Understanding the Endangered Species Act of 1973

The Endangered Species Act of 1973 (ESA) provides for both the conservation and protection of plant and animal species that face the threat of extinction as well as for "the ecosystems upon which they depend." Species must be endangered or threatened throughout a significant portion of their range. The ESA replaced the Endangered Species Conservation Act of 1969 and has been amended several times.

Why Do We Need an Endangered Species Act?

Challenger, a 10 year-old male bald eagle, sits quietly during an event to celebrate the success of the Endangered Species Act

Georges De Keerle / Getty Images

Fossil records show that in the distant past, animals and plants have had finite lifetimes. In the 20th century, scientists became concerned about the loss of common animals and plants. Ecologists believe that we are living in an era of rapid species extinctions that are being triggered by human action, such as over-harvesting and habitat degradation (including pollution and climate change).

The Act reflected a change in scientific thinking because it envisioned nature as a series of ecosystems; in order to protect a species, we have to think "bigger" than just that species.

Who Was President When the ESA Was Signed?

Republican Richard M. Nixon. Early in his first term, Nixon created the Citizens Advisory Committee on Environmental Policy. In 1972, Nixon told the nation that existing law was insufficient to "save a vanishing species" (Spray 129). Nixon not only "asked Congress for strong environmental laws ... [he] urged Congress to pass the ESA" (Burgess 103, 111).

The Senate passed the bill on a voice vote; the House voted 355-4 in favor. Nixon signed the legislation on 28 December 1973 as Public Law 93-205.

What's the Effect of the Law?

The Endangered Species Act makes it illegal to kill, harm or otherwise "take" a listed species. A "taking" means to "harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct."

The ESA requires that the Executive branch of government ensure that any activities the government undertakes are not likely to jeopardize any listed species or result in the destruction or adverse modification of designated critical habitat. The determination is made by an independent scientific review by the government.

What Does It Mean to Be Listed Under the ESA?

The law considers a "species" to be endangered if it is in danger of extinction throughout a significant portion of its range. A species is categorized as "threatened" when it is likely to soon become endangered. Species that have been identified as threatened or endangered are considered "listed."

There are two ways that a species can be listed: either the government can initiate the listing, or an individual or organization can petition to have a species listed.

Who's in Charge of the Endangered Species Act?

The National Oceanic and Atmospheric Association's National Marine Fisheries Service (NMFS) and the U.S. Fish and Wildlife Service (USFWS) share responsibility for implementing the Endangered Species Act.

There is also a "God Squad"—the Endangered Species Committee, composed of cabinet chiefs—that can overrule an ESA listing. The God Squad, created by Congress in 1978, met for the first time over the snail darter (and ruled for the fish) to no avail. It met again in 1993 over the northern spotted owl. Both listings made their way to the Supreme Court.

How Many Listed Species Are There?

According to NMFS, as of 2019 there are approximately 2,244 species listed as threatened or endangered under the ESA. In general, NMFS manages marine and anadromous species; the USFWS manages land and freshwater species.

  • Nixon/Ford: 23.5 listings per year (47 total)
  • Carter: 31.5 listings per year (126 total)
  • Reagan: 31.9 listings per year (255 total)
  • G.W.H. Bush: 57.8 listings per year (231 total)
  • Clinton: 65.1 listings per year (521 total)
  • G.W. Bush: 8 listings per year (60 total)
  • Obama: 42.5 listings per year (340 total)

Additionally, 85 species have been removed between 1978 and 2019, either due to recovery, reclassification, discovery of additional populations, errors, amendments, or even, sadly, extinction. A few key delisted species include:

  • Bald Eagle: increased from 417 to 11,040 pairs between 1963 and 2007
  • Florida's Key Deer: increased from 200 in 1971 to 750 in 2001
  • Gray Whale: increased from 13,095 to 26,635 whales between 1968 and 1998
  • Peregrine Falcon: increased from 324 to 1,700 pairs between 1975 and 2000
  • Whooping Crane: increased from 54 to 436 birds between 1967 and 2003

ESA Highlights and Controversies

In 1966, Congress passed the Endangered Species Preservation Act in response to concerns about the whooping crane. A year later, USFWS bought its first endangered species habitat, 2,300 acres in Florida.

In 1978, the Supreme Court ruled that the listing of the endangered snail darter (a small fish) meant that construction of the Tellico Dam had to stop. In 1979, an appropriations bill rider exempted the Dam from ESA; bill passage allowed the Tennessee Valley Authority to complete the dam.

In 1995, Congress again used an appropriations bill rider to limit ESA, imposing a moratorium on all new-species listings and critical habitat designations. A year later, Congress released the rider.

Resources and Further Reading