The Pantanal Giant Armadillo Project has been running since July 2010, establishing a long-term ecological study of giant armadillos and other species of Xenarthra at the Baía das Pedras Ranch in the Nhecolandia sub-region of the Brazilian Pantanal. One of the project’s main goals is to research the ecology and biology of giant armadillos in the region, and understand the contribution this species makes to its ecosystem.
The giant armadillo is the largest species in a group of animals known as the Xenarthra, which also includes sloths and anteaters, and can reach up to 1.5 metres in length and weigh up to 50 kilograms. This nocturnal species is highly adapted to life underground, with large scimitar-shaped claws on its forefeet that help it to dig deep burrows.
Found east of the Andes, from Colombia and Venezuela southwards to Paraguay and northern Argentina, the giant armadillo occurs in a wide variety of habitats, including tropical forests and open savannahs. However, it is rare across its entire range, and very little is known about this rather secretive species. The giant armadillo has declined as a result of habitat loss and hunting, and is now classified as Vulnerable on the IUCN Red List of Threatened Species and as Critically Endangered on many State lists in Brazil.
In the Pantanal, most local people have never seen a giant armadillo, and there are fears this species could go extinct before its natural history is properly understood. The Pantanal Giant Armadillo Project set out to use a variety of methods, including camera trapping, fitting radio transmitters, conducting burrow surveys, resource mapping and interviews, to get a better insight into the life of this mysterious mammal. What the researchers discovered showed the true importance of the giant armadillo to the species with which it shares its habitat.
For over two years, giant armadillo burrows were monitored using camera traps set up near the burrow entrance. These cameras are triggered by motion, and hundreds of images of 57 different species were obtained in this way during the research period. Interestingly, it was found that giant armadillo burrows provide new habitats and influence resources for at least 24 of these species.
“It’s amazing to see that such a secretive species which occurs at such low densities can play such an important role within the ecological community,” said Arnaud Desbiez, Project Coordinator from The Royal Zoological Society of Scotland.
Giant armadillo burrows can be up to five metres deep, and the camera trap images showed that 16 different species used these areas as a refuge against predators or against temperature extremes, as well as places to seek certain resources. The three other armadillo species found within the study area were all registered spending prolonged periods of time in the giant armadillo’s burrows, but the most surprising discovery came in the form of another member of the Xenarthra: the southern tamandua. The southern tamandua is known to be a tree-dwelling species, yet astonishingly it was the animal most often documented using the giant armadillo’s underground dwelling place. A whole host of other species, including ocelots, crab-eating foxes, lizards, tortoises and collared peccaries were also photographed entering the burrows.
The sand mound
The researchers found that it wasn’t just the refuge provided by the deep burrows which was of use to other species. Giant armadillo burrows have a characteristic large mound of sand in front of them, and the study showed that this area, too, was used by a surprising number of other species. White-lipped peccaries, collared peccaries and feral pigs were all seen using the sand mound to wallow in, rest and cool down, while giant anteaters were also photographed taking sand baths in the mound. Lowland tapirs and pumas were discovered using the pile of earth as a resting spot, whereas various raccoons, ocelots, lizards, small rodents and various other species were captured on film searching for their prey in the mound.
Through the creation of burrows, the giant armadillo physically alters its surroundings, and creates a host of new habitats which have now been found to influence the resources of at least a further 24 species – this is known as ecosystem engineering. As ecosystem engineers, giant armadillos are extremely important components of their environment, with their burrows and the large sand mound affecting the characteristics of the ecosystem, from geomorphology and hydrology to the vegetation and animal communities in the area, both on a small and large scale. The role of giant armadillos as ecosystem engineers has also been recorded in the Amazon by Dr Renata Leite Pitman, who documented the rare short-eared dog, as well as several other species, using giant armadillo burrows.
“Climate change is predicted to increase maximum air temperatures. Our data loggers placed inside giant armadillo burrows demonstrate that temperatures within the burrow remain constant at 24 degrees Celsius,” said Desbiez. “Giant armadillo burrows offer an important refuge from extreme conditions, and their role may become more important as impacts from climate change increase.”
Although rarely seen, the giant armadillo plays a key role in the ecological community in which it lives, and it is vital that this species is better understood and protected.
Find out more about the Pantanal Giant Armadillo Project.
Read more about this and other Xenarthrans with the IUCN SSC Anteater, Sloth and Armadillo Specialist Group.
Kathryn Pintus, ARKive Content Officer