How Effective is the Endangered Species Act? An Evaluation of Coverage Across Multiple Animal Taxa

Abstract

The Endangered Species Act (ESA) was passed in 1973 and is the most effective legislation in the United States for the protection of threatened and endangered species. However, even valuable legislation can have faults. This study examines the effectiveness of the ESA across the following animal taxa: mammals, birds, reptiles, amphibians, fish, and invertebrates. Favorable public opinion is heavily skewed towards mammals and birds, which are the groups that receive the most conservation funding and protection under the ESA. Other less popular taxa, such as amphibians, show 80% under recognition on the ESA when compared to species listed on the International Union for Conservation of Nature (IUCN) Red List. There are 307 invertebrate species listed on the ESA, but based on statistical estimates, the actual number of imperiled invertebrates in the United States ranges from 8,600 to 25,000. Even though mammals are the best protected group, there is still 50% under-recognition of mammals on the ESA when compared to the IUCN Red List. Several species listed as endangered on the ESA were used as case studies throughout this paper, showcasing differences in conservation management across species. After an extensive literature search, certain groups appear to be underrepresented on the ESA such as amphibians, invertebrates (especially freshwater invertebrates), and island species. Future management should focus more attention on less publicly charismatic species, as there are many less well-known species that provide an important component to their ecosystem and need increased protection to recover.