Species accounts

Northern raccoon

Procyon lotor

SUBFAMILY

Procyoninae

TAXONOMY

Ursus lotor (Linnaeus, 1758), Americae maritimis (Pennsylvania). OTHER COMMON NAMES

English: Raccoon, coon; French: Raton laveur; German: Waschbär; Spanish: Mapache.

PHYSICAL CHARACTERISTICS

Body length 18-25 in (50-65 cm), tail 8-12 in (20-30 cm), mass 10-35 lb (4-16 kg). Large rounded head, round ears, black mask across face, long digits and naked feet, long, thick fur, and long tail with numerous concentric dark bands.

DISTRIBUTION

Southern Panama north to the fringe of the boreal forests in Canada. Introduced into Russia and Germany.

HABITAT

Raccoons thrive in a variety of habitats including forests to mixed forests, prairies, and urban areas.

BEHAVIOR

Nocturnal, raccoons spend the day sheltered in abandoned houses, barns, culverts, hollow trees, brush piles, or dens of other animals. Home ranges vary according to food abundance, and range from 12 to 6,000 acres (0.5-25 km2). Densities range

from one to 600 individuals per mi2 (0.5-300 per km2), and highest densities occur in urban areas. In northern environments, raccoons accumulate large amounts of fat during late summer and autumn in preparation for an extended period of sleep (up to six months) during winter. Longevity up to 17 years in captivity, but rarely reaches five years in the wild. Main predators are coyotes, bobcats, and alligators.

FEEDING ECOLOGY AND DIET

Raccoons are opportunistic and consume whatever foods they encounter. Most often, diet consists of fruits, berries, cereal grains, hard mast, crayfish, frogs, and bird eggs. Although historically believed to wash their food before eating, this habit is a myth and simply the result of raccoons often searching for and handling aquatic food with their dexterous forepaws.

REPRODUCTIVE BIOLOGY

Promiscuous. Mating in February or March. Gestation 63 days, litter size is one to seven. Males do not provide care for the young.

CONSERVATION STATUS Not threatened.

SIGNIFICANCE TO HUMANS

The raccoon is important to humans for meat, fur, as a pest and as a carrier of rabies. The meat is consumed mostly in southern United States and Central America. The raccoon is also an important furbearer across the United States and Canada. Raccoons are sometimes killed as pests, especially for damage caused to crops (corn), for consuming and spreading garbage in urban areas, or for perceived threats to domestic animals (chicken) or wild game birds, especially ducks. In the eastern United States, the raccoon is of significant concern as a carrier of rabies. The ability of raccoons to thrive in the presence of humans is a major factor leading to its importance as a pest: currently, the highest densities of raccoons anywhere are found in large cities such as Chicago (USA), Cincinnati (USA), and Toronto (Canada). ♦

Kinkajou

Potos flavus

SUBFAMILY

Potosinae

TAXONOMY

Lemur flavus (Schreber, 1774), Surinam. OTHER COMMON NAMES

English: Honey bear; French: Kinkajou; German: Wickelbar; Spanish: Marta.

PHYSICAL CHARACTERISTICS

Body length 16-30 in (40-75 cm), tail 16-24 in (40-60 cm), mass 3-10 lb (1.4-4.6 kg). Tawny olive pelage with large rounded head and ears, short snout, prehensile tail, and large protruding eyes.

DISTRIBUTION

Southeast Mexico through Central America into Brazil.

HABITAT

Southern tropical forests. BEHAVIOR

Solitary and arboreal, kinkajous rest in hollow trees during the day. They scent mark, possibly to communicate or advertise sexual status. Kinkajous are not territorial, and animals may aggregate near good food sources. Density may reach 30-75/mi2 (12-30/km2). Longevity may reach 23 years in captivity.

FEEDING ECOLOGY AND DIET

Fruits, honey, insects, bird eggs and nestlings, and rarely small mammals.

REPRODUCTIVE BIOLOGY

Promiscuous. Breeding throughout the year. Gestation 112-118 days, litter size typically one, but rarely two.

CONSERVATION STATUS

Not threatened.

SIGNIFICANCE TO HUMANS May be eaten in some localities. ♦

White-nosed coati

Nasua narica

SUBFAMILY

Procyoninae

TAXONOMY

Viverra narica (Linnaeus, 1766), America (Vera Cruz).

