Cerdocyon thous
TAXONOMY
Canis thous (Linnaeus, 1766), Surinam. This species is quite similar to the more widespread genus of South American canids, Dusicyon, and has been included in the latter genus on several occasions. Molecular evidence is needed to resolve this issue. Fossil Cerdocyon from North America probably represent a colonization from South America. Five subspecies have been erected but are not well defined.
OTHER COMMON NAMES
English: Common fox, forest fox; Spanish: Zorro comun, zorro sabanero, zorro perro.
PHYSICAL CHARACTERISTICS
A medium sized canid weighing about 11.0 lb (5 kg) (range: 6.6–19.8 lb [3–9 kg]), Cerdocyon has relatively short legs (second only to the bush dog amongst the canids in its ratio of fore-limb to body length). The hair is pale gray with black hair tips. A reddish tinge on the belly and flanks is also common. The skull dimensions best represent the average skull for the family falling in the middle of a multi-variate plot.
DISTRIBUTION
Crab-eating foxes occupy a large area of eastern South America from Venezuela in the north to northern Argentina in the south. They do not occur in the densest parts of the Amazon forests.
HABITAT
The species occupies a wide range of habitats. They are most common in "edge" habitats with a mixture of woodlands and open country. They can also survive in closed-canopy forests and grassland. However, they do not occupy more open country if Dusicyon gymnocercus, Azara's fox, is present in that habitat. They live in the seasonally flooded areas of Amazonia but not the thick forests.
BEHAVIOR
The species is monogamous and pairs live in territories, which are marked by the pair with urine and feces. Territories can be as small as 0.2 mi2 (0.5 km2) and as large as 3.9 mi2 (10 km2) in less productive areas. In the seasonally flooded Llanos ranges shift and are less rigorously defended in the wet season when food is abundant. Pairs use a loud whistling vocalization to reunite.
FEEDING ECOLOGY AND DIET
The species forages at night and solitarily. They are omnivorous with a very varied diet. During the dry season in Venezuela 48% of the diet is vertebrates with 31% land crabs. During the wet season 54% of the diet is invertebrates, mainly beetles and grasshoppers, and small mammals make up 20%. Fruit and carrion form the remainder of the food. Frogs, lizards, mushrooms, and snails have also been found in stomachs.
REPRODUCTIVE BIOLOGY
Monogamous. Breeding occurs once a year in the wild, but is not strictly seasonal. (In captivity females can produce a litter every eight months, and reproduction does not seem to be tightly linked to patterns of daylight length.) Litter size varies from two to six with an average of four after a gestation of 52–59 days. Both parents provision the young and pups start to forage on their own around four months. Dispersal occurs from six to nine months.
CONSERVATION STATUS
The species remains widespread. It can colonize areas of cleared forest and can live close to human settlement. Like almost all canids it is hunted, but its fur is not useful.
SIGNIFICANCE TO HUMANS
The crab-eating fox is usually inconspicuous. It may kill chickens but is not of great significance to humans.
