- A sighting of one of the rarest mammals in the world, the elusive Chacoan fairy armadillo, was recently documented by a team of Bolivian biologists.
- Seldom seen, the animal–which lives among the Gran Chaco dry forests of Argentina, Bolivia and Paraguay–has a population that is considered ‘data deficient’ by the IUCN, and is likely quite small.
- The species uses its huge claws and strong front legs to ‘swim’ into the Chaco’s sandy soils: its armor and tail are similarly adapted to facilitate their subterranean lifestyle.
- “This was a dream come true to see this animal,” one expert told Mongabay, since such sightings top the wishlists of mammal enthusiasts around the world.
The four-wheel-drive bumped over a rutted road. Rain that began as soon as they left the pavement was so thick that the road, compacted by traffic, became slippery, and the tires dug-in. It was 8 a.m.
At the wheel was Nick Mcphee, Australian conservationist-turned Bolivian ecotourism uber-specialist, and with him were Bolivian biologist Huáscar Bustillos Cayoja, environmental impact social biologist Paula Silva, and professional photographer Ivan Gutierrez.
They thought they might get stuck in the mud, but there was no thought of turning back. It would take another hour and a half to get to their destination. Giving up was not an option.
They were after a holy grail of conservationists — a live sighting and registration of one of the rarest of the rare armadillos in the world, the elusive Chacoan fairy armadillo (Calyptophractus retusus), also known as the greater fairy armadillo, the mythical culotapado of local lore, or tatujeikurajoyava to the Guaranis of the Bolivian Chaco. Alternatively called tatu or coseberu by those in the cities, or “the cryer” by its 18th-century discoverers, it is also known to science as Burmeister’s armadillo. There was a lot of excitement.
The night before at around 6 pm, in the region of La Florida in the westernmost part of Santa Cruz Department in eastern Bolivia, farmer Milton López Viruez was driving his truck slowly on the sandy road of his farm when his headlights shone on something pink in front of his truck.
Stopping to investigate, he leaned over to take a look. He had never seen such a thing. It was a weird and extraordinarily odd little animal, whose appearance did not fit any known category or explanation, a truly unusual creature.
It did not run fast, but it did begin to burrow. López emptied a bag of corn and used it to pick the strange little critter up. It was a rare living thing, alright, but just how rare he had no idea.
Back at the ranch, he and his wife Ana Laura Moreno set out to find out what they had in their hands. Among myriad options online, she found an article about a peculiar little animal found drowned after torrential rains near the town of Warnes north of Santa Cruz de la Sierra, Bolivia’s largest city and economic engine. It seemed like what they had was just like it, making it one of the rarest animals in the world.
López contacted the biologist who had investigated and recorded the find. Soon he was on the phone with Bustillos.
In a matter of one hour, Bustillos called Mcphee to put together a team to go see the animal and register it officially. “I want to go,” Mcphee responded immediately. Hearts were pounding with anticipation.
Early the next morning, the team was headed east, up Bolivia’s Highway 7, Doble Via La Guardia, toward the mining town of Camiri in the transition area between Amazonia and the Chaco dry forest. One hour along the paved road, their route took them onto a dirt road in the direction of the site of one of the great battles of the liberation of South America, and the setting of an important battle in the independence of Argentina — La Florida, where the López’s ranch is located, at Cabezas, near the entrance to the Parabanó Protected Area.
After an hour-and-a-half on the dirt road, they were meeting López and being led toward a bucket of sand that contained what Bustillos was able to confirm was a unique find — the form of its shield-like tail, the small, near-cylindrical body, a notably short neck, the small ears and beady eyes, the light pink color.
“There was no doubt, we had a culotapado,” said Bustillos, using the local name for the Chaco fairy armadillo, grateful to observe one of the rarest species in the world, alive. He explained how its back end appears to be sealed with a shield that keeps soil from sliding back as it digs down, and permits it to move and “swim” down at a 45-degree angle. The name is a blending of the Spanish words for the anatomical bottom, and for “closed.”
Delighted to observe it in real life, how it behaves, how it digs and burrows, and how it lives underground, (perhaps the reason why it is seldom seen), Bustillos said those were important observations of this unique animal, just fractions of an inch to an inch longer than its smaller cousin, the pink fairy armadillo of Argentina.
It acts like a mole in its adaptations to subterranean life, said Bustillos, but instead of caving in search of food or escape, it submerges itself — swimming in the sand — and there it lives unnoticed.
