98-32:Endangered Species List Revisions:
A Summary of Delisting and Downlisting (cont'd)

Downlisted Species

Lahontan cutthroat trout, Paiute cutthroat trout, Arizona trout
American alligator
Gray wolf
Greenback cutthroat trout
Red lechwe
Leopard
Arctic peregrine falcon
Utah prairie dog
Snail darter
Tinian monarch
Aleutian Canada goose
Nile crocodile
Louisiana pearlshell
Siler pincushion cactus
Small whorled pogonia
Virginia round-leaf birch|
Bald eagle
MacFarlane's four-o'clock
Maguire daisy
Australian saltwater crocodile

Appendix: Regulations for Amending Lists of Endangered and Threatened Wildlife and Plants

Downlisted Species

Species that have stabilized or increased in number may be reclassified from endangered to threatened status. ESA proponents assert that downlisting can be an important part of the recovery process, and a measure of success for the ESA. However, these species are often not counted by opponents as successes for the ESA because they have not met the Act's goal of complete removal from the list. Twenty-two species have been downlisted from endangered to threatened status.

Lahontan cutthroat trout, Pajute cutthroat trout, Arizona trout. The Lahontan cutthroat trout (Oncorhynchus (=Salmo) clarki henshawi), Paiute cutthroat trout (O. C. seleneris), and Arizona trout (Oncorhynchus apache) are western trout species with limited distributions. O. C. henshawi occurs in most streams of the Truckee, Carson, and Walker River drainages in California and Nevada. O. C. seleneris occurs in Silver King Creek and its tributaries in Alpine County, California. O. apache occurs in the headwaters of the Salt and Little Colorado Rivers in east central Arizona.

These species were listed as endangered under the ESCA of T969 due to "destruction, drastic modification, or severe curtailment of their habitat," and hybridization with introduced trout species, especially the brook and rainbow trout. State and federal recovery programs successfully cultured and reintroduced populations in areas from which they were depleted, and reduced the threat of hybridization by eliminating exotic species. In 1975, the FWS downlisted the Lahontan cutthroat trout, Paiute cutthroat trout, and Arizona trout from endangered to threatened (40 FR 29863). A special rule under this downlisting action allows the regulated taking of these species for sport fi:shing purposes.

American alligator. See section under "Recovered Species."

Gray wolf. The gray wolf (Canis lupus) was historically found over most of North America, from central Mexico to the Arctic Ocean. Systematic eradication programs, habitat destruction, and over-hunting of prey populations eliminated wolves fiorn most of the contiguous United States by the 1940's. In 1967, the timber wolf subspecies Canis lupus lycaon, was listed as endangered under the ESPA of 1966 (32 fR 4001). In 1973, the FWS listed the northern Rocky Mountain subspecies, C. I. irremotus, and the Texas subspecies, C. I. monstrabilis, as endangered under the ESA (38 FR 14678). In 1978, the Secretary clarified the legal and taxonomic confusion that arose from these listings by downlisting the Minnesota population of wolves from endangered to threatened, while all other North American gray wolf populations south of Canada remained listed as endangered, without reference to subspecies (43 FR 9607).10

Greenback cutthroat trout. The greenback cutthroat trout (Oncorhynchus (=Salmo) clarki stomias) is a fish endemic to the headwaters of the South Platte and Arkansas Rivers in Colorado. Habitat destruction caused by mining, logging, grazing and irrigation projects, in addition to hybridization with introduced trout, drastically reduced populations of the greenback cutthroat. By 1930, this species was believed to be extinct. Later rediscovery allowed state and federal conservation programs to culture and reintroduce populations in its historical range. These programs also eliminated many of the exotic species responsible for hybridization problems. In 1978, the FWS downlisted the greenback cutthroat trout from endangered to threatened (43 FR 16343), recognizing that threats from habitat destruction and hybridization remain. A special rule under this downlisting action allows for the regulated taking of this species for sport fishing purposes.

Red lechwe. The red lechwe (Kobus leche) is a species of African antelope whose historical range included parts of Namibia, Botswana, Angola, Zaire, and Zambia. Unregulated commercial and subsistence hunting, combined with habitat destruction, led to population declines through the first half of the 20th Century. The FWS listed the red lechwe as endangered under the ESCA in 1970 (35 FR 8495). Control of hunting and listing on Appendix I of CITES resulted in stable or increasing populations over much of their range. In 1979, the Conference of the parties to CITES changed the listing of the red lechwe from Appendix I to Appendix II, and in 1980, the FWS downlisted the red lechwe from endangered to threatened (45 FR 65132). With the Appendix 11 listing, § 9(c)(2) of the FSA allows "the importation of legally taken sport-hunted trophies."

