The Argentine gray fox is wide spread throughout Patagonia and western Argentina. It was introduced to Tierra del Fuego in 1951 to control the European rabbit. This area now has the highest population density. These foxes are also found on several small islands off the western coast of West Falkland, in Chile, southern Peru, and are believed to exist in central Peru. They live on both sides of the Andes Mountains (23° S to 55° S). Both hunting, legal and illegal, and the Lycalopex culpaeus may limit the gray fox’s distribution, even though their territories do not overlap. (Nowak, 1999; The World Conservation Union, Species Survival Commission, Canid Specialist Group, 1998)
The Argentine gray fox likes to live in lowlands and foothills of coastal mountain ranges, plains, pampas, deserts, low open grasslands and forest edge habitats. They live on shrubby sandy soils. (Nowak, 1999; The World Conservation Union, Species Survival Commission, Canid Specialist Group, 1998)
The coat is brindled gray, the underparts paler grays. The head is a rust color flecked with white and a black spot on the chin. The Argentine gray fox has large ears and a long and bushy tail. The molars are well developed, and the carnassials are relatively short. This fox can grow up to 2 to 4 kg. Its shoulder height is 40 to 45 cm, decreasing as latitude increases from 33° S to 54° S. The head-body length is 42 to 68 cm, and the tail length is from 30 to 36 cm. (The World Conservation Union, Species Survival Commission, Canid Specialist Group, 1998; Yahnke, 1995)
- Sexual Dimorphism
- sexes alike
- Range mass
- 2 to 4 kg
- 4.41 to 8.81 lb
- Range length
- 42 to 68 cm
- 16.54 to 26.77 in
Studies of (Nowak, 1999)in Patagonia indicate that mating is monogamous, with a mated pair maintaining their territory throughout the year. Occasionally, a second female was present on the territory, and assisted in rearing the young, although she did not produce young herself.
The Argentine gray fox mates from August through September and the pups are born by October. The gestation period is 53 to 60 days and the litter size is 2 to 6 pups. Time of weaning is not known, but when the pups are 4 to 6 weeks, they start to leave the den with their mothers. By January, they go out by themselves to hunt for small mammals and arthropods. Age of sexual maturity is about 1 year. (Johnson, 1992; The World Conservation Union, Species Survival Commission, Canid Specialist Group, 1998)
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- Breeding interval
- Argentine gray foxes breed once yearly.
- Breeding season
- Breeding occurs from August through October.
- Range number of offspring
- 2 to 6
- Range gestation period
- 53 (high) days
- Average gestation period
- 60 days
- Average age at sexual or reproductive maturity (female)
- 1 years
- Average age at sexual or reproductive maturity (male)
- 1 years
Both males and females are active in caring for the young. As in all mammals, the female nurses the young, although there are not good data on lactation in this species. In general, canid young are altricial. The male helps to maintain the territory where prey are obtained, and, as in other members of the genus Pseudalopex , may help to provide food for the growing family. Occasionally, an additional female is present on the territory, and she apparently also assists in rearing the young. (Nowak, 1999)
- Parental Investment
- post-independence association with parents
- extended period of juvenile learning
Communication and Perception
Argentine gray foxes are omnivorous and diet changes seasonally. European rabbits and birds are preferred, as well as fruits, seeds, berries, small mammals, insects, scorpions, lizards, frogs, and bird eggs. Sheep predation is minimal and usually only eaten as carrion. In the winter months, carrion seems to become the most important food source, along with rodents and armadillos. (Johnson,1992; Puig, 1997; Jaksic, 1983) In areas of human habitation, (Jaksic and Yanez, 1983; Johnson, 1992; Nowak, 1999)may take domestic poultry (Nowak, 1999).
- Primary Diet
- Animal Foods
- terrestrial non-insect arthropods
- Plant Foods
- seeds, grains, and nuts
Predation on this species has not been described in the literature.
The Argentine gray fox helps to control small mammal and bird populations. It also disperses seeds by eating the fruit then defecating the seeds.
- Ecosystem Impact
- disperses seeds
Economic Importance for Humans: Positive
There is an important pelt trade in South America. According to CITES, from 1980 to 1983, 381,000 fox skins were exported, 98% of which were purported to have originated in Argentina. Over 7,000 skins were recorded as being exported from Chile, despite the species being protected in that country. Most exports were made to West Germany (72%), Switzerland (7.2%), and Italy (4.4%).
