There is good news for a bird called the Guam kingfisher, which was declared extinct in the wild in 1988 due to predation from brown tree snakes.
The Guam kingfisher comes from Guam, a tropical island in the western Pacific Ocean. It is the largest island in the chain of islands called Micronesia.
The unwelcome predator of Guam
The brown tree snake lives in Asia. It is a venomous snake that eats birds, lizards, and small mammals. It also lives on Guam, but it is not a native species.
During the Second World War, brown tree snakes found their way to the island. It is thought they snuck into supplies being transported from some part of Asia. This was a great opportunity for the snakes: they found themselves in a new habitat with good food, no competition from other snakes, and nothing trying to eat them.
The arrival of the brown tree snake was a catastrophe for the native birds of Guam
Before the brown tree snake arrived, there were no venomous snakes on Guam. And the birds, lizards, and small mammals on Guam never evolved defenses to protect themselves against snakes. The rapidly multiplying brown tree snakes ate birds and eggs in great numbers and drove several bird species extinct in the wild.
The rescue of the sihek
The Guam kingfisher is known locally on Guam as sihek. The sihek is one of the species that went extinct in the wild due to the brown tree snake.
A rescue operation in the 1980s brought 29 sihek individuals into captivity. These individuals formed a breeding program that has kept the species alive for the past 35 years.
On Sept. 23, 2024, six young captive-raised sihek were released from their temporary aviaries into the lush forests of Palmyra Atoll, a predator-free sanctuary about 5,900 kilometers (3,700 miles) west of Guam. Palmyra Atoll is a fully protected U.S. Fish and Wildlife Service National Wildlife Refuge.
The birds were transported by plane to the atoll in late August 2024, where they underwent a period of acclimatization before their release. Researchers will provide supplemental food to help the sihek transition to feeding in the wild, where they will need to hunt insects, geckos, and other small prey.
Each released bird has been fitted with a tiny radio tracker. These will allow researchers to monitor their movements, habitat use, and eventual breeding activities. The data will be crucial for understanding how the sihek adapts to life in the wild after generations in captivity.
The sihek release is part of a larger plan to establish a breeding population of 10 pairs of sihek on Palmyra Atoll. Scientists hope this will serve as a stepping stone toward the ultimate goal of returning the sihek to its native Guam. The release on Guam depends on finding solutions to the threats from brown tree snakes.
David Brown adapted this story for Mongabay Kids. It is based on an article by Liz Kimbrough, published on Mongabay News:
