Lycalopex culpaeus
culpeo

Culpeos, or colored foxes, have a wide distribution, occuring throughout most of the western half of South America. They are found as far south as the island of Tierra del Fuego, Argentina, as far north as Ecuador, and as far east as the eastern Andean slopes of Argentina.

Culpeos inhabit grasslands (pampas) and deciduous forests. On the western side of the Andes mountains they are found between 1000m and 4500m in elevation, but they have never been detected in the wetter lowland forests of the eastern slopes. Across much of their range culpeos avoid denser forests for the open grasslands that sustain large populations of mice and hares. One preferred habitat is pluvial p·ramo: flat, muddy terrain covered by grasses and shrubs. They also inhabit sloped regions that provide good shelter.

Culpeos show some variation in pelage coloration, but generally are distinguishable from other closely-related species by their white chin spot and reddish thigh that lacks a posterior dark spot. Culpeo dorsal bands are either absent or poorly marked. Their underparts range from brownish to cream-colored, with their sides being brownish or brownish-gray, and their upper parts brownish. The guard hair varies in length. Their ears are reddish to dark brown, and their heads range from reddish to brownish.

Culpeo society is hierarchical and matriarchal in the sense that female foxes of a litter fight for dominance. Dominant females inherit the territory of their parents, while males leave their natal territory. The ranges of both sexes do not overlap those of gray foxes (Pseudalopex griseus, their closest relatives and competitors), leading to a partitioning of resources and a reduction of interspecific competition.

Intraspecific competition is dealt with through the social hierarchy, with the dominant, or alpha, female eating first. The dominant female of each territory also has exclusive breeding rights. Submissive females must leave and establish their own territory in order to breed. Courtship is an important ritual for culpeos, it takes place during the winter months. Only dominant females mate, and only after a lengthy ritual involving mock fighting and bipedal wrestling where each fox's forelimbs rest on the other's shoulders. Copulation may take up to half an hour, during which time the foxes remain hidden by foliage.

Culpeo's main prey items are mammals. Hares and rabbits are the most common prey item but many rodent species are taken as well. Lizards, birds, carrion, insects, and berries are also eaten, making them carnivorous scavengers with omnivorous tendencies. Depending on prey population densities, they range from nearly totally carnivorous (95% to 97% animal matter in diet) to quite omnivorous (about 30% plant matter in diet). Culpeos are opportunistic, solitary hunters that show little selectivity in prey choice. They do, however, consume a higher percentage of young rabbits in the spring. About 80% of their diet is limited to prey weighing less than 55 grams. Due to the small size of the fox's prey, the fur and bones are usually ingested and expelled in the feces.

Culpeos occasionally eat poultry and sheep, but are not considered huge threats to livestock. Scavenging on guanacos, sheep and cattle represent less than 5% of their vertebrate prey items, as compared with 20% of the similar gray fox (Pseudalopex griseus). Losses to ranchers are usually tolerated.

Culpeo's pelt and flesh can be valuable, to a limited degree, for local consumption or export. They may also be hunted for sport. They also control hare and rodent populations that may be damaging to agriculture and may transmit disease.

Culpeos are common in their preferred habitats. However, they are considered rare because these foxes are habitat specialists and hence have a low mean low population density when their entire range is considered, even though that range is quite large. Critical to its continued survival is adequate habitat. Increasingly this is being limited to reserves and national parks such as Rio Abiseo National Park, Peru; Torres del Paine National Park, Chile; and Parque Nacional Fray Jorge, Chile. Human colonization, which brings agriculture and ranching, is the largest cause of habitat loss.

Lycalopex culpaeus has also been included in the genera Pseudalopex, Dusicyon, and Canis.