Chacoan Peccary

MammalSouth America

3 Jun

Written By Alexander Julius Jensen

Catagonus wagneri

The Chacoan peccary was initially described as an extinct species from fossils discovered in 1930. In the early 1970s, a living population was found in an isolated area of Paraguay — in a region known as the Gran Chaco. This species is the largest and rarest of the three living peccaries.

Prehistoric Peccaries

Paleoart recreation of the holotype peccary specimens found at Hagerman Fossil Beds in 1934: an adult and two juveniles.
Art by Reid Psaltis¹

In the year 1930, a palaeontologist in northern Argentina described the fossil remains of a new peccary species, dating them back to the Pleistocene epoch (2.6 million to 11,700 years ago). This wasn't a particularly groundbreaking find; the peccaries — bristly-furred, pig-like ungulates that split from true pigs some 40 million years ago — have had a long history in the New World.

Long ago, peccary ancestors expanded from Eurasia to North America. An extinct proto-peccary known as Perchoerus minor, an adorably cat-sized species, was already trotting around North America 37 million years ago. The long-nosed peccary lived across North and Central America during the Late Miocene (11.6 to 5.3 mya), while the flat-headed peccary crossed over into South America some 3 million years ago during the Great American Interchange, when a land bridge formed across the Isthmus of Panama, connecting the two continents. Both species went extinct around 11,700 years ago, not long after the first humans arrived.

This new fossil — described as Catagonus wagneri — was, in all likelihood, just another prehistoric peccary that perished with its long-nosed and flat-headed relatives, as well as most of the New World megafauna, at the dawning of the Holocene. The bones were stashed away alongside the other extinct peccaries, and no more attention was paid to Catagonus wagneri.¹

The Third Peccary

For over a century, science knew of two living peccary species: the collared peccary and the white-lipped peccary, which range widely across North, Central, and South America.² Then, in the early 1970s, some forty years after C. wagneri was described as an extinct species, this fossil peccary was spotted roaming an isolated area of Paraguay, in part of a region known as the Gran Chaco — C. wagneri was resurrected as the Chacoan peccary.

This new extant species turned out to be the largest of the three, standing up to 69 centimetres (2.2 ft) at the shoulder and weighing as much as 40 kilograms (90 lb). Its body is covered in a brown-grey coat of bristly hairs, some of the guard hairs growing to be 22 cm (8.8 in) long, with a light collar across its shoulders and under its chin forming a whitish "beard" — a collar not quite as pronounced as that of the collared peccary. Its head is massive, featuring long, donkey-like ears and an extended snout ending in a wide, porcine nose. Its hefty mass is balanced atop little hooves — each made up of two digits, with three hind toes instead of the typical two — and short-looking legs that belie its ability to sprint at great speed. Overall, the peccary appears like the primitive version of a wild boar; a creature out of the Pleistocene.

The Pig from Green Hell

The Chacoan peccary is named for the Gran Chaco, a region nearly the size of Egypt, spanning parts of Argentina, Paraguay, Bolivia, and Brazil. The high Andes mountains stand to the west, casting a rain shadow over the Chaco. It is an arid reflection of the lush Amazon to its north; in place of dense, vine-choked palms decorated with multi-coloured bromeliads, the Chaco forests are clusters of hardwood quebrachales, or breakaxe trees, standing over semi-arid savannah.

The Chacoan peccary was discovered long before it was officially described in 1972; locals spoke of three peccary species and called this one the taguá. Its nickname, the "pig from green hell", hints at why it's been so elusive to the rest of the world for so long. Its large nose features well-developed sinuses for breathing the dry, dusty air of its arid home, and its tiny hooves help it tiptoe through thorny shrubs and stunted succulents that make up the vegetation. The Chacoan peccary lives in the least hospitable parts of an unwelcoming land: the Dry Chaco.

Its diet is that of a desperate soul lost in the desert. The peccary takes its pick from a menu of succulents — cacti with oblong limbs sprouting crooked red flowers, or flat-paddle cacti covered in toothpick-length spines. It plucks these delicacies and marinates them in a dirt bath, rolling them around with its tough snout to remove their prickly parts or pulling the spines out with its teeth before munching on the green flesh. The tough meal travels down into its two-chambered stomach while its specialised kidneys break down the excess acids. To the peccary, the cactus is both food and drink. Finished with its feast, it reaches for the seasoning; the peccary treks to its favourite salt lick — a mineral-rich rock formed from a leaf-cutter ant mound — where it slurps up a healthy dose of sodium, calcium, magnesium, and chlorine.

