Myrmecophaga tridactyla Linnaeus, 1758

Distinguishing Features

The giant anteater (Myrmecophaga tridactyla Linnaeus, 1758) can be identified by its large size, long narrow muzzle, and long bushy tail.

Body Length

Its total body length ranges from 182 to 217 cm (72 to 85 in).

Weight

Males weigh 33 to 50 kg (73 to 110 lb), while females weigh 27 to 47 kg (60 to 104 lb), making this species the largest living member of its suborder.

Head Structure

Its head, which measures 30 cm (12 in) long, is especially elongated even compared to other anteaters. A cylindrical snout makes up most of the head, and its eyes, ears, and mouth are all relatively small.

Sensory Capabilities

Giant anteaters have poor eyesight but a powerful sense of smell that is 40 times stronger than a human's.

Sexual Dimorphism

While males are larger and more robust than females, telling the sexes apart from a distance can be difficult. The male's genitals are located inside its body, and its urogenital opening is smaller and positioned farther from the anus than the female's.

Female Anatomy

The female has two mammary glands located between her front legs.

Neck Structure

Even for an anteater, the neck is particularly thick when compared to the back of the head, with a small hump protruding behind the neck.

Base Coat Color

The giant anteater's coat is mostly grayish brown or black with mottled white markings. It has white front legs with black rings around the wrists and hands, dark hind legs, and a brown tail.

Coat Markings

A thick black mark with white outlines and sharp tips runs from the throat to the shoulders. The coat hairs are long, especially on the tail, which makes the tail look larger than it actually is.

Dorsal Mane

An erect mane runs along the animal's back.

Coat Function

This bold patterning was originally thought to act as disruptive camouflage, but a 2009 study suggests it is actually warning coloration.

Rib and Toe Structure

Giant anteaters have broad ribs and five toes on each foot. Three toes on the front feet have claws, with particularly large claws on the third digits.

Front Foot Locomotion

It walks on its front knuckles, similar to gorillas and chimpanzees, which keeps it from scraping its claws against the ground. The middle digits, which support most of the animal's weight, have long metacarpophalangeal joints and bent interphalangeal joints.

Hind Foot Structure

Unlike the front feet, all five toes of the hind feet have short claws, and giant anteaters walk plantigrade on their hind feet.

Digging Adaptations

As a "hook-and-pull" digger, the giant anteater has a large supraspinous fossa that gives the teres major more leverage, increasing the pulling power of the front limbs, while the triceps muscle helps control the thickened middle digit.

Body Temperature

As a mammal, the giant anteater has an unusually low body temperature of around 33 °C (91 °F), which is a few degrees lower than the typical mammalian temperature of 36 to 38 °C (97 to 100 °F).

Metabolic Rate

Xenarthrans as a group generally have lower metabolic rates than most other mammals, a trend thought to correlate with their dietary specializations and low mobility.

Modern Range

The giant anteater is native to Central and South America, with its known modern range stretching from Honduras to Bolivia and northern Argentina.

Fossil Range

Fossil remains of the species have been found as far north as northwestern Sonora, Mexico.

Regional Extirpations

It is largely absent from the Andes, and has been completely wiped out in Uruguay, Belize, El Salvador, and Guatemala, as well as in parts of Costa Rica, Brazil, Argentina, and Paraguay.

Habitat Tolerance

The species can live in both tropical rainforests and arid shrublands, as long as enough prey is available to support it.

IUCN Conservation Status

The International Union for Conservation of Nature lists this species as vulnerable, due to the number of regional extirpations of the species.

CITES Listing

It is listed under Appendix II by CITES, which tightly restricts international trade in giant anteater specimens.

Global Population Decline

By 2014, the total global population had declined by more than 30 percent over the last three generations.

Wildfire Mortality

In 1994, around 340 giant anteaters died from wildfires at Emas National Park in Brazil. The animal is particularly vulnerable to fires because its coat can easily catch fire, and it is too slow to escape.

