The people of Guam have not seen a sihek in over 16 years. The birds were thought to have gone extinct on their native island in 1988.

But Chicagoans have a chance to see them all the time.

Sihek is the Chamorro word for Guam’s Micronesian kingfishers, and at times, Brookfield Zoo has been home to almost one-third of the world’s population. However, things are changing for the better, and recently kingfishers have returned to Guam. The U.S. Fish & Wildlife Service has set up a breeding facility on the island with the intention of eventually re-releasing the birds. One of the first birds back on the island was hatched and handreared by keepers at Brookfield Zoo. It is fitting for this bird to be on Guam. He is the offspring of one of the last kingfishers captured on the island.

Still in Trouble
The trouble for Micronesian kingfishers started in World War II when Guam was used as a military airbase. Amidst the movement of supplies and troops, brown tree snakes were accidentally introduced to the ecosystem. The snakes quickly overran the island, decimating the bird populations, which were unused to this type of predator.

In the 1980s, scientists realized that the island’s birds were in danger of disappearing and formed the Guam Bird Rescue Project to collect Micronesian kingfishers, Marianas crows, and Guam rails for captive breeding programs. Some of the last kingfishers removed from the island were sent to Brookfield Zoo and bred successfully.

By late 1980s, Micronesian kingfishers were assumed to be extinct in the wild, existing only in a small handful of American zoos. Zoos worked hard to save the species, but simply maintaining the population was tough. Since 1986, the population has seen ups and downs, but for the most part there have only been 50 to 65 birds. Captive breeding programs produced only enough kingfishers to maintain the population. Experts hope that a return to the native climate, light cycles, and food sources in Guam will spur a bird baby boom.

In Good Hands on Guam
On Guam, the birds will be cared for by U.S. Fish & Wildlife biologists who were trained at Brookfield Zoo, Milwaukee County Zoo, and San Diego Zoo. Training included work on husbandry methods, preparation for breeding, handrearing of chicks, and behavior tracking standards. They were also taught techniques for handling Guam kingfishers because the birds they currently work with are significantly larger.

All that training should not imply that the biologists are not knowledgeable. In fact, they have gotten far with the reintroduction of two other Guam bird species. Though the island is still too snake-infested to release kingfishers, the USF&W biologists have managed to begin a re-release program with Marianas crows. Radio collars are used to track the birds to their nest sites. Once the sites are identified, biologists must “snakeproof” the nest trees. They prevent snakes from getting anywhere near the nests by pruning the branches of all nearby trees and placing electrified wire around the trunk.

Unfortunately, since kingfishers are relatively slow fliers and ambush predators, the biologists would be unable to protect them. When hunting, Micronesian kingfishers simply park themselves on a tree branch and wait for small reptiles to pass by. This makes them easy prey for the snakes. Until more can be done to rid the island of the invasive species, the kingfishers will continue to be bred in captivity.

Slimming Down Back at the Zoo
While the work on Guam is exciting, there is plenty going on at the zoo in support of the birds.

The media is filled with stories covering “America’s Obesity Problem.” At Brookfield Zoo, Kerri Slifka is doing her part to investigate the problem---though only for Micronesian kingfishers. It is a big issue for the birds, which often suffer from other medical problems because of obesity in captivity. Slifka is a nutritionist at the zoo and the nutrition advisor to the Micronesian Kingfisher Species Survival Program. Her staff has scoured nearly 20 years’ worth of the SSP’s data and examined the typical diets fed to the birds. Brookfield’s nutritionists have begun to analyze the nutritional values of anole lizards and baby mice (referred to as “pinkies”) because they are typical food items for kingfishers in zoos. On Guam, the birds typically eat native geckos (a different small lizard), so the nutritionists are studying them, too. They hope to find a difference in nutritional values among the food items that will point to dietary supplements that can be used to make the birds healthier in zoo settings.

Creating a Crib
New diets are only a part of the “extreme makeover” for Guam’s Micronesian kingfishers. Keepers and exhibit designers have been experimenting with high-tech homes for the birds. Normally, the kingfishers nest in logs that they have excavated. However, this presents problems for keepers because they are not able to monitor the birds as closely as they would like in the nest cavity, and because they must ensure the wood has been disinfected. Keepers worked with the zoo’s exhibit crew to develop a new nest that would fix both problems. They came up with an artificial epoxy log with a special camera compartment. The fake log is filled with wood shavings to allow the birds to dig out their nest---but keepers will be able to keep closer tabs on what is happening inside.

Currently, the zoo is home to seven Micronesian kingfishers. Keepers hope that the changes in the bird’s exhibits and care will result in many new chicks---and the eventual release of those chicks back onto the island of Guam where they belong.

Triumphant Return…Maybe

Male Micronesian kingfisher---this individual was one of the last birds evacuated from Guam

View inside one of Guam's Micronesian kingfisher nest logs

Biologist training at Brookfield Zoo

Kingfisher chick

View inside a kingfisher nest log