OTHER COMMON NAMES

English: Coatimundi; French: Coati a nez blanc; German: Nasenbär; Spanish: Tejon.

PHYSICAL CHARACTERISTICS

Body length 16-30 in (40-67 cm), tail 13-18 in (32-69 cm), mass 6-13 lb (3-6 kg). Reddish brown pelage above and yellow to dark brown below. White muzzle, chin and throat. Movable, trunk-like snout, and long, banded tail.

DISTRIBUTION

Southwestern United States south to Panama. HABITAT

Mostly in wooded areas.

BEHAVIOR

Diurnal and highly gregarious. Females with young often form large bands of up to 25 individuals, whereas males are mostly solitary. Gregariousness of females with young likely is an adaptation to reduce predation of young by males or other predators. Animals usually carry the tail erect, except for the curled tip. Longevity up to 14 years. Predators include big cats and large snakes.

FEEDING ECOLOGY AND DIET

Invertebrates, fruits, lizards, and small rodents. Individuals do not share or cache food.

REPRODUCTIVE BIOLOGY

Promiscuous. Gestation 74 days, litter size is one to six. CONSERVATION STATUS

One subspecies, sometimes considered a separate species, the Cozumel Island coati (N. n. nelsoni) is Endangered.

SIGNIFICANCE TO HUMANS

Coatis are hunted for their meat and fur. ♦

Ringtail

Bassariscus astutus

SUBFAMILY

Procyoninae

TAXONOMY

Bassaris astuta (Lichtenstein, 1830), Mexico City. OTHER COMMON NAMES

English: Ring-tailed cat, cacomistle, miner's cat; German: Nordamerikanisches Katzenfrett; Spanish: Mico de noche.

PHYSICAL CHARACTERISTICS

The smallest procyonid. Body length 12-16 in (30-42 cm), tail 12-18 in (30-45 cm), mass 1.8-3.0 lb (800-1400 g). Long banded tail, flat head, large ears, and long, tapered snout.

DISTRIBUTION

Southern Oregon, southwest United States into Mexico (including Baja California) and south to Veracruz and Oaxaca.

HABITAT

Rocky, semi-desertic areas, often near water. BEHAVIOR

Nocturnal, it shelters in rock crevices during the day. Agile climber.

FEEDING ECOLOGY AND DIET

Rodents, insects, birds and bird eggs, reptiles, fruits, vegetable matter.

REPRODUCTIVE BIOLOGY

Promiscuous. Gestation is 60 days, litter size 2-4, parturition from March to June.

CONSERVATION STATUS Not threatened.

SIGNIFICANCE TO HUMANS

Ringtails are harvested as furbearers in southern United States. ♦

Red panda

Ailurus fulgens

SUBFAMILY

Ailurinae

TAXONOMY

Ailurus fulgens F. G. Cuvier, 1825, East Indies. OTHER COMMON NAMES

English: Lesser panda; French: Petit panda; German: Kleiner Panda, Katzenbar; Spanish: Panda rojo.

PHYSICAL CHARACTERISTICS

Body length 20-24 in (50-60 cm), tail 12-20 in (30-50 cm), mass 6.5-11 lb (3-5 kg). Overall pelage reddish, with well furred and banded tail. Large round ears with white fringe, two black stripes from the eyes down on the cheeks.

DISTRIBUTION

Nepal, India, Bhutan, Myanmar, and south central China, possibly also in Tibet and Assam.

HABITAT

Occupies bamboo forests.

BEHAVIOR

Mostly nocturnal. Capable climber but forages mostly on the ground. Red pandas are territorial, and territorial boundaries are

scent marked. Territories occupy 0.4-1.5 mi2 (1-3.5 km2). Density is roughly one animal/mi2 (0.4/km2).

FEEDING ECOLOGY AND DIET

Bamboo sprouts, grasses, roots, fruits, acorns, and rarely animal prey.

REPRODUCTIVE BIOLOGY

Promiscuous. Mating occurs in July and August. Gestation lasts 134 days, litter size is one to four.

CONSERVATION STATUS Endangered.

