Endangered Mammals

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CHAPTER 7
ENDANGERED MAMMALS

The majority of threatened and endangered mammals are imperiled for the same reasons as other biological species—habitat destruction, pollution, competition with invasive species, and so on. However, some mammals have also been intentionally killed-off by humans. For example, in the nineteenth century, the quagga of southern Africa was hunted to extinction because it competed with sheep for grazing land. Similarly, in the late nineteenth and early twentieth centuries, the thylacine, or Tasmanian tiger, was driven to extinction through hunting, in response to its attacks on domestic sheep.

Other mammal species have been driven to endangerment or extinction because they are seen as dangerous. Large predators such as grizzly bears, wolves, and mountain lions are endangered at least partly for this reason. Changing attitudes have led to interest in preserving all species, and conservation measures have allowed several predatory mammals to recover. As their populations increase, however, encounters with humans are also becoming more common.

  • In California, following a ban on mountain lion hunting, reports of mountain lions rose through the 1990s. In January 2004 a mountain lion killed one bicyclist and severely injured a second in southern California. The mountain lion was later found and shot. In 114 years, California has reported a total of fourteen mountain lion attacks, of which six were fatal.
  • In Yosemite National Park in California, black bears have increasingly confronted park visitors, causing significant damage and occasional injury. However, biologists attribute the incidents not to aggressive bears but to careless park visitors. In 2001 park officials killed a female bear, the mother of two cubs, because she was allegedly teaching her cubs to raid cars, campsites, and picnic areas for food.
  • In 2000 biathlete Mary Beth Miller was mauled to death by a black bear as she ran along a wooded path during her training routine in Quebec, Canada. The tragedy ignited controversy over attempts by Canadian officials to protect the species, including the cancellation of an annual bear hunt.

LEVELS OF ENDANGERMENT

In 2004 there were a total of 342 threatened and endangered mammals listed under the Endangered Species Act. Of the endangered mammals, 65 are found in the U.S. and 251 are foreign. Of the threatened species, 9 are found in the U.S. and 17 are foreign. U.S. threatened and endangered mammals are shown in Table 7.1. Some mammalian groups that are particularly well-represented on the U.S. list include bats (9 species), bears (3 species), kangaroo rats (6 species), mice (10 species), and whales (7 species).

The 2003 Red List report of the World Conservation Union (IUCN) reports that 1,130 mammals, or 24 percent of species examined, are threatened globally. Nearly all are imperiled because of human activity. The last major IUCN assessment of the Red List, in 2000, revealed that a large majority—83 percent—are endangered due to loss of habitat. This was significantly worse than in the 1996 assessment, when 478 species were listed. The IUCN Director-General, Maritta con Bieberstein Koch-Weser, described the 2000 results as "a jolting surprise, even to those already familiar with today's increasing threats to biodiversity." The habitat types occupied by the largest numbers of threatened mammal species are lowland and tropical rainforests, both of which are being rapidly degraded. In 2003, the countries that harbored the largest number of threatened mammals included Indonesia (147), India (86), China (81), Brazil (74), Mexico (72), Australia (63), Papua New Guinea (58), Kenya (50), the Philippines (50), Madagascar (50), Malaysia (50), Peru (46), Russia (45), Vietnam (42), Tanzania (41), the Democratic Republic of the Congo (40), Myanmar (39), the United States

StatusSpecies nameStatusSpecies name
EBat, gray (Myotis grisescens)EMouse, St. Andrew beach (Peromyscus polionotus peninsularis)
EBat, Hawaiian hoary (Lasiurus cinereus semotus)EOcelot (Leopardus [=Felis] pardalis)
EBat, Indiana (Myotis sodalis)XN, TOtter, southern sea (Enhydra lutris nereis)
EBat, lesser long-nosed (Leptonycteris curasoae yerbabuenae)EPanther, Florida (Puma [=Felis] concolor coryi)
EBat, little Mariana fruit (Pteropus tokudae)TPrairie dog, Utah (Cynomys parvidens)
EBat, Mariana fruit (=Mariana flying fox) (Pteropus mariannus mariannus)EPronghorn, Sonoran (Antilocapra americana sonoriensis)
EBat, Mexican long-nosed (Leptonycteris nivalis)EPuma (cougar), eastern (Puma [=Felis] concolor couguar)
EBat, Ozark big-eared (Corynorhinus [=Plecotus] townsendii ingens)T(S/A)Puma (mountain lion) (Puma [=Felis] concolor [all subsp]. except coryi)
EBat, Virginia big-eared (Corynorhinus [=Plecotus] townsendii virginianus)ERabbit, Lower Keys marsh (Sylvilagus palustris hefneri)
T(S/A)Bear, American black (Ursus americanus)ERabbit, pygmy (Brachylagus idahoensis )
XN, TBear, grizzly (Ursus arctos horribilis)ERabbit, riparian brush (Sylvilagus bachmani riparius)
TBear, Louisiana black (Ursus americanus luteolus)ERice rat (Oryzomys palustris natator )
ECaribou, woodland (Rangifer tarandus caribou)ESeal, Caribbean monk (Monachus tropicalis)
EDeer, Columbian white-tailed (Odocoileus virginianus leucurus)TSeal, Guadalupe fur (Arctocephalus townsendi)
EDeer, key (Odocoileus virginianus clavium)ESeal, Hawaiian monk (Monachus schauinslandi)
E, XNFerret, black-footed (Mustela nigripes)E, TSea-lion, Steller (Eumetopias jubatus)
EFox, San Joaquin kit (Vulpes macrotis mutica)ESheep, bighorn (Ovis canadensis)
EJaguar (Panthera onca)ESheep, bighorn (Ovis canadensis californiana )
EJaguarundi, Gulf Coast (Herpailurus [=Felis] yagouaroundi cacomitli)EShrew, Buena Vista Lake ornate (Sorex ornatus relictus)
EJaguarundi, Sinaloan (Herpailurus [=Felis] yagouaroundi tolteca)ESquirrel, Carolina northern flying (Glaucomys sabrinus coloratus)
EKangaroo rat, Fresno (Dipodomys nitratoides exilis)E, XNSquirrel, Delmarva Peninsula fox (Sciurus niger cinereus)
EKangaroo rat, giant (Dipodomys ingens)ESquirrel, Mount Graham red (Tamiasciurus hudsonicus grahamensis)
EKangaroo rat, Morro Bay (Dipodomys heermanni morroensis)TSquirrel, northern Idaho ground (Spermophilus brunneus brunneus)
EKangaroo rat, San Bernardino Merriam's (Dipodomys merriami parvus)ESquirrel, Virginia northern flying (Glaucomys sabrinus fuscus)
EKangaroo rat, Stephens' (Dipodomys stephensi [including D. cascus)]EVole, Amargosa (Microtus californicus scirpensis)
EKangaroo rat, Tipton (Dipodomys nitratoides nitratoides)EVole, Florida salt marsh (Microtus pennsylvanicus dukecampbelli)
TLynx, Canada (Lynx canadensis)EVole, Hualapai Mexican (Microtus mexicanus hualpaiensis)
EManatee, West Indian (Trichechus manatus)EWhale, blue (Balaenoptera musculus)
EMountain beaver, Point Arena (Aplodontia rufa nigra)EWhale, bowhead (Balaena mysticetus)
EMouse, Alabama beach (Peromyscus polionotus ammobates)EWhale, finback (Balaenoptera physalus)
EMouse, Anastasia Island beach (Peromyscus polionotus phasma)EWhale, humpback (Megaptera novaeangliae)
EMouse, Choctawhatchee beach (Peromyscus polionotus allophrys)EWhale, right (Balaena glacialis [including australis)
EMouse, Key Largo cotton (Peromyscus gossypinus allapaticola)EWhale, Sei (Balaenoptera borealis)
EMouse, Pacific pocket (Perognathus longimembris pacificus)EWhale, sperm (Physeter catodon [=macrocephalus])
EMouse, Perdido Key beach (Peromyscus polionotus trissyllepsis)E, XN, TWolf, gray (Canis lupus)
TMouse, Preble's meadow jumping (Zapus hudsonius preblei)E, XNWolf, red (Canis rufus)
EMouse, salt marsh harvest (Reithrodontomys raviventris)EWoodrat, Key Largo (Neotoma floridana smalli)
TMouse, southeastern beach (Peromyscus polionotus niveiventris)EWoodrat, riparian (=San Joaquin Valley) (Neotoma fuscipes riparia)
E = Endangered
T = Threatened
T(SA) = Similarity of appearance to a threatened taxon
XN = experimental population, non-essential
source: Adapted from "U.S. Listed Vertebrate Animal Species Report by Taxonomic Group as of 02/17/2004," Threatened and Endangered Species System (TESS), U.S. Fish and Wildlife Service, Washington, DC, 2004 [Online] http://ecos.fws.gov/tess_public/TESSWebpageVipListed?code=V&listings=0#E [accessed February 17, 2004]

