Breeding season for the Guam kingfisher is typically December to August, and we have three pairs to introduce this year. So, we have our work cut out for us. Historically, Guam Kingfishers have been difficult to breed for multiple reasons, one of which is mate compatibility — a fancy way of saying they are very picky about whom they will breed with. As an animal keeper, I spend a lot of time observing the birds and assessing whether they are compatible and ready to be paired for breeding. The survival of the species rides on the production of new and healthy offspring, but no pressure!
The Guam kingfisher is known as the “sihek” (see-heck) in Chamorro, the native language of the Marianna Archipelago, and is the rarest species we have here at the Smithsonian Conservation Biology Institute in Front Royal, Virginia. This bird is classified by the IUCN as extinct in the wild — meaning not a single wild Guam kingfisher exists. The last remaining 29 birds were captured in the 1980s and taken to zoos to try to save the species. It is a sad, but all too common story: When brown tree snakes (Boiga irregularis) were accidentally brought to Guam on military cargo ships and planes after World War II, they quickly wiped out 10 of the 12-13 species of birds on the island. Today, the only remaining forest birds on the island of Guam are the Micronesian starling and the Mariana swiftlet.
This accidental introduction of brown tree snakes caused an ecological disaster on Guam. Think of an ecosystem like a puzzle, where each plant and animal is a puzzle piece. Now, imagine how incomplete that puzzle looks when you start to take pieces away. All the birds that are now missing from Guam served their own important purpose within the ecosystem. The Guam kingfisher helped keep the insect and lizard populations in check. With birds removed, populations of insects, and particularly spiders, have increased to the point that people often carry walking sticks to clear the way of spider webs. Forests are also becoming thinner or disappearing, because there are few seed- or fruit-eating birds to consume and spread the seeds of the trees. It’s important that we try to replace as many pieces of this ecosystem puzzle as we can, and the Guam kingfisher is one.
Today, there are only 140 Guam kingfishers in the entire world, all within zoological facilities dedicated to bringing them back from the brink and one day returning them to the wild. SCBI has six of these rare and special birds — and hopefully more after this breeding season!