Cerdocyon thous (Linnaeus, 1766)

Common Name & Base Coloration

Cerdocyon thous, commonly known as the crab-eating fox, is predominantly greyish-brown, with reddish areas on the face and legs, and black tips on its ears and tail.

Limb & Coat Structure

It has short, strong legs, a long, bushy tail, and a short, thick coat.

Color Variation Range

Its coloration can range from grey to brown, yellowish, pale, and dark grey.

Markings on Torso & Limbs

There is a black streak along the back legs and a black stripe along the spine, with more reddish fur on the muzzle, ears and paws.

Extremity Coloration

The tail, legs and ear tips are black.

Head & Torso Shape

It has wide, round ears, and a somewhat narrow torso.

Tail Behavior

The dense, hairy tail stays upright when the animal is excited.

Population Color Variation

There is significant color variation between populations, ranging from very dark to light grey-yellow.

Size & Weight Measurements

The average head and body length is 64.3 centimetres (25.3 in), the average tail length is 28.5 centimetres (11.2 in), and adult weight ranges between 10 and 17 pounds (4.5 and 7.7 kg).

Genetic Karyotype

Genetically, this species has 74 diploid chromosomes, arranged as 36 pairs.

Native Continent

The crab-eating fox is a canid native to South America.

Core Geographic Range

Its range extends from Colombia and southern Venezuela in the north, south to Paraguay, Uruguay and northern Argentina.

Extralimital Sightings

It has also been sighted in Panama since the 1990s.

Preferred Habitats

It occupies savannas, woodlands, subtropical forests, prickly shrubby thickets, tropical savannas including caatinga, plains and campo, and wooded riverbanks such as riparian forest.

Avoided Habitats

It avoids rainforests, high mountains, and open grassy savannas.

Seasonal Range Shifts

During the rainy season, the crab-eating fox’s range shifts uphill; during drier periods, it moves to lower ground.

Local Population Threats

In some parts of its range, local populations are threatened with extirpation.

Hunting & Reproductive Grouping

For hunting, crab-eating foxes form monogamous pairs, and groups of multiple monogamous pairs may gather during the reproductive season.

Population Density Estimates

Population density estimates range from one individual per 4 km² in Venezuela to 0.0003 individuals/km² in Argentinian wetlands.

Seasonal Territoriality

The species shows territorial behavior during the dry season, and pays less attention to territory boundaries in the rainy season when food is more abundant.

Den Location Characteristics

Hideouts and dens are most often found in bushes and thick grass, and most dens have multiple entrance holes.

Den Construction Behavior

While crab-eating foxes are capable of digging their own tunnels, they prefer to take over burrows built by other animals.

Vocalization Types & Context

They make several distinct vocalizations, including barking, whirring and howling, which occur most often when paired individuals lose contact with each other.

Activity Pattern

This is a nocturnal species, with activity peaks around midnight and early morning.

Sexual Maturity Age

Crab-eating foxes reach sexual maturity at 9 to 10 months old.

Annual Litter Frequency

Adult females produce one or two litters per year, depending on climate and food availability.

Reproductive Period Timing

The reproductive period most often begins in November or December, with a second period starting in July.

Gestation & Birth Timing

Gestation lasts approximately 56 days, and birth typically occurs in January, February, or sometimes March for the first litter, and between September and October for the second.

Single Litter Birth Timing

If a female only produces one litter per year, it is typically born in early spring.

Parental Care Behavior

Breeding pairs are monogamous, and both parents raise the pups together.

Pup Weaning & Independence

Pups are weaned at around three months old, and become independent from their parents between 5 and 8 months old.