The crab-eating fox (''Cerdocyon thous''), also known as the forest dog, wood fox, bushfox (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 described by Peter Wilhelm Lund from fossils ...

) or maikong, is an

extant Extant or Least-concern species, least concern is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Exta ...

species of medium-sized

canid Canidae (; from Latin, ''canis'', "dog") is a family (biology), biological family of caniform carnivorans, constituting a clade. A member of this family is also called a canid (). The family includes three subfamily, subfamilies: the Caninae, a ...

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 considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

since at least the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

epoch. Like South American foxes, which are in the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

''Lycalopex'', it is not closely related to true foxes. ''Cerdocyon'' comes from the

Greek Greek may refer to: 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 of all kno ...

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 use of the term in English is in the discipline of anthropology. The definition is contested, in part due to conflict ...

which appeared around 6.0 million years ago (Mya) in

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

as '' Ferrucyon avius'' 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. 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 Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Here ''sets of chromosomes'' refers to the number of maternal and paternal chromosome copies, ...

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) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach th ...

woodland A woodland () is, in the broad sense, land covered with woody plants (trees and shrubs), 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 sunli ...

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

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" comes from the Tupi word '' ka'atinga'', meaning "white forest" or "white vegetat ...

'',

plain In geography, a plain, commonly known as flatland, 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 ...

s, and ''campo'', from

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

and southern

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

in the north to

Paraguay Paraguay, officially the Republic of Paraguay, is a landlocked country in South America. It is bordered by Argentina to the Argentina–Paraguay border, south and southwest, Brazil to the Brazil–Paraguay border, east and northeast, and Boli ...

Uruguay Uruguay, officially the Oriental Republic of 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 the Río de la Plata to the south and the A ...

and northern

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

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, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...

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, Sink (geography), sink, or reservoir. Due to the broad nature of the definitio ...

. 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 forests characterized by a closed and continuous tree Canopy (biology), canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropi ...

, 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 lengthy sustained sounds, loud and audible over long distances, often with ...

, 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. Adult females give 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 Breeding pair is a pair of animals which cooperate over time to produce offspring with some form of a bond between the individuals. For example, many birds mate for a breeding season or sometimes for life. They may share some or all of the task ...

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. Floodplains stretch from the banks of a river channel to the base of the enclosing valley, and experience flooding during periods of high Discharge (hydrolog ...

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 other crustaceans, tortoises, turtle eggs, bird eggs, insects, lizards, fruit, and

carrion Carrion (), also known as a carcass, is the decaying flesh of dead animals. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures ...

. 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 or monsoon season) is the time of year when most of a region's average annual rainfall occurs. Generally, the season lasts at least one month. The term ''green season'' is also sometimes used a ...

, the diet contains more 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 t ...

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

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

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, inv ...

Species of Wild Fauna and Flora (

CITES CITES (shorter acronym 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 inte ...

) 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 The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

lists the crab-eating fox as being of "

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

". 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 In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

, 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 Guyana, officially the Co-operative Republic of Guyana, is a country on the northern coast of South America, part of the historic British West Indies. entry "Guyana" Georgetown, Guyana, Georgetown is the capital of Guyana and is also the co ...

Suriname Suriname, officially the Republic of Suriname, is a country in northern South America, also considered as part of the Caribbean and the West Indies. It is a developing country with a Human Development Index, high level of human development; i ...

French Guiana French Guiana, or Guyane in French, is an Overseas departments and regions of France, overseas department and region of France located on the northern coast of South America in the Guianas and the West Indies. Bordered by Suriname to the west ...

North

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

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

Bolivia Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...

and

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

. * ''C. t. germanus'',

Bogotá Bogotá (, also , , ), officially Bogotá, Distrito Capital, abbreviated Bogotá, D.C., and formerly known as Santa Fe de Bogotá (; ) during the Spanish Imperial period and between 1991 and 2000, is the capital city, capital and largest city ...

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 Carnivorans 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