Wild Cam: Human development limits giant anteater populations

At up to seven feet long and up to 110 pounds, it’s no wonder that giant anteaters are sometimes called ant bears. These large mammals are near cousins of sloths, but unlike those animals and other anteater species, they are the only fully terrestrial members of their order.

Size, claws and hairiness aside, they don’t appear much like bears. Giant anteaters sport narrow, straw-like snouts perfect for vacuuming up whole colonies of ants and termites. Their fur sports patterns reminiscent of striped skunks, while their bushy tails often stick straight out behind their body as they travel through the forests and savannas of South and Central America.

Besides the basics, little is known about giant anteater populations. Researchers in Brazil wanted to determine how these peculiar looking animals cope with human disturbance.

In a study published recently in the Journal of Wildlife Management, Alessandra Bertassoni, a postdoctoral researcher at the Federal University of Goiás, and her colleagues used trail cameras to track anteaters through a small protected area called the Santa Bárbara Ecological Station in Sao Paulo state in the Brazilian Cerrado.

While giant anteaters (Myrmecophaga tridactyla) may look unique, it’s still hard to distinguish individuals. But Bertassoni and her colleagues found that each individual had unique patterns on its wrist and elbows.

Still, identifying the animals was difficult, since they are mostly active at night in this region. But from 127 photos, they identified nine individuals in March to May 2015. They estimated that the Santa Barbara reserve carried between 12 to 25 animals depending on the model they used.

“It’s not a lot, but we have this population living inside the reserve,” Bertassoni said. The reserve is relatively small at roughly 27 square kilometers and surrounded by human disturbance.

The anteaters in this population are breeding—the cameras captured photos of females with cubs on their backs. But telemetry devices attached to some of the animals also showed that males are often hanging about on the edge of the reserve. “Their home ranges are [usually] bigger than the reserve,” she said. “They are looking for places that are not available.”

Due to development around the reserve—Sao Paulo is one of Brazil’s most populated states—the anteaters there face conflicts with humans and dogs. Natural predators like cougars (Puma concolor) are also found in the area.

The team also found that the anteaters’ numbers are likely decreasing, based on a population viability analysis. In the next century, they estimated that only eight individuals would be left. “It’s sad because Santa Barbara is too small,” Bertassoni said.

While giant anteaters in captivity sometimes live up to 32 years old, the analysis found they only live until about 15 years old on average in the wild.

Now that they have an idea of the numbers of anteaters, Bertassoni said that researchers, conservationists and the government can increase awareness about these animals for ranchers and landowners in the region in an effort to improve conservation and increase private land reserves.

Species other than the anteaters also showed up on the camera trap images, such as maned wolves (Chrysocyon brachyurus), red-legged seriema (Cariama cristata) and crab-eating foxes (Cerdocyon thous).

Bertassoni said that the technique the researchers used in this study could be replicated to determine the numbers of other populations like these in Latin America—especially those found in forests.

“We don’t have any information about populations of giant anteaters in the Amazon because it’s a forest and it’s super difficult to do capture-recapture using traditional methodology,” she said, but, she added, trail cameras could help.

Information from these population density analyses could also be used to estimate how many giant anteaters might be affected by wildfires or in areas with a high number of roadkill.

Meanwhile, she is working on follow-up research as part of the Anteaters and Highways Project to learn more about the behavior of females and cubs, including how young anteaters learn to reign terror down on termite and ant colonies.

This photo essay is part of an occasional series from The Wildlife Society featuring photos and video images of wildlife taken with camera traps and other equipment. Check out other entries in the series here. If you’re working on an interesting camera trap research project or one that has a series of good photos you’d like to share, email Josh at jlearn@wildlife.org.

This article features research that was published in a TWS peer-reviewed journal. Individual online access to all TWS journal articles is a benefit of membership. Join TWS now to read the latest in wildlife research.