SIGNIFICANCE TO HUMANS

Red pandas are not harvested for their fur or meat, and are popular zoo animals. They are threatened by deforestation and increased agriculture.4

Common name / Scientific name/ Other common names

Physical characteristics

Habitat and behavior

Distribution

Diet

Conservation status

Crab-eating raccoon Procyon cancrivorus Spanish: Mapache cangrejero

Upperparts are brown or grayish in color. Underparts are lighter. Mask of black on eyes and rings on tail. Very short hair, large. Head and body length 21.7-29.9 in (55-76 cm), tail length 3.9-5.9 in (10-15 in).

Marshy and jungle areas of Central and South America. Solitary animal, active during evening and at night.

Argentina, Bolivia, Brazil, Colombia, Costa Rica, Guyana, Panama, Peru, Suriname, Trinidad and Tobago, and Venezuela.

Frogs, toads, crabs, shrimp, turtle eggs, fruits, and seeds.

Not listed by IUCN

Bahaman raccoon Procyon maynardi Spanish: Mapache de las Bahamas

Coloration is gray to black, 5 to 10 rings on well-furred tail. Head and body length 16.323.6 in (41.5-60 cm), tail length 7.9-15.9 in (20-40.5 cm). Males generally larger than females.

Timbered and brushy areas, usually near water. More nocturnal than diurnal. Build dens for shelter and do not hibernate.

New Providence Island, Bahamas.

Crayfish, crabs, other arthropods, frogs, fish nuts, seeds, acorns, and berries.

Endangered

Cozumel Island raccoon Procyon pygmaeus Spanish: Mapache pigmeo

Coloration is gray to black, 5 to 10 rings on well-furred tail. Head and body length 16.323.6 in (41.5-60 cm), tail length 7.9-15.9 in (20-40.5 cm). Males generally larger than females.

Timbered and brushy areas, usually near water. More nocturnal than diurnal. Build dens for shelter and do not hibernate.

Cozumel Island off northeastern Yucatán, Mexico.

Crayfish, crabs, other arthropods, frogs, fish nuts, seeds, acorns, and berries.

Endangered

[continued]

Common name /

Scientific name/

Physical

Habitat and

Conservation

Other common names

characteristics

behavior

Distribution

Diet

status

Guadeloupe raccoon

Coloration Is gray to black, 5 to 10 rings on

Timbered and brushy

Guadeloupe Island,

Crayfish, crabs, other

Endangered

Procyon minor

well-furred tail. Head and body length

areas, usually near water. More

Lesser Antilles.

arthropods, frogs, fish,

Spanish: Mapache de Guadalupe

16.3-23.6 in (41.5-60 cm), tail length

nocturnal than diurnal. Build

nuts, seeds, acorns, and

7.9-15.9 in (20-40.5 cm). Males generally

dens for shelter and do not

berries.

larger than females.

hibernate.

Cozumel Island coati

Short, fairly soft hair. Coloration is generally

Mainly in wooded areas. Use tail

Cozumel Island off north

Fruits, other plant matter,

Endangered

Nasua nelsoni

reddish brown to black. Muzzle, chin, and

as balancing organ, primarily

eastern Yucatán, Mexico.

large rodents.

throat whitish and feet blackish. Striped tail.

diurnal. Loose band of to 20

Head and body length 16.1-23.4 in

individuals. Single reproductive

(41-67 cm), tail length 12.6-27.2 in

season.

(32-69 cm).

Ring-tailed coati

Tawny red with black face; a small white spot

Mainly in wooded areas. Use tail

Arizona, United States, to

Fruits, other plant matter

Not threatened

Nasua nasua

above and below each eye and a large one on

as balancing organ, primarily

Argentina.

large rodents.

Spanish: Coatí isleño

each cheek; white throat, belly; black feet,

diurnal. Loose band of 4 to 20

black rings on tail. Head and body length

individuals. Single reproductive

31.5-51.2 in (80-130 cm).

season.

Cacomistle

Color is buffy gray to brownish, tail is ringed

Tropical forests and is very

Southern Mexico to

Insects, rodents, birds,

Lower Risk/Near

Bassariscus sumichrasti

with buff and black. Ears are pointed, tail is

arboreal. Enters estrus in winter

western Panama.

fruits, and other vegetable

Threatened

French: Bassarai rusé; Spanish:

long. Head and body length 15-18.5 in

spring, or summer. Late winter

matter.

Babisuri

(38-47 cm), tail length 15.4-20.9 in

is main breeding season.

(39-53 cm).