| Common name / Scientific name / Other common names | Physical characteristics | Habitat and behavior | Distribution | Diet | Conservation status |
| Arctic fox Alopex lagopus Spanish: Zorro polar | Two color phases, white and blue. Head and body length 18–26.6 in (45.8–67.5 cm), tail length 10–16.7 in (25.5– 42.5 cm). | Mainly in alpineand arctic tundra, usually in coastal areas. Makes den in low mounds with 4 to 12 entrances. Seasonal movements associated with food availability. | Circumpolar, entire tundra zone of the Holarctic, including most of the Arctic islands. | Any human food, dead or alive, carrion, marine mammals, invertebrates, sea birds, and fish. Predator of the ringed seal in winter and lemmings when on land. | Not threatened |
| Short-eared dog Atelocynus microtis Spanish: Zorro de orejas cortas | Upperparts dark gray to black, underparts rufous mixed with gray and black. Thickly haired, black tail. Head and body length 28.3–39.4 in (72–100 cm), tail length 9.8–13.8 in (25–35 cm). | Tropical forests from sea level to about 3,280 ft (1,000 m). Males dominant in most activities. | Amazon, upper Orinoco, upper Parana basins in Brazil, Peru, Ecuador, Colombia, and probably Venezuala. | Nothing is known about the food habits of this species in the wild. Observations suggest a carnivorous diet, although may eat fruit in the wild if prey is scarce. | Data Deficient |
| Side-striped jackal Canis adustus Spanish: Chacal de dorso franjeado | Coat is long, soft, partially mottled gray. Each side of body is lined with white hair, followed by line of dark hair. Underparts and tip of tail are white. Head and body length 25.6–31.9 in (65–81 cm), tail length 11.8–16.1 in (30–41 cm). | Moister parts of savannas, thickets, forest edge, cultivated areas, and rough country up to 8,860 ft (2,700 m) in elevation. Strictly nocturnal. Social groups are well spaced. Litters consist of 3 to 6 young. | Open woodland and semi-arid grassland from Senegal to Ethiopia, south to northern Namibia, northern Botswana, Zimbabwe, Mozambique, and northern South Africa. | Consists of various types of invertebrates, small vertebrates, carrion, and plant material. | Not threatened |
| Black-backed jackal Canis mesomelas Spanish: Chacal de lomo negro | Dark saddle on length of back to tip of tail. Sides, head, limbs, and ears are rufous. Underparts pale ginger. Slender build, very large ears. Head and body length 26.8–29.3 in (68–74.5 cm), tail length 11.8–15 in (30–38 cm). | Dry grassland, brushland, and open woodland. Basic social unit is mated pair and their young. About four young per litter. | Africa, south of the tropical rainforest in the west and as far north as Ethiopia and Sudan in the east. | An important predator of sheep. | Not threatened |
| Dhole Cuon alpinus Spanish: Dolo | Upperparts are rusty red, underparts pale, tail tipped with black. Head and body length 34.6–44.5 in (88–113 cm), tail length 15.7–19.7 in (40–50 cm). | Many types of habitat, but avoids deserts. Alpine areas, dense forest, and thick scrub jungles are a few. Hunts in packs. Five to 10 individuals within a pack. | Southern Siberia and central Asia to India and the Malay Peninsula, and on the islands of Sumatra and Java, but not Sri Lanka. | Mainly mammals larger than itself, including deer, wild pigs, mountain sheep, gaur, and antelope. | Vulnerable |
| Common name / Scientific name / Other common names | Physical characteristics | Habitat and behavior | Distribution | Diet | Conservation status |
| Falkland Island wolf Dusicyon australis Spanish: Zorro de las Malvinas | Upperparts are brown, some rufous and speckles of white. Underparts pale brown. Coat is soft and thick. Tail is short, bushy, tipped with white. Head and body length 38.2 in (97 cm), tail length 11.2 in (28.5 cm). | Found 250 mi (400 km) away from mainland, on islands. Very tame toward humans. Little is known. | Falkland Islands. | Consists mainly of birds, especially geese and penguins, as well as pinnipeds. | Extinct |
| Pampas fox Pseudalopex gymnocercus Spanish: Zorro gris mayor | Coloration is pale yellow, underparts and back are gray. Head, neck, and large ears are reddish. Muzzle is black. Long, bushy tail with two black spots. Throat and belly are whitish. Head and body length 24.4 in (62 cm), tail length 13.4 in (34 cm). | Pampas grasslands, hills, and deserts. They prefer plains and fields with tall grass, sierras, small narrow woods, and areas along streams. | Argentina, north of Rio Negro, Paraguay, Uruguay, southern Brazil, and eastern Bolivia. | Rodents of all kinds, birds, rabbits, frogs, lizards, fruit, and other vegetable matter like sugar cane stalks. | Not threatened |
