Endangered Species Handbook

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Madagascar and other Islands

Madagascar’s Lessons

Madagascar's story is one of ecological catastrophe and the gradual extermination of its life forms. One's first response might be that its experience is as far from the rest of the world as it is geographically remote. However, it is from the extremes that one acquires basic knowledge. The effects of immigrants, whether human, animal, plant or disease, can devastate natural ecosystems wherever they occur. Islands are especially vulnerable to the effects of invasive species, including humans, because their flora and fauna have limited habitats and tend to be endemic, with small populations.
Exotic or non-indigenous species threaten 350 species of birds, or 30 percent of all threatened birds listed by BirdLife International in Threatened Birds of the World (BI 2000). Likewise, 361 plant species and 69 species of mammals listed by the 2000 IUCN Red List of Threatened Species are threatened as a result of non-indigenous species (Hilton-Taylor 2000). The effects of invasive species, including humans, have been the major cause of extinction of virtually all bird species, almost all of which have occurred on islands. In the case of Madagascar, the Malagasy and other immigrant peoples and their livestock, and their subsequent hunting and habitat destruction, presented the vulnerable native species with threats against which they had no defense. Islands throughout the world continue to suffer losses in biodiversity, as do areas with large numbers of endemic species in mainland areas. Species with restricted ranges are the most likely to go extinct or become endangered. Such species dominate the list of birds in Threatened Birds of the World (BI 2000). In this age of international commerce, where plant diseases and other viruses are brought into countries in shiploads of lumber or ballast water, and exotic animals and plants continue to colonize and be released in delicate ecosystems with endemic species, whether on islands or mainlands, it has become extremely difficult to defend native species from such invasions. Nevertheless, through preserving native plants and animals and legislating against such introductions, while removing non-native species, ecosystems and their diversity can be protected. Preserving natural ecosystems is vitally important, not just for wildlife preservation, but for humans as well, so that precious water supplies, topsoils and biological diversity, which stabilize all ecosystems, are protected. These lessons have not yet been put into practice in Madagascar or in many other parts of the world, including developed countries. Ecological and faunal changes may be so gradual that they go unnoticed until ecosystems have been destroyed.

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