Allen's olingo

Upperparts are pinkish buff to golden, mixed

Tropical forests from sea level to

Ecuador east of the Andes,

Mainly fruit, but also

Not threatened

Bassaricyon alleni

with black or grayish. Underparts are pale

6,560 ft (2,000 m). Primarily

and Peru to Cuzco

insects and warm-blooded

Spanish: Olingo leonado

yellowish. Tail is flat and body is elongate.

aboreal and nocturnal. There is

Province; Bolivia; and

animals.

Head and body length 13.8-18.5 in (35-47

no definite breeding season.

possibly into Venezuela.

cm), tail length 15.7-18.9 in (40-48 cm).

Females give birth to one off

spring per year

Beddard's olingo

Upperparts are pinkish buff to golden, mixed

Tropical forests from sea level to

Guyana, and possibly

Mainly fruit, but also

Lower Risk/Near

Bassaricyon beddardi

with black or grayish. Underparts are pale

6,560 ft (2,000 m). Primarily

adjacent Venezuela and

insects and warm-blooded

Threatened

Spanish: Olingo de Guayana

yellowish. Tail is flat and body is elongate.

aboreal and nocturnal. There is

Brazil.

animals.

Head and body length 13.8-18.5 in (35-47

no definite breeding season.

cm), tail length 15.7-18.9 in (40-48 cm).

Females give birth to one off

spring per year

Olingo

Coloration is light brown with cream under

Rainforests of Central America

Central Nicaragua, Costa

Mostly fruits, nectar,

Lower Risk/Near

Bassaricyon gabbii

sides and neck. Tail has 11-13 dark brown

and northwestern South

Rica, Panama, western

insects, small mammals,

Threatened

Spanish: Olingo grisáceo

rings. Long muzzle and no prehensile tail.

America, at elevations from sea

Colombia, and western

and birds.

Head and body length 14-16 in (35.6-40.6

level to 6,560 ft (2,000 m).

Ecuador.

cm), tail length 15-19 in (38.1-48.3 cm).

Arboreal, nocturnal, and solitary.

There is no particular breeding

season. Females give birth to

one offspring per year

Harris's olingo

Upperparts are pinkish buff to golden, mixed

Tropical forests from

Known only from type

Mainly fruit, but also

Endangered

Bassaricyon lasius

with black or grayish. Underparts are pale

sea level to 6,560 ft (2,000 m).

locality: 6-8 mi (9.7-12.9

insects and warm-blooded

Spanish: Olingo costarricense

yellowish. Tail is flat and body is elongate.

Primarily arboreal and nocturnal.

km) south of Cartago,

animals.

Head and body length 13.8-18.5 in (35-47

Spends day in nest. Lives alone

Costa Rica, near the

cm), tail length 15.7-18.9 in (40-48 cm).

or in pairs.

source of the Rio Estrella,

at an altitude of about

4,500 ft (1,370 m).

Books

Nowak, R. M. Walker's Mammals of the World, 6th ed. Baltimore: John Hopkins University Press, 1999.

Wilson, D. E., and D. M. Reeder. Mammal Species of the World: A Taxonomic and Geographic Reference, 2nd ed. Washington, DC: Smithsonian Institution Press, 1993.

Zeveloff, S. I. Raccoons: A Natural History. Washington, DC: Smithsonian Institution Press, 2002.

Periodicals

Baskin, J. A. "Tertiary Procyonidae (Mammalia: Carnivora) of North America." Journal of Vertebrate Paleontology 2 (1982): 71-93.

Ford, L. S., and R. S. Hoffman. "Potos flavus." Mammalian Species 321 (1988): 1-9.

Goldman, E.A. "Raccoons of North and Middle America." North American Fauna 60 (1950): 1-156.

Resources

Gompper, M. E. "Nasua narica." Mammalian Species 487 (1995): 1-10.

Helgen, K. M., and D. E. Wilson. "Taxonomic Status and Conservation Relevance of the Enigmatic Raccoons (Procyon spp.) of the West Indies." The Zoological Society of London 259 (2003): 69-76.

Lotze, J.-H., and S. Anderson. "Procyon lotor." Mammalian Species 119 (1979): 1-8.

Poglayen-Neuwall, I., and D. E. Toweill. "Bassariscus astutus." Mammalian Species 327(1988): 1-8.