| Culpeo Pseudalopex culpaeus German: Andenschakal; Spanish: Zorro colorado | Size increases the farther south the range is. Males are larger than females. Coloration is brownish tawny, underparts are paler. Back is gray, tail is tipped with black. | Pampas grasslands and deciduous forests of their range. Hierarchical matriarchal society. Mating period is from August to October. Strong hierarchical sense in social groups. | From Tierra del Fuego through the Andes of Chile and Argentina to the highlands of Bolivia, Peru, Ecuador, and Colombia. | Rodents and lagomorphs (rabbits and hares), as well as lambs a week old and younger. | Not threatened |
| Bush dog Speothos venaticus Spanish: Perro vinagre | Coloration is ochraceous fawn or tawny into dark brown or black on back and tail. Underparts are dark with a light patch on chin and throat. Stocky body, short, with broad muzzle. Tail is short. Head and body length 22.6–29.5 in (57.5– 75 cm), tail length 4.9–5.9 in (12.5– 15 cm). | Forests and wet savannas, often near water. Mainly diurnal, semi-aquatic. Litter of two to three individuals are produced during the rainy seasons. | Forested areas of Bolivia, Paraguay, and Brazil (except the semiarid northeast), eastern Peru, Ecuador, Colombia, Venezuela, Guyana, French Guiana, Suriname, and Panama. | Mainly large rodents. | Vulnerable |
| Gray fox Urocyon cinereoargenteus Spanish: Zorro gris plateado | Underparts are gray or white, ventral parts are rusty. Tail is tipped in black and the pelage is coarse. Head and body length 19–27 in (48.3–68.5 cm), tail length 10.8–17.5 in (27.53–44.5 cm). | Wooded and brushy country, often in rocky or broken terrain. Prefer pine-oak woodland bordering fields. Frequently climbs trees. Mostly nocturnal. | North America from Oregon, Nevada, Utah, and Colorado in the West and the USA-Canadian border in the East through Central America to northern Colombia and Venezuela. | Many kinds of small vertebrates, insects, and vegetable matter. | Not threatened |
| Island fox Urocyon littoralis Spanish: Zorro gris isleño | Underparts are gray, ventral parts are rusty. Head and body length 18.9–19.7 in (48–50 cm), tail length 4.3–11.4 in (11–29 cm). | Wooded and brushy country, often in rocky or broken terrain. Prefer pine-oak woodland bordering fields. Frequently climbs trees. Mostly nocturnal. | Islands off the Pacific Coast of southern California, United States. | Many kinds of small vertebrates, insects, and vegetable matter. | Lower Risk/Conservation Dependent |
| Tibetan fox Vulpes ferrilata English: Tibetan sand fox; Spanish: Zorro tibetaño | General coloration of upperparts is gray or sandy, underparts pale. Tip of tail is white. Head and body length 22.6–27.6 in (57.5–70 cm), tail length 15.7–18.7 in (40–47.5 cm). | Barren slopes and in stream beds at 9,840–13,120 ft (3,000–4,000 m) in the Mustang District of Nepal. Dens are made of boulders. Two to five young born a year. | China, in Tibet, Tsinghai, Kansu, and Yunnan; and Nepal. | Consists of rodents, lagomorphs, and ground birds. | Not threatened |
| Corsac fox Vulpes corsac Spanish: Zorro corsac | Fur is thick, soft, generally pale reddish gray, underparts are white or yellow. Head and body length 19.7–23.6 in (50–60 cm), tail length 9.8–13.8 in (25–35 cm). | Steppes and semi-desert. Lives in a burrow. Mainly nocturnal activity, but has been seen by day. Nomadic, does not keep fixed home range. Very social. | Kazakhstan, Russia, central Asia, Mongolia, Transbaikalia, north-eastern China, and northern Afghanistan. | Consists mostly of small rodents, but also pikas, birds, insects, and plant material. | Data Deficient |
| Swift fox Vulpes velox English: Kit fox; Spanish: Zorro veloz | Coloration of upperparts is dark buffy gray, underparts are buff to pure white. Coat is redder in summer. Head and body length 14.8–20.7 in (37.5– 52.5 cm), tail length 8.9–13.8 in (22.5– 35 cm). | Prairies, especially those with grasses of short and medium height. Builds burrows for shelter. Primarily nocturnal. | Central North America from southeastern British Columbia, south-central Alberta and southwestern Saskatchewan (Canada) to northwest Texas (panhandle) and eastern New Mexico, east of Rockies (United States). | Consists mostly of lagomorphs, as well as rodents, birds, lizards, and insects. | Lower Risk/Conservation Dependent |
