According to an international survey of the world's mammals, up to half of all species are experiencing declines in population. The latest "Red List" published by the Switzerland-based International Union for the Conservation of Nature (IUCN) shows that 188 species are "critically endangered," although the real number may be higher since scientists were unable to gather sufficient information on about 836 species to determine the health of their populations. And rates of extinction appear to be increasing. Some 76 mammals are known to have become extinct since 1500, but today 1,141 of the 5,487 mammal species are considered to be "threatened." The leading cause, according to the study, appears to be destruction of habitat, followed by pollution and the hunting of animals for food, medicine, and materials. A dire situation? You betcha, as my favorite politician would say. Just read Julia Whitty.