Crab-eating fox [1] | |
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Cerdocyon thous from Colombia | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Carnivora |
Family: | Canidae |
Subfamily: | Caninae |
Tribe: | Canini |
Genus: | Cerdocyon C. E. H. Smith, 1839 |
Species: | C. thous |
Binomial name | |
Cerdocyon thous (Linnaeus, 1766) | |
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Crab-eating fox range | |
Synonyms | |
Canis thousLinnaeus, 1766 |
The crab-eating fox (Cerdocyon thous), also known as the forest fox, wood fox, bushdog (not to be confused with the bush dog) or maikong, is an extant species of medium-sized canid endemic to the central part of South America since at least the Pleistocene epoch. [1] [2] [4] Like South American foxes, which are in the genus Lycalopex, it is not closely related to true foxes. Cerdocyon comes from the Greek words kerdo (meaning fox) and kyon (dog) referring to the dog- and fox-like characteristics of this animal. [5]
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. [4]
Cerdocyonina is a tribe which appeared around 6.0 million years ago (Mya) in North America as Ferrucyon avius becoming extinct by around 1.4–1.3 Mya. living about 4.7 million years. 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. [6]
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. [7] All close relatives of the crab-eating fox (Cerdocyon thous) are extinct. It is the only living representative at present of the genus Cerdocyon.
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 64.3 centimetres (25.3 in), and the average tail length is 28.5 centimetres (11.2 in). [8] It can weigh between 10 and 17 pounds (4.5 and 7.7 kg). [9] [10]
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. [4]
Genetically, there are 74 diploid chromosomes (36 pairs).
The crab-eating fox is a canid that ranges in savannas; woodlands; subtropical forests; prickly, shrubby thickets; and tropical savannas such as the caatinga , plains, and campo, from Colombia and southern Venezuela in the north to Paraguay, Uruguay and northern Argentina at the southernmost reaches of its range. [11] The crab-eating fox has also been sighted in Panama since the 1990s. [12]
Its habitat also includes wooded riverbanks such as riparian forest. In the rainy season, their range moves uphill, whilst in drier times they move to lower ground. [13] Their habitat covers all environments except rainforests, high mountains, and open grassy savannas. In some regions of their range, they are threatened with extirpation.
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. [8] [14] [15] Territorialism was noticed during the dry season; during rainy seasons, when there is more food, they pay less attention to territory. [13] 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, 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. [16]
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. [15] 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, [17] typically in January, February or sometimes March, [13] 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. [15]
The crab-eating fox searches for crabs on muddy floodplains 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. Their diet is varied and has been found to differ by different researchers, suggesting opportunistic feeding and geographical variation. During the wet season, the diet contains more crustaceans, while during the dry season it contains more insects. [8] The crab-eating fox contributes to the control of rodents and harmful insects.
The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) lists the fox as not threatened by extinction. [18] The IUCN lists the crab-eating fox as being of "Least Concern". [2] There are no precise estimates of the population size, but it is common within its range and the population is stable. [4]
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. [14]
The crab-eating fox has five recognized subspecies, [1] differing in sizes and coloring of fur. [19]
Canidae 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. The family includes three subfamilies: the Caninae, the extinct Borophaginae and Hesperocyoninae. The Caninae are known as canines, and include domestic dogs, wolves, coyotes, foxes, jackals and other species.
Foxes are small- to medium-sized omnivorous mammals belonging to several genera of the family Canidae. They have a flattened skull; upright, triangular ears; a pointed, slightly upturned snout; and a long, bushy tail ("brush").
The culpeo, also known as culpeo zorro, Andean zorro, Andean fox, Paramo wolf, Andean wolf, and colpeo fox, is a species of South American fox. Despite the name, it is not a true fox, but more closely related to wolves and jackals. Its appearance resembles that of foxes due to convergent evolution.
The maned wolf is a large canine of South America. It is found in Argentina, Brazil, Bolivia, Peru, and Paraguay, and is almost extinct in Uruguay. Its markings resemble those of foxes, but it is neither a fox nor a wolf. It is the only species in the genus Chrysocyon.
The bush dog 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 in Brazilian caves and was believed to be extinct.