(39), Columbia (39), Cameroon (38), Thailand (37), and Japan (37).

The biggest cause of mammalian decline and extinction in the twentieth century is habitat loss and degradation. As humans convert forests, grasslands, rivers, and wetlands for various uses, they relegate many species to precarious existences in small, fragmented habitat patches. Primates, for example, are highly threatened partly because they are dependent on large expanses of tropical forests, a habitat under siege worldwide. In regions where tropical forest degradation and conversion have been most intense, such as South and Southeast Asia, Madagascar, and Brazil, as many as 70 percent of native primate species face extinction.

The introduction of invasive species by humans has also taken a toll on mammalian wildlife. Australia is overrun with domestic cats whose ancestors were brought by settlers to the island continent two hundred years ago. Stray domestic cats have driven indigenous species such as bandicoots, bettongs, numbats, wallabies, and dozens of other bird and mammal species, most of which are found nowhere else on Earth, towards extinction. Richard Evans, a member of the Australian Parliament, claims the feral cats are responsible for the extinction of at least thirty-nine species in Australia. He has called for total eradication of cats from the island by 2020, to be achieved by neutering pets and spreading feline diseases in the wild. The Australian National Parks and Wildlife Service reports that each house cats kills twenty-five native animals each year on average, and feral domestic cats kill as many as 1,000 per year.

THE BLACK-FOOTED FERRET

The black-footed ferret (see Figure 7.1) is a small furrow-digging mammal and member of the weasel family. Nocturnal creatures, ferrets help to control populations of snakes and rodents, including their primary prey, black-tailed prairie dogs. Black-footed ferrets once ranged over eleven Rocky Mountain states as well as parts of Canada. They have declined drastically because of the large-scale conversion of prairie habitats to farmland, and because their primary prey, prairie dogs, have been nearly exterminated by humans. Prairie dogs are considered pests because they dig holes and tunnels just beneath the ground surface. These can cause serious injury to horses or other large animals that step into them. (Some municipalities also poison prairie dogs in city parks, where burrow holes can trip and injure humans.) Poisons used to kill prairie dogs may also kill some ferrets.

Black-footed ferret populations had declined so greatly that the species was put on the Endangered Species List in 1973. However, prairie dog poisonings continued, and by 1979 it was believed that the black-footed ferret was extinct. In 1981 a ferret was sighted in Wyoming and discovered to be part of a remnant population. Rewards were offered for more sightings, and by the end of the year a few black-footed ferret populations had been located. These typically existed in close proximity to prairie dog populations in sagebrush-heavy areas. In 1985 ferret populations were struck by disease, and by 1987, only eighteen blackfooted ferrets were in existence. These individuals were captured and entered into a captive breeding program.

The captive breeding of ferrets has been reasonably successful. There are now core populations of 269 breeding-age individuals in five zoos in the U.S. and Canada as well as one Fish and Wildlife Service facility. In 1999 a total of 133 kits were born. The Fish and Wildlife Service has also tried to reintroduce black-footed ferrets in several states. Studies suggest that each population of black-footed ferret requires approximately 10,000 acres of black-tailed prairie dog habitat to survive. Unfortunately, prairie dogs are also in decline due to habitat loss and episodes of sylvatic plague, which have decimated many populations. Although some reintroductions have failed, two are doing well—one in National Forest habitat in Conata Basin/Badlands, South Dakota, and another in the Charles M. Russell National Wildlife Refuge in Montana. In 2000 there were already many more wild-born than captive-born ferrets at those sites. The Fish and Wildlife Service recovery plan for black-footed ferrets hopes to move the species from endangered to threatened status by 2010. This would require that 1,500 breeding adults exist in the wild in a minimum of ten separate locations, with a minimum of 30 breeding adults included in each population. Captive breeding and reintroductions of black-footed ferrets were organized by the Black-Footed Ferret Recovery Implementation Team, and involved twenty-six separate state and federal organizations, conservation groups, and Native American tribes.