Roberts, M. S., and J. L. Gittleman. "Ailurus fulgens." Mammalian Species 222 (1984): 1-8.

Serge Lariviere, PhD

Weasels, badgers, skunks, and otters

(Mustelidae)

Class Mammalia Order Carnivora Family Mustelidae

Small-to-medium carnivores characterized by long tubular shape or stocky build, short limbs, large necks, small heads, and habits that are either terrestrial or semi-aquatic

Size

4-60 in (0.1-1.5 m), 0.5-100 lb (0.25-45 kg)

Number of genera, species

25 genera; 65 species

f . ^ /

Forests, prairie, steppes, tundra, waterways, and seashore

Distribution

North and South America, Europe, Asia, Africa, and introduced in New Zealand

Conservation status

Extinct in the Wild: 1 species; Endangered: 7 species; Vulnerable: 8 species; Lower Risk/Near Threatened: 1 species; Data Deficient: 4 species

Evolution and systematics

The first Mustelidae appeared in the late Eocene to Oligocene from Europe and North America. Migrations to southern continents occurred first in Africa during the early Miocene, and then in South America in the Quarternary. Mustelids were among the first carnivore families to enter South America from the Panamanian land bridge, and they diversified in South America to 14 extant species.

Considered the most successful of the small carnivores, mustelids never evolved large body forms (less than 200 lbs or 100 kg), or cursorial open-country predators. Instead, mustelids are small to medium-sized, and dominate densely vegetated habitats where they occupy terrestrial, arboreal, and aquatic environments. The extant family Mustelidae includes five subfamilies: the Mustelinae (weasels, mink, polecats, and martens); the Mellivorinae (honey badgers), the Melinae (badgers), the Mephitinae (skunks), and the Lutrinae (otters). Skunks (genera Conepatus, Mephitis, and Spilogale) and stink badgers (genus Mydaus) have been suggested as belonging to their own family, the Mephitidae, based on genetic analyses. However, this classification proposed in 1997 has not yet been uniformly accepted.

Physical characteristics

The body may be either long and slender with a long tail (weasels, mink, martens, andotters), or compact with a short tail (badgers and wolverines); there are five fingers and toes with non-retractile claws. Otters have fully webbed hind feet, and most also have webbed front feet (Pteronura, Lutra, and

European badgers (Meles meles) are nocturnal and live together in large underground catacombs called "setts." (Photo by Hans Reinhard. Bruce Coleman, Inc. Reproduced by permission.)

Spraying defense of the western spotted shunk (Spilogale gracilis). 1. After noticing the threat, the skunk pulls up its tail and fluffs its fur to accentuate its warning markings. It may stamp its feet. 2. The skunk handstands, sometimes moving toward the threat. 3. If the threat does not withdraw, the skunk makes eye contact, moves into position, and sprays. (Illustration by Gillian Harris)

The yellow-throated marten (Martes flavigula) comes to the ground to An American marten (Martes americana) in its forest habitat. (Illus- feed. (Photo by Tom McHugh/Photo Researchers, Inc. Reproduced by tration by Gillian Harris) permission.)

A juvenile striped skunk (Mephitis mephitis) foraging for insects. (Photo by E & P Bauer. Bruce Coleman, Inc. Reproduced by permission.)

Lontra) but one genus has long, dexterous, and unwebbed forefeet (Aonyx). Size varies from 4-10 in (11-26 cm) in the least weasel (Mustela nivalis), which is both the smallest mustelid and the smallest carnivore, to 40-60 in (100-150 cm) in the giant otter (Pteronura brasiliensis), the largest mustelid. Depend-

A spotted skunk (Spilogale putorius) in a hollow log. (Photo by Jeff Foott. Bruce Coleman, Inc. Reproduced by permission.)

An ermine (Mustela erminea) turns from summer brown to winter white. (Photo by E & P Bauer. Bruce Coleman, Inc. Reproduced by permission.)

The American marten (Martes americana) is found in coniferous forests in northern North America south to the Rocky Mountains and east into New England. (Photo by Malsowski/Photo Researchers, Inc. Reproduced by permission.)

Northern river otters (Lontra canadensis) run on the ice at the edge of a river in Wyoming, USA. (Photo by Bob & Clara Calhoun. Bruce Coleman, Inc. Reproduced by permission.)

