The geography of vulnerability: incorporating species geography and human development patterns into conservation planning

In any country, the geography of species needing protection is central to the development of conservation strategies. In this study we mapped the distribution of restricted-range birds and butterflies not listed as threatened or endangered under the Endangered Species Act in the conterminous United States, as well as measures of projected increases in human population and development. Areas with both restricted-range species and high growth rates were identified as "hot spots of vulnerability" - areas vulnerable to future species loss. These hot spots of vulnerability corresponded to many of the areas currently supporting large numbers of endangered species in the United States. Many of the restricted-range species identified, however, have existing ranges in Mexico and Central and South America. The conservation of these peripheral populations in the United States becomes even more important given that adjacent countries do not have legislation that protects endangered species. The methodology we present here could be used in other countries to identify species and areas of vulnerability before they become endangered. (C) 2000 Elsevier Science Ltd. All rights reserved.