2 Into The Wild - Classroom http://www.bagheera.com/inthewild/classroom.htm Subtopics to Explore: Introduction Overexploitation The Extinction Crisis Introduced Species Threatened and Endangered Species Pollution Why it Matters Other Factors Causes of the Extinction Crisis Conservation Actions Habitat Loss Case Studies Cause of Endangerment Questions for Thought Conservation Biology: A Response to the Extinction Crisis When is a species or subspecies considered to be endangered?