A badger (Taxidea taxus) guards its den in Montana, USA. (Photo by James Allen. Bruce Coleman, Inc. Reproduced by permission.)

A river otter (Lutra canadensis) eating trout. (Photo by Joe McDonald. Bruce Coleman, Inc. Reproduced by permission.)

ing on species, males are 10-100% larger than females. All species have strong canine teeth for capturing and killing prey.

Coloration ranges from completely white (winter coloration of least weasels) to silver (badgers Taxidea taxus and Meles meles), pale to dark brown (mink, fisher Martes pennanti, and otters), and black and white (skunks). Pelage is either uniform (mink and otters), spotted or marbled (genera Spilogale and Vormela), or striped (Gulo and Mephitis). Many species have facial stripes (skunks and badgers), or marking on the throat (American marten [Martes americana], spotted-necked otter [Lutra maculicollis], giant otter, and American mink [Mustela vison]). All species possess anal glands, and skunks (genera Conepatus, Mephitis, and Spilogale), zorillas (genus Ictonyx), and stink badgers (genus My-daus) can spray the liquid secretions to repel aggressors.

Distribution

Mustelids occupy all continents except Antarctica. Mustelids were originally absent from Australia, but stoats (ermine or Mustela erminea), least weasels, and ferrets (Mustela putorius) were introduced to New Zealand to control rabbits.

Habitat

The Mustelidae are a diverse family that occupies a wide range of habitats from aquatic systems (otters and mink) to prairies (black-footed ferret, Mustela nigripes, and North American badger, Taxidea taxus), steppes (steppe polecat, Mustela eversmanni), treeless tundra (wolverine, Gulo gulo), and forests (most mustelids). Some species, such as striped skunk (Mephitis mephitis), tolerate humans well and abound in urban areas.

Behavior

Mustelids are mostly nocturnal, terrestrial (most species), or semi-aquatic (mink and otter), and they shelter in burrows, hollow trees, dense vegetation, rock crevices, or abandoned buildings during the day. Many species such as weasels, mink, and ferrets shelter in burrows of their prey. Most mustelids are agile tree climbers and good swimmers. One species, the sea otter (Enhydra lutris), is almost entirely aquatic.

Most species are solitary, but group living occurs in otters and European badgers (Meles meles). Some species defend exclusive territories (e.g., groups of European badgers), while others (such as striped skunk) use non-exclusive ranges that overlap with both males and females of the same species. Many species, such as otters, use their anal glands for scent marking, and skunks and stink badgers use their anal glands for defense.

Vocalizations are most developed in the Lutrinae (otters), which display a wide range of calls from purring sounds, threatening growls, and alarm calls. Skunks, zorillas (genus Ictonyx), and marbled polecats (Vormela peregusna) communicate their noxiousness to potential predator species through warning displays, whereas other mustelids may growl (badgers and wolverine) or release musk from their anal glands when threatened (weasels and mink). Most mustelids escape predation by escaping inside burrows (badgers and skunks), climbing trees (weasels, martens and wolverine), or seeking refuge in water (mink and otter). Play behavior occurs mostly in juveniles, and in adults is best known in otters sliding down muddy or snowy banks, or playing with inanimate objects in the water.

Feeding ecology and diet

Mustelids are either true carnivores (weasels, martens, and otters) or omnivores that also consume fruits and plant material (skunks, badgers, and tayra). Most species are proficient predators, killing rodent prey with a bite at the back of the neck. Small mammals such as mice and voles constitute the staple prey for most species; fish, crustaceans, and amphibians dominate the diet of otters. Most species consume reptiles opportunistically. Some species such as wolverines and fishers are opportunistic scavengers.

The long tubular shape of many mustelids allows them access to burrows of their prey. Weasels often hunt in burrows of small rodents, and American mink regularly access burrows of the muskrat (Ondatra zibethicus). Similarly, ferrets access the burrows of rabbits and hares.

Some mustelids display feeding specialization or associations with other species. The black-footed ferret depends on prairie dogs (genus Cynomys) for both food and shelter. American mink also relies heavily on muskrats as prey and use muskrat burrows and lodges as shelter. In northern Canada and the United States, the northern river otter (Lontra canadensis) uses burrows and lodges of beavers (Castor canaden-sis) for daily shelter and as maternity dens. Fishers probably evolved as expert predators of North American porcupines (Erethizon dorsatum). Others such as wolverines often associate with larger predators such as wolves (Canis lupus) to scavenge remains of their kills.

