The Guam Kingfisher

By Judith Fong

There are approximately seven billion people in the world.  So imagine being a Micronesian Kingfisher and having fewer of your own species than most teenagers have Facebook friends.  While humans struggle to control their population from exploding in many parts of the world, this kingfisher species has fought just to stay on this planet. Human overpopulation has exacerbated the negative environmental impacts of human activity and pushed our natural resources to their capacity. The Micronesian Kingfisher is one of many species that has been forced to pay the toll of our actions.

A male Kingfisher in captivity. A female rests in a separate cage beside him in preparation for breeding. Photo by Judith Fong.

The Guam Kingfisher, one subspecies of the Micronesian kingfisher, was once only found on the island of Guam. Today, there are one hundred and thirty-four individuals, and these exist only in zoos and aquariums across the U.S.  The small birds, scientifically named Todiramphus cinnamomina cinnamomina, generally dwell in woodlands and forested areas such as native forest, agroforest, riparian areas, and strand vegetation. They are strictly carnivores and in the wild consumed insects, small reptiles, and fish, although their diet in captivity consists of mice, mealworms, and crickets. Male Kingfishers are characterized by orange-brown feathers, long beaks, and blue wings. Females appear similar except for their white stomachs.

Shortly after World War II, the island began to see the introduction of a non-native snake species. The brown tree snake, originating from Australia, Indonesia, and Papua New Guinea, was most likely transported to Guam in military cargo ships. The results were devastating. The most impacted were Guam’s bird species; most of the island’s eleven native forest bird were wiped out by the 1980s.

With no natural predators, the brown tree snake proceeded to prey on any native lizards or birds in its reach. The Guam Kingfisher was just one of its many victims. The snake was able to overpower the surrounding ecosystem because there were no native snakes in Guam to compete with. Furthermore, any species specific to an island as small as Guam are more sensitive to change. The kingfishers were simply not able to tolerate the introduction of such an aggressive species as the brown tree snake. The brown tree snake was able to decimate the kingfisher population by consuming the birds and their eggs in high numbers.  As the snake population grew uncontrollably, kingfisher bird sightings became increasingly less frequent. Only after several decades were scientists able to connect the loss of kingfishers with the aggressive invasive snake. Although the Guam Kingfisher was listed as an Endangered Species act in 1984, by then it was too late and the population had reached under fifty.

Because Guam is a U.S. territory, it has been much easier for the U.S. Fish and Wildlife Services to establish Kingfisher restoration efforts. In 1985, a consortium of U.S. zoos guided by the Association of Zoo and Aquarium Institutions (AZA) traveled to Guam to collect the twenty-nine remaining kingfishers, and by 1988 there were no kingfishers in the wild.  The Philadelphia Zoo was one of the main facilities that were able to house the few Guam Kingfishers and Guam Rails left. The only living Guam Kingfishers exist in captive breeding sites in the U.S. and in Guam. Several zoos and aquariums contribute to the Guam Kingfisher’s Species Survival Plan (SSP), which includes captive breeding, reintroduction, habitat preservation, and education. The Aquarium of the Pacific was recently added to contribute to the kingfisher’s Species Survival Program last year. The Aquarium is currently soliciting funds of about $47,000 to build an exhibit or modify an existing exhibit for kingfishers. On the other hand, the DAWR (Division of Aquatic Wildlife Resources) is the responsible entity in Guam for kingfisher husbandry and reintroduction efforts.

Captive Breeding programs at these facilities attempt to restore populations with the hope that they will eventually be reintroduced into the wild. The programs are faced with breeding the limited supply of kingfishers they have, a task that has proved to be challenging due to the aggressive nature of the birds. Both male and female kingfishers are extremely territorial and often become defensive and violent against each other and the chicks. Kingfishers mate after two years of age and typically produce two to three eggs that both parents care for. Often zoos will have to take away one egg to maximize the chance of survival, as the stronger offspring will overpower and kill the weaker one, either by force or by out-competing.

The captive breeding program faces several other challenges that have made population rehabilitation steady but slow. Understanding the biological nature and behaviors of the Guam Kingfisher has taken time. Although both the Guam Kingfisher and the Guam Rail captive breeding programs have been fairly successful, the Rail has seen higher numbers throughout the years. As Rob Mortensen, a bird and mammal curator at the Aquarium of the Pacific who has been heavily involved in the kingfisher’s Species Survival Plan reflected, “Guam Rails turned out to have a higher rate of fecundity…There was a little but of a learning curve with the Guam Kingfishers. [The success rate] has definitely gone up over the years.” Researchers are constantly learning new things about the species that could help improve population rate, such as adding lizards to their diet or adjusting light conditions to match their natural nesting cycle. Getting two Kingfishers to breed is also harder than simply putting them together, as often they are unwilling even if they get along. When questioned about further challenges, Mortensen responded, “Obviously there is a big financial challenge to make sure you have the proper setup and facility for them. The biggest thing is just learning how to breed them. You could do everything the exact same way another facility would do it and have different results.” As the programs continue to work with kingfishers, new discoveries are made that will improve breeding efforts in the future.

Author pictured with one of the remaining 129 Guam Kingfishers in the captive breeding program. Photo by Judith Fong.

It is important to protect endangered species because in many cases they reflect the overall health of the environment around them. The effects of the brown tree snake do not stop at the kingfisher; the snake has also threatened the Guam Rail among other bird species, as well as climbing power poles and causing thousand of costly power outages. The Endangered Species Act protects species only after they have already been stressed. In the case of the Guam Kingfisher, the situation became so drastic the effects of the invasive snake were near irreversible. The captive breeding efforts have required tedious time, dedication, and resources. These types of costly programs, while admirable, could potentially be avoided if preventative measures to protect habitat and regulate the introduction and control of non-native species were strengthened. While the ESA is one of the most important pieces of environmental legislation, in general we should be trying to act on the environment before the situation becomes as drastic as the Guam Kingfisher.


Works Cited

Surviving because zoos got involved . (2003). Retrieved from

Species profile: Brown tree snake. (2012, Febr 01). Retrieved from

Endangered species in the pacific islands. (2010, March 29). Retrieved from

Mullen, W. (2010, June 28). One of world’s most endangered species, guam kingfishers live on in zoos in struggle to survive. Retrieved from

Mortensen, R. (2012, May 09). Interview by J. Fong [Web Based Recording]. Interview with Rob Mortensen regarding the Guam Kingfisher.

About the Author: Judith Fong is a freshman in the USC Dana and David Dornsife College of Letters, Arts and Sciences working towards a B.S. degree in Environmental Studies. She hopes her participation in scientific scuba diving will help open new opportunities to explore marine biology and field research.

Editor’s note: Scientific Research Diving at USC Dornsife is offered as part of an experiential summer program offered to undergraduate students of the USC Dana and David Dornsife College of Letters, Arts and Sciences. This course takes place on location at the USC Wrigley Marine Science Center on Catalina Island and throughout Micronesia. Students investigate important environmental issues such as ecologically sustainable development, fisheries management, protected-area planning and assessment, and human health issues. During the course of the program, the student team will dive and collect data to support conservation and management strategies to protect the fragile coral reefs of Guam and Palau in Micronesia.

Instructors for the course include Jim Haw, Director of the Environmental Studies Program in USC Dornsife, Assistant Professor of Environmental Studies David Ginsburg, SCUBA instructor and volunteer in the USC Scientific Diving Program Tom Carr and USC Dive Safety Officer Gerry Smith of the USC Wrigley Institute for Environmental Studies.

This entry was posted in Guam. Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s