第2个回答 2008-10-07
1), the reasons for their species
Special species and genetic failure, often leading to endangered species and even the underlying causes of extinction. Certain types of wild animals in the long-term evolution, adapted to a particular habitat and have had a special habits (including diet) to make it difficult to adapt to changes in the environment or other environmental and eventually end up "does not have been Out of "ending. Such as the giant panda into a special bamboo mainly for food, lose their existing habitat or a large area of bamboo flowering dead, no giant edible bamboo, a large number of inevitable death, appeared to survive the crisis. Some of the wildlife in the long-term evolution, for various reasons have been viability receded and the heritability of the threat of a recession, leading to its population and tend to be difficult to restore endangered
2), habitat destruction and loss
Human deforestation for economic development, Wu Wai Wai Hai farmland, overgrazing, and so on, as a direct result of the loss of wildlife habitat, and indirectly led to the Endangered Species of Wild Animals. Forests and grasslands are wild animals, especially mammals, birds, insects, reptiles, as well as one of the most important habitats. Deforestation and land reclamation, followed by overgrazing and grassland, wild animals accounted for only inherent in their homes, wild animals will be divided into many small island-like stocks, making their survival of the race was very Great. �
4), environmental pollution
Of this century, due to the pesticide, poison, chemical fertilizers, coal, oil, widely used to produce a large number of industrial "three wastes" and toxic substances, and serious pollution of the atmosphere, soil and water, wildlife damage to health, the growing low fecundity, Many rivers and lakes are no longer suitable for aquatic wildlife to survive and multiply. Some higher niche in the food chain because of wild animals also have been implicated in varying degrees.