Extinction - Indirect Extinction

Many of the species now facing imminent extinction do so not because people have set out to destroy them - but rather because they have stepped in the path of their "progress". Of all the causes of indirect extinction the most widespread and devastating must be the destruction of habitat. 

Five phases of huge natural extinctions are thought to have occurred over the earth’s history and many think that we may be in a sixth phase as current extinction rates are an estimated 1,000 to 10,000 times higher than the natural rate. This phase is unique in that the causes of these mass extinctions are largely due to the activities of humans.

In summary, the reasons why animals are endangered are due to: hunting, unsustainable fishing methods, loss and fragmentation of habitat and degregation of habitat through pollution, plus climate change is becoming an increasingly important factor.  Invasive species and disease also play their part.