Caretakers released six Guam kingfishers, a bird species known locally as sihek, into the wild on Palmyra Atoll on Sept. 23, marking their first free flight in nearly four decades and a triumphant return from being classified as “extinct in the wild.”
“Our Guam Sihek, a symbol of our island’s beauty, with their cerulean blue and cinnamon coloration mirroring our ocean blue water and red-orange sunsets, have been achieving the seemingly impossible,” Yolonda Topasna, from the Guam Department of Agriculture’s Division of Aquatic and Wildlife Resources, said in a statement. “Today, the Sihek were set free from their aviaries! Their return to the wild is a testament to our people’s spirit and our commitment to preserving our heritage.”
The sihek (Todiramphus cinnamominus) was once endemic to the forests of Guam, an island in the western Pacific that is today a U.S. territory. The accidental introduction of the brown tree snake (Boiga irregularis) in the 1940s devastated the island’s native wildlife, including many local birds whose eggs were eaten by the snakes.
A rescue operation in the 1980s brought 29 birds into captivity. These individuals formed the foundation of a breeding program that has kept the species alive for the past 35 years, even as the sihek was declared extinct in the wild by 1988.
Finally, on Sept. 23, 2024, six young 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) east of Guam.
The journey to this release began earlier in the year when the first sihek chick of the season hatched in April at Sedgwick County Zoo in the U.S. state of Kansas. Given that only 45 breeding females remained in the world at that time, the hatching was a big win for the program. A team of specialists, including keepers from the Zoological Society of London’s Whipsnade and London zoos in the U.K., provided round-the-clock care for the chick.
The birds were transported by plane to the atoll in late August, where they underwent a period of acclimatization before their release. Researchers will provide supplemental food to help the sihek transition to foraging 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, allowing 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 next few months will be critical as the birds establish territories and potentially begin breeding.
“It has been a multiyear endeavor to get the birds to this point, from breeding the sihek, incubating the eggs, hand rearing the chicks and now releasing them in Palmyra,” said Erica Royer, an aviculturist from the Smithsonian’s National Zoo and Conservation Biology Institute in Washington, D.C., U.S. “As someone who cares for sihek on a daily basis, it is monumental to be able to reintroduce these individuals into the wild after more than three decades.”
The release is part of a larger plan to establish a breeding population of 10 pairs of sihek on Palmyra Atoll, a fully protected U.S. Fish and Wildlife Service National Wildlife Refuge. Scientists say they hope this will serve as a stepping stone toward the ultimate goal of returning the sihek to its native Guam once the threat from brown tree snakes there is adequately addressed.
This historic event is the culmination of years of collaborative work by the Sihek Recovery Program, a partnership dedicated to reestablishing the species in the wild and involving the U.S. Fish and Wildlife Service, Guam Department of Agriculture’s Division of Aquatic & Wildlife Resources, Zoological Society of London, The Nature Conservancy, Sedgwick County Zoo, and the Association of Zoos and Aquariums.
However, having only a handful of individuals left in a species is risky, especially if they’re all in one place. Events like natural disasters, disease, lack of commitment from institutions maintaining these populations, or just the random bad luck of having a generation of offspring that are all one sex could end a species.
Donal Smith, a postdoctoral researcher at ZSL, pointed to the Catarina pupfish as a cautionary tale. This small freshwater fish disappeared from the wild in 1994, partly due to groundwater extraction from the native springs where it lived in northeastern Mexico. There were still some fish in captivity, but because of poor coordination and communication among their caretakers, the fish went extinct in captivity 20 years after going extinct in the wild.
“By the time people realized there was a crisis,” Smith said, “it was too late to act.”
“Conservationists, and society more widely, must do better,” Smith wrote in an op-ed with conservation ecologist Sarah Dalrymple. “We know that outright extinction is a real threat.”
Extinction is not only a threat but a harsh reality. Scientists agree we are experiencing a mass extinction event. Previous major extinctions, like the one that wiped out the dinosaurs, were caused by catastrophes such as volcanic eruptions, depletion of oxygen, and asteroid impact. Each of these events wiped out an estimated 70-90% of life on Earth at the time.
Our current extinction crisis is caused by humans, driven by habitat destruction and fragmentation, poaching, illegal trade, overharvesting, the introduction of nonnative and domesticated species into the wild, pathogens, pollution, and climate disruption.
When it comes to extinction, there is some hope. Several extinct-in-the-wild species have been successfully reintroduced, such as the red wolf (Canis rufus), Española giant tortoise (Chelonoidis hoodensis), Przewalski’s horse (Equus ferus przewalskii), California condor (Gymnogyps californianus), Ko’ko’ bird (Hypotaenidia owstoni), Arabian oryx (Oryx leucoryx), black-footed ferret (Mustela nigripes), tequila splitfin fish (Zoogoneticus tequila), Yarkon bream (Acanthobrama telavivensis), the Mediterranean flower Diplotaxis siettiana, and the Hawaiian tree Hibiscadelphus giffardianus, revived from the single remaining tree on the Big Island.
Keeping a species alive and healthy in captivity or cultivation takes tremendous work, resources, coordination, and long-term commitment. “Thanks to decades of tireless work saving species,” Smith said, “we have the opportunity to reestablish more populations in the wild; it’s imperative that conservation zoos, aquariums, botanical gardens and seed banks are given the financial — and intergovernmental — support to do so.”
This article by Liz Kimbrough was first published by Mongabay.com on 25 September 2024. Lead Image: A sihek in Sedgewick County Zoo. Image courtesy of Thomas Manglona / KUAM.
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