Reasons for the Extinction of Mammals

The Scientific American reports that nearly 25 percent of the world's mammals face extinction. Biologist Jan Schipper, quoted in the article, notes that 50 percent of the world's mammal populations are declining while only 5 percent are increasing. Many different factors threaten mammal populations. Hunting, deforestation and habitat destruction, global warming, and natural phenomena all contribute to animal extinction.

  1. Hunting

    • Many mammals in India, Africa, and around the world are considered endangered species strictly because they are being hunted out of existence. African locals hunt mammals such as the elephant and gorilla in order to exist on a day-to-day basis. According to the Scientific American, the people of central Africa eat 2.2 billion pounds of mammal meat each year, which is equivalent to four million cattle. In India, the cheetah completely disappeared at one point because of being over-hunted.

    Deforestation and Destruction

    • Many mammals depend upon the forest or other habitats to survive. Rural places around the world are now being deforested -- the trees removed for use elsewhere and the land cleared -- and settled as small or large urban cities. The new cities drive away mammals, forcing them to find new places to live. For example the St. Lucia Musk Rat, native to Paris and London, disappeared over a hundred years ago when the area was cleared for plantations.

    Global Warming

    • Mammals such as the polar bear live in habitats threatened by global warming. As the planet warms and sea ice melts, animals have less places to live and hunt. Climate change can also increase the spread of disease and invasive species as well as the chance for fires that destroy habitats and kill animals. One study found that a temperature rise of only two degrees Celsius can remove the moisture from dead trees and other plant life, increasing the chance sixfold of a fire in the midwestern United States.

    Natural Phenomena

    • Statistically and historically mammals, and all animals, experience population waves. Over a given period of time the population of a species in a particular region may grow to be very large, then die back to what people today consider an endangered level. While this can happen because of hunting, deforestation or global warming, it is also likely that it is a natural cycle and can be activated by phenomenon such as natural selection or regional triggers such as natural disasters.