As animal habitats decrease, the populations are forced into smaller areas, which causes further habitat destruction. Most mammals that have become extinct have done so because humans released non-original species who successfully competed for food. Unlike other animals, humans can change their environment to suit them, instead of having to change to suit the environment. However, when humans change the environment too quickly, other animals cannot adapt quickly enough and die. When the white men were still settling frontier lands, they took on the attitude that every animal and their land had one purpose - to serve their own needs.
Most endangerment today occurs as a result of man.
They are hunted for their fur, for sport, and to protect livestock. Commercial and protective hunting is more difficult to regulate and are most dangerous to a species. Most species, however, are not directly killed. For example, when tall trees were cut down in Mississippi, the ivory-billed woodpeckers who lived in them disappeared. There has not been a confirmed ivory-billed woodpecker sighting in over 30 years.