NORTHERN IDAHO GROUND SQUIRREL

The Northern Idaho ground squirrel was listed as a threatened species in April 2000. It occurs only in two counties in Idaho. The species was initially listed after the population dropped from 5,000 individuals in 1985 to less than 1,000 in 1998. In 2002, an estimated 450–500 ground squirrels were believed to exist. Figure 7.2 shows the historical range of the species as well as current primary and secondary populations.

The Northern Idaho ground squirrel is threatened primarily by habitat loss. It occupies dry rocky meadows at moderate elevation which have been increasingly lost to forest encroachment. Other factors leading to its threatened status include shooting by humans, poisoning, natural events, and competition from the Columbian ground squirrel, a larger species. The listing factors and recovery action recommendations, from the recovery plan completed in July 2003, appear in Table 7.2.

WOLVES

Wolves were once among the most widely distributed mammals on Earth. Prior to European settlement, wolves ranged over most of North America, from central Mexico to the Arctic Ocean. Their decline has largely resulted from hunting. In 1914 Congress authorized funding for

Listing factorThreatStill a threat?
AForest encroachment into grassland meadows/fire suppressionYes
AConversion of meadows to agricultureYes
AGrazing practicesUnknown/needs evaluation
AResidential constructionYes
ADevelopment of recreational facilities, e.g., golf coursesYes
ADam expansion for irrigationYes
ARoad construction and maintenanceYes
BRecreational shootingYes
CPredation, primarily by badgersYes
CDisease, plaguePotential only
DInadequate local land use ordinances relating to housing developmentsYes
ELand ownership patternsYes
EWinter mortalityYes
Listing factors:
A. The present of threatened destruction, modification, or entailment of its habitat or range
B. Overutilization for commercial, recreational, scientific, educational purposes (not a factor)
C. Disease or predation
D. The inadequacy of existing regulatory mechanisms
E. Other natural or man made factors affecting its continued existence
source: Adapted from "Table 4. Cross-Reference of Recovery Actions and Listing Factors for the Northern Idaho Ground Squirrel," in Recovery Plan for the Northern Idaho Ground Squirrel (Spermophilus brunneus brunneus), U.S. Fish and Wildlife Service, Region 1, Portland, OR, July 2003

the removal of all large predators, including wolves, from federal lands. By the 1940s wolves had been eliminated from most of the contiguous United States. In 1973 the wolf, which had all but disappeared, became the first animal listed as endangered under the Endangered Species Act. Two species of wolves exist in North America today, the red wolf and the gray wolf. Both are imperiled.

The Gray Wolf Reintroduction Program

In 1991 Congress instructed the Fish and Wildlife Service to prepare an environmental impact report on the possibility of reintroducing wolves to habitats in Yellowstone National Park and central Idaho. Reintroductions began in 1995, when fourteen Canadian gray wolves were released in Yellowstone National Park.

Wolf reintroductions were not greeted with universal enthusiasm. Ranchers, in particular, were concerned that wolves would attack livestock. They were also worried that their land would be open to government restrictions as a result of the wolves' presence. Some ranchers said openly that they would shoot wolves they found on their land. Several measures were adopted to address ranchers' concerns. The most significant was that ranchers would be reimbursed for livestock losses from a compensation fund maintained by the Defenders of Wildlife, a private conservation group based in Washington, D.C. As of 2004 the fund had paid out $359,124 to 295 ranchers, covering the losses of 399 cattle, 1001 sheep, and 49 other animals killed by wolves.

Nonetheless, wolf introductions were legally challenged in 1997, when the American Farm Bureau Federation initiated a lawsuit calling for the removal of wolves from Yellowstone. The farm coalition scored an initial victory, but in January 2000 the 10th Circuit Court of Appeals in Denver overturned the decision upon appeal by the United States Department of the Interior, the World Wildlife Fund, and other conservation groups.

As of 2002 the FWS had reintroduced forty-one wolves into Yellowstone and thirty-five wolves into central Idaho. Wolf packs in both Yellowstone and Idaho have thrived. Figure 7.3 shows the number of breeding pairs in northwest Montana, Yellowstone, and Central Idaho from 1979 to 2002. A map of the wolf recovery area is shown in Figure 7.4.

Despite the concern of ranchers and livestock owners, a recovered wolf population in the Yellowstone Park area has only slightly reduced populations of cattle, sheep, elk, moose, bison, and deer. In fact, wolves weed out sick and weak animals, thus improving the overall health of prey populations. Wolf predation on herbivorous species also takes pressure off vegetation and produces carrion for an array of scavengers including eagles, ravens, cougars, and foxes. Finally, wolves have increased visitor attendance to Yellowstone National Park, generating an estimated $7–10 million in additional net income each year.

In 2002 the wolf population in the continental United States was estimated at 3,500 individuals. The gray wolf was officially reclassified by the Fish and Wildlife Service from endangered to threatened in March 2003, and delisted in areas outside the western and eastern recovery regions.

The Mexican Gray Wolf

In 1998 the Fish and Wildlife Service began to reintroduce rare Mexican gray wolves, the smallest of North America's gray wolves, into federal lands in the Southwest. This distinct subspecies once occupied habitats in central and southern Arizona, central New Mexico, western Texas, and northern Mexico. The Mexican gray wolf had been hunted to near extinction in the late 1800s and early 1900s in the United States. By 1960 only seven individuals survived in captivity. Captive breeding programs in the U.S. and Mexico have helped to increase population numbers. Released Mexican gray wolves are being tracked using radio collars. Subsequent releases are expected to create a viable population of one hundred individuals by 2005.

