The Commonwealth of the Northern Mariana Islands, a group of small tropical islands in northwestern Micronesia, is inhabited by an array of endemic tropical birds. Like other island ecosystems, the Mariana Islands have been subjected to a variety of pressures that have dramatically affected populations of native species. Several species and subspecies of birds have been forced to extinction and others are now considered to be highly endangered. Recognizing the need to preserve the Islands' biodiversity, the Marianas Archipelago Rescue and Survey (MARS) project was started in 1992 to help the Rota bridled white-eye (Zosterops conspicllata), a candidate endemic subspecies, the endangered Mariana crow (Corvus kubaryi), and the non-endangered Mariana fruit dove (Ptilinopsu roseicopilla). Funded by the U.S. Fish and Wildlife Service (USFWS) in conjunction with the Division of Wildlife of the Commonwealth of the Northern Mariana Islands, the project currently includes nine AZA-accredited institutions: North Carolina Zoological Park, Philadelphia Zoological Garden, National Zoological Park, Memphis Zoological Garden and Aquarium, St. Louis Zoological Park, Louisville Zoological Garden, Houston Zoological Gardens, San Diego Zoo and Honolulu Zoo.
Bird species in the Commonwealth of the Northern Mariana Islands face many of the same problems that have plagued bird populations on Guam, the southern most island in the Mariana Archipelago. All of the native forest birds on Guam are presently extinct in the wild; two species, the Guam rail (Rallus owstoni) and the Micronesian kingfisher (Halcyon cinnamomina cinnamomina), survive in captivity in U.S. zoos. Habitat destruction and alteration resulting primarily from World War II, introduction of predatory species, such as the brown tree snake (Boiga irregularis), and introduction of competitive species, such as the black drongo (Dicrurus macrocercus) all contributed to the catastrophic extinction of Guam's entire native forest avifauna. Similar types of forces face species found in the other islands of the archipelago; pressure from rapid development is an additional factor for the Mariana Islands.
The MARS project addresses these problems through a combination of captive population management, research, education and support for habitat conservation. During the past few years, field trips have been taken to the island of Rota to collect Rota bridled white-eye, the Mariana crow and the Mariana fruit dove in order to develop protocols for captive management. These species were selected because they were all endemic and taxonomically unique with a high chance of success for captive management. Also, captive facilities and expertise already existed and habitat was still available if reintroduction became a necessity or a possibility. An additional field trip is presently being planned to obtain additional founding stock of Mariana fruit doves to bring the total captive founding population to the planned 15 pairs. Another aspect of the MARS project has been to conduct an historical avifaunal survey of the Mariana Islands. A research team, including a paleontologist and archeologist, a museum bird curator, and two zoo biologists, took a five-week field trip to three of the islands in the archipelago in 1994. This team investigated rock shelters and caves looking for fossil and subfossil bones of birds in sediments. Although still preliminary, results have identified a number of birds that were not previously recorded as being from these islands. Also, several species of birds historically known to be only from Guam may have occurred on other islands in the archipelago as well. Additional surveys are still needed to complete the analysis of the avifauna of the past for these islands. This information is valuable because it may help identify additional relocation sites for extant birds, if needed.
The MARS project plans to expand in the future. Educational material will be developed with local educators for school programs throughout the Mariana Islands. Local aviaries, built in snake-free areas of the islands, may be established by local biologists so that captive bred birds can eventually be released on appropriate islands. Captive birds in zoos or local aviaries could also be used for research purposes on the islands. Ultimately, local commitment and assistance will be key to the future development of the MARS project and the continued survival of the bird populations in the Mariana Islands. (Excerpted from Swaringen and Bowdoin, AZA Communique August 1995 and personal communication, John Groves.)
For more information, contact: John Groves, Curator of Reptiles and Amphibians, North Carolina Zoological Park, 4401 Zoo Parkway, Asheboro, NC 27203. Tel: (910) 879-7620.
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