Leopard. The leopard (Panthera pardus) is widely distributed across Africa, China, Japan, Korea, India, Sri Lanka, and Southeast Asia. An uncontrolled commercial fur trade (e.g., the United States imported more than 17,000 leopard hides from 1968 to 1969) sharply depleted leopard populations. In 1970, the FWS listed the leopard as endangered under the ESCA (35 FR 8495), prohibiting the import of live animals, their parts and products. P. pardus was also added to Appendix I of CITES, providing for further control of commercial trade in hides. Subsequent surveys determined that leopard populations in some areas were recovering, and in 1982, the FWS downlisted the southern Africa leopard populations from endangered to threatened (47 FR 4204). A special rule allows the import of "legally taken sport-hunted leopard trophies." Other populations of leopard remain listed as endangered under the ESA.

Arctic peregrine falcon. See section under "Recovered Species."

Utah prairie dog. The Utah prairie dog (Cynomys parvidens) is a burrowing rodent of the squirrel family that occurs only in southern Utah. Early ranchers believed that the prairie dog competed directly with livestock for food. The ranchers actively sought to eliminate them through habitat alteration and poisoning. In 1973, the FWS listed the Utah prairie dog as endangered under the ESA (38 FR 14678), pursuant to the ESCA of 1969. The protections provided by the ESA allowed populations to increase, and in 1984, the FWS downlisted the Utah prairie dog from endangered to threatened (49 FR 22330). To mitigate conflict between ranchers and expanding prairie dog populations, a special rule was included in the downlisting that allows the "taking" of up to 5,000 prairie dogs per year.

Snail darter. The snail darter (Percina tanasi) is a small fish, typically less than 3.5 inches, that occurs in sandbar habitat in six tributaries of the Tennessee River. The FWS listed the snail darter as endangered under the ESA in 1975 (40 FR 47506), at which time it was known from only one population at the mouth of the Little Tennessee River. In 1979, federal law exempted the Little Tennessee River Tellico Reservoir Project from the ESA, allowing a dam to be completed that inundated the known population. Before and after dam completion, the FWS introduced the snail darter into other streams in the area with only limited success. Subsequent surveys, however, found populations in six Tennessee River tributaries in Tennessee and Alabama. These discoveries allowed the FWS to downlist the snail darter from endangered to threatened in 1984 (49 FR 27501). This historic conflict between an endangered species and development played a major role in the evolution of the ESA.11

Tinian monarch. The Tinian monarch (Monarcha takatsukasae) is a small brownish song bird that is endemic to the island of Tinian, north of Guam in the Mariana Archipelago. Deforestation, first for sugarcane production, and later as a result of World War II combat activities, caused a severe depletion of the monarch population. The FWS listed the Tinian monarch as endangered in 1970 under the ESCA (35 FR 8495) based on pre- and post-war data. The island has since become revegitated with a shrubby legume (Leucaena leucocephala) in which the monarch has thrived. In 1987, the FWS downlisted the Tinian monarch from endangered to threatened (52 FR 10890). The Service noted three threats preventing the complete delisting of the species: 1) potential defoliation of Leucaena by introduced plant lice; 2) potential introduction of the predatory brown tree snake (Boiga irregularis) 12; and 3) the species' existence is limited to one small island.

Aleutian Canada goose. The Aleutian Canada goose (Branta canadensis leucopareia), one of the smallest of 11 subspecies of Canada geese, nests on remote islands off the coast of the Alaska Peninsula and in the Aleutian Archipelago. Most Aleutian geese migrate along the Pacific coast flyway of North America and winter in Oregon and California. Some geese migrate along the western coast of the Pacific and winter in Asia and Japan. Populations of Aleutian geese declined due to arctic fox (Alopex lagopus) introductions on their breeding islands, and recreational and subsistence hunting in the Pacific flyway. The FWS added B. c. leucopareia to the list of U.S. endangered species under the ESPA in 1967 (32 FR 4001), and to the list of foreign endangered species under the ESCA in 1970 (35 FR 8495). Fox control programs on breeding islands and hunting closures in important wintering areas are primarily responsible for increasing goose populations. In 1990, the FWS downlisted all populations of the Aleutian Canada goose from endangered to threatened (55 FR 51106), noting that the species still faces threats from disease, predation, and, especially on the wintering grounds, storms and habitat loss.

