Rare Peruvian Diving-Petrels Nesting on Chañaral Island Following Decades of Absence

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By Island Conservation

A growing chick demonstrates the success of the project to restore this threatened bird on the largest historical nesting site in Chile.

For the first time in more than 40 years a Peruvian Diving-petrel chick has hatched on Chañaral Island, representing a significant milestone on an island once devastated by invasive species. Team members from nonprofit Island Conservation, working in partnership with Chile’s National Forestry Corporation (CONAF), The Nature Conservancy and Universidad Católica del Norte, discovered a downy chick in a naturally dug burrow – a breakthrough that offers hope for a species considered “endangered” by the International Union for the Conservation of Nature (IUCN) just two years ago.

AN ISLAND HEALING FROM DESTRUCTIVE INVASIVE SPECIES

Peruvian Diving-petrels (known locally as “yuncos”) are small ground-nesting seabirds endemic to the Humboldt Current System that flows along the western coast of South America. Chañaral Island, located just a few miles off the coast of Chile, once supported what may have been the world’s largest population of the species before invasive rabbits and foxes were introduced many years ago. Coral Wolf, Conservation Science Program Manager at Island Conservation, explains the negative impact this had over the years:

First deployment site Monitoring team two years after implementation. ©Maria Jose Vilches

“Rabbits and foxes decimated the island’s sensitive desert landscape. Foxes fed on yuncos, while rabbits ejected them from their nests, and stripped bare the herbs and shrubs. As a result, Diving-petrel numbers decreased dramatically. Eventually, no Diving-petrels were living on Chañaral, and within the region they could only be found on a handful of islands. They were at risk of global extinction.”

However, in 2013, in an effort to restore and rewild the Humboldt Penguin National Reserve, Island Conservation and CONAF began a project to remove the invasive rabbits from Chañaral and neighboring Choros Island.

“Since the invasive rabbits were successfully removed in 2017, and with no foxes on the island for many decades, we have been focused on re-establishing the Peruvian Diving-petrel population and building resilience for them and the many other species unique to this region,” says Wolf.

USING SOCIAL ATTRACTION TO REVIVE THE POPULATION

CONAF monitoring artificial and natural burrows with a borescope. ©CONAF

In September 2019, Island Conservation, CONAF and Universidad Católica del Norte (with technical support from Project Puffin) initiated a social attraction project on Chañaral. Social attraction methods leverage the natural behavior of seabirds by mimicking the sights and sounds of a real breeding colony, for example by broadcasting bird calls on a sound system. Cristian Rivera, Chañaral Island Park Ranger in the Humboldt Penguin National Reserve, details the unique approach on Chañaral:

“We used artificial PVC nests and two sets of solar-powered speakers that play petrel calls to attract nearby adults to nest on the island,” he recalls. “This was one of the first projects of its kind on any Chilean island. Only a few days after the two sound systems were installed, petrels began arriving on the island to explore the surroundings.”

A long-term monitoring project was then initiated, with funding provided by American Bird Conservancy (for the first year) and The David and Lucile Packard Foundation. Relatively quickly, motion-sensing cameras documented the frequent presence of the petrels at the two established social attraction sites. Additionally, many footprints were recorded exploring artificial nests, and a year and a half after project implementation, the construction of the first natural burrows was detected.

“Just three years after starting the project, our team had already found three naturally dug burrows, and an incredible surprise was waiting within them,” Rivera explains. “Using a burrowscope, which allows one to see deep inside a nest chamber, we were able to observe our first documented Peruvian Diving-petrel chick on the island in at least 40 years!”

The field team installed the sound box for the social attraction. ©Island Conservation

A MODEL FOR GLOBAL SEABIRD CONSERVATION AND A BRIGHT FUTURE FOR CHANARAL’S YUNCOS

Seabirds are the most threatened of all bird groups globally. However, Dr. Nick Holmes, Associate Director for Oceans at The Nature Conservancy of California, highlights the value of restoration methods like social attraction to reverse this trend:

“Seabird restoration approaches like social attraction have high success rates and are powerful ways to protect threatened populations and restore the key roles of seabirds to island ecosystems,” he explains. “Restoring Chañaral as a yunco breeding colony once again strengthens population resilience across the entire Humboldt Current.”  

Island Conservation Island Restoration Specialist María José Vilches says the success will have a knock-on effect on conservation in the region:

Peruvian Diving-Petrels in the surroundings of Chanaral Island. ©Ivan Torres

“The lessons learned from the social attraction sites on Chañaral have catalyzed interest in deploying social attraction tools at additional, appropriate sites nearby,” she says. “For example, Island Conservation is planning to add Peruvian Diving-petrel social attraction sites on Pajaros Uno Island, where we successfully removed invasive rats that were mistakenly introduced by humans, and in just a short period had made it impossible for the yuncos colonies to survive. This work offers hope to these incredible creatures, which were on the brink of losing their natural habitat permanently.”

This project doesn’t just benefit the local yunco habitats; the islands form part of an interconnected coastal system that is vital to multiple endemic plants and animals. 

“The Humboldt Current Upwelling System contains biodiversity of global importance,” explains Guillermo Luna from Universidad Católica del Norte. “What’s more, there are communities that rely on sustainable ecosystems for fishing and tourism. That’s why it’s vital to integrate all these coastal islands into a comprehensive conservation and management system.”

For Jorge Carabantes, Head of Protected Wilderness Areas at CONAF Atacama, the results obtained to date are a welcome surprise, and offer hope that the island could return to its natural state. 

Carbantes said, “Not only did we focus on the destructive rabbits, but we worked to control several other invasive species, such as aggressive Mesembryanthemum (ice plant). With continued planning, implementation and patience, we offer Mother Nature a hand in achieving ecological balance.”  

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©Ivan Torres

Island Conservation is our world’s only international nonprofit conservation organization dedicated solely to preventing extinctions on islands. Our collaborations with local island communities aim to improve livelihoods, manage invasive species, and reintroduce native animals and plant life. Island Conservation is a United States-based 501(c)(3) charitable organization working through diverse local and international partnerships to foster sustainable development, climate resilience, and healthy island-marine ecosystems across the globe.


This piece was prepared online by Panuruji Kenta, Publisher, SEVENSEAS Media