New chick observed, marking second year in a row for nesting of grey-backed terns at Palmyra Atoll

A second grey-backed tern chick has been documented at Palmyra Atoll, further validating that seabird attraction efforts are working, according to leaders with The Nature Conservancy. Science volunteers Oliver Dunn and Cassidy Crittenden observed the chick in mid-May as part of their monthly monitoring of the seabird social attraction project on Barren Island.

This marks the second year in a row grey-backed terns have nested at Palmyra Atoll. This bird is one of eight seabird species known to the region that has been conspicuously absent from the atoll, likely due to invasive rats that were introduced during the World War II era. In 2011, rats were successfully eradicated from Palmyra Atoll and in 2020 scientists began deploying social attraction techniques including hand-painted seabird decoys mimicking colonies and “seabird discotheques” that play the calls of targeted, absent seabird species 24/7, according to TNC.

“This is very exciting news,” said Katie Franklin, Island Conservation Strategy Lead for The Nature Conservancy, Hawaiʻi and Palmyra. “Our science volunteers Oliver and Cass saw five adults in the last month and three adults in the area near the chick. They also saw an adult feeding a chick. Thanks to their efforts, we have more data to show that our seabird attraction efforts are working.”

Grey-backed terns (Sterna lunata), or Pākalakala in Hawaiian, are found in Hawai‘i as well as other remote islands across the Pacific. While they are not endangered, they are especially vulnerable to invasive predators as they lay a single egg per season. They feed on small fish and squid, according to TNC.

“This is a very important milestone in our seabird restoration program and it emphasizes the regional importance of Palmyra’s protected habitat,” said Alex Wegmann, Lead Scientist for TNC’s Island Resilience Strategy. “It also emphasizes the value of decades of conservation and management by TNC, the US Fish and Wildlife Service and our many partners, as well as the efficacy of seabird social attraction methods.”   

Approximately 30% of seabirds are endangered, making them one of the most threatened bird groups on the planet. They play a vital role in island ecosystems—their guano provides nutrients for plants and trees on land and directly increases the health and resilience of coral reefs and fish. TNC says providing safe havens that are predator-free, like Palmyra Atoll or areas with predator-proof fencing, gives these birds a chance to thrive.