Guam Kingfishers, Struggle With Reproductive Diseases in Captivity, Study Shows

The Guam kingfisher, or sihek, is one of the rarest birds in the world. It has been extinct in the wild for more than 30 years, due to the invasion of the brown tree snake that decimated its population.

However, thanks to the efforts of conservationists, zookeepers and scientists, there is hope for its recovery and reintroduction to its native habitat.

A recently published paper in Animal Conservation provides crucial insights into the health of sihek, revealing the challenges and opportunities for their survival.

The Gender Gap: Why Female Sihek Are More Vulnerable Than Males

(Photo : JACK GUEZ/AFP via Getty Images)

One of the findings of the paper is that female sihek are at greater risk for death and disease than their male counterparts.

The researchers examined the causes of death in the birds and found differences between males and females.

Females succumbed to reproductive diseases-a phenomenon not observed in males. The incidence of reproductive diseases among female sihek was also notably higher than in other avian species.

The paper's principal investigator, Dr. Amanda Trask from The Zoological Society of London, said that it is still unclear why this is occurring, but added that the team's upcoming research will delve into a potential correlation with increased egg production.

Other causes of death, such as nutritional and metabolic diseases, were seen in both males and females, but females tended to succumb at younger ages than males.

Trask thanked the Morris Animal Foundation for supporting her work and said that they must continue to review and build upon existing knowledge of their care to ensure that the species has the best possible chance.

She also said that the sihek is a species on the very brink of being lost forever-and it is only due to the care and expertise of conservation zoos that these birds still exist, giving them a chance to return to the wild.

Also Read: Saving Colorful Guam Kingfisher: Scientists Hopeful To Conserve Declining Bird Population

The Countdown: How 3D Printing Technology Is Preparing Sihek for Reintroduction

Another challenge for sihek conservation is how to track and monitor them once they are released into the wild.

Scientists need to determine which harness materials can carry a tracking device and stand the test of time.

That's where six of the Smithsonian Conservation Biology Institute's (SCBI) kingfishers come in. They are participating in "test flights" using replica transmitters made by 3D printing technology.

Bird keeper Erica Royer from SCBI said that they are working with other Sihek Recovery Team partners to crack the code of how to care for and breed this amazing species.

She said that siheks are considered extinct in the wild by the International Union for Conservation of Nature and that their numbers are growing thanks to intensive captive breeding and conservation efforts.

SCBI hatched its first chick in 1985 and since then, 22 chicks have hatched there as part of the Association of Zoos and Aquariums' Guam Kingfisher Species Survival Plan.

Today, there are 140 individuals in human care, and SCBI cares for 12 of them.

The goal is to reintroduce sihek into their native Guam forests or other suitable habitats, such as the Palmyra Atoll.

However, Guam still can't sustain wild sihek because of the brown tree snake's unyielding presence, despite extensive eradication efforts.

Therefore, scientists need to find alternative locations where sihek can thrive and be protected from predators.

Royer said that they are using 3D printing technology to create different types of harnesses and transmitters that can fit sihek comfortably and securely.

They are testing them on six birds at SCBI to see how they affect their behavior, flight performance and health. They are also collecting data on how long the harnesses last and how well they transmit signals.

She said that this is a crucial step toward reintroducing one of the world's rarest animals back into the wild and that they are hopeful that they will be able to do so soon.

The Guam kingfisher, or sihek, is a symbol of conservation hope these days. It has been extinct in the wild for more than 30 years, but thanks to intensive captive breeding and conservation efforts, it now stands on the brink of being released back into the wild.

However, there are still many challenges and uncertainties for its survival, such as gender disparity, reproductive diseases, tracking technology, and habitat suitability.

Scientists are working hard to overcome these obstacles and ensure that sihek can soar over their native forests once again.

Related article: Rare Moustached Kingfisher "Collected" From the Field Stirs Ethical Controversy