introduced species

The case histories previously discussed often implicate introduced species as a cause of species extinctions. Humans have spread species deliberately as they colonized new areas, just one example being the Polynesians as they settled the eastern Pacific islands. New Yorkers in the 1890s…

The introductions of Texas pumas into the Florida panther population and of captive-reared condors back into parts of their original habitat were successful, as discussed above. So were the introductions to North America of the starling, also discussed above, and the house sparrow…

habitat degradation The spread of introduced species (that is, non-native species that negatively affect the ecosystems they become part of) The growing influence of global warming and chemical pollution Unsustainable hunting Disease

…in this category are disease-causing microbes. Early European colonists of the New World and the Pacific introduced organisms that cause the common cold, smallpox, sexually transmitted diseases, and other illnesses to lands whose people had no resistance to them. Beginning in the late 1960s, a strain of human immunodeficiency virus…