The Red Wolf

The red wolf (see Figure 7.5) was once found throughout the eastern United States, but declined as a result of habitat loss and aggressive hunting by humans. It has been considered endangered since 1967. The red wolf is a smaller species than its relative, the gray wolf, and, despite its name, may have any of several coat colors including black, brown, gray, and yellow. In 1975, to prevent the immediate extinction of this species, the Fish and Wildlife Service captured the twenty-some remaining individuals and began a captive breeding program. The red wolf reintroduction program began in 1987, marking the first reintroduction of a species extinct in the wild. Red wolves now reside over about one million acres in North Carolina and Tennessee, including three National Wildlife Refuges, a Department of Defense bombing range, some state-owned lands, and private property (with the permission and cooperation of landowners). As of 2002 there are nearly one hundred red wolves in these populations, with about 90 percent of these born in the wild. There are also approximately two hundred red wolves managed among captive-breeding facilities around the lower forty-eight states.

BEARS AND PANDAS

Bears and pandas are imperiled worldwide. In 2002 seven species were listed as in immediate danger of extinction under Appendix I of the Convention on International Trade in Endangered Species (CITES): the giant panda (China), red panda (Himalayas), Asiatic black bear, sloth bear (Asia), sun bear (Asia), spectacled bear (South America), and grizzly bear (North America). U.S. bear species listed by the Fish and Wildlife Service in 2004 included the American black bear, the Louisiana black bear, and the grizzly bear.

Many bears are endangered due to habitat loss. According to the Fish and Wildlife Service, bears have been eliminated from about 50 to 75 percent of their natural ranges. Some bears have traditionally been hunted because they are considered predatory or threatening. Others are hunted for sport. In addition, bears are killed in large numbers by poachers, who sell bear organs and body parts in the illegal wildlife trade. These organs usually end up in Asia, where they are valued as ingredients in treatments for ailments or illnesses, or to delay the effects of aging—although there is no evidence that such treatments are effective.

Grizzly Bears

The grizzly bear was originally found throughout the continental United States, but has now been eliminated from every state except Colorado, Idaho, Montana, Washington, and Wyoming. In 2004, there were an estimated 1,000 individuals in the wild, down from some 50,000 to 100,000 before human interference. The grizzly bear has declined due primarily to aggressive hunting and habitat loss. It is listed as threatened under the Endangered Species Act.

Grizzly bears are large animals, standing four feet high at the shoulder when on four paws, and as tall as seven feet when upright. Males weigh 500 pounds on average but are sometimes as large as 900 pounds. Females weigh 350 pounds on average. Grizzlies have a distinctive shoulder hump, which actually represents a massive digging muscle. Their claws are two to four inches long. They are more aggressive than black bears.

The federal government has established recovery zones for the grizzly bear in Yellowstone National Park, the North Continental Divide, the Selkirk and Bitterroot Mountains in Idaho, the North Cascades, the San Juan Mountains in Colorado, and the Cabinet/Yaak area on the Canadian border. (See Figure 7.6.) Recovery plans for this species are coordinated under the Interagency Grizzly Bear Committee, which was created in 1983.

Giant Pandas

Few creatures have engendered more human affection than the giant panda, with its roly-poly character, small ears, and black eye patches on a snow-white face. Giant pandas are highly endangered, with only approximately 1,000 pandas in the wild and some one hundred individuals in captivity. Pandas are found only in portions of southwestern China, where they inhabit a few fragmentary areas of high altitude bamboo forest. Unlike other bear species, to which they are closely related, pandas have a vegetarian diet that consists entirely of bamboo. Pandas also have a "sixth digit" which functions like a thumb, and which they use to peel tender bamboo leaves from their stalks.

Pandas have become star attractions at many zoos, where they draw scores of visitors. Despite tremendous efforts, pandas have proven notoriously difficult to breed in captivity. The birth of a giant panda cub, named Hua Mei, at the San Diego Zoo in 1999 was a major event, with millions of people following the cub's progress online and in the papers through her first days of life. A second panda cub was born at the zoo in 2003. The San Diego Zoo pays China $1 million annually for the loan of the pandas. These funds are used to support panda conservation efforts in China, including the purchase of land for refuges as well as the development of habitat corridors to link protected areas. The agreement also requires that pandas born at the San Diego Zoo will be returned to China after they are three years old. Hua Mei was flown to China in February 2004 to join nearly seventy pandas at the Wolong Giant Panda Protection Research Centre in the Sichuan Province of China.

Red Pandas

The red panda is also called the lesser panda because it is significantly smaller than the giant panda. Red pandas are not, like giant pandas, related to bears—they are actually raccoon relatives. Red pandas are virtually extinct in the wild, mostly because of habitat loss and degradation. Red pandas occupy temperate forests in the foothills of the Himalayas in Nepal, Burma, and southwestern China at altitudes between 5,000 and 13,000 feet. They are solitary creatures, occupying non-overlapping home ranges of approximately one square mile for females and two square miles for males. Like giant pandas, red pandas eat bamboo, focusing on the most tender leaves. Because bamboo is not very nutritious, red pandas spend as much as thirteen hours each day eating in order to acquire the nutrients they need. Red pandas have difficulty recovering from population declines because of a slow rate of reproduction. A captive breeding effort for red pandas is underway at zoos across the world to prevent the complete extinction of this species. Over three hundred red pandas are found in captivity.

BIG CATS

Of the nearly forty feline, or cat, species, only one—the domestic cat—is believed to be secure. As undeveloped land becomes harder to find, large cats, such as lions, panthers, tigers, jaguars, and cheetahs, are left with less and less natural habitat in which to live.

Mountain Lions—America's Large Cat

The mountain lion is a seven-foot-long cat that can weigh between 70 and 170 pounds. It was once found throughout North America from southern Argentina to northern British Columbia, making it one of the most widely distributed terrestrial species on the continent. It is also known as the panther, puma, or cougar, and preys on large animals, particularly deer. Mountain lions may also eat wild hogs, rabbits, and rodents. They require large home ranges for securing food—a single individual may have a home range spanning 85 square kilometers. By 1900 the species was nearly extinct due to habitat loss and hunting. Until the 1960s, many states offered monetary rewards for the killing of mountain lions. Mountain lions are now found primarily in mountainous, unpopulated areas.

