Endangered species and species protection policy

DEFINITIONS: Plant and animal species whose numbers are so reduced that the species are in danger of becoming extinct if protection is not provided, and high-level governmental plans of action to support the survival and recovery of endangered and threatened species

Natural causes as well as pollution, habitat fragmentation and destruction, and other environmental stresses imposed by human activity can drive species toward extinction. Once a population's size declines past a certain point, various factors will eventually wipe out the population entirely. Implementing protective policies can save a declining species from extinction and, ideally, enable it to recover and thrive.

Extinction of a species does not occur in a vacuum. Causes, typically environmental, are many and often complex. Likewise, because of the many intricate, interconnected relationships existing within ecosystems, the loss of any member may have a ripple effect, eventually having profound negative results. For example, the extinction of a single insect, bird, or bat species may result in the extinction of one or more plant species dependent on the animal species for pollination. If the plant is a critical item in the diet of certain animals, those too may be adversely affected.

Paul R. Erhlich and Anne H. Ehrlich introduce their book Extinction: The Causes and Consequences of the Disappearance of Species (1981) by referring to fictitious "rivet poppers"—workers whose job it is to remove rivets from the wings of airplanes. The expectation is that many rivets could be removed without the wings falling off. By analogy, the Ehrlichs consider many world leaders—politicians, bureaucrats, industrialists, engineers, religious leaders, and even some scientists—to be rivet poppers. Through their policies and practices, these leaders espouse programs that will, by design or neglect, result in the loss of endangered species. Ecosystems, by their nature, are somewhat redundant: They are likely to continue to function even after the loss of several species. Ecologists refer to this capacity as "resistance." Ecosystems also possess resilience, or the ability to recover after disturbances, including those in which species are lost. However, just as one would not wish to fly in an airplane from which even a few rivets have been removed, it seems only prudent to take reasonable steps to prevent endangered species from becoming extinct.

Extinction is the conclusion of a long, gradual process typically involving a considerable span of time. When a species undergoes a drastic reduction in the extent of its range, accompanied by a reduction in the number of individuals, it may be designated as a rare species. As this trend continues, the species is likely to be considered threatened prior to being recognized as endangered.

Factors Contributing to Species Loss

The issue of species loss is complex and affected by many factors, yet does not threaten all species equally. Whether because of their intrinsic nature or environmental conditions, some species are naturally more predisposed to becoming endangered or extinct than others. As one would expect, species with smaller numbers of individuals are more vulnerable than those with more—though even huge populations can rapidly collapse due to human influence, as in the infamous case of the passenger pigeon. Each species has a critical population size. Once the numbers fall below that size, the species is especially subject to extinction. Natural populations undergo year-to-year fluctuations in numbers; therefore, a small population will "crash" more readily than a large one.

Several categories of animal and plant species are at high risk of becoming endangered or extinct. Among these are species restricted to special habitats. Most such animal or plant species, by becoming tolerant of an unusual situation, lose their ability to compete in a more general one. One example is island species: If threatened by humans, predators, competing exotic species, or diseases, native island species cannot easily escape. A disproportionate number of animals native to islands have become extinct. Large species with low reproductive rates are also at risk. Large species require more space than do smaller species; therefore, the number of large specimens occupying a given area is lower than the number of smaller ones. Also, most large species, whether whales or trees, are likely to reproduce less often than smaller ones. Even when large species are protected, it is difficult for them to increase their numbers.

Neotropical migratory birds such as warblers, orioles, and tanagers winter in tropical Central or South America or the Caribbean and breed in eastern North America. Their migratory pattern is advantageous in that they can take advantage of the availability of summer food in the north while escaping harsh conditions in winter. Migration, however, is a process that is fraught with danger. As the tropical forests in which they spend the winter are destroyed and the temperate forests in which they breed are fragmented, neotropical migrants may be threatened; thus, they are subject to double jeopardy.