The South American foxes (Lycalopex), commonly called raposa in Portuguese, or zorro in Spanish, are a genus from South America of the subfamily Caninae. Despite their name, they are not true foxes, but are a unique canid genus more closely related to wolves and jackals than to true foxes; some of them resemble foxes due to convergent evolution. The South American gray fox, Lycalopex griseus, is the most common species, and is known for its large ears and a highly marketable, russet-fringed pelt.
Caniformia is a suborder within the order Carnivora consisting of "dog-like" carnivorans. They include dogs, bears, raccoons, and mustelids. The Pinnipedia are also assigned to this group. The center of diversification for the Caniformia is North America and northern Eurasia. Caniformia stands in contrast to the other suborder of Carnivora, the Feliformia, the center of diversification of which was in Africa and southern Asia.
Darwin's fox or Darwin's zorro is an endangered canid from the genus Lycalopex. It is also known as the zorro chilote or zorro de Darwin in Spanish and lives on Nahuelbuta National Park, the Cordillera de Oncol, Cordillera Pelada in mainland Chile and Chiloé Island. This small, dark canine weighs 1.8 to 3.95 kg, has a head-and-body length of 48 to 59 cm and a tail that is 17.5 to 25.5 cm. Darwin's fox displays no key differences between male and female other than the fact that the male has a broader muzzle. Males display no territorial behavior and are not aggressive towards other males roaming around their territory.
The Sechuran fox, also called the Peruvian desert fox or the Sechuran zorro, is a small South American species of canid closely related to other South American "false" foxes or zorro. It gets its name for being found in the Sechura Desert in northwestern Peru.
The short-eared dog, also known as the short-eared zorro or small-eared dog, is a unique and elusive canid species endemic to the Amazonian basin. This is the only species assigned to the genus Atelocynus.
The Pampas fox, also known as grey pampean fox, Pampas zorro, Azara's fox, or Azara's zorro, is a medium-sized zorro, or "false" fox, native to the South American Pampas. Azara in some of its alternative common names is a reference to Spanish naturalist Félix de Azara.
The hoary fox or hoary zorro, also known as raposinha-do-campo in Brazil, is a species of zorro or "false" fox endemic to Brazil. Unlike many other foxes, it feeds primarily on small invertebrates such as insects.
The South American gray fox, also known as the Patagonian fox, the chilla or the gray zorro, is a species of Lycalopex, the "false" foxes. It is endemic to the southern part of South America.
The pale fox is a species of fox found in the band of African Sahel from Senegal in the west to Sudan in the east. It is one of the least studied of all canid species, in part due to its remote habitat and its sandy coat that blends in well with the desert-like terrain. The pale fox is distinguished by its light-colored fur and oversized ears, which enable it to excel in camouflage and survival in harsh environments.
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 originally interpreted as a relative of the modern crab-eating fox, and described as a species belonging to the genus Cerdocyon. Ruiz-Ramoni et al. (2020) reinterpreted it as a vulpine canid related to North American species Metalopex macconnelli, and to the Eurasian genus Nyctereutes. This reinterpretation necessitated removal of "Cerdocyon" avius from the genus Cerdocyon, and Ruiz-Ramoni et al. (2020) transferred it to the separate genus Ferrucyon.
Cerradomys scotti, also known as Lindbergh's oryzomys, is a rodent species from South America in the genus Cerradomys. It is terrestrial and is found in the cerrado (savanna) ecozone of south central Brazil, Bolivia and Paraguay. The species is common and appears to tolerate a degree of agricultural habitat modification.
Rangelia is a genus of parasitic alveolates of the phylum Apicomplexa.
Cerdocyonina is an extant subtribe of the canines and is exclusively endemic to the Americas. Often described to be "fox-like" in appearance and behavior, they are more closely related to the wolf-like canids such as Canis than they are to the fox genus Vulpes. Its members are colloquially known as the South American canids and there are 10 extant species. They are sometimes referred to as South American foxes in the older literature, but the term zorro has been recommended by mammalogists to avoid confusion with the true foxes of the tribe Vulpini, which includes the genus Vulpes.
Dogxim, or Graxorra in Portuguese, was a female canid hybrid between a Pampas fox and a domesticated dog that was discovered in Brazil during 2021. The canid showed a mixture of fox and dog behaviours, and a team of geneticists led by Thales Renato Ochotorena de Freitas and Rafael Kretschmer announced in 2023 that she was a distinct hybrid genetically that "represents the first documented case of hybridization between these two [fox and dog] species".
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