Nile crocodile. The Nile crocodile (Crocodylus niloticus) is a large aquatic reptile that was historically found throughout Africa and as far north as Syria. Habitat destruction, unregulated commercial trade in hides, and hunting to eliminate threats to humans, livestock, and fisheries led to significant population declines. The crocodile was first listed as endangered under the ESCA in 1970 (35 FR 8495), and on Appendix I of CITES in 1975. As countries began to implement management practices, especially ranching for the controlled harvest of hides, crocodile populations stabilized or increased. Zimbabwe's successful management led to a downlisting of their ranched populations in 1987 (52 FR 23148), and a downlisting of their wild populations in 1988 (53 FR 38451). In 1993, the FWS downlisted all populations of the Nile crocodile from endangered to threatened (58 FR 49870). The species has also been moved from Appendix I to Appendix II of CITES in Botswana, Malawi, Mozambique, and Zambia, allowing for regulated commercial trade in crocodile hides from these countries.

Louisiana pearlshell. The Louisiana pearishell (Margaritifera hembeli) is a freshwater mussel approximately 4" long that was known to exist only in the Bayou Boeuf drainage, Rapides Parish Louisiana. Due to its limited distribution and threats from destruction of river habitat, the FWS listed this species as endangered under the ESA in 1988 (53 FR 3567). Since the listing, M. hembeli has been found in the Red River drainage, Grant Parish, Louisiana. Subsequent surveys done under the recovery plan expanded the known range to eight streams of the Red River drainage and 11 streams of the Bayou Boeuf drainage. While the discovery of additional populations removes the immediate threat of extinction, threats remain from population fragmentation by impoundments, collecting, and sedimentation from gravel mining. For these reasons, the FWS downlisted the Louisiana pearl shell from endangered to threatened in 1993 (58 FR 49935).

Siler pincushion cactus. The Siler pincushion cactus (Pediocactus sileri) is a 4-5" spherical or cylindrical cactus with 1" spines and yellow flowers. It is found primarily on gypsum soils at altitudes between 2,800 and 5,400 feet in southwest Utah and northwest Arizona. The FWS listed this species as endangered under the ESA in 1979 (44 FR 61786) based on evidence that its small populations with limited habitat were threatened by gypsum mining, off-road vehicle use, road construction, collection, livestock, and development of the Warner Valley Power Plant. Under the Siler Pincushion Cactus Recovery Plan, the FWS closed certain areas to off-road vehicles, fenced off areas of high cactus density, and surveyed potential habitat. As a result of these and other measures, the FWS determined that the Siler pincushion cactus was no longer in danger of extinction, and in 1993, downlisted it from endangered to threatened (58 FR 68476).

Small whorled pogonia. The small whorled pogonia (Isotria medeoloides) is a perennial orchid that inhabits young and maturing stands of mixed-deciduous or mixed-deciduous/coniferous forests. The species was widely distributed from southern Maine and New Hampshire, through the Atlantic seaboard states, to southern Tennessee and northern Georgia. The FWS listed I medeoloides as endangered under the ESA in 1982 (47 FR 39827) when they estimated less than 500 individuals remained in 17 populations. Since listing, the FWS has identified three primary population centers: 1) the Appalachian foothills of New England; 2) the Blue Ridge mountains where Tennessee, North and South Carolina, and Georgia share borders; and 3) coastal plain and piedmont counties of Virginia. Management actions at these and other sites have provided adequate protection and allowed populations to stabilize or increase to meet recovery plan objectives. Thus, the FWS downlisted the small whorled pogonia from endangered to threatened in 1994 (59 FR 50852).

