12 May 2024

An extinct-in-the-wild sihek (also known as Guam kingfisher) has successfully hatched, marking a key milestone of an ambitious project to return the species into the wild.  

We are part of The Sihek Recovery Program,  an international collaboration between wildlife experts across the world who are working together to restore a wild population of this species, which is currently only found in human care.  

The female chick hatched on 28 April at Sedgwick County Zoo in Kansas, US, and is being cared for around the clock by a team of specialists to ensure the precious youngster’s survival – including two keepers from our conservation zoos, London and Whipsnade, who travelled to the US as part of the organisations wider initiative to recover extinct-in-the-wild species.  

What are siheks?

Known as sihek by the indigenous CHamoru* people, the species once flourished on the North Pacific island of Guam. However, the accidental introduction of the brown tree snake to the island in the 1940s wiped out many native birds, bats and lizards.  

The last wild sighting of sihek was in 1988 and the birds are now considered Extinct in the Wild by the IUCN. There are currently only 141 sihek left in the world, all under human care. Now the sihek Recovery Program is working to establish a temporary wild population on the island of Palmyra Atoll - where there are no invasive snakes or other predators such as rats - before their eventual return to Guam. 

Sihek (Guam kingfisher) sitting on branch
A 10 day old sihek chick

How are conservationists working to save siheks? 

Nine zoos across the US are taking part in the collaborative breeding programme of the sihek in preparation for this year's hopeful release. With only 45 breeding females left in the world, this female chick is vital to restore this species back to the wild.  

The first chick was hatched from an egg which was transported more than 1000km across the US, from Cincinnati Zoo, Ohio, to the central facility at Sedgwick County Zoo where a team of specialists – including two of our expert bird keepers - were ready and waiting to help rear the precious arrival.  

Bird keeper Charlotte James from London Zoo said: “Each egg is about the size of a marble, so monitoring them requires a lot of care and patience. It's such a priceless moment seeing the first signs of hatching as these tiny eggs start to crack, revealing an invaluable new member of this unique species beneath their hard shells."

While the chick is currently enjoying a nutritious diet of mice and insects provided by her carers, in the forests of Palmyra Atoll the birds will have to learn to hunt and forage for everything from insects to geckos

Conservationist works with a chick of the extinct in the wild sihek
A newly hatch Guam kingfisher chick is being fed by keepers

Charlotte added: “Looking after these chicks during hatching is just the start of our work. With her eyes closed, a distinct lack of feathers and weighing no more than a pencil, this chick entered the world rather strange looking and completely dependent on us. But in just 30 days, she’ll have grown almost ten times heavier and be covered in beautiful blue and cinnamon-coloured plumage. From feeding, weighing and monitoring them, we’re using the knowledge we've gained from raising chicks previously to make sure we’re giving these birds the strongest possible start.  

"Despite their small size, each individual is a huge beacon of hope for the future of this species.” 

Rebuilding a wild population of siheks

Yolonda Topasna, from the Guam Department of Agriculture’s Division of Aquatic and Wildlife Resources said: "We’re all thrilled that this year’s first chick has hatched and is doing so well. These beautiful birds haven’t sung in the forests of Guam for over 30 years, but this exciting moment brings us one step closer to the release of Guam sihek onto Palmyra Atoll - a pivotal step towards the eventual reintroduction of this stunning creature to Islan Guahan."

With more chicks due to hatch over the coming weeks, the collaborative Sihek Recovery Program hopes to release nine chicks onto the predator-free zone and fully protected island of Palmyra Atoll later this year. Here the birds will continue to be raised in aviaries at The Nature Conservancyʻs preserve at Palmyra Atoll until they are ready to be released into the wild across the atoll and into the U.S. Fish and Wildlife Service National Wildlife Refuge, making them the first wild population of sihek in almost 40 years. The releases will be repeated annually until 20 sihek successfully establish as breeding pairs. They will then be tracked and monitored, before hopefully raising the first wild-born sihek chicks since the 1980s.  

Gloved hand holds a tiny egg
Sihek Guam Kingfisher © John Ewen, ZSL
© John Ewen, ZSL

Rescuing species from the brink of extinction

Professor John Ewen, from ZSL’s Institute of Zoology and Sihek Recovery Program Team Chair said: “Conservation zoos have played a vital role in saving these birds from certain extinction through a recovery operation initiated in the 1980s with an ongoing breeding programme. Now, in a growing global partnership, we’re working towards the next exciting step of releasing sihek back into the wild, first on Palmyra Atoll where they will find a safe wild home to thrive in, but ultimately then to a snake-free Guam.”

John also underlined the complexity involved in re-establishing a wild sihek population: “Returning species to the wild is a long, carefully planned-out journey built upon global scientific expertise. When a species is as close to the edge of extinction as the sihek, low population numbers mean we often face challenges such as a lack of eggs and reduced fertility. As a result, only 1 of the 7 eggs that have made the journey to Sedgwick County Zoo so far has successfully hatched – highlighting not only how special this tiny chick is, but why it’s so vital that we continue to build large populations of Extinct in the Wild species under human care and work as quickly as possible to restore their wild numbers.

“We're hoping to release nine chicks on Palmyra Atoll later this year - but this all depends on what happens over the next few weeks.”

However, the team remain hopeful for the future of this colourful bird. John continued: "It’s still early days on the road to establishing a thriving wild population of sihek, but we know from other successes – such as the 2023 downlisting of the previously Extinct in the Wild scimitar horned oryx after the antelope’s reintroduction to Chad - that we can reverse the fate of the species on the very brink of extinction. Siheks deserve a chance to flourish in the wild once again – and it’s well worth taking our time to get it right.” 

 *“CHamoru” (capitalizing “CH”) is recognized by the CHamoru Language Commission as the orthographically correct spelling.


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