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Translocation in wildlife conservation is the capture, transport and release or introduction of species, habitats or other ecological material (such as soil) from one location to another. It contrasts with reintroduction, a term which is generally used to denote the introduction into the wild of species from captive stock. Translocation is an effective management strategy and important topic in conservation biology. It decreases the risk of extinction by increasing the range of a species, augmenting the numbers in a critical population, or establishing new populations thus reducing the risk of extinction.〔Rout, T. M., C. E. Hauser and H. P. Possingham. Optimal translocation strategies for threatened species. http://www.mssanz.org.au/modsim05/papers/rout.pdf. 2007. Accessed on 11 May 2007. 〕 This improves the level of biodiversity in the ecosystem. Translocation may be expensive and is often subject to public scrutiny,〔B. Griffith, J. M. Scott, J. W. Carpenter, C. Reed, (1989) "Translocation as a Species Conservation Tool: Status and Strategy" ''Science'' 245 (4917): pp. 477 - 480 〕 particularly when the species involved is charismatic or perceived as dangerous (for example wolf reintroduction).〔Bath, AJ (1989) "The public and wolf reintroduction in Yellowstone National Park." ''Society and Natural Resources'' 2 (4): 297-306.〕 Translocation as a tool is used to reduce the risk of a catastrophe to a species with a single population, to improve genetic heterogeneity of separated populations of a species, to aid the natural recovery of a species or re-establish a species where barriers might prevent it from doing so naturally.〔Shirey, P.D. and G.A. Lamberti. 2010. (Assisted colonization under the U.S. Endangered Species Act. ) ''Conservation Letters'' 3(1): 45-52.〕 It is also used to move ecological features out of the way of development. Several critically endangered plant species in the southwestern Western Australia have either been considered for translocation or trialled. ''Grevillea scapigera'' is one such case, threatened by rabbits, dieback and degraded habitat. == Three types of translocations == The first of three types of translocation is introduction. Introduction is the deliberate or accidental translocation of a species into the wild in areas where it does not occur naturally. Introduction of non-native species occurs for a variety of reasons. Examples are economic gain (Sitka Spruce), improvement of hunting and fishing (fallow deer), ornamentation of roads (rhododendron) or maintenance (sweet chestnut). In the past, the costs of translocation introductions of non-native species to ecosystems far outweighed the benefits of them.〔Holdgate, M. (1999) Lancaster: British Association of Nature Conservationists/National Trust Conference - Nature in Transition.〕 For example, eucalyptus trees were introduced in California during the Gold Rush as a fast-growing timber source. By the early 1900s, however, this did not happen because of early harvesting and the splitting and twisting of cut wood. Now the introduction of non-native eucalyptus, particularly in the Oakland Hills is causing competition among native plants and encroaching on habitat for natural wildlife. The second of the three types of translocation is re-introduction. Re-introduction is the deliberate or accidental translocation of a species into the wild in areas where it was indigenous at some point, but no longer at the present. Re-introduction is used as a wildlife management tool for the restoration of an original habitat when it has become altered or species have become extinct due to over-collecting, over-harvesting, human persecution, or habitat deterioration. Lastly, the third type of translocation is re-stocking. Re-stocking is the translocation of an organism into the wild into an area where it is already present. Re-stocking is considered as a conservation strategy where populations have dropped below critical levels and species recovery is questionable due to slow reproductive rates or inbreeding. The World Conservation Union recommends that re-stocking only occur when the causes of population decline have been removed, the area has the capacity to sustain the desired population, and individuals are of the same race as the population into which they are released but not from genetically impoverished or cloned stock. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Species translocation」の詳細全文を読む スポンサード リンク
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