The crab-eating fox (''Cerdocyon thous''), also known as the forest fox, wood fox, bushdog (not to be confused with the

bush dog The bush dog (''Speothos venaticus'') is a canine found in Central and South America. In spite of its extensive range, it is very rare in most areas except in Suriname, Guyana and Peru; it was first identified by Peter Wilhelm Lund from fossi ...

) or maikong, is an extant species of medium-sized

canid Canidae (; from Latin, '' canis'', " dog") is a biological family of dog-like carnivorans, colloquially referred to as dogs, and constitutes a clade. A member of this family is also called a canid (). There are three subfamilies found withi ...

endemic to the central part of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...

since at least the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

epoch. Like South American foxes, which are in the genus ''Lycalopex'', it is not closely related to true foxes. ''Cerdocyon'' comes from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

words ''kerdo'' (meaning fox) and ''kyon'' (dog) referring to the dog- and fox-like characteristics of this animal.

Taxonomy and evolution

The crab-eating fox was originally described as ''Canis thous'' by Linnaeus (1766), and first placed in its current genus ''Cerdocyon'' by Hamilton-Smith in 1839. Cerdocyonina is a

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English is in the discipline of anthropology. This definition is contested, in part due to confli ...

which appeared around 6.0 million years ago (Mya) in North America as ''

Ferrucyon avius ''Ferrucyon'' is an extinct genus of omnivorous mammal of the family Canidae, which inhabited North America during the Pliocene, Blancan in the NALMA classification, from about 4.9 to approximately 2.6 Ma. The type species, ''F. avius'', was o ...

'' becoming extinct by around 1.4–1.3 Mya. living about . This genus has persisted in South America from an undetermined time, possibly around 3.1 Mya, and continues to the present in the same or a similar form to the crab-eating fox. As one of the species of the tribe Canini, it is related to the genus ''Canis''. The crab-eating fox's nearest living relative, as theorized at present, is the

short-eared dog The short-eared dog (''Atelocynus microtis''), also known as the short-eared zorro or small-eared dog,de la Rosa, Carlos L.; and Nocke, Claudia. A Guide to the Carnivores of Central America: Natural History, Ecology, and Conservation. Austin: Uni ...

. This relationship, however, has yet to be supported by mitochondrial investigations. Two subgenera (''Atelocynus'' and ''Speothos'') were long ago included in ''Cerdocyon''. ''Cerdocyon thous'', ''C. avius'' and other species of the genus ''Cerdocyon'' underwent radiational evolution on the South American continent.De Lavigne, Guillaume. Free Ranging Dogs-Stray, Feral or Wild?. Lulu Press, Inc, 2015. All close relatives of the crab-eating fox (''Cerdocyon thous'') are extinct. It is the only living representative at present of the genus ''Cerdocyon''.

Description

The crab-eating fox is predominantly greyish-brown, with areas of red on the face and legs, and black-tipped ears and tail. It has short, strong legs and its tail is long and bushy. The head and body length averages , and the average tail length is .Annalisa Berta; Cerdocyon thous, Mammalian Species, Issue 186, 23 November 1982, Pages 1–4, https://doi.org/10.2307/3503974 It can weigh between .Yahnke CJ, Johnson WE, Geffen E, Smith D, Hertel F, Roy MS, Bonacic CF, Fuller TK, Van Valkenburgh V, Wayne RK (1996) Darwin’s fox: a distinct endangered species in a vanishing habitat. Conserv Biol 10:366–375 The coat is short and thick. Coloration varies from grey to brown, to yellowish, to pale, to dark grey. There is a black streak along the back legs, with a black stripe along the spine. On muzzle, ears and paws there is more-reddish fur. The tail, legs and ear tips are black. The ears are wide and round. The torso is somewhat narrow; legs are short but strong. The dense hairy tail stays upright when they are excited. There is significant variation in color between population, from very dark to light grey-yellow. Genetically, there are 74 diploid chromosomes (36 pairs).

Habitat

The crab-eating fox is a canid that ranges in

savanna A savanna or savannah is a mixed woodland- grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...

woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ''plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (se ...

s; subtropical forests; prickly, shrubby thickets; and tropical savannas such as the ''

caatinga Caatinga (, ) is a type of semi-arid tropical vegetation, and an ecoregion characterized by this vegetation in interior northeastern Brazil. The name "Caatinga" is a Tupi word meaning "white forest" or "white vegetation" (''caa'' = forest, v ...

'',

plain In geography, a plain is a flat expanse of land that generally does not change much in elevation, and is primarily treeless. Plains occur as lowlands along valleys or at the base of mountains, as coastal plains, and as plateaus or uplands ...

s, and ''campo'', from Colombia and southern

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...

in the north to

Paraguay Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...

Uruguay Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while bordering ...

and northern

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

at the southernmost reaches of its range.J.F. Eisenberg, K.H. Redford Mammals of the Neotropics – The Central Neotropics, vol. 3, University of Chicago Press, Chicago (1999) The crab-eating fox has also been sighted in

Panama Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Co ...

since the 1990s. Its habitat also includes wooded riverbanks such as

riparian forest A riparian forest or riparian woodland is a forested or wooded area of land adjacent to a body of water such as a river, stream, pond, lake, marshland, estuary, canal Canals or artificial waterways are waterways or engineered chann ...