It is a species of armadillo in the family Chlamyphoridae. “It has a unique tail which he can use as a tripod,” Bustillos told Mongabay. No other armadillo has that use of its tail, he said. “The tail is long and it drags behind. Ears, eyes small. And its claws: huge, strong and very well-developed, its front legs extremely large, muscular and strong,” said Bustillos.
The animal is a digger. “In biology, there are two types of adaptations,” explained Bustillos. “Gophers which dig with the mouth, and the technique of the insectivorous and others in Africa that develop muscles in the claws.”
Neither rodents nor marsupials, armadillos belong to the order Cingulata, with only two surviving families: Chlamyphoridae containing the fairy armadillos, and Dasypodidae which encompasses the more common banded armadillos. They are xenarthran, placental animals unique to the Americas, having a common ancestor with anteaters, and sloths in an evolutionary path that goes back some 59 million years to the Paleocene period.
What distinguishes the Chacoan fairy armadillo from other armadillos is that all others have a hard shell, Bustillos explained. This one has a soft shell, like skin; the scales are soft, and bare on the top. And on the flanks, it has a coating of wiry but soft white bristles that give it the appearance of something made of ill-fitting parts of different origin.
Bustillos found in its soft shell an interesting evolutionary adaptation, permitting it to wiggle its way into the soil, moving easily in the sand.
Observing the live specimen, Bustillos understood that it was adapted to sand. When it was put on more compact, rocky soil, it had difficulty digging, he said. “It looks for sandy soil instinctively in order to hide.”
He has seen this animal tied so closely to sand before. About eight years ago, along the main thoroughfare that leads out of the city of Santa Cruz de la Sierra, about four kilometers before Viru Viru International Airport on the busy Avenida Banzer, Bustillos noticed a bulge in the sand. “It was a dying culotapado,” he said. “It died shortly thereafter.”
He was able to discern that it came from a mound of sand unloaded by a dump truck delivering sand for construction, which was probably obtained six kilometers away on the banks of the Pirai river that runs near the city.
“It is one of the rarest species in the world. Seeing it, holding it, it is a very gratifying experience,” said Bustillos, noting that big networks like the BBC have invested a great deal to come to the area to see the animal.
Now, seeing this live creature and recalling his previous encounter, Bustillos says, it is its color that is striking — that pink. Unforgettable. “It is because the soil is sandy, and when it is wet, it is pink. Subterranean mammals take on the color of the soil,” he said.
“Seeing it was a magical moment. I would put seeing it in my top three best wildlife experiences ever,” said Mcphee, an expert in wildlife and biodiversity in Bolivia. “It was just a shock seeing such a strange naked pink-looking animal,” he added. “Huge claws for its size. Delicate looking. It makes a noise like a baby.”
That noise was heard, by many of the first to see the peculiar little animal, as a cry of the imaginary “duende,” the ghost-like pixie humanoid of South American myth, and so it is also called, “el lloron,” the crier.
It is a haunting cry, one that has cost the species many lives, says Bustillos. The Guarani people who live in the foothills of Cordillera de los Andes — the mountains visible from the López ranch , and who inhabit the region as it spreads into the Gran Chaco — call it tatujeikurajoyava. They consider its cry a bad omen and a harbinger of death, so they kill and burn any specimen they encounter in order to prevent death from visiting their families.
In the Chiquitano transitional forest to the east, Bustillos says its cry is noticed for its mournful tone and so is thought to be the spirit of babies that have died. It does sound like the sadness-filled wail of a toddler.
“Other armadillos I have seen make grunting noises,” said Mcphee. He’s fascinated with armadillos of all sizes, including the elusive 5-foot long giant armadillo (Priodontes maximus) at the other end of the size range. The six-inch Chacoan fairy armadillo fits in the palm of your hand, and is the second smallest of its kind.
Closely related to anteaters and sloths, but not to the similar-in-appearance pangolins, armadillos range in color from the baby pink in Bustillos’s hands to the dark brown of the ‘tatou,’ as the giant armadillo is also known.
But after direct observation of the live Chacoan fairy armadillo in Cabezas, and from his previous experience, Bustillos makes a distinction within a distinction — there is a subtle but significant difference in the hue of the pink in this armadillo versus those of the same species found in the Gran Chaco itself, he says.
The ones found in the Amazonian region are a baby pink color, like a pale salmon, he notes, while in the dry forest of the Chaco the same species is a darker, stronger, more vivid pink. “Subtle, but very different,” Bustillos says.