Among the other at-risk species are those at the end of long food chains. Animals such as hawks, owls, and various cat species suffer when any of the links in their food chain are affected. Also, they may be more subject to damage by toxic substances such as environmentally persistent pesticides because of chemical amplification along the food chain. Finally, species of economic value are also in a precarious situation. Many animals have been hunted to extinction; an often-cited example is the passenger pigeon. Plants used medicinally, such as ginseng, have been subjected to overcollecting. Regulatory protections are in place to control the harvesting of American ginseng, which has been dug in eastern North America for centuries.

Conservation and Management

In order to preserve biodiversity and not lose species that are important to the health and existence of an ecosystem, wildlife conservation and management practices must be put into effect. There are three basic approaches to wildlife conservation and management: the species approach, the ecosystem approach, and the wildlife management approach.

The species approach involves giving endangered species legal protection, protecting and managing their habitats, propagating species in captivity, and reintroducing species into safe habitats. In 1903, President Theodore Roosevelt established the first wildlife refuge in the United States. The refuge, located on Pelican Island on the east coast of Florida, was developed to protect the brown pelican, which was in decline. (Only in 2009 was the species officially declared to be out of danger.) As of 2022, the National Wildlife Refuge System had 588 refuges and other units. Habitats in the United States are also protected through the national park and forest systems and the National Wilderness Preservation System. In addition to the government, private conservation organizations such as the National Audubon Society, the Sierra Club, and the Nature Conservancy have been of tremendous value in acquiring and protecting sensitive landscapes.

According to statistics reported by the World Database on Protected Areas (WDPA), by 2023, over 267,085 protected areas had been established in 245 countries and territories, an increase from approximately 30,000 in 2000. These areas, which include strict nature reserves and wilderness areas, national parks, natural monuments, habitat and species management areas, protected landscapes and seascapes, and managed resource protected areas, represented 15.8 percent of the planet's land surface and 8.16 percent of total ocean area in 2023. The IUCN also maintains a Red List of Threatened Species, ranking the conservation status of individual species on a scale from "least concern" to "extinct"; "endangered" and "critically endangered" are the stages preceding "extinct in the wild." The list also includes classification of species with insufficient data, those which have not been evaluated, and those which are nearly threatened.

Other forms of the species approach to saving diversity include gene banks, seed banks, botanical gardens, and zoos. The seeds of many endangered plant species are preserved in climatically controlled environments. The organization Botanic Gardens Conservation International estimated in the early 2020s that more than eighty thousand plant species were in cultivation in the world's botanic gardens. Many botanical gardens, such as Kew Gardens in England, are repositories for plant species that are endangered or have even ceased to exist in the wild. Some of these plants are reintroduced into native habitats after being cultivated for decades in these gardens or seed banks.

Egg pulling and captive breeding are two methods that zoos and animal research centers use for preserving endangered animal species. Egg pulling involves collecting eggs from endangered species in the wild and hatching the eggs in zoos or research centers, as was done with California condors beginning in 1983. Endangered species still in the wild are sometimes captured and put into research centers to breed in a controlled environment. When the captive populations become large enough, some of the individuals are reintroduced into protected habitats. The Arabian oryx, a large antelope species that originated in the Middle East, was hunted to extinction in the wild; however, the species survived thanks to captive breeding programs that began in San Diego, Los Angeles, and Phoenix zoos. The oryx has since been reintroduced into its native habitats, although the captive population outnumbers the population in the wild.

The second approach to saving biodiversity is the ecosystem approach, which emphasizes preserving balanced populations of species within their native habitats. It involves establishing legally protected wilderness areas and wildlife reserves. An important part of making sure that the habitat is safe is to eliminate all alien or invasive species from the area. The Minnesota Zoo has formed a partnership with other organizations to help protect certain animals in their native habitats, notably the desert black rhino and Hartmann's mountain zebra. Instead of moving these animals to Minnesota, the zoo supports conservation efforts to study and protect these animals in their native habitats in Namibia.