. In the rainy season, their range moves uphill, whilst in drier times they move to lower ground. Their habitat covers all environments except

rainforests Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainforest ...

, high mountains, and open grassy savannas. In some regions of their range, they are threatened with extirpation.

Behaviour and ecology

The crab-eating fox creates monogamic teams for hunting; groups of several monogamic pairs may form during the reproductive season. Population density estimates vary between one individual per 4 km² in Venezuela to 0.0003 individuals/km² in Argentinian wetlands.

Territorialism Territorialism can refer to: * Animal territorialism, the animal behavior of defending a geographical area from intruders * Environmental territorialism, a stance toward threats posed toward individuals, communities or nations by environmental even ...

was noticed during the dry season; during rainy seasons, when there is more food, they pay less attention to territory.Nowak, Ronald M. (2005). ''Walker's Carnivores of the World''. Baltimore: Johns Hopkins Press. Hideouts and dens often are found in bushes and in thick grass, and there are typically multiple entrance holes per den. Despite being capable of tunneling, they prefer to take over other animals' burrows. Several characteristic sounds are made by the crab-eating fox such as barking, whirring and

howling Howling is a vocal form of animal communication seen in most canines, particularly wolves, coyotes, foxes, and dogs, as well as cats and some species of monkeys. Howls are generally lengthy sustained sounds, loud and audible over long distances, ...

, which occur often when pairs lose contact with one another. The crab eating fox is nocturnal, with peaks of activity in the middle of the night and the early morning.

Reproduction

The foxes reach sexual maturity within 9–10 months year. Adult females gives birth to one or two litters per year, depending on the climate and the availability of food. The reproductive period most often begins in November or December, and again in July. The birth of offspring follows after an approximately 56-day gestation,Brady, Charles A.
Reproduction, growth and parental care in crab-eating foxes Cerdocyon thous at the National Zoological Park, Washington
" International zoo yearbook (1978). typically in January, February or sometimes March, then again from September to October. If giving birth to one litter, they typically give birth in the early spring. The breeding pair is monogamous and raises the pups together, which are weaned at around three months old and become independent of their parents around 5–8 months old.

Diet

The crab-eating fox searches for crabs on muddy

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

s during the wet season, giving this animal its common name. It is an opportunist and an omnivore, preferring insects or meat from rodents and birds when available. Other foods readily consumed include turtle eggs, tortoises, fruit,

eggs Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can ...

s, insects, lizards and carrion. Their diet is varied and has been found to differ by different researchers, suggesting opportunistic feeding and geographical variation. During the

wet season The wet season (sometimes called the Rainy season) is the time of year when most of a region's average annual rainfall occurs. It is the time of year where the majority of a country's or region's annual precipitation occurs. Generally, the sea ...

, the diet contains more crabs and other crustaceans, while during the

dry season The dry season is a yearly period of low rainfall, especially in the tropics. The weather in the tropics is dominated by the tropical rain belt, which moves from the northern to the southern tropics and back over the course of the year. The te ...

it contains more insects. The crab-eating fox contributes to the control of

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...

s and harmful insects.

Conservation

The Convention on International Trade in

Endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and in ...

Species of Wild Fauna and Flora (

CITES CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of interna ...

) lists the fox as not threatened by extinction.Hutton, Jon, and Barnabas Dickson, eds. Endangered species, threatened convention: the past, present and future of CITES, the Convention on International Trade in Endangered Species of Wild Fauna and Flora. London: Earthscan, 2000. The IUCN lists the crab-eating fox as being of "

Least Concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

". There are no precise estimates of the population size, but it is common within its range and the population is stable. It is considered a threat to livestock by farmers, which leads to illegal hunting in some countries. The primary threat to the fox is disease from unvaccinated dogs.

Subspecies

The crab-eating fox has five recognized subspecies, differing in sizes and coloring of fur.BISBAL, Francisco J. "A taxonomic study of the crab-eating fox, Cerdocyon thous, in Venezuela." Mammalia 52.2 (1988): 181-186. * ''C. t. thous'',

, Guyana, Suriname,

French Guiana French Guiana ( or ; french: link=no, Guyane ; gcr, label=French Guianese Creole, Lagwiyann ) is an overseas department/region and single territorial collectivity of France on the northern Atlantic coast of South America in the Guianas. ...

North

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

. * ''C. t. azarae'', North

. * ''C. t. entrerianus'',

, Bolivia.

and

. * ''C. t. aquilus'', north

and Colombia. * ''C. t. germanus'', Bogotá region ( Colombia).

References

External links

Detailed Cerdocyon thous PDF article
at th
Canid Specialist Group
(CSG) site (2004).

{{Taxonbar, from=Q321376 Cerdocyonina crab-eating fox Mammals of Brazil Mammals of Bolivia Mammals of Argentina Mammals of Colombia Mammals of Paraguay Mammals of Uruguay Mammals of Venezuela crab-eating fox crab-eating fox