The Geography of Endangermen

AS mandated by the Endangered Species Act, the U.S. Fish and Wildlife Service watches over about 800 domestic plant and animal species—a figure that is likely to double during the next decade. These protected species are spread unevenly and often unexpectedly. As one might surmise, Bronx County, New York—the Bronx—contains no species on the federal threatened or endangered list. But nearby Suffolk County, in densely populated Long Island, has seven. In the Southwest heavy use of water imperils the area’s thermal pools; as a result, the desert states of Nevada and Arizona lead the country in endangered fish.

Places come to have a high number of federally protected species because they are home to a lot of species sensitive to human encroachment, or to a lot of human beings to encroach upon species of any kind, or both. The Tennessee River valley, for example, has many unique species of mollusk, more than forty of which are endangered by dams. The coasts show the effects of population pressure. During the 1980s coastal counties, which occupy five percent of the nation’s land area, accounted for 42 percent of the nation’s growth.

No map like this is complete without caveats. One problem is our incomplete knowledge of the home range of particular species. For example, in Indiana all the counties but one have recorded the presence of the endangered Indiana bat. Yet only one of the twenty-one bordering counties in Ohio and Illinois lists that bat—curious, given that the bat does not respect state lines. Furthermore, the number of officially protected species is lower than the number actually in trouble, although there is no evidence that the map above misrepresents the distribution of endangered biodiversity in the United States.

Number of endangered species per county

0 species

1 species

2 to 4 species

5 to 9 species

10 to 71 species

Source: U.S. Fish and Wildlife Service

—text by Charles C. Mann and Mark L. Plummer