Bird species lost from wild for almost 40 years lays first eggs on new island home

04/21/25 - Sihek – an endangered bird recently returned to the wild – have laid eggs on their new Pacific island home at Palmyra Atoll, making them the first wild eggs for the species in almost 40 years.

Nine young Sihek – also known as Guam kingfishers – hand-reared by zookeepers, were released at The Nature Conservancy’s (TNC’s) Palmyra Atoll Preserve in September 2024 by the Sihek Recovery Program, a global collaboration of conservationists dedicated to rewilding these magnificent, colorful birds. 

The team behind the project are now celebrating as the eggs mark how the birds have flourished since their arrival to the Pacific Atoll, located about 1,000 miles south of Honolulu, Hawaiʻi. 

After their remarkable release last autumn, the four female and five male birds quickly explored their new home, learning how to forage and hunt new prey within the tropical forest. Four pairs have since established territories, built nests, and three of the pairs have laid eggs, marking the first time the species has bred in the wild since its extinction from their native island of Guam in the 1980s.

“We’re delighted that all nine of the birds are not only surviving on Palmyra Atoll, they’re already starting the next stage of their journey as we work to reestablish a thriving and fully self-sustaining Sihek population in the wild,” says Dr. Caitlin Andrews, Bird Conservation Scientist with TNC’s Island Resilience Strategy and ZSL (Zoological Society of London). “It’s taken years of planning to get to this point, and it’s wonderful seeing their instincts kick in as they’ve been catching geckos and spiders and excavating nests. Their strength provides hope they will one day be back on Guam.” 

With the mated pairs less than a year old, this is their first time incubating and caring for eggs, meaning it’s likely it will take a few rounds of egg laying for the birds to hone their skills and hatch chicks. Nonetheless, these eggs demonstrate both the tremendous resilience of these remarkable birds and the power of conservation to create a second chance for species on the brink of extinction. 

Sihek, as the birds are known by the indigenous CHamoru* people of Guam, also known as Guåhan, were decimated when the brown treesnake was accidentally introduced to the island in the 1940s. The last wild Sihek was seen in 1988. But as the population crashed, Guam biologists brought 29 Sihek under human care, starting a conservation breeding program in Association of Zoos and Aquariums (AZA)-accredited zoos across the United States (US). 

Palmyra Atoll was selected as the home for the first wild Sihek in almost 40 years because it is largely predator-free and fully protected. TNC’s Palmyra Preserve is encompassed by the U.S. Fish and Wildlife Service’s Palmyra Atoll National Wildlife Refuge (out to 12 nautical miles) and by the Pacific Islands Heritage Marine National Monument (out to 50 nautical miles), one of the largest swaths of ocean and islands protected in the world. Protected regions like Palmyra Atoll are essential to protecting biodiversity as wildlife globally continues to face threats such as habitat loss and climate change.   

The Sihek released at Palmyra Atoll last fall are the result of a cooperative of the following institutions who either contributed eggs to be hatched or staff to assist with their care: Brookfield Zoo Chicago, Cincinnati Zoo & Botanical Garden, Disney’s Animal Kingdom, National Aviary, Sedgwick County Zoo, Smithsonian’s National Zoo and Conservation Biology Institute, Tracy Aviary, and ZSL’s London and Whipsnade Zoos. The eggs were hatched and raised by staff members of the cooperative institutions in a purpose-built facility at Sedgwick County Zoo in Wichita, Kansas, where they received expert care until they were mature enough to make the journey to the atoll. Some of the birds were named in an online voting process and with ongoing care at Palmyra Atoll, the team has become deeply connected with each individual bird.

“The Guåhan Sihek continue to etch their story upon us, marking milestones with Tutuhan again at the forefront! Tutuhan was the first hatchling last year and now is the first to produce eggs. Her name means beginning and she showed signs of strength from the beginning, wanting to feed herself before being old enough to do so,” says Yolonda Topasña, Guam Department of Agriculture Division of Aquatic and Wildlife Resources (DAWR) Program Coordinator. “Tutuhan challenged two other females for Hinanao’s partnership and won! Now our pair take turns watching over their precious eggs,” she says. 

“The connection I feel with Tutuhan is a kinship I hope for all to feel. I envision our people, the CHamoru, those who dwell in our beloved Guåhan and those scattered across the vast oceans, to feel the same stirring of ancestral pride,” shares Topasña. “A dear friend in Washington, but whose roots run deep on Guåhan, shared a memory, a vision of Sihek soaring freely over their lancho (farm) in Dededo, in the mid-1970s. My friends’ father warned the family to leave Sihek alone and they respected and obeyed. These are the stories that bind us, the whispers of our past that illuminate our present. These conversations are what will bring us all together to celebrate the lives of the Sihek thriving on Palmyra Atoll and in turn, will help us all take pride in our culture and heritage.”

Plans are underway for more young Sihek to be released at Palmyra Atoll this summer. 

Egg laying season is underway at participating AZA-accredited institutions across the US. When they grow to maturity, these chicks will also journey to Palmyra, with the ultimate goal of establishing ten breeding pairs there. This project paves the way for a growing, wild Sihek population for the first time since the 1980s.

“It has been the honor of my life to work with the Sihek, who embody the spirit of the CHamoru people, with their incredible resilience and adaptability in the face of adversity,” says Kayla Baker, Senior Bird Conservation Specialist with TNC’s Island Resilience Strategy and ZSL. “Seeing the eggs in the nest for the first time left us all with tears in our eyes. Watching these birds show such strong parental instincts gives me great hope that the Sihek will continue to thrive both here on Palmyra Atoll and when they are returned home to Guåhan.” (Press Release)