Anthropogenic Threats

Human-caused threats to the giant anteater include vehicle collisions, dog attacks, and habitat destruction. One study of anteater mortality along roads found that anteaters are likely to be struck on linear roads near native plants.

Road Impact Study (2018)

A 2018 study in Brazil found five key results: (1) roads are more harmful to anteaters from habitat fragmentation rather than vehicle accidents, (2) 18–20% of satisfactory anteater habitat did not meet minimum patch size requirements, (3) 0.1–1% of the species' range had dangerously high road density, (4) 32–36% of the anteater's distribution makes up critical areas for its survival, and (5) more conservation opportunities exist in the northern part of Brazil.

Road Mortality Population Impact

A 2020 study in the Brazilian Cerrado found that road mortality can reduce local population growth by 50 percent.

Hunting in Bolivia

Giant anteaters are commonly hunted in Bolivia, both for trophies and as food. In the Chaco region, the animal's thick, leathery hide is used to make horse-riding equipment.

Hunting for Body Parts

In Venezuela, giant anteaters are killed for their claws. They are also killed because they are perceived as dangerous, particularly during threat displays.

Conservation Strengths

The species' biggest ecological strengths are its wide range and adaptability. The Amazon, Pantanal, and Cerrado contain multiple protected areas where giant anteaters can find refuge.

Regional Protection

In Argentina, some local governments list it as a national heritage species, granting it official protection.

Research Gaps

Despite its well-known status, the giant anteater has not been well studied in the wild, and research has been limited to certain areas.

Habitat Use

The species may use multiple different habitats; a 2007 study of giant anteaters in the Brazilian Pantanal found that the animals move and forage in open areas and rest in forests, which provide shade when temperatures rise and retain heat when temperatures drop.

Daily Movement Distance

On average, anteaters travel around 3,700 m (12,100 ft) per day.

Activity Patterns

Giant anteaters can be either diurnal or nocturnal. A 2006 study in the Pantanal found that they are mostly nocturnal in warm weather, but become more active during daylight hours as temperatures drop.

Diurnality Observations

Diurnal giant anteaters have been observed at Serra da Canastra. Nocturnality in anteaters may be a response to human disturbances.

Sleeping Site Preferences

Giant anteaters prefer dense brush for sleeping, but they may use tall grass when temperatures are cooler. When resting, they carve a shallow cavity into the ground.

Sleeping Posture

They sleep curled up with their bushy tail draped over their body, both to stay warm and to camouflage themselves from predators. One anteater was recorded sleeping flat on its side with the tail unfolded on a 17 °C (63 °F) morning, which may have allowed its body to absorb sunlight for warmth.

Swimming Behavior

Giant anteaters sometimes enter water to bathe, and will even swim across wide rivers.

Climbing Behavior

They are also capable of climbing, and have been recorded climbing both termite mounds and trees while foraging. One individual was observed trying to climb a tree by rearing up and grabbing onto a branch above it.

Mating Season

Giant anteaters mate year-round. A male follows an estrous female, who then partially raises her tail.

Courtship Behavior

Courting pairs have been recorded sharing the same insect nest while feeding. For mating, the female lies sideways and the male hunches over her.

Mating Pair Duration

A mating pair may stay together for up to three days and mate multiple times during that period.

Gestation and Birth

Giant anteaters have a 170–190 day gestation period, which ends with the birth of a single pup while the female stands upright. There is some evidence that this species can experience delayed implantation.

Newborn Characteristics

Pups are born weighing 1–2 kg (2.2–4.4 lb), and their eyes remain closed for the first six days after birth.

Pup Carrying Behavior

The mother carries her dependent young on her back. The pup can camouflage against its mother by aligning its own black and white band with the mother's.

Early Maternal Care

The mother grooms and nurses her young, which communicate with her using sharp whistles. After three months, grooming becomes less frequent, and the young begin to eat more solid food.

Juvenile Dispersal

Both grooming and nursing stop at 10 months of age, which is when the young leave their mother.

Sexual Maturity

Giant anteaters reach sexual maturity at 2.5–4 years of age.