History of introduction, population status, and management of Philippine deer (Cervus mariannus) on Micronesian Islands

Abstract

Summary. - Introduced populations of Philippine deer (Cen-us mariannus) occur on four islands in Micronesia : Guam. Rota, and Saipan in the Mariana Islands, and Pohnpei in the Caroline Islands. Deer were initially taken to Guam in 1771 or 1772, followed by introductions on Rota in about 1880, Saipan in 1900, and Pohnpei probably in 1904 or 1905. Two failed attempts to create populations occurred on Pohnpei in 1880 and on Tinian, Mariana Islands, in the early 1960s, where animals survived until about 1980. Historic trends in extant C. mariannus populations have varied in relation to hunting intensity and the clearing of forested habitats. Currently, deer abundance appears to be expanding on Guam, and is stable or declining on Rota, Saipan, and Pohnpei. Population estimates are not available for any island, but numbers are probably largest on Guam, with the highest densities found on several military installations. Hunting occurs extensively on each island and is a major source of mortality. Regulated hunting seasons exist on Guam and Rota, while deer are fully protected on Saipan, however, considerable illegal hunting occurs on each island. Deer are not legally protected on Pohnpei. C. mariannus consumes a variety of native and introduced plants, including cultivated species. Damage to native ecosystems or crops has been reported on Guam, Rota, and Pohnpei during periods of high deer abundance. Browsing damage to native forests can be extensive, causing significant changes in forest structure and species composition. The objectives of current deer management programs in the Marianas arc not compatible with the conservation of native ecosystems and recovery of endangered species. Recommendations are made to reduce deer densities dramatically through intensive continuous harvest over large areas of each island and to eradicate deer from sites of significant ecological value. Resume. - Des populations de cerfs des Philippines (Cewus mariannus) ont etc introduites dans 4 lies dc la Micronesie : Guam, Rota et Saipan dans les lies Mariannes, et Pohnpei dans les iles Carolines. Les premiers cerfs ont ete introduits a Guam en 1771 ou 1772, puis a Rota en 1880, Saipan en 1900, et a Pohnpei probablement en 1904 ou 1905. Deux tentatives de peuplemcnt ont cchoue : Pohnpei en 1880 et Tinian dans les Mariannes vers 1960, ou les animaux ont survecu jusqu'en 1980. Sur le plan hisloriquc importance des populations de C. mariannus a