The third approach to preserving biodiversity is the wildlife management approach. When it is decided which species or group of species will be managed in a given area, a management plan is put into effect. Steps in the plan include investigating and determining the kinds of cover, food, water, and space the targeted species requires. Action is then taken to grow the plants that provide the needed cover and food for the species.

Hunting and International Cooperation

Legal and illegal commercial hunting has led to the extinction or near extinction of many animal species. Despite policies to regulate hunting, poaching remains a lucrative business, particularly in underdeveloped countries. Some threatened and endangered species are killed for their hides, horns, or other ornamental or medicinal parts, while others are captured and smuggled alive, as there is a market for exotic pets and decorative plants.

Species, primarily game species, are managed through the establishment of laws that regulate hunting and hunting quotas. Hunters are required to have licenses and to use only certain types of hunting equipment and are permitted to hunt only during certain months of the year. Limits are set on the size, number, and sex of animals that can be hunted in a given game refuge.

Management plans and international treaties have been developed to protect migrating game species, such as waterfowl. In North America, waterfowl such as ducks, geese, and swans nest in Canada during the summer and migrate to the United States and Central America in the fall and winter. The United States, Canada, and Mexico have signed agreements to protect these waterfowl from overhunting and habitat destruction.

Some wildlife refuges in the United States include human-built nesting sites, ponds, and nesting islands for waterfowl. The US National Wildlife Refuge System includes thirty-eight wetland management districts administering more than twenty-six thousand waterfowl production areas, which contribute to the protection of migratory birds. In 1986, amid concerns regarding record lows in waterfowl populations, the United States and Canada entered into an agreement (later joined by Mexico) to attempt to restore the continental waterfowl population and associated habitats.

In July 1975, a wide-reaching treaty to protect endangered species, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) went into force. This agreement, which by 2022 had been agreed to by 184 parties, extended varying protections to 38,700 plant (5,950) and animal (32,800) species in 2019. Under CITES, some endangered and threatened species cannot legally be commercially traded, either alive or as products. Others can be traded, but only by persons who obtain the proper export licenses. One of the best-known results of the CITES agreement is the 1989 ban (subsequently weakened) on the international trade in ivory. The ban was enacted to halt the decline of the African elephant, which had dwindled in population from 2.5 million animals in 1950 to approximately 350,000 at the treaty's inception. The end of the international ivory trade has been a major factor in improving elephant population levels; however, illegal trade and poaching remained a problem in 2024.

In 1980, the World Wildlife Fund (later the World Wide Fund for Nature), the United Nations Environment Programme, and IUCN developed a World Conservation Strategy (WCS). The plan, which was expanded in 1991, seeks to preserve biological diversity, combine wildlife conservation and sustainable development, encourage rehabilitation of degraded ecosystems, and monitor sustainability of ecosystems. Initially adopted by thirty countries, by 2023, the WCS had become an international non-governmental organization under the International Union for Conservation of Nature (IUCN) umbrella, inspiring and supporting hundreds of conservation programs globally.

US Laws

Important US laws that control imports and exports of endangered wildlife and wildlife products began with the Lacey Act of 1900, passed in response to an egret population decline resulting from the commercial value of their feathers as decoration. The Lacey Act prohibited transporting live or dead wild animals or their parts across state borders without a federal permit. Later came the Endangered Species Preservation Act of 1966, then the Endangered Species Act (ESA) of 1973, which has been amended several times. The ESA was unique in that, where previous wildlife regulations had focused primarily on game animals, the ESA program focused on identification of all endangered species and populations in order to save biodiversity, regardless of the species' usefulness to humans. The act classifies endangered species as those that are in immediate danger of extinction and threatened species as those that are likely to become endangered in a given habitat in the future. Some species are classified as being locally threatened even though they can be found in fairly large numbers in some parts of their former habitats. The US Fish and Wildlife Service is required to prepare a recovery plan for each species that the ESA lists as officially endangered. By 2019 the ESA listings for endangered and threatened US species included over 1,450 animals and 940 plants. By 2024, the number of endangered or threatened plants and animals in the United States had decreased to about 1,300.