Conservation efforts have met with success in some portions of the country. In fact, there are now so many encounters between humans and mountain lions in California that hikers and park officials are given instruction in how to react to these large cats. Scientists attribute the increased encounter rate to more wilderness ventures by humans as well as a larger mountain lion population—an estimated 6,000 individuals. Because of these events, some people are demanding that hunting be reinstituted.

In most of the eastern United States, however, mountain lions have long been presumed extinct. If they are present, they are still extremely rare. In 1997 several sightings were reported in the Appalachian Mountains, but these have not been confirmed.

THE FLORIDA PANTHER.

The Florida panther is one of twenty-seven subspecies of the mountain lion. It has been considered endangered since 1967, and there are only thirty to fifty individuals surviving in the wild. The Florida panther has declined due to loss of habitat to urbanization and development, water contamination, and highway traffic. Its population is now so small that many individuals suffer from genetic disorders due to inbreeding. Ninety percent of male Florida panthers suffer from sperm abnormality, sterility, congenital heart defects, and possible immune deficiencies due to long-term inbreeding. Experts fear the species may die out in less than 20 years without aggressive intervention.

In 1994 and 1995 scientists and wildlife managers introduced Texas cougars, the Florida panthers' closest relatives, into habitats in Florida. Eight female Texas cougars were released. Biologists hoped that interbreeding would strengthen and diversify the Florida panther gene pool. "This is a very drastic measure and not one we ordinarily undertake," reported Dr. John Fay of the U.S. Department of the Interior. Dr. Fay noted that the strategy had helped save woodland caribou in Idaho and Washington in the 1980s, when individuals were interbred with Canadian caribou. In fact, Florida panthers and Texas cougars once formed a single, interbreeding population that ranged freely throughout the southeastern United States. They were eventually isolated from each other by human encroachment a little more than a hundred years ago.

Other efforts are also underway to help maintain the existing Florida panther gene pool. A captive breeding program was initiated in 1991 with ten panther cubs that had been removed from the wild. It is hoped that captive breeding will allow for the establishment of two additional populations of 50 individuals each. Scientists are also hopeful that the habitat destruction that threatens the Florida panther has slowed. The primary issue in panther conservation today is providing large enough expanses of protected habitat for the species. This is particularly challenging not simply because the carnivores need large home ranges to feed, but because male panthers are territorial and will not tolerate the presence of other males. About half the area occupied by Florida panthers is private land, including farms, ranches, and citrus groves adjacent to protected reserves. Efforts are being made to secure the cooperation of landowners in conservation efforts.

As a result of the Florida panther's plight and public affection for the animal, in 1982 Florida declared the panther its state animal. Florida businessman Wayne Huizenga named his National Hockey League (NHL) team the Florida Panthers and has pledged many thousands of dollars to panther recovery efforts.

Jaguars

The jaguar is the largest cat in the Americas, measuring five to six feet long and weighing some two hundred pounds. Jaguars once ranged from Arizona to Argentina, but are now quite rare in the United States, where they may still occur in low numbers in Arizona, New Mexico, and Texas. Jaguars are listed as endangered throughout their range, which also includes Mexico and Central and South America. An estimated 15,000 individuals remain in the wild. Jaguars occupy a wide variety of habitats, from dense jungle and scrubland to reed thickets, forests, and even open country. They prey on wild pigs, rodents, deer, sloths, tapirs, and a variety of smaller species. They are endangered primarily due to habitat destruction and habitat fragmentation. Because they are so rare, much of what is known about the species comes from studying zoo populations.

Tigers

Wild tigers are found exclusively in Asia, from India to Siberia. Although the world tiger population surpassed 100,000 in the nineteenth century, experts fear that as few as 7,000 tigers remained in 2004. Approximately 2,000 of these are found in captivity. In addition to habitat loss, countless tigers fall victim to the illegal wildlife trade every year. Many tiger body parts are used as ingredients in traditional Chinese medicine, and the big cats are also prized in the exotic pet industry.

In 1999 the Wildlife Conservation Society reported a rebound in the world tiger population, in part because of a worldwide moratorium on tiger hunting imposed by CITES listing. However, ecologists warn that tigers, which hunt deer, wild pigs, cattle, antelope, and other large mammals, are threatened seriously by loss of prey, much of which consists of non-protected species being eliminated by hunters.

In January 2004 Indian officials announced that the endangered Bengal tiger population might be increasing in the Sunderbans Forest, a World Heritage Site and one of the last protected wild habitat areas for tigers. The census was completed by locating, plaster-casting, and studying tiger paw prints, or pugmarks, in the forest. Tiger pugmarks are unique the same way human fingerprints are unique. Most encouraging was the fact that the number of cub prints had increased in 2004.

On the other hand, the World Conservation Union (IUCN) declared that the Sumatran tiger was on the verge of extinction in March 2004, with only four hundred to five hundred individuals remaining in the wild. The IUCN also called on the Indonesian government to stop habitat destruction and poaching. Approximately fifty Sumatran tigers were killed each year by poachers between 1998 and 2002.

THE SIBERIAN TIGER.

The Siberian tiger (see Figure 7.7) is the largest cat in the world and one of the world's most endangered species, with only five hundred individuals estimated to exist in the wild. There are also several hundred Siberian tigers in captivity. The Siberian tiger, also known as the Amur tiger, once occupied mixed deciduous and coniferous forest habitats in the Amur-Ussuri area in Siberia, as well as in northern China and Korea. It is now believed to be extinct, or nearly extinct, in China and Korea. Individuals reach lengths of eight to ten feet and weigh up to 800 pounds. They eat wild boars, Sika deer, and elk. Siberian tigers are territorial and require large home ranges of some 500 to 600 square miles.

Populations have suffered greatly from habitat loss caused by logging and deforestation, as well as illegal trade. The Siberian tiger is sought for its skin, bones, eyes, whiskers, teeth, internal organs, and genitals. These are used for everything from skin cures to tooth medicine. In Russia, where unemployment is high, poachers have flooded nearby Asian markets with tiger parts. In 1995 alone, poachers killed more than sixty-five Siberian tigers. The financially strapped Russian government can devote neither money nor time to protecting the tigers. Like the Florida panther, the Siberian tiger has also been weakened by inbreeding, which increases the possibility of reproductive problems and birth defects.

