Pantanal: Giant Armadillo Isabel reveals secrets of the species – 02/16/2024 – Science

Even for those who live in regions considered their natural habitat, such as the Pantanal, seeing a giant armadillo is considered a rare feat.

The animal, which only exists in Latin American countries, is solitary, only comes out at night to feed on ants and can spend up to three quarters of its life in underground burrows.

For those who are lucky enough to find it, the sight is impressive: it is the largest of the armadillo species, weighing up to 60 kg, being 1.5 meters long and with claws that can reach 20 centimeters on the third finger — the longest of the animal kingdom.

Until a few years ago, information about the species was scarce. Data on behavior and reproduction, something considered basic among biologists, made the giant armadillo a mystery.

It was with the motivation to explore this animal practically unknown to science that, in 2010, researcher Arnaud Desbiez, now part of ICAS (Institute for the Conservation of Wild Animals), began working with camera traps in the Pantanal.

“Isabel, as we later named her, was the first animal of the species that we were able to monitor. In the beginning, I spent sleepless nights trying to follow her on foot, and in the morning I looked for the hole in her burrow”, says Desbiez.

It was from the discoveries made with Isabel, the female giant armadillo who is now approximately 20 years old, that the world was able to learn valuable information about the species.

“As scientists, we shouldn’t have favorite animals, but I confess that Isabel is my favorite armadillo. She was our teacher about the species. She taught us about the giant armadillo’s movement, habitat selection, reproduction characteristics… With her, we have many ‘first discoveries’.”

The discoveries made with Isabel

“Isabel was the first step, but then the data was confirmed, analyzed with more than 40 animals in other biomes, such as cerrado and Atlantic forest”, explains Desbiez, describing that the discoveries below —about the ecology and biology of an entire species— they could not be based on a single animal.

reproduction

In 2017, the BBC documentary “Hotel Armadillo: Natural World” revealed to the world the precious discoveries of the first seven years of study.

Among them, the film shows the first images of a baby giant armadillo ever recorded: Isabel and her offspring at night, captured by a camera trap.

“We caught Isabel sharing a den with a male and five months later we had the first cub recorded, it was super exciting”, recalls Desbiez.

Before, explains the researcher, science did not know the duration of gestation or that the female gives birth to one baby at a time.

Over the years, Desbiez and his team, now made up of 20 people, continued to find pieces to put together the species’ reproduction puzzle.

“Our studies show that the giant armadillo reaches sexual maturity between seven and nine years old, and, when we met her, Isabel had already reproduced, something we confirmed by testing a genetic sample and discovering an animal that was born from her. With this, we were able to estimate her age when we started the project.”

In 2023, new images of Isabel with a baby, her fourth descendant, surprised the team, as they showed that an armadillo over 20 years old can continue reproducing.

“The maximum age of reproduction, until an animal reproduces in the wild, is a crucial piece of data for many population models. It is important for the calculation for generation time and also for categorizing the animal on the red list. Again, it is Isabel is the one who brings this data to us.”

Parental care

The way giant armadillo mothers treat their babies was another important discovery for the team.

“It’s such a strong and robust animal, and when we see how delicately she treats the baby, we can’t help but get emotional,” says Desbiez.

By observing different animals of the species, it was found that every 15 days the mother takes the baby to a different hole.

“She guides the little one, who has been blind for up to 50 days (another thing we discovered with Isabel), to another hole, which will be about 200 meters further away”, narrates the researcher.

When the females come out, they close their holes by throwing dirt and plant material with their sharp claws, something they don’t do when they are alone.

“With the camera traps that accompanied Isabel, we were able to understand everything in this step by step, how long she stays out to feed, when she returns to breastfeed, and the ‘affectionate’ moments between mother and cub.”

Breastfeeding is exclusive until 6 and 8 months of age and weaning takes place when the baby turns one year old. Even after that, the calf remains dependent on its mother until it is 18 months old, and until it is two years old it is still found within its mother’s territory.

Genetic tests also showed that her babies were from different males, indicating that females of the species have more than one partner — something that was confirmed with other giant armadillos observed.

“The males can come a long way, they have an exploratory behavior, they visit the females’ holes when they are in heat. But in Isabel’s territory there were already two males, which made reproduction easier.”

It was also with Isabel that the group documented something that had never been seen in other animals during 13 years of research.

“When Isabel’s cub was four weeks old, a male who lived more than 15 km away came, kicked her out of the den and killed her cub. Eight months later, we discovered that she was pregnant with that same male. This indicates that the male committed the murder to make the female return to heat more quickly, as they normally reproduce once every three years”, says Desbiez.

Natural habitat and burrows

In the Pantanal, researchers were able to discover that the preferred areas of giant armadillos are what are called Murundu, small elevated fields, usually with a termite mound in the middle and the surrounding Cerrado vegetation.

There, Isabel and other giant armadillos make their den under the termite mound to protect themselves and any offspring from predators such as ocelots and pumas.

The first images taken of the hole, which were of course from Isabel’s house, show that, when she was not at home, the hole was used by dozens of other species.

Among some of the visitors were small rodents, which took advantage of the burrow to look for food and escape the heat, lesser anteaters, which took shelter to protect themselves from predators and rest, and peccaries, which used the earth in the armadillo’s burrow to cool off. .

In the Pantanal, the population density estimated by ICAS in 2021 was 7 and 8 individuals for every 100 km².

The home range covers around 25 km² — an almost exclusive territory for each individual. Each animal is capable of traveling, on average, 1.6 km during a single night. Males tend to move more when they are looking for females in heat.

Threats to the species

Data from ICMBio (Chico Mendes Institute for Biodiversity Conservation) showed that the giant armadillo population has decreased by 30% in the last 24 years as a result of hunting, deforestation, being run over on highways and fire.

“Regarding the latter, which is quite common in the Pantanal, we recognize the importance of fire as an essential tool in traditional pasture management, but out-of-control fires represent a significant danger.”

In partnership with the Ecological Research Institute (IP) at Fazenda Baia das Pedras, where the project is based, Desbiez’s group established a community brigade in 2021.

“Every year, we carry out three training sessions, provide equipment to neighboring farms and promote regular training.”

Furthermore, the researcher considers it crucial to promote awareness and environmental education to protect this species.

“Familiarity with the giant armadillo is surprisingly low, even among those who live in areas of natural occurrence. Through the project, communities are involved, and when we capture a giant armadillo, we invite people to observe and appreciate the animal .”

The idea of ​​the initiative, he adds, is to encourage respect for the species, for its uniqueness and importance for the ecosystem.

“Understanding and celebrating the giant armadillo are fundamental steps towards the preservation of this species, which is still little known and understood.”