The ESA provides that a listed species cannot be harassed, harmed, pursued, hunted, shot, trapped, killed, captured, or collected, either on purpose or by accident. It further prohibits importing or exporting endangered species, as well as possessing, selling, transporting, or offering to sell any endangered species. Violators face fines and imprisonment. In 1995, the US Supreme Court ruled to extend further protection for endangered species by ruling that habitat essential for species survival must be protected, whether on public or private land.

Critics view the ESA as a major stumbling block to economic progress. A classic example is the delay that occurred in the late 1970s in the construction of Tellico Dam in the mountains of eastern Tennessee because of the presence of the snail darter, a small endangered fish. The dam was ultimately completed, and other populations of the fish were unexpectedly found elsewhere, resulting in the removal of the snail darter from the endangered list. Some people who criticize the ESA assert that business and public interests should take precedence over the protection of wildlife, especially plants and animals of no obvious value to human beings. Along these lines, various political movements have sought to weaken the regulations, often stirring controversy. In 2020, for example, President Trump reduced the protections of endangered species by limiting the habitat area which could be legally considered protected under the act. This legislation was reversed in 2022 by US Federal District Judge Jon Tigar.

Despite criticism, some of the ESA's recovery plans have proved highly successful. Bald eagles, which numbered only 800 in 1970, were able to rebound to a population of at least 71,400 nesting pairs in the contiguous United States and approximately 316,700 total individuals in North America by 2020, largely because of the US ban on the pesticide dichloro-diphenyl-trichloroethane (DDT). The American alligator was listed as an endangered species in 1967 after its population declined because of habitat destruction and high demand for alligator meat and products made from alligator hides. Because of ESA protection, the alligator was reestablished in its southern range; it was removed from the endangered list in 1987. In 2023, roughly five million American alligators inhabited the southern states, demonstrating the effectiveness of the ESA.

Most of the ESA success stories have involved such "charismatic megafauna." Less glamorous endangered species, such as fungi, wildflowers, liverworts, mosses, and insects, receive less attention even though their roles in ecosystems may be more important. In spite of ESA protection, a number of species remain critically endangered, largely because their standing was so precarious by the time they were listed as protected. ESA listed status has not saved some species from going extinct.

Other Protective Measures

The loss of aquatic species has generally attracted less attention than the extinction of land species. With the realization of the importance of healthy freshwater and marine species, however, governments have begun establishing marine preserves. Fishing, construction, tourism, pollution, and other human disturbances are closely regulated and restricted in these areas. The National Marine Sanctuary Program, which was developed in 1972 in the United States, established a number of sanctuaries and marine national monuments. In 2023, the most extensive of these, the Papahānaumokuākea Marine National Monument in the northwest Hawaiian Islands, was the single largest conservation area in the United States and one of the world's largest fully protected marine areas. It encompassed 582,578 square miles, including both marine and terrestrial habitats.

International measures to protect species from destruction or exploitation include the 1946 International Convention for the Regulation of Whaling. The high prevalence of whaling worldwide caused a huge decline in whales, from an estimated 4.4 million in 1900 to approximately 1 million by the end of the twentieth century. Overharvesting whales affected almost every whale species. In 1946, the International Whaling Commission (IWC) was established to set annual whaling quotas to prevent commercial overharvesting and the extinction of whales. However, many whaling countries ignored the suggested quotas. In 1971, the United States stopped all commercial whaling and banned imports of all whale products. In 1974, the IWC began to regulate whaling according to the principle of maximum sustainable yield. When a given species of whale—such as the right whale, bowhead whale, or blue whale—fell below the optimal population for such a yield, the IWC issued a ban on hunting that species. Despite these efforts, in 2024, the most whale species had not begun to recover, and many endangered whale species populations declined further, largely due to human factors. However, some, such as Pacific humpback whales, recovered to the point that they reached carrying capacity. A shortage of food, along with a heat wave caused by climate change, caused their numbers to decline, although not to the point of being threatened.

