When the word "endangered" is menti

When the word "endangered" is mentioned, people usually think of particular species, like the panda or whooping crane. However, we would like to encourage you to think about (41) endangerment in a broader context. It is (42) habitats , the physical places where species live and interact with one another. Although the development of special breeding programs, also known as captive conservation, may help some species in some cases, it is clearly not (43) an answer to the global problem. Indeed, (44) unless we are able to protect natural areas where endangered species actually live, they have no future. .
Species become endangered for a wide (45) variety of reasons. By analyzing and grouping many individual cases, however, we find the same broad causes (46) appearing again and again. They are Habitat Destruction, Exotic Species, and Overexploitation. Among other factors threatening particular species are limited: distribution, disease, and pollution. Limited distributions are often a consequence of other threats: populations confined to one or a few small areas because of habitat (47) loss , for example, may be disastrously affected by random factors. Diseases can have severe (48) impact on species lacking natural genetic protections against particular pathogens, like the rabies and canine distemper viruses that are currently devastating carnivore populations in East Africa. Domestic animals are usually the reservoirs of these and other diseases affecting wild (49) populations , showing once again that human activities lie at the root of most causes of endangerment. Pollution has seriously done harm (50) to number of terrestrial species, although species living in freshwater and marine ecosystems are also suffering.