It’s not the meal that matters most, but the quality of the company, and rarely does a peccary dine alone. Chacoan peccaries live in families of as many as ten individuals, travelling in the late morning and retiring for a midday siesta in the shade — the Dry Chaco sees some of the hottest temperatures across the entire continent. After napping off the heat, the family all rise, only to plonk down again for a dust bath; prickly masses of fur rolling around on the ground as if they themselves were cacti that needed de-spining. Then they're off marching again. Always on the move — travelling their home range in a cycle that repeats every 42 days or so — the peccaries use glands on their backs to make scent markers, keeping the family connected via odour in dense foliage, and applying musky group markers by spraying one another with scent.

Behind the parent peccaries, trail their young, heavily furred like the adults but looking more like rabbits than pigs with their small statures and long ears — I daresay they're cuter even than piglets. A few hours after birth, a peccary is already trotting about on its little legs, but the little ones mustn't stray too far from the group, for a newborn peccary, no matter how fast it trots, can't outrun a mountain lion or jaguar. Safety, then, is found in numbers. Together, the adult peccaries line up to form a defensive wall like some kind of feral Roman legion, raising their spiny fur like porcupines flashing their quills, grunting and chattering their teeth. This belligerent barrier might be enough to discourage a lone hunting cat, but the Chacoan peccaries must increasingly contend with a much bolder, craftier predator.

Hunting Land

The name Chaco comes from the Quechua word chaku, meaning "hunting land". While the peccary's home is a near-wasteland, the Gran Chaco also contains the second-largest forest in all of South America, and while it may not be so lush or biodiverse as the Amazon, there is still plenty of life here.

In the western parts — in the so-called Humid Chaco — there are marshlands home to marsh deer, broad-snouted caimans, peaceable capybaras, and jabiru storks with black-and-red inflatable necks. Across the adjacent grasslands flit strange-tailed tyrants with overlong tail feathers, overhead soar crowned solitary eagles like pale grey phantoms, spotted ocelots prowl through the grass, and maned wolves stand above it on stilt-like legs.

A broad-snouted caiman (*Caiman latirostris*).

A strange-tailed tyrant (*Alectrurus risora*).

To the east, even the Dry Chaco has its diverse fauna. Guanacos, the wild ancestors of domestic llamas, browse on dry grasses and flowers; black-and-white tegus, burly monochrome lizards that are a lot more intelligent than they look, bathe in the early morning sun; king vultures rule the skies, their faces decorated with ornate and grotesque embellishments; rabbit-like maras, much skinnier relatives of the capybara, peek out from their deep burrows; while some of those same burrows hide deadly squatters, boa constrictors over 3 metres (10 ft) long.

An Argentine black-and-white tegu (*Salvator merianae*).

A Chacoan mara (*Dolichotis salinicola*).

The driest part of the Dry Chaco, the Chacoan peccary's home, has long been pretty isolated, and it's really no wonder why; all heat, dust, and cacti. But humans are among the most opportunistic animals on the planet. We scrounge a living anywhere a living is to be made. Chacoan peccaries are large and — apparently — quite tasty. It's no surprise that, in a place where cacti are a staple food, the peccaries became a desirable source of protein for local communities.

Historically, the locals hunted peccaries opportunistically. Over the years, those opportunities would come less frequently, as the Chacoan peccaries dwindled to the point where even low-level hunting became a concern. The peccary's defensive barricade is ineffective against a human with a gun. When one peccary is killed, the family scatters in fear, but they soon return to their fallen companion- — only to be shot down themselves. In a display of compassion and grief, the whole herd falls.

It wasn't hunting, however, that drove the Chacoan peccary to such a low point. As the years went by, the Dry Chaco became less isolated. Roads now cut through the ancient pathways travelled by peccaries, and their bones lay scattered along the roadsides of the Paraguayan Chaco. More people arrived, bringing axes and cattle, turning natural forest into pasture and soy plantations. Economic crises led to chunks of the Chaco being sold for cheap — as little as $2 a hectare in Argentina — drawing more and more ranchers to the region. In the last 39 years, the Chaco experienced a 15.1% loss in natural vegetation, and, as a result, the peccaries were forced to subsist on less and less space in an already resource-poor environment. The Chacoan is by far the rarest of the three living peccaries: there are currently estimated to be 3,000 surviving in the wild, and the species is considered 'endangered'.

Fossils Again

In 1985, serious concern for the dwindling peccaries spawned the Tagua Project — a captive breeding program run by the CCCI (in English, the Chacoan Centre for Conservation and Research). Today, zoos from San Diego to Calgary to Berlin hold Chacoan peccaries, teaching visitors about these little-known not-pigs and safeguarding them as reserve populations if something should happen to those in the wild. In South America, the CCCI has been working for over thirty years, with the goal of its Tagua Project to raise Chacoan peccaries in good health and create new families to be released into the wild.

But, is it safe for these peccaries to return?