Reproductive biology

Only one species of mustelid, the giant otter, is monogamous; all other Mustelidae are promiscuous, meaning that individuals of both sexes will mate with numerous members of the other sex. Pair-bonds are typically short, and in some species such as striped skunk, American mink, and wolverine, ovulation is induced by copulation. Females have one litter per year, and males do not provide care for the young.

Implantation of the blastocyst into the uterine wall is delayed in many species such as wolverine, American marten, fisher, and sea otter. However, not all mustelids have delayed implantation, and many species closely related do not share this trait. For example, ermines (Mustela erminea) have de layed implantation whereas least weasels do not. Similarly, western spotted skunks (Spilogale gracilis) have delayed implantation whereas eastern spotted skunk (Spilogale putorius) do not. Delayed implantation likely offers species living in seasonal environments an advantage by allowing decoupling of mating and parturition and allowing parturition to occur at the peak availability of resources.

Conservation status

Many species are threatened because of habitat loss (e.g., black-footed ferret and many otters), or competition from other, non-native mustelids (European mink, Mustela lutre-ola). In contrast, several mustelids are extremely abundant and considered pests: stoats in New Zealand for depredation of native birds, skunks in North American cities for risk of rabies, and American mink in Europe for competition with the declining European mink. In 2003, 21 species of extant mustelids were listed by the IUCN. Among those, the black-footed ferret is listed as Extinct in the Wild, and seven additional species were listed as Endangered: the sea otter, the marine otter (Lontra felina), the southern river otter (Lontra provocax), the Colombian weasel (Mustela felipei), the European mink, the Indonesian mountain weasel (Mustela lutre-olina), and the giant otter.

Black-footed ferrets, the most endangered of all mustelids, once occurred throughout the Great Plains in 12 states and two Canadian provinces, and possibly portions of northern Mexico. By the 1960s, the only known population of black-footed ferrets was a small colony in southwestern South Dakota, which disappeared in l974 for unknown reasons. In 1981, a black-footed ferret was killed by a ranch dog in northwestern Wyoming, and this event led to the discovery of about 130 ferrets near Meeteetse, Wyoming. However, outbreaks of sylvatic plague and canine distemper killed nearly all of the Meeteetse population. Consequently, the remaining 18 ferrets were taken into captivity between 1985 and 1987 in an effort to save the species. Beginning in Wyoming, reintroduction efforts have since expanded to sites in Montana, South Dakota, and Arizona. The Recovery Plan for the black-footed ferret calls for the establishment of 10 or more separate, self-sustaining wild populations. In 2003, black-footed ferret still occupied less than 2% of its original range.

Significance to humans

Mustelids are of great significance to humans as furbear-ers. In North America, annual harvest of weasels, mink, martens, fishers, otters, and wolverines significantly contributes to the economy. In Russia, the fur trade is especially strong for sables (Martes zibellina).

Few mustelids are consumed for meat. In North America, striped skunks are an important vector of rabies, especially in the midwestern United States and Canada and the southwestern United States. In Europe, the European badger carries bovine tuberculosis, which is a significant concern to European farmers and consequently led to persecution of the badger near farms. Other mustelids also are considered pests on occasion. When near human habitations, skunks damage lawns, consume human refuse, and occasionally spray pets; weasels and ferrets may depredate domestic chickens; and otters may visit commercial fish ponds.

In Asia, species of otters such as Asian small-clawed otters (Amblonyx cinereus) and smooth-coated otters (Lutrogale per-

spiciallata) are tamed and used by indigenous people to catch fish. Throughout the world, ferrets are kept as pets. In North America, striped skunks also are kept as pets after their anal glands are surgically removed. Mustelids are popular in zoological gardens, especially otters, because of their playful behavior and underwater agility, and most importantly, willingness to be active during the daytime.

G Harris ©2003

1. Tayra (Eira barbara); 2. American mink (Mustela vison); 3. European badger (Meies meles); 4. Ermine (Mustela erminea) white winter phase; 5. Ermine (M. erminea) breeding phase; 6. Wolverine (Guio guio); 7. European otter (Lutra lutra); 8. Striped skunk (Mephitis mephitis). (Illustration by Gillian Harris)

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