Cheetahs

The cheetah is the fastest land animal on Earth, able to sprint at speeds up to 70 mph. Cheetahs occupy grassland, shrubland, and woodland habitats. Their range once extended through most of Africa as well as southwestern Asia. Currently, cheetahs are found only in a few areas in Iran, North Africa, and sub-Saharan Africa. Cheetahs hunt small prey, particularly Thomson's gazelle. The cheetah has been listed in CITES Appendix I since 1975. In 2004 there were an estimated 10,000 cheetahs in the wild.

Cheetah populations have declined for many reasons. Much of the species' habitat has been developed for agricultural or ranching use, and many of the cats are shot by farmers who wish to protect their livestock. In addition, cheetahs are badly inbred, and many individuals are infertile. In addition, cheetahs are smaller and less aggressive than other predators that share their environment (including lions and leopards) and often have their food kills stolen or their cubs killed. Conservation biologists have determined that in order to save the cheetah, human assistance in the form of habitat protection, protection from competitor species, and measures to improve the genetic diversity of the species are required.

RHINOCEROS

Rhinoceros are among the largest land mammals. They weigh up to 8,000 pounds—as much as fifty average-sized men—and are herbivorous grazers. The name rhinoceros is made up of two Greek words meaning "nose" and "horn," and rhinos are in fact the only animals on Earth that have horns on their noses. Figure 7.8 shows an African white rhinoceros with two horns. The female may be identified by her longer, more slender primary horn.

Rhinoceros have roamed the land for more than 40 million years, but in less than a century, humans—their only predators—have reduced populations to dangerously low levels. There are five species of rhinoceros—the black rhino (African), white rhino (African), Sumatran rhino (found in Borneo, Malaysia, and Sumatra), Javan rhino (found in Indonesia and Vietnam), and Indian rhino (found in both India and Nepal). Certain rhino species can be divided into distinct subspecies. For example, the Javan rhino has two subspecies, one found in Vietnam, the other in Indonesia. The Vietnamese subspecies consists of only one tiny population of five to seven individuals, and was thought extinct until this tiny population was discovered in 1999. All rhinos are close to extinction. In 2004 the International Rhino Foundation (IRF) estimated populations of 11,670 for the white rhino, 3,100 for the black rhino, 2,400 for the Indian rhino, 300 for the Sumatran rhino, and 60 for the Javan rhino. Some individuals are also found in captivity.

Hunting has been the primary cause of rhinoceros decline. Rhinoceros horn is highly prized as an aphrodisiac, as well as an ingredient in Chinese medicine (although its potency has never been shown). Rhinos were first listed by CITES in 1976. This banned international trade in the species and their products. In 1992 CITES also started requiring the destruction of horn caches confiscated from poachers. Nonetheless, people continue to buy and consume rhinoceros horn, and many poachers are willing to risk death to acquire it.

Indian Rhinos

Conservation efforts have improved the status of some rhino species. The Indian rhinoceros, which was reduced to fewer than one hundred individuals in the mid-1970s, has experienced significant population growth in the past twenty-five years. In 2004 the IRF reported some 2,400 Indian rhinos in the wild. Population increase resulted from habitat protection, including the designation of several national parks, as well as measures that curbed poaching.

The Royal Chitwan National Park was established in Nepal in 1973 and includes over 1,000 square kilometers of protected habitat. At the time of establishment, fewer than 80 Indian rhinos were found in the park. Troops from the Royal Nepalese Army were dispatched to help prevent poaching. Indian rhinos flourished at Royal Chitwan, and individuals were later transported to a second rhino conservation area at Royal Bardia National Park, a few hundred miles from Royal Chitwan. In April 2002 the Department of National Parks and Wildlife Conservation in Nepal reported 529 rhinos at Royal Chitwan and 63 at Royal Bardia, a substantial increase from when conservation efforts began.

However, in April 2002 the Department of National Parks and Wildlife Conservation reported that thirty-nine rhinos had died in the past twelve months at Royal Chitwan. Of these, only nine were believed to have died from natural causes. Twenty-five were almost certainly killed by poachers. Horns and other body parts had been removed from the carcasses. Two other rhinos were found electrocuted and three had been poisoned. These were found intact by park officials, who believe that they were killed by villagers whose crops were damaged by rhinos in areas adjacent to the park. The 2002 numbers represent the continuation of a disturbing pattern—forty-two rhinos died in 1999 and twenty-three were killed in 1997–1998.

African Rhinos

Africa is home to two species of highly imperiled rhinoceros, the black rhino and the white rhino. Both species have a second, smaller horn situated slightly behind the larger main horn. They are threatened primarily by poaching. Wildlife officials in Zimbabwe, Swaziland, and Namibia have gone so far as to sever rhino horns in an effort to curtail poaching. Most experts, however, discourage the practice, as animals use their horns for both digging and defense. In 2004 the IRF reported 3,100 black rhinos in the wild. Of the black rhinoceros subspecies, the northwestern variety is the most severely endangered, with only ten currently found in the wild. Approximately 11,000 white rhinos were reported in 2004. African rhino numbers have risen in recent years, primarily due to improved management as well as private sector and community involvement. Captive breeding efforts for the African rhino species have also met with some success, particularly at the San Diego Wild Animal Park, and may aid in the conservation of these species.

ELEPHANTS

Elephants are the largest land animals on Earth. They are frequently described as the "architects" of the savanna habitats in which they live. Elephants dig water holes, keep forest growth in check, and open up grasslands that support other species, including the livestock of African herders. Elephants are highly intelligent, emotional animals and form socially complex herds. There are two species of elephants, African elephants and Asian elephants, both of which are highly endangered. The African elephant (see Figure 7.9), which sometimes weighs as much as six tons, is the larger species. In 2004 there were an estimated 500,000 African elephants and 50,000 Asian elephants in the wild.

