The Endangered Species Act: Half a Century of Essential Protections

High in the clear blue skies over the Grand Canyon, California condors wheel slowly, searching for their next meal. In the shortgrass prairie of Wyoming, the dark eyes of black-footed ferrets peek out from the safety of old prairie dog burrows. Across the woods and marshes of eastern North Carolina, the howls of elusive red wolves declaring their territory pierce the evening air. In the cool, clear waters of Tennessee rivers, small fish called snail darters flit across gravel streambeds in pursuit of prey.

photo by Kerry Hargrove
Black-footed ferret; photo by Kerry Hargrove

These species may have little in common, but they are bound by a common thread—each still exists because of the Endangered Species Act. December 2023 marks the 50th anniversary of the ESA, a law enacted to stem the ongoing tide of extinction resulting from “economic growth and development untempered by adequate concern and conservation.” At the time, bipartisan support for the bill was overwhelming—unanimous passage in the Senate and 96 percent approval in the House of Representatives. President Nixon, who had called on Congress to increase endangered species protections, signed it into law on December 28, 1973. Five decades on, it has been credited with saving 99 percent of listed species from extinction and is hailed as the world’s strongest conservation law, one that serves as a global model for the preservation of imperiled wildlife. 

Making the list

The ESA provides a framework to protect and recover species at risk of extinction, both domestically and abroad, by promoting the conservation of the ecosystems upon which those species depend. The law is implemented by the US Fish and Wildlife Service (USFWS) for terrestrial species and by the National Marine Fisheries Service (NMFS) for marine species. To qualify for ESA protections, a species must first be listed under the law as either “threatened” (likely to become endangered in the foreseeable future) or “endangered” (currently in danger of extinction). The agencies are required to complete a status review at least every five years for each listed species.

A listing evaluation may be initiated by a petition from an individual, organization, or state agency, or through the federal government’s own candidate assessment programs. The ESA requires that listing decisions be based solely on the best scientific and commercial data available. By law, a species usually must be listed if it is deemed threatened or endangered due to any of the following five factors: (1) destruction, modification, or curtailment of habitat or range; (2) overutilization for commercial, recreational, scientific, or educational purposes; (3) disease or predation; (4) inadequacy of existing regulatory mechanisms to protect the species and its habitat; or (5) other natural or manmade factors affecting the species’ continued existence.

The ESA currently protects approximately 1,700 domestic and 700 foreign species. Listed US species include the Florida manatee, rusty-patched bumble bee, northern long-eared bat, polar bear, and American crocodile. The list once included the bald eagle. Decades of dedicated effort, however, led to a spectacular recovery for our national symbol, which was delisted in 2007. Foreign species on the list include the scarlet macaw, cheetah, orangutan, pink fairy armadillo, African lion, Panamanian golden frog, and African and Asian elephants.

photo by Michael Durham/Minden Pictures
Northern long-eared bat; photo by Michael Durham/Minden Pictures

Unfortunately, hundreds of additional species await listing decisions, and the agencies (particularly the USFWS) have been slow to review candidate species due to chronic underfunding and limited personnel. Reviews take 12 years on average, a decade longer than mandated under the law.

Once a domestic species is listed, the agencies must designate and protect critical habitat, subject to certain exceptions. Critical habitat consists of areas that contain the physical and biological features essential for the species’ conservation, whether or not currently occupied by the species. Three years after the ESA was enacted, Congress expressly recognized that the “ultimate effectiveness of the Endangered Species Act will depend on the designation of critical habitat.

Upon listing of a domestic species, the USFWS or NMFS generally must also draft a recovery plan, which provides federal, state, and tribal agencies, as well as private individuals, with detailed conservation management actions, recovery criteria, and anticipated resource needs. Although the actions delineated in recovery plans are not mandatory, they are used to set management priorities.