As noted previously, these carnivorous foxes eat both European rabbits and small rodents. They are therefore probably important in limiting pest populations. (The World Conservation Union, Species Survival Commission, Canid Specialist Group, 1998)
- Positive Impacts
- body parts are source of valuable material
- controls pest population
Economic Importance for Humans: Negative
Local people believe that these foxes prey upon sheep and domestic fowl, although scat analysis indicates that such predation is probably not common. (Nowak, 1999)
The Argentine gray fox is protected by law in Chile but enforcementof this law is lax. No hunting or skin trade has been permitted since 1929 in some areas, although fox skins are still exported through Chile via Argentina. The Argentine Wildlife Board (Direccion Nacional de Fauna Silvestre) has classified the species as endangered. Hunting is banned year-round in some areas.
In Rio Nego, Patagonia, population levels have been stable since 1983, in spite of heavy harvesting for furs. Deep snowfall can depress population levels, but recovery is usually speedy. (Nowak, 1995; The World Conservation Union, Species Survival Commission, Canid Specialist Group, 1998)
Darwin’s foxes (Pseudalopex fulvipes) were previously considered a subspecies of Argentine gray foxes, as Pseudalopex griseus fulvipes. They are now considered a separate species, reasons include: their shorter legs and a darker pelage and the fact that they don't interbreed where the two are sympatric. Tests of mitochondrial DNA have concluded that Darwin’s foxes and Argentine gray foxes are distinct species (Yahnke et al., 1996). The cranium size has a shorter, broader facial region, a smaller auditory bullae, heavier dentition, occlusion of the premolars nearly complete, mandible angle deeper and heavier; all of which brings it closer to the Sechurae fox, rather than the Chilla fox, supporting a sister relationships between Argentine gray foxes and Darwin’s foxes (Yahnke, 1995).
Vulpes about 7 million years ago. It evolved into its current form about 1 or 2 million years ago (Johnson, 1992).seems to have split from a more wolf-like lineage than did
Kenlyn Knop (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor), University of Wisconsin-Stevens Point.
living in the southern part of the New World. In other words, Central and South America.
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
- bilateral symmetry
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
flesh of dead animals.
Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.
uses smells or other chemicals to communicate
- cooperative breeder
helpers provide assistance in raising young that are not their own
- desert or dunes
in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
Having one mate at a time.
having the capacity to move from one place to another.
- native range
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
an animal that mainly eats all kinds of things, including plants and animals
- scrub forest
scrub forests develop in areas that experience dry seasons.
- seasonal breeding
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
associates with others of its species; forms social groups.
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
- tropical savanna and grassland
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
- temperate grassland
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
Jaksic, F., J. Yanez. 1983. Rabbit and Fox Introductions in Tierra del Fuego: History and Assessment of the Attempts at Biological Control of the Rabbit Infestation. Biological Conservation, 26: 367-374.
Johnson, W. 1992. Patagonia's Little Foxes. Natural History, 101: 26-28.
Nowak, R. 1999. Walker's Mammals of the World, Sixth Edition. Baltimore nd london: The Johns Hopkins University Press.
Nowak, R. 1995. "Walker's Mammals of the World, Online. South American Foxes" (On-line). Accessed November 28, 2001 at http://www.press.jhu.edu/books/walker/carnivora.canidae.pseudalopex.html.
Puig, S. 1997. Mammalia, 61: 617-621.
The World Conservation Union, Species Survival Commission, Canid Specialist Group, 1998. "Gray Zorro" (On-line). Accessed November 28, 2001 at http://www.canids.org/SPPACCTS/dgriseus.htm.
Yahnke, C. 1995. Metachromism and the Insight of Wilfred Osgood: Evidence of Common Ancestory for Darwin’s Fox and the Sechura Fox. Revista Chilena de Historia Natural, 68: 459-467.
Yahnke, C., W. Johnson, E. Geffen, D. Smith, F. Hertel. 1996. Darwin’s Fox: A distinct endangered species in a vanishing habitat. Conservation Biology, 10(2): 366-375.