HONOLULU — The population of white terns in Honolulu increased by more than 50% over the past decade, with 691 eggs and chicks counted in trees across the city as of April 2026. Disease and introduced predators have caused populations of many native Hawaiian bird species to collapse.

A 2023 population survey by Hui Manu-o-Kū found that the number of breeding adult white terns on Oahu rose 1.5 times to 3,600 compared to 2016. Oahu, home to about one million people, is the only major Hawaiian island where white terns have settled. Scientists first observed the species breeding on the island in 1961, when they spotted a pair of adults with a single egg.

"This is our big city. It's crazy to me that they're getting to such a big population within Honolulu," said Kaʻiulani Murphy, a Polynesian voyaging navigator. "It's just a special feeling," Murphy said.

Globally, white terns are found near islands in warm waters, and in Hawaii they primarily inhabit remote, mostly uninhabited atolls in the northwest of the archipelago. The birds, which have a body length similar to pigeons but a larger wingspan, hunt for food at sea and lay eggs on land. They can fly up to about 120 miles (193 kilometers) from land and feed on small fish and squid driven to the ocean surface by larger species such as tuna. White terns can breed year-round, with breeding activity peaking from winter into early spring.

White terns are the only seabirds that lay eggs on bare surfaces instead of building nests, placing their eggs on bare tree branches, cliff ledges or window sills. After hatching, young terns remain on a branch until they can fly, using their strong claws to hold on during storms.

Since human arrival in Hawaii, 71 of the 113 bird species endemic to the islands have gone extinct, and many of the remaining native species are listed as threatened or endangered. The remaining native Hawaiian bird species are often found in small populations in higher-elevation forests.

Hui Manu-o-Kū, named after the Hawaiian name for the white tern meaning "bird of Kū," the god of war, works to protect the birds in the urban landscape. Staff members tie blue plastic ribbons around the trunks of trees containing white tern eggs and chicks to alert tree trimmers to avoid those trees. The ribbons and an online map also help bird-watchers monitor the terns across the city.

Honolulu designated the white tern as its official bird in 2007, and an annual festival celebrating the species is held each May. School children in Honolulu sing songs about the bird. Photographer Joyce Hsieh has spent eight years documenting white terns during egg incubation, feeding of young and hatchling rearing. Hsieh's preferred location is a Target parking garage, where she drives to the third floor to photograph the birds in nearby trees.