Other international agreements to protect endangered species include the Convention on the Conservation of Migratory Species of Wild Animals (Bonn Convention), which entered into force in 1983, and the Convention on Biological Diversity (CBD), which entered into force in 1993. The Bonn Convention is the only international treaty that focuses on the conservation of terrestrial, marine, and avian migratory species, their habitats, and their migration routes. The CBD, which opened for signature at the 1992 Earth Summit in Rio de Janeiro, Brazil, concerns the significance of biodiversity for future generations, the sovereignty of each nation over its resources, and each nation's need and right to conserve and protect its own biodiversity. The treaty details a plan that directs industrialized countries to help fund projects for the protection of biodiversity within developing countries; it also stresses the right of national governments to decide who may have access to their resources. The treaty provides for a sharing of technologies, particularly biotechnologies that have been developed from plants originating in developing countries, thereby giving developing countries substantial benefits from any technologies that are developed based on the genetic resources within their borders. Agenda 21, a comprehensive international plan of action adopted at the 1992 Earth Summit, addresses the need for nations to "promote the rehabilitation and restoration of damaged ecosystems and the recovery of threatened and endangered species." In 2015, Agenda 21 became Agenda 2030, retaining all goals originally established in 1992 while expanding and updating goals and plans.

Bibliography

"About the Endangered Species Program." United States Environmental Protection Agency, 29 Mar. 2022, www.epa.gov/endangered-species/about-endangered-species-protection-program. Accessed 17 July 2024.

"A.I. Sorts Public Photos to Show Recovering Pacific Humpback Whales Hit Climate Ceiling." NOAA Fisheries, 27 Feb. 2024, www.fisheries.noaa.gov/feature-story/ai-sorts-public-photos-show-recovering-pacific-humpback-whales-hit-climate-ceiling. Accessed 17 July 2024. Bräutigam, Amie, and Martin Jenkins. The Red Book: The Extinction Crisis Face to Face. Gland, Switzerland: IUCN, 2001.

Chiras, Daniel D. "Preserving Biological Diversity." In Environmental Science. 8th ed. Sudbury, Mass.: Jones and Bartlett, 2010.

“Eagle Population Status: U.S. Fish & Wildlife Service.” FWS, www.fws.gov/project/eagle-population-status. Accessed 17 July 2024.

Friedman, Lisa. "US Significantly Weakens Endangered Species Act." The New York Times, 12 Aug. 2019, www.nytimes.com/2019/08/12/climate/endangered-species-act-changes.html. Accessed 17 July 2024.

Groom, Martha J., Gary K. Meffe, and Carl Ronald Carroll. Principles of Conservation Biology. 3d ed. Sunderland, Mass.: Sinauer, 2006.

The IUCN Red List of Threatened Species, International Union for Conservation of Nature and Natural Resources, 2019, www.iucnredlist.org/. Accessed 17 July 2024.

“Listed Species Summary.” Environmental Conservation Online System, U.S. Fish & Wildlife Service, 2023, ecos.fws.gov/ecp/report/boxscore. Accessed 17 July 2024.

Mackay, Richard. The Atlas of Endangered Species. Rev. 3d ed. Sterling, Va.: Earthscan, 2009.

McNeely, Jeffrey A., et al. Conserving the World's Biological Diversity. Washington, D.C.: Island Press, 1990.

“Population (Abundance) Estimates.” International Whaling Commission, iwc.int/about-whales/status. Accessed 17 July 2024.

Vié, Jean-Christophe, Craig Hilton-Taylor, and Simon N. Stuart, eds. Wildlife in a Changing World: An Analysis of the 2008 IUCN Red List of Threatened Species. Gland, Switzerland: IUCN, 2009.

Wagner, Viqi, ed. Endangered Species: Opposing Viewpoints. Detroit: Greenhaven Press, 2008.

"What Is CITES?" Convention on International Trade in Endangered Species of Wild Fauna and Flora, 2018, www.cites.org/eng/disc/what.php. Accessed 17 July 2024.