Virginia round-leaf birch. The Virginia round-leaf birch (Betula uber) is a species from southwestern Virginia with smooth, dark-brown or black bark that can reach heights of 45 feet. Botanists assumed this species to be extinct when no specimens could be found from 1950 to 1975. In 1975, 41 trees were found along Cressy Creek, Smyth County, Virginia. Due to its limited population, the FWS listed B. uber as endangered under the ESA in 1978 (43 FR 17910). Although this natural population declined from vandalism and transplantation in the late 1970's, a FWS recovery plan established additional populations through propagation management with the help of the U.S. National Arboretum, the Virginia Agricultural Experimental Station, and others. Populations have met recovery plan goals, and in 1994, the FWS downlisted the Virginia round-leaf birch from endangered to threatened (59 FR 59173).

Bald eagle. The bald eagle (Haliaeetus leucocephalus) is typically associated with estuaries, large lakes, major rivers, and seacoast habitats. Tts historical range included most of North America from central Alaska and Canada to northern Mexico. Beginning in the mid to late 1800's, a decline in eagle populations was attributed to a drop in waterfowl and shorebird prey populations, direct killing, and habitat destruction. The Bald Eagle Protection Act of 1940 (16 U.S.C. 668) prohibited direct killing in most of the eagle's range except Alaska, where the state paid a bounty for killing eagles to protect the salmon fishery In 1952, the exemption allowing Alaska's bounty was revoked.

Following World War II, the widespread use of the organochlorine pesticide DDT caused significant reproductive failure, leading to another sharp decline in eagle populations. DDE, the primary breakdown product of DDT, caused eggshells to be thin and to break easily. The FWS listed bald eagle populations south of the 40th parallel as endangered under the ESPA in 1967 (32 FR 4001). In 1978, the FWS listed all remaining birds in the lower 48 states as endangered under the ESA, with the exception of populations in Michigan, Minnesota, Wisconsin, Oregon, and Washington, where eagles were listed as threatened (43 FR 6233). The EPA banned the use of DDT in the United States in 1973 (37 FR 13369). Bald eagle recovery plans were developed in each of five established recovery regions. With annual spending exceeding $1 million during the period 1985-1995, eagle populations have increased across most of the United States. FWS data for 1995 estimate 4,712 breeding pairs in the lower 48 states, up from a low of 417 pairs in 1963. In 1995, the FWS downlisted the bald eagle from endangered to threatened in all of the lower 48 states (60 FR 36000).

MacFarlane' s four-o'clock. MacFarlane's four-o'clock (Mirabilis macfarlanei) is a perennial plant with hemispherical clumps 24-47" in diameter, and large, funnel-shaped magenta flowers. The species was described in 1936 from a population found along Snake River, Oregon. From 1947 to the mid 1970's, M macfarlanei was not found and was thought to be extinct. In 1977, two populations were located containing approximately 27 individual plants. The FWS listed the four-o'clock as endangered under the ESA in 1979 based on this limited distribution (44 FR 61912). Extensive surveys conducted as part of the species' 1985 recovery plan located over 7,000 plants in three disjunct areas: the Snake River unit, Idaho County, Idaho, and Wallowa County, Oregon; the Salmon River unit, Idaho County, Idaho; and the Imnaha River unit, Wallowa County, Oregon. With reclassification objectives of the recovery plan met, the FWS downlisted MacFarlane's four-o'clock from endangered to threatened in 1996 (61 FR 10693), but noted that continued threats from habitat loss warrant continued protection as a threatened species.

Maguire daisy. The Maguire daisy (Erigeron maguirei) is a perennial herb with both white and orange flowers that is endemic to sandstone canyons and mesas of San Rafael Swell, Emery County, Utah, and Capitol Reef, Wayne County, Utah. In 1985, the FWS listed E. m. var. rnaguirei as an endangered species under the ESA due to its limited distribution (50 FR 36090). Later studies determined that populations formerly recognized as E. m. var.maguirei and E. m. var. harrisonii "do not merit recognition as separate varieties." By considering these two former varieties as a single unit of E. maguirei, the FWS found there to be more individuals than previously believed. In 1996, the FWS downlisted the Maguire daisy from endangered to threatened (61 FR 31054), noting that the small, reproductively isolated populations continue to face threats from mineral development, recreation activities, livestock trampling, and loss of genetic variability.

