Guam kingfisher: Reintroduction to Palmyra after extinction in the wild

The Guam kingfisher, last seen in the wild in 1986, is now poised to return to nature. After successful breeding in captivity, it is planned to release the offspring of this nearly extinct bird species on Palmyra Atoll. This remote atoll, located about 1,600 kilometers southwest of Hawaii, offers a safe habitat, free from land predators, making it the perfect place for reintroduction.

The Guam kingfisher (Todiramphus cinnamominus cinnamominus) was once native exclusively to the island of Guam in the Western Pacific. However, the population of this species was decimated after the accidental introduction of the invasive brown tree snake (Boiga irregularis) in the 1940s or 1950s.

Due to the lack of natural predators, the snake species found ideal conditions and was able to rapidly increase in number – with an estimated density of more than 10,000 individuals per square kilometer. As efficient predators of bird eggs and young birds, this led to the extinction of the Guam kingfisher in the wild. Today, nearly all of Guam’s formerly endemic bird species are gone or extinct, including the Guam flycatcher (Myiagra freycineti) and the bridled white-eye (Zosterops conspicillatus).

The reintroduction of the Guam kingfisher to Palmyra is part of a broad initiative aimed at preserving this bird subspecies through the release of specimens bred in captivity. Originally, there were plans to also reintroduce the Guam kingfisher to its native habitat on the island of Guam. However, as Caitlin Andrews, a bird conservation scientist at the Nature Conservancy Hawaii and Palmyra, explained to ABC Pacific, a return is currently not possible: “Unfortunately, we can’t put them back on Guam because the snakes are still there.” Therefore, suitable protected areas must first be established on Guam and further measures taken to combat the threat posed by the brown tree snake.