Crab-eating fox

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Crab-eating fox [1]
Crab-eating Fox (cropped).JPG
Cerdocyon thous from Colombia
CITES Appendix II (CITES) [3]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Canidae
Tribe: Canini
Subtribe: Cerdocyonina
Genus: Cerdocyon
C. E. H. Smith, 1839
Species:
C. thous
Binomial name
Cerdocyon thous
(Linnaeus, 1766)
Crab-eating Fox area.png
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]

Contents

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. [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.

Description

C. thous Cachorro do mato (Cerdocyon thous).JPG
C. thous

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).

Habitat

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.

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. [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]

Reproduction

A juvenile crab-eating fox in captivity Cerdocyon thous, Colombia.JPG
A juvenile crab-eating fox in captivity

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]

Diet

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.

Conservation

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]

Subspecies

The crab-eating fox has five recognized subspecies, [1] differing in sizes and coloring of fur. [19]

Related Research Articles

<span class="mw-page-title-main">Canidae</span> Family of mammals

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, and the extinct Borophaginae and Hesperocyoninae. The Caninae are known as canines, and include domestic dogs, wolves, coyotes, foxes, jackals and other species.

<span class="mw-page-title-main">Fox</span> Genera of mammal

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").

<span class="mw-page-title-main">Culpeo</span> Species of carnivore

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.

<span class="mw-page-title-main">Maned wolf</span> Species of carnivore

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.

<span class="mw-page-title-main">Swift fox</span> Species of mammal

The swift fox is a small light orange-tan fox around the size of a domestic cat found in the western grasslands of North America, such as Montana, Colorado, New Mexico, Kansas, Oklahoma and Texas. It also lives in southern Manitoba, Saskatchewan and Alberta in Canada, where it was previously extirpated. It is closely related to the kit fox and some mammalogists classify them as conspecific. However, molecular systematics imply that the two species are distinct. Interbreeding between the two species does occur where their ranges overlap, but this hybridization is quite restricted in scope.

<span class="mw-page-title-main">South American fox</span> Genus of carnivores

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.

<span class="mw-page-title-main">Caniformia</span> Suborder of mammals

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.

<span class="mw-page-title-main">Darwin's fox</span> Species of canid

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 in 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.

<span class="mw-page-title-main">Sechuran fox</span> Species of carnivore

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.

<span class="mw-page-title-main">Short-eared dog</span> Species of carnivore

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.

<span class="mw-page-title-main">Pampas fox</span> Species of carnivore

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.

<span class="mw-page-title-main">Hoary fox</span> Species of carnivore

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.

<span class="mw-page-title-main">South American gray fox</span> Species of carnivore

The South American gray fox, also known as the Patagonian fox, the chilla or zorro gris, is a South American species of Lycalopex in the Canidae family, which includes dogs, wolves, jackals, coyotes and foxes, among other canids. It is endemic to the southern parts of Argentina and Chile, primarily Patagonia and Tierra Del Fuego.

<span class="mw-page-title-main">Pale fox</span> Species of carnivore

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.

<span class="mw-page-title-main">Cerdocyonina</span> Subtribe of carnivores

Cerdocyonina is an extant subtribe of the canines that is 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.

<span class="mw-page-title-main">Dogxim</span> Canid hybrid between a Pampas fox and a domesticated dog

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".

References

  1. 1 2 3 Wozencraft, W. C. (2005). "Order Carnivora". In Wilson, D. E.; Reeder, D. M. (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 578. ISBN   978-0-8018-8221-0. OCLC   62265494.
  2. 1 2 3 Lucherini, M. (2015). "Cerdocyon thous". IUCN Red List of Threatened Species . 2015: e.T4248A81266293. doi: 10.2305/IUCN.UK.2015-4.RLTS.T4248A81266293.en . Retrieved 13 November 2021.
  3. "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  4. 1 2 3 4 Canids : foxes, wolves, jackals, and dogs : status survey and conservation action plan (PDF). Claudio Sillero-Zubiri, Michael Hoffmann, David W. Macdonald, IUCN/SSC Canid Specialist Group, IUCN--The World Conservation Union. Gland, Switzerland. 2004. ISBN   2-8317-0786-2. OCLC   57570754. Archived from the original (PDF) on September 3, 2022.{{cite book}}: CS1 maint: location missing publisher (link) CS1 maint: others (link)
  5. Braun, Janet K.; Mares, Michael A. (1995). "The Mammals of Argentina: An Etymology" (PDF). Mastozoología Neotropical. 2 (2). SAREM: 173–206. ISSN   0327-9383. Archived from the original (PDF) on October 18, 2016.
  6. Tetford, Richard H.; Wang, Xiaoming; Taylor, Beryl E. (September 2009). "Phylogenetic Systematics of the North American Fossil Caninae (Carnivora: Canidae)". Bulletin of the American Museum of Natural History. 325: 1–218. doi:10.1206/574.1. S2CID   83594819.
  7. De Lavigne, Guillaume. Free Ranging Dogs-Stray, Feral or Wild?. Lulu Press, Inc, 2015.
  8. 1 2 3 Annalisa Berta; Cerdocyon thous, Mammalian Species, Issue 186, 23 November 1982, Pages 1–4, https://doi.org/10.2307/3503974
  9. Amanda Hover. "Cerdocyon thous (crab-eating fox)". Animal Diversity Web. Retrieved 2022-09-18.
  10. 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
  11. J.F. Eisenberg, K.H. Redford Mammals of the Neotropics – The Central Neotropics, vol. 3, University of Chicago Press, Chicago (1999)
  12. Tejera-N, VH; Araúz-G., V. León, A. R. Rodríguez, P. González, S. Bermúdez & R. Moreno. 1999. Primer registro del zorro cangrejero Cerdocyon thous (Carnivora: Canidae), para Panamá. Scientia 14: 103-107
  13. 1 2 3 Nowak, Ronald M. (2005). Walker's Carnivores of the World. Baltimore: Johns Hopkins Press. ISBN   0-8018-8032-7
  14. 1 2 "Crab-eating fox | Canids". www.canids.org. Retrieved 2022-09-18.
  15. 1 2 3 Faria-Corrêa, Mariana; Balbueno, Rodrigo A.; Vieira, Emerson M.; de Freitas, Thales R. O. (2009-05-01). "Activity, habitat use, density, and reproductive biology of the crab-eating fox (Cerdocyon thous) and comparison with the pampas fox (Lycalopex gymnocercus) in a Restinga area in the southern Brazilian Atlantic Forest". Mammalian Biology. 74 (3): 220–229. doi:10.1016/j.mambio.2008.12.005. ISSN   1618-1476.
  16. Monteiro-Alves, Priscila Stéfani; Helmer, Débora Molino; Ferreguetti, Atilla Colombo; Pereira-Ribeiro, Juliane; Rocha, Carlos Frederico Duarte; Bergallo, Helena Godoy (2019-06-27). "Occupancy, detectability, and density of crab-eating fox (Cerdocyon thous) in two protected areas of restinga habitats in Brazil". Canadian Journal of Zoology. 97 (10): 952–959. doi:10.1139/cjz-2018-0322. S2CID   198245440.
  17. Brady, Charles A. "Reproduction, growth and parental care in crab-eating foxes Cerdocyon thous at the National Zoological Park, Washington." International zoo yearbook (1978).
  18. 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.
  19. BISBAL, Francisco J. "A taxonomic study of the crab-eating fox, Cerdocyon thous, in Venezuela." Mammalia 52.2 (1988): 181-186.