Elephants have huge protruding teeth—tusks—made of ivory. Ivory is valued by humans for several reasons, particularly for use in making jewelry and figurines. Piano keys were also once made almost exclusively of ivory; however, that practice has ceased. The market for ivory has had tragic consequences for African elephants. Their numbers dropped from over 10 million individuals in 1900 to only 600,000 in 1989. As a result of this decline, the UN-administered CITES banned worldwide commerce in ivory and other elephant products in 1990. However, like rhinoceros horns, elephant tusks continue to be illegally traded. Numerous elephants are poached each year. The price of poached elephant ivory is reported to be as high as $90 per pound.

Despite continued poaching, elephant populations have recovered somewhat since receiving CITES protection. In 1997 Zimbabwe requested that CITES change the listing status of the African elephant in three South African nations—Zimbabwe, Botswana, and Namibia— from Appendix I status (a species in immediate danger of extinction) to Appendix II status (threatened in the absence of trade controls), and include a yearly quota for ivory trade. South Africa has requested a similar downlisting. Kenya, India, and other nations, along with many environmental organizations, opposed the downlisting, in part because they felt that a reopening of the ivory trade might cause a resurgence in demand and poaching. CITES responded by downlisting the elephant to Appendix II, while simultaneously initiating a program, the Monitoring of Illegal Killing of Elephants (MIKE) to better assess poaching. Although MIKE statistics would not be available until 2003, CITES did approve an experimental interim proposal allowing a one-time sale of stockpiled ivory from Namibia, Botswana, and Zimbabwe to Japan. This one-time ivory transaction was made in 1999 and grossed approximately $5 million.

At the 2000 CITES Conference, South Africa, Zimbabwe, Namibia, and Botswana again petitioned CITES to authorize ivory sales. South Africa also spearheaded a movement to allow the culling of elephants, noting that its national conservation parks were overrun. At South Africa's Kruger Park, for example, 7,000 elephants occupied an area designated to support 5,000 individuals. Under the South African plan, the funding for elephant culling would be obtained through a legitimate, but limited, international trade in ivory and elephant skin. Kenya and India, on the other hand, renewed a request to relist the elephant under CITES Appendix I, as immediately endangered. In the end, the opposing factions reached a compromise in which both proposals were withdrawn—elephants remained listed under Appendix II, and the ban on ivory sales remained in effect.

At the 2002 CITES Conference, CITES conditionally accepted one-time sales by Botswana, Namibia, and South Africa of ivory collected from elephants that died a natural death. However, the sales can occur only after data is collected on poaching and population levels. CITES Secretary-General Willem Wijnstekers said:

The African elephant is valued and admired by people all over the world. But it is significant that today's decision embodies an African solution to an African problem—the challenge of conserving the continent's wild herds of elephants in an age of growing human needs and population. While richer countries can often afford to promote conservation through strict protection, many poorer nations must do so in ways that benefit local communities and bring in much-needed cash for conservation. In the African context, a conservation strategy based on sustainable use may offer elephants the best possible long-term future. The key is finding solutions that benefit states that rely on tourism as well as those that seek income from elephant products.

Although the ivory trade has always been the largest threat to elephants, conflicts between humans and elephants are an increasing issue. The ranges of many elephant herds now extend outside protected refuges, and elephants frequently come into contact with farmers, eating or otherwise destroying crops. Increasing human settlement in areas inhabited by elephants will likely result in more conflicts over time.

PRIMATES

The World Conservation Union (IUCN), in its 2003 Red List of Threatened Species, reported that the 295 examined species of primates (excluding humans) are among the most endangered mammals. Since the 1996 IUCN assessment, the number of "critically endangered" primates increased from thirteen to twenty species, and the number of "endangered" primates rose from twenty-nine to forty-seven. Another forty-seven primates are considered "vulnerable." Critically endangered primate species included the Roloway monkey (lowland tropical rainforest in Ghana and Cote d'Ivoire), Mentawai macaque (Indonesia), Sclater's black lemur (lowland tropical rainforest, Madagascar), red-handed howling monkey (Brazil), and the black lion tamarin (lowland tropical rain-forest, Brazil), among others. Much of the increased endangerment of primate species is due to loss of habitat and hunting.

Brazil is home to the largest number of primate species—seventy-seven at present—followed by Indonesia (33), Democratic Republic of Congo (33), and Madagascar (30). Many of the most endangered primate species are found on Madagascar, which has a diverse and unique primate fauna. The majority of Madagascar's primate species are endemic—that is, they are found nowhere else on earth.

Habitat loss, especially the fragmentation and conversion of tropical forests for road building and agriculture, contributes to the decline of nearly 90 percent of all IUCN-listed primates. In Indonesia and Borneo, for example, home to most of the world's 20,000 to 30,000 orangutans (see Figure 7.10), deforestation has shrunk orangutan habitat by over 90 percent. A 2004 census suggested that the total orangutan population has halved in the last fifteen years. Logging and extensive burning have caused many orangutans to flee the forests for villages, where they have been killed or captured by humans.

Thirty-six percent of threatened primates also face pressures from excessive hunting and poaching. Today, almost all countries have either banned or strictly regulated the trade of primates, but these laws are often hard to enforce. Large numbers of primates are also used in medical research because of their close biological relationship with humans.

Not all relationships between primates and humans are exploitative. People in some regions protect primates from harm by according them sacred status or by making it taboo to hunt or eat them. One of the rarest African monkeys, the Sclater's guenon, survives in three areas of Nigeria in part because residents regard the animal as sacred.

Good news arrived in January 2004 when it was announced that the highly endangered mountain gorilla had experienced a population rebound, with numbers increasing 17 percent since 1989 in the Virunga forest of Rwanda, Uganda, and The Democratic Republic of Congo. Gorilla populations had plummeted in the 1960s and 1970s due to civil unrest, habitat destruction, and poaching. A total of 380 mountain gorillas were counted in the Virunga Forest, and an additional 320 were identified in the Bwindi Impenetrable Forest National Park in Uganda.

BIGHORN SHEEP

A hundred years ago, desert bighorn sheep were commonly seen climbing the mountains of the American West. The species is named for its large, curved horns, which males use to battle for access to females, wrestling with horns interlocked. Overhunting and disease have decimated bighorn sheep populations across the U.S. In Texas, for example, the number of bighorn sheep had fallen to 500 by 1903, when hunting was finally banned. In 1945 the state set aside 11,625 acres for bighorn sheep habitat in the Sierra Diablo Wildlife Management Area near Big Bend National Park. As populations continued to decline, Texas began to import desert bighorns from other states for captive breeding. Despite these efforts, the last native bighorn in Texas is believed to have died in the 1960s.