It was 1859 when the first population was discovered in the area of the Pari battlefield in what is today nearly the center of the city of Santa Cruz de la Sierra. It would be 1863 before it was scientifically described, and the number of registered encounters since has been scant. The area is in the Chaco ecoregion, thus the geographic reference in its name, but is itself an area of tropical lowlands.
Encounters with the lighter-hued fairy armadillos in this area are still fewer— just 12 registrations in the 161 years since 1859, making it the rarest of the rare.
Underscoring the rarity of this find and the difference in appearance, Bustillos noted that after a 10-year intensive effort by the Wildlife Conservation Society in the Kaa-Iya del Gran Chaco National Park and Integrated Management Natural Area, Bolivia’s largest national park, the result was just 12 official registrations between 2000 and 2010.
Related audio: Arnaud Desbiez of the Giant Armadillo Conservation Project discusses the largest armadillo living in the Chaco and nearby Cerrado, here on Mongabay’s podcast:
Only three have ever been registered in Argentina, and Paraguay registered eight in the period of 1959 to 2020, he said, though two of them were in the last couple of years by biologists in the Teniente Agripino Enciso National Park, he said. All of those were the deeper pink variety of the Chaco population. Despite the enormity of the Chaco area, the area of first registration was in the Amazon basin and a decidedly urban area, noted Bustillos. All those found there are the softer pink; they are not mixed populations.
There is a greater quantity of threats there in the city, says Bustillos: due to the area being developed, habitat destruction plus the introduction of pets and other predatory species causes the Chacoan fairy armadillo to adapt differently in Santa Cruz than those which reside in the Chaco forest itself, he said.
The Chaco population is in a protected area, which gives it certain legal protection, not just to the species but also its habitat. Bustillos says that those differences put the populations on different adaptive and evolutionary paths, which is already evident in the color differences — and is looking on a hypothetical basis at differentiating them taxonomically as Calyptophractus retusus-cruceniences and Calyptophractus retusus-chacoenses, considering the possibility of a developing subspecies — depending on results of further study.
For the population where the species was originally found, the biologist is now compiling a list of its adaptations, evolution, and differentiation with the aim of increasing the recognition of where this species lives. He is compelled by his new, first-hand observations to create a body of environmental education to promote a declaration of the animal as a natural heritage of the city that now stands where it was first found.
The aim is official awareness of the destruction of the habitat of these animals, of the impact of the loss of the ecological belt of protection that the Pirai River represents to the area, and how normal human activities like the introduction of dogs, cats, roosters, and chickens can cause predation, adding to the effects of climate change and floods that cause mortalities in this species.
Rising as a voice and a force for the study and consciousness of this indigenous creature, Bustillos hopes that the new discoveries about the animal made possible by this important find will help create conservation areas for the species within the urban areas. He says he is going to do everything in his power to make it so the creature does not vanish from its native land.
“After seeing this species in real life, it makes you work harder to want to protect animals that are not cute, iconic or well-known,” said Mcphee, who dedicates his life to spotting, protecting, and teaching about wildlife in its natural habitat.
“I want to learn more about this species, tell the world that it exists and that it deserves protection,” he said, inspired by the experience and already planning to visit other communities where this animal is known to live, to teach locals a few things about this species, and perhaps limit risks, like roaming domestic animals.
The animal is known worldwide by mammal watchers — themselves known for their specialized kind of ecotourism — as a kind of ‘Holy Grail’ since it’s often on the top ten list of least-observed mammals on the planet. Mcphee added that it is “on everyone’s bucket list to observe,” since seeing one is virtually impossible.
“This was a dream come true to see this animal,” said Mcphee. “From thousands of visits to wilderness areas in Bolivia, it was my first encounter of this species and likely my last. It was an amazing day, and one I won’t personally forget.”
Milan Sime Martinic is a writer, researcher, analyst, and author of the novel “Ironway: Watching over Benjamin Hill.” He is currently working on a book on the 2020 pandemic and can be reached via Twitter @MilanSimeMrtnc.
Huascar Bustillos Cayoja is a field researcher with the new Vertebrate Ecology Laboratory at the University of Bern in Switzerland, and a professor of Ecology and Protected Areas at Udabol University in Bolivia.
Nick Mcphee is a conservationist and operator of Nick’s Adventures, an eco-tourism outfit specializing in Andean, Amazonian and Chacoan wildlife in Bolivia.
Photographer Ivan Gutierrez Lemaitre can be found on Instagram, here.