Giant armadillo, new research

This video is called Mammals of the World: Giant Armadillo.

On babies and motherhood: how giant armadillos are surprising scientists (photos)

Jeremy Hance

Uncovering the reproductive mysteries of the little-known giant armadillo.

Arguably the most important moment in any animal’s life— whether it be a whale, a human, or a mosquito— is the act of giving birth, of bringing a new member of the species into the world. It’s no wonder that biologists treat reproduction— from conception to birth to child-rearing— as vital not only for understanding an animal’s natural history, but also its conservation. While some species have had their reproduction studied ad nauseum (think pandas) we still know very little about how most species reproduce, including some large, charismatic mammals. Until ten years ago scientist’s knowledge of the reproductive habits of the giant armadillo— the world’s biggest— were basically regulated to speculation. But a long-term research project in the Brazilian Pantanal is changing that: last year researchers announced the first ever photos of a baby giant armadillo and have since recorded a second birth from another female.

The giant armadillo is the only member of the genus Priodontes and the largest member of the Xenarthra order (including anteaters and sloths) which goes back at least 65 million years. Despite its hefty bulk— weighing in at 50 kilograms (110 pounds)— the giant armadillo is notoriously difficult to observe. Its rarity, nocturnal habits, and burrowing lifestyle mean people who live in the area are often wholly ignorant they share the wilderness with these great, shelled beasts.

“After working in the field for eight years I still had never seen a giant armadillo,” said Arnaud Desbiez, the head of the Giant Armadillo Project in an interview with mongabay.com. “Then one day my wife returned from an expedition in the field having seen one in her study area. I could not believe it! A few months later the owner of the ranch found a fresh carcass recently killed by a puma. I decided I wanted to try to learn more about this elusive species.”

Desbiez, a French native who has lived in the Pantanal for 14 years, started the Giant Armadillo Project in 2010. Since then his dedicated team have employed camera traps and radio tracking to unlock the hidden lives of giant armadillos.

What they found was amazing: for one thing giant armadillos are far more maternal than expected. Scientists had thought that giant armadillo babies only spent six weeks with their mother, but the project’s research discovered that in fact juveniles spend at least ten times that amount learning from their mother.

“We have not been able to determine exactly when it becomes fully independent. Although it starts exploring and foraging on its own after six months, it continues sharing a burrow with or near its mother for several more months,” explained Desbiez, who is also the Regional Coordinator for Latin America for the Royal Zoological Society of Scotland (RZSS).

The project has also discovered that gestation lasts five months instead of four and that giant armadillos give birth to only one young at a time, instead of usually two as long believed. This information has huge impacts on the conservation of the massive, relict species.

“Each birth requires an incredibly high investment from the mother and we suspect they have a young only once every two years. Population growth rates are therefore very low. This explains why the population density of giant armadillos is so low, and why this species can so easily go locally extinct,” Desbiez said, who added that the project is now trying to determine how many young a female giant armadillo could have in a lifetime.

The giant armadillo is currently categorized as Vulnerable by the IUCN Red List and is imperiled by habitat loss and hunting.

“It feels like we have barely scratched the surface and we still have many more questions than answers,” noted Desbiez. “The question that intrigues me most is we still do not understand how these solitary creatures meet and interact. They have huge home ranges and overlap seems minimal. We believe communication is olfactory through scents left in the burrows and sand mounds.”

Desbiez said giant armadillos are not alone in the fact that researchers know very little about its most basic behaviors.

“The truth is only a few species have been the focus of long term studies and many endangered and even iconic species lack real studies,” he said. “The giant armadillo is only one among many species in South America about which we knew very little. I would blame this on an overall lack of funding for species research and conservation. There are so many species that need urgent attention and too few people able to dedicate their lives to them due to the scarcity of funds.”

Desbiez has received the bulk of his funding from zoological institutions, including the Royal Zoological Society of Scotland, which runs two zoos.