Prohibiting “take”

One of the law’s primary protective measures is a prohibition on the “take” of listed species. “Take” means to harass, harm (which includes significantly modifying or degrading habitat), pursue, hunt, shoot, wound, kill, trap, capture, or collect listed animals. The prohibition applies to both private and government entities. Moreover, every federal agency has a duty to conserve imperiled species, which the ESA explicitly elevates over agencies’ primary missions. In furtherance of this duty, no federal agency may authorize, fund, or carry out any action likely to threaten the existence of a listed species or harm its habitat. Potentially harmful agency actions cannot go forward absent consultation with the USFWS or NMFS to ensure that they will not jeopardize the species or cause the destruction or adverse modification of designated critical habitat.

The prohibition on take, however, is not absolute. The USFWS or NMFS can issue permits allowing “incidental take” (described as “unintentional, but not unexpected, taking”) of a listed species during an otherwise lawful public or private action, such as building a residential development, drilling for oil and gas, or logging on public lands. In such instances, limited take may be authorized if mitigation measures are implemented.

AWI and endangered species

AWI and our partner organizations have long been involved in efforts to protect listed species. In a settlement of a lawsuit brought by AWI and allies, the USFWS agreed this year to resume efforts to reestablish red wolves in the wild. We work to save North Atlantic right whales from extinction due to entanglement in fishing gear and ship strikes. We are supporting innovative scientific research and community education efforts to save Hawaiian honeycreepers—songbirds that are quickly disappearing due to non-native, disease-carrying mosquitos, exacerbated by climate change. We also campaign to end trade in live African elephants for public display, and work to ban the import of sport-hunted trophies of ESA-listed species. 

We help to get at-risk species listed under the law as well. This year, in response to petitions from AWI and allies, NMFS proposed to list the Atlantic humpback dolphin as endangered and to ban import and export of threatened Banggai cardinalfish. We successfully opposed a petition last year to remove ESA protections for southern sea otters. In 2018, a petition from AWI and allies resulted in an endangered listing for the Taiwanese white dolphin.

Internationally, we have long participated in meetings of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) to prevent unchecked collection and global trade of vulnerable wildlife. In the United States, CITES is implemented through Section 8 of the ESA, which provides for CITES enforcement within this country. For some species, it is important to seek the increased protections afforded by an ESA listing in addition to the international trade restrictions that accompany a listing on CITES Appendix I or II. 

Importance of the ESA

As we celebrate and honor the 50th anniversary of the ESA, it is important to recognize not only the progress we have achieved in protecting species under this landmark legislation, but also to soberly reflect on the toll humankind continues to take on the planet’s biodiversity.

photo by Harry Collins
Piping plover; photo by Harry Collins

Each species plays a unique and essential role in its ecosystem—the extinction of any is an incalculable and irreplaceable loss. Through habitat destruction, overcollection, and other activities, however, humans are engineering a sudden mass extinction unlike anything in our own species’ history. Many species have already been lost, with many more in imminent danger—1 million species globally are at risk of extinction in the next few decades, including 27 percent of the world’s mammals, 41 percent of amphibians, 37 percent of sharks and rays, and 21 percent of reptiles. 

Extinctions tear at the intricate, interwoven web that sustains life on this planet. Failing to stem the current tide of extinction would be catastrophic. In the text of the ESA, Congress declared that species “so depleted in numbers that they are in danger of or threatened with extinction” are “of esthetic, ecological, educational, historical, recreational, and scientific value to the Nation and its people.” In an important decision issued five years after the ESA was enacted, the US Supreme Court held that Congress’s intent was to “halt and reverse the trend toward species extinction, whatever the cost”—a stark recognition that the cost of not doing so would be vastly greater. 

The ESA is more essential now than ever. Yet, notwithstanding the law’s successes, its bipartisan beginnings, and surveys consistently indicating continued support for the law from more than four in five Americans, it has come under increasing political attack in recent years. On Capitol Hill, AWI and allies work to fend off attempts to weaken the ESA, even as we fight to secure sufficient funding to fully realize the law’s protective potential. On this monumental anniversary, please join us in sending a message to your members of Congress in support of the ESA and imperiled species. We have an obligation to protect animals from extinction, for their own sake and for ours. The ESA provides the strongest tool we have to do so.