With the exception of indigenous people, hunting the Chacoan peccary has been made forbidden in Argentina and Paraguay, while in Bolivia, hunting is allowed with particular permits and never within protected areas. That's well and good, but if the Chacoan peccary is to live, it needs a Chaco to live in. Unfortunately, halting the progress of human expansion is more challenging than raising peccaries in captivity or outlawing hunting. As of 2017, only 12% of this species' “highly suitable” habitat was protected, and only 9% of the Gran Chaco's total area is protected as of 2023.

Without the Chaco, there is no Chacoan peccary. And without the Chacoan peccary to till up the soil with its hooves and snout, making space for plant communities to flourish, there is no Chaco — at least, not the kind of diverse ecosystem it should be. All of the species, all the communities, that make up the Chaco are linked in a web of interactions. Causes and effects ripple across the various ecosystems, affecting every member from the caimans in the marshes, to the maned wolves in the grasslands, the vultures in the skies, and the communities of people that live in and rely on the Chaco.

A Chaco without its peccaries would be less like a puzzle with a missing piece, but a tower with a missing brick — it may not topple yet, but the surrounding bricks jiggle and slide; unsupported, they too might fall out. Brick by brick, the tower weakens, until a slight gust of wind could bring the whole thing down. Remove enough species from an ecosystem, remove the roles they play — hunting, being hunted, altering the landscape — those links which bind the parts together, and the whole thing may fail in a cascade that leaves no one, no matter how big or small or smart they may be, unaffected.

In the least hospitable parts of the Chaco, the Chacoan peccary has been walking its own evolutionary path for over 8 million years. It is one of three species representing a once much larger family. It's the sole surviving member of its genus, Catagonus — the type specimen, Catagonus metropolitanus, and the narrow-headed peccary, Catagonus stenocephalus, are long extinct, just like the Chacoan peccary was initially believed to be. If the Chaco were to vanish, the Chacoan peccary really might become no more than some fossils in a museum storeroom, some scattered bones in the ground.

¹ Only 4 years later, in 1934, the fossils of another new peccary species, given the name Platygonus pearcei, were discovered. Catagonus wagneri didn't seem very special at all.

² The collared peccary is split by some into three separate species: the North American collared peccary (Pecari angulatus), Central American collared peccary (Pecari crassus), and South American collared peccary (Pecari tajacu). The start of the 21st century saw the potential discovery of a fourth peccary species: the giant peccary (Pecari maximus). Lack of evidence called its existence into doubt and, eventually, its behavioural and physiological similarity to the collared peccary led scientists to conclude that it was of the same species.

**Where Does It Live?**

⛰️ Hot, semi-arid thorn forests and plains.
📍 The Dry Chaco; Paraguay, Bolivia, and northern Argentina.

Size // Medium
Length // 90 - 112 cm (35 - 44 in)
Weight // 30 - 40 kg (66 - 88 lb)
Activity: Diurnal ☀️
Lifestyle: Social 👥
Lifespan: ~9 years in the wild, up to 18 years in captivity
Diet: Omnivore
Favourite Food: Cacti 🌵
Class: Mammalia
Order: Artiodactyla
Family: Tayassuidae
Genus: Catagonus
Species: C. wagneri

This peccary was assumed dead upon discovery — the species was described from fossils found in northern Argentina in 1930, fossils dating to the Pleistocene epoch (2.6 million to 11,700 years ago).
For over a century, science recognized two living species of peccaries: the collared peccary and the white-lipped peccary. Then, in the early 1970s, a "fossil" peccary was seen roaming an isolated area of Paraguay, in a region known as the Gran Chaco.
The Chacoan peccary is the largest of the living peccaries, standing up to 69 centimetres (2.2 ft) at the shoulder and weighing as much as 40 kilograms (90 lb).
It lives in the Dry Chaco and has well-developed sinuses for breathing the dusty air of its arid home, along with tiny hooves that allow it to tiptoe through thorny shrubs.
Much of the Chacoan peccary's diet is made up of succulents. It plucks their spiny morsels, rolling them around with its snout to remove their prickly parts or pulling the spines out with its teeth before munching on the juicy, green flesh.
It digests its meal in a two-chambered stomach, while its specialised kidneys break down the excess acids. Afterwards it treks to a salt lick — a mineral-rich rock formed from a leaf-cutter ant mound.
Chacoan peccaries live in families of up to ten individuals, who travel, take midday naps, and dust-bathe together. They also face danger together; forming a living wall, raising their spiny fur, grunting and chattering their teeth when confronted with a threat.
This species, returned to us from the Pleistocene, is now threatened with habitat destruction, as natural forests are cleared for pasture and soy plantations (much of that soy going to feed livestock in Europe). There are currently estimated to be 3,000 Chacoan peccaries left in the wild, and the species is considered 'endangered'.