There are numerous reasons why many animal species will simply disappear from the earth. The World Wildlife Fund calls some of these reasons the HIPPO Dilemma. HIPPO is an acronym, a word formed from the first letters of a series of words, for: Habitat loss, Introduced species, Pollution, Population growth, and Over-consumption/ Over-Exploitation. Other reasons include diseases and climatic changes. All of these reasons represent threats to the biodiversity of the earth.

Teachers, you print this page. Students should work in cooperative groups of two or four to find the answers.


1. In your own words explain habitat loss.



2. Introduced species often create more problems than they solve. Give two 
   examples of an introduced specie that has turned out to be a hard-to-control 
   pest that wreaks environmental havoc.

3.  Pollution in the air, water, ground, and from noise threatens wildlife.  List
    instances of pollution that you've observed that could endanger animals.

4.  Increasingly, people have displaced animals as cities grow.  Explain how 
    population growth makes a difference to places the Indiana Dunes.

5. Given the fact that the Indiana Dunes have been set aside as a National Park, are
    are animals there in danger from over-consumption and over-exploitation?