Although there are many causes for declines in U.S. species, two in particular stand out. These are the loss or degradation of natural habitats and the introduction and spread of non-native species. Poised to eclipse even these, however, is the rapid acceleration of climatic changes, which already is beginning to cause disruptions and transformations of natural ecosystems and declines in native species (Staudinger et al. 2013).
Next Page: Habitat Loss
Author
Bruce Stein, Ph.D., Chief Scientist and Associate Vice President
National Wildlife Federation