Since then, however, new management efforts have met with some success. Private landowners have donated the use of thousands of acres of mountainous terrain as breeding grounds for reintroduced bighorns. Unlike other subjects of restoration efforts, such as wolves, bighorns pose no threats to ranchers—they do not prey on livestock, and they graze in remote areas, where they do not compete with livestock. Bighorn sheep also offer landowners potential income through the sale of hunting permits—when biologists determine the sheep population has surplus rams, the state may issue a limited number of hunting permits. The permits are rare and are very expensive, frequently commanding five-figure prices. They are issued only to landowners participating in the restoration effort. The first Texas permit sold for $61,000. In 1993 a hunter paid more than $300,000 at auction for an Arizona permit. Money raised from hunting permits is put back into bighorn sheep conservation. In 1998 experts estimated the population of bighorn sheep in Texas at 320 and at almost 30,000 nationwide.

In 1998 the Fish and Wildlife Service proposed an emergency endangered listing for the California peninsular bighorn sheep, a subspecies of the common bighorn. In July 2000 the Fish and Wildlife Service proposed critical habitat for these sheep. Estimated at 1.5 million in the early 1800s, the population size had dwindled due to disease, overhunting, loss of habitat, fragmentation of habitat, and predation. A helicopter survey conducted in fall 2000 estimated that some the population of peninsular bighorn is around four hundred.

BISON

Sixty million bison (see Figure 7.11)—or buffalo—once roamed the grasslands of America. Historical accounts describe herds stretching as far as the eye could see. Although Native Americans hunted bison, it was not until European settlers came with firearms that their numbers fell drastically. Many people shot the animals for fun, while others sold the hides. Bison numbers were eventually reduced to fewer than 1,000. Today they are found in the Great Plains from Mexico to Canada.

The bison is the largest terrestrial animal in North America. It has short, pointed horns and a hump over the front shoulders. The head, neck, and front parts of the body are covered by a thick, dark coat of long, curly hair; the rear has shorter, lighter hair. Adult males weigh as much as 1,800 to 2,400 pounds; females are smaller. Adult males also have black "beards" about a foot long. Bison are social animals and travel in herds. Considering their size and weight, bison are remarkably light on their hooves—unlike cattle, they love to run and are surprisingly fast. Bison were central to the existence of Plains Native Americans, who used them for food and made clothing from their hides and tools from their bones. The dried dung, called buffalo chips, was used for fuel.

Bison first received protection from the U.S. government in 1872, with the establishment of Yellowstone National Park in Wyoming and Montana. However, the welfare of the small herd of bison in the park was largely ignored until 1901, when it was discovered that only twenty-five individuals remained. The herd was restored to 1,000 by 1930 with bison imported from the Great Plains. As the Yellowstone herd multiplied, the park service shot animals to keep the population under control. This practice was unnecessary, however, because harsh winters caused the herd to dwindle naturally. The park service stopped shooting bison in the 1960s, and by 1994 the population of the Yellowstone herd had reached a peak of 4,200 animals. Over 3,000 individuals were documented in April 2002.

However, conflict over bison management continues at the park. Half the Yellowstone bison are carriers of a cattle disease called brucellosis. In domestic cattle, it can cause miscarriage in pregnant cows. Although there is no evidence that the disease can be transmitted from bison to livestock, and the popular elk in the area also carry brucellosis, ranchers are nonetheless wary.

Today some populations of bison are managed as livestock because they have become a food source for humans. Bison are a source of high-protein, low-fat, low-cholesterol meat. The National Bison Association estimates that 150,000 bison are slaughtered for food each year, producing 7.5 million pounds of meat. Bison meat is not expected to replace beef, but some people think it might become an alternative red meat source. In Bring Back the Buffalo! (Washington, DC: Island Press, 1996), researcher and writer Ernest Callenbach argues that bison will gradually gain support as a food source, as it becomes evident that bison are better adapted to grasslands and require much less human management than cattle. There are even bison ranchers abroad, including in Canada, Southern France, Switzerland, and Belgium.

By the end of the twentieth century, the National Bison Association reported a total of over 350,000 bison in the 48 continental United States, Alaska, and Canada—344,000 bison were privately owned, and 13,000 lived in public herds. An additional 1,000 lived in zoos or outside of the United States and Canada.

REBIRTH OF THE QUAGGA

Why do zebras have stripes? Nobody knows for sure. Although scientists have proposed a variety of theories, none has proved conclusive. What is known is that among the varieties of African plains zebras, those that are native to southern Africa display less striping than zebras that inhabit the northern regions. Perhaps the most uniquely striped variety of zebra was the quagga, or Burchell's zebra. The quagga, a lightly browned zebra, displayed virtually no striping on its hindquarters and legs (see Figure 7.12). In the nineteenth century, sheep and goat herders who settled within the quagga's grazing range hunted the odd-looking animal literally to extinction. When the last living quagga died at the Amsterdam Zoo on August 12, 1883, all that remained of the species were 23 preserved animal skins.

Approximately 100 years later, scientists analyzed tissue from an old quagga skin and discovered that, genetically, the quagga was nearly identical to other zebras—it was therefore likely to be a subspecies of zebra and not a separate species, as had originally been thought. A selective breeding project was undertaken in 1987 in an attempt to breed zebras that had the striping traits of the extinct quagga. South African taxidermist Reinhold Rau spearheaded the project. He hypothesized that the genes that code for the distinctive color and striping patterns of quaggas existed recessively in South African zebras of the late twentieth century. Quagga project members assembled a collection of zebras that most closely resembled the extinct quagga in striping and coloring and began the slow process of breeding successive generations that increasingly resembled the quagga. By 2000 the project had produced a number of individuals that resembled the preserved quagga skins in pattern, and others that resembled the skins in color. However, no individuals resembled the extinct animal in both striping and coloring. The project received public funding for the first time in June 2000, as breeding attempts continued.

A similar project was underway to rebreed the endangered Mongolian Przewalski horse and another to rebreed the tarpan, a European wild horse.

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