Australian saltwater crocodile. The saltwater crocodile (Crocodylus porosus) is a large aquatic reptile distributed across southwest India, Southeast Asia, the Pacific Islands, and the northern coast of Australia. Due to habitat loss, unregulated hunting, and poaching for a cominercial trade in hides, all populations of the saltwater crocodile, except for Papua New Guinea's (where the species was somewhat more healthy), were moved from Appendix II to Appendix I of CITES in 1979. In the same year, the FWS listed all populations outside Papua New Guinea as endangered under the ESA (44 FR 75074). In 1985, Australia's saltwater crocodiles were returned from Appendix I to Appendix II of CITES due to their successfril management of wild and ranched populations. The Appendix II listing of CITES allows for the export of ranch-produced hides in 1996, the FWS downlisted the Australian population of saltwater crocodile from endangered to threatened, with a special rule that allows the import of ranched crocodiles and their products (61 FR 32356). The FWS has proposed a classification of Papua New Guinea's population of crocodile as threatened due to similarity of appearance (59 FR 18652).

Appendix: Regulations for Amending Lists of Endangered and Threatened Wildlife and Plants

50 CFR § 424.11 Factors for listing, delisting, or reclassifying species.

(a) Any species or taxonomic group of species (e.g., genus, subgenus) as defined in § 424.02(k) is eligible for listing under the Act. A taxon of higher rank than species may be listed only if all included species are individually found to be endangered or threatened. In determining whether a particular taxon or population is a species for the purposes of the Act, the Secretary shall rely on standard taxonomic distinctions and the biological expertise of the Department and the scientific community conceming the relevant taxonomic group.

(b) The Secretary shall make any determination required by paragraphs (c) and (d) of this section solely on the basis of the best available scientific and commercial information regarding a species status without reference to possible economic or other impacts of such determination.

(c) A species shall be listed or reclassified if the Secretary determines, on the basis of the best scientific and commercial data available after conducting a review of the species' status, that the species is endangered or threatened because of any one or a combination of the following factors:

(1) The present or threatened destruction, modification, or curtailment of its habitat or range;

(2) Overutilization for commercial, recreational, scientific, or educational purposes;

(3) Disease or predation;

(4) The inadequacy of existing regulatory mechanisms; or

(5) Other natural or manmade factors affecting its continued existence.

(d) The factors considered in delisting a species are those in paragraph (c) of this section as they relate to the definitions of endangered or threatened species. Such removal must be supported by the best scientific arid commercial data available to the Secretary after conducting a review of the status of the species. A species may be delisted onlv if such data substantiate that it is neither endangered nor threatened for one or more of the following reasons:

(1) Extinction. Unless all individuals of the listed species had been previouslv identified and located, and were later found to be extirpated from their previous range, a sufficient period of time must be allowed before delisting to indicate clearly that the species is extinct.

(2) Recovery. The principal goal of the U.S. Fish and Wildlife Service and the National Marine Fisheries Service is to return listed species to a point at which protection under the Act is no longer required. A species may be delisted on the basis of recovery only if the best scientific and com'mercial data available indicate that it is no longer endangered or threatened.

(3) Original data for classification in error. Subsequent investigations may show that the best scientific and commercial data available when the species was listed, or the interpretation of such data, were in error.

(e) The fact that a species of fish, wildlife, or plant is protected by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (see part 23 of this title 50) or a similar international agreement on such species, or has been identified as requiring protection from unrestricted commerce by any foreign nation, or to be in danger of extinction or likelv to become so within the foreseeable fliture by any State agency or by any agency of a foreign nation that is responsible for the conservation of fish, wildlife, or plants, may constitute evidence that the species is endangered or threatened. The weight given such evidence "will vary" depending on the international agreement in question, the criteria pursuant to which the species is eligihle for protection under such authorities, and the degree of protection afforded the species. The Secretary shall give consideration to any species protected under such an international agreement, or by any State or foreign nation, to determine whether the species is endangered or threatened.

(f) The Secretary shall take into account in making determinations under paragraph (c) or (d) of this section, those efforts, if any, being made by any State or foreign nation, or any political subdivision of a State or foreign nation, to protect such species, whether by predator control, protection of habitat and food supply, or other conservation practices, within any area under its jurisdiction, or on the high seas.

Endnotes

11 For more information about the history of this species, which was the centerpiece of arguably the most famous legal battle in tlie history of the ESA, see CRS Report 90-242 ENR, Endangered Species Act: The Listing and Exemption Process, Appendix B.

12 For more information, see CRS Report 97-5O7 ENR, Non-Indigenous Species: Government Response to the Brown Tree Snake and Issues for Congress.