not a native species to the island and likely arrived as stowaways on visiting boats. Invasive rats prey on animals like seabirds and often outcompete native species, pushing many to face extinction/to the brink of extinction. 

Two years after the start of Island Conservation’s project, the island was declared predator-free.  

Then, Island Conservation scientists installed sound systems on the island to play recordings of the Peruvian diving petrel’s bird call, hoping to draw the birds back to their homes. Island Conservation and partners had previously proven the success of this method on the nearby island of Chañaral. 

Not long after, Island Conservation’s field cameras captured photos of nesting pairs of Peruvian diving petrels on the restored island. 

“It was so thrilling to discover these nesting pairs so soon after the island was restored,” said María José Vilches, Island Restoration Specialist at Island Conservation. “We were preparing dinner and heard the Peruvian Diving-petrels’ call. We quickly took a GPS and a flashlight and ran towards the source of the sound while putting on our shoes. We couldn’t believe it when we found the burrows.”

Vilches said that knowing the birds will be safe from predators gives her hope for the survival of the species. Pajaros Uno Island is home to multiple colonies of Chilean seabird species, including Peruvian Boobies, Kelp Gull, and Humboldt Penguins. Seabirds play a crucial role depositing vital nutrients like nitrogen, phosphate, and potassium that enrich both land and ocean ecosystems. 

Restoring the population of seabirds to the island will reinstate the essential nutrient flow, enhancing the health and resilience of both terrestrial and marine ecosystems. 

Eradicating the rats and the return of the Peruvian diving petrels will also make it safer and more sanitary for the local fishermen who stay on the island and boost economic development opportunities for the local fishing community to expand into sustainable tourism related to the rare birds. 

“This project’s success will also have huge implications for restoration work beginning in Peru,” said Jose Luis Cabello, Island Conservation’s Head of Operations in Latin America. 

Cabello and his team will use what they’ve learned working on Pajaros Uno Island to help restore ecosystems along the entire Humboldt current that spans from southern Chile to Ecuador. 

Oceanic islands in this region and around the world where seabirds breed represent a disproportionately large conservation need and opportunity. The removal of invasive species is a proven tool for recovering endangered seabird species populations and can promote the sustainable development and climate-change preparedness of the many communities that share their islands with seabirds. 

The Packard Foundation is continuing to partner with Island Conservation in their work to protect and restore threatened seabird species across the globe and to work with local communities to promote climate resiliency. Island Conservation’s work on Pajaros Uno Island was also supported by the National Fish and Wildlife Foundation.  

Photos and videos courtesy of Island Conservation