Poop Hunters: University researchers spend months studying aardvark excrement for climate clues

Oregon State University researchers spent several months in sub-Saharan Africa collecting poop from aardvarks.

The researchers concluded that the aridification of sub-Saharan Africa is isolating aardvarks, which may threaten their long-term survival.

“Everyone had heard of aardvarks, and they are considered very ecologically important, but there has been little study of them,” Clint Epps, a wildlife biologist at Oregon State, said. “We wanted to see if we could collect enough data to begin to understand them.”

In a paper published in Diversity and Distribution, these researchers examined genetic information from 104 aardvark poop samples to better understand the range of where they live.

“During times of rapid environmental change, evaluating and describing changes in the landscape where a species lives is important for informed conservation and management decisions,” Rachel Crowhurst, a wildlife geneticist who works with Epps and a co-author on the paper, said.

Nocturnal, burrowing mammals that can weigh up to 180 pounds, aardvarks have long snouts, like that of a pig, that they use, in conjunction with their claws, to find and dig out ant and termite hills. They primarily live in the bottom two-thirds of Africa.

Aardvarks are the only living member of the order Tubulidentata, aardvarks are not closely related to pigs or South American anteaters. They are more closely related to golden moles, elephants, and manatees.

The International Union for the Conservation of Nature puts aardvarks in its “least concern” category, partially because they inhabit a broad range of ecosystems.

"However, little is known about current population trends or their actual distribution across the landscape," the release said. "The Oregon State researchers believe the species is understudied because they are nocturnal, hard to trap, and exist in low densities across large and often remote landscapes."

As a result, Epps and his team undertook the first wild aardvark genetics study using noninvasive methods.

"People have examined aardvark DNA in the past for studies of mammalian evolution, but never across wild populations," the release said.

About 20 years ago, Epps learned to recognize aardvark tracks and poop, which the animal buries. He learned this while working as a post-doctoral researcher in Tanzania.

In 2016, he went back to Africa for six weeks to see if he could find aardvark digging signs, locate them through the bush and find their poop.

“I wanted to work on a system that was understudied, where anything I learned would likely be truly new information to the scientific community,” Epps said. “I also wanted to work over large landscapes, on foot, alone or with a friend or with guards when needed, in protected areas, with minimal logistical support and little cost.”

The study cost a few thousand dollars a season and was funded using flexible funds from other research, according to the scientist.

During that 2016 trip, he learned how to find aardvark feces. He returned to Africa in 2017 on a shorter trip with a graduate student, Rob Spaan, and in 2018 with Crowhurst.

The researchers surveyed eight protected and four privately owned areas in South Africa, two protected areas in Eswatini, and one location in Kenya. They gathered 253 fecal samples and used 104 of the best quality for genetic information.

The researchers used the genetic information to deduce where aardvarks live and their movement across Africa.

"For example, if genetic testing showed that fecal samples collected in different spots came from the same aardvark, they then used this information to determine the scale of individual movements," a release said.

Genetic information gathered in South Africa indicated that the country had three regional divisions of aardvarks, somewhat isolated from each other.

"Individuals were detected at multiple locations separated by up to 7 kilometers, indicating that home ranges could be larger than previously determined, particularly in arid areas where food resources may be low," the release said.

Aardvarks up to 44 kilometers apart were closely related, the genetic material revealed, according to the release. However, even aardvarks within 55 kilometers of each other had genetic similarities.

"Thus, they found aardvarks may disperse up to 55 km from where they are born," the release said.

Their research also found that, when the landscape was more arid, there was more genetic variation between individual aardvarks. The researchers think this means arid landscapes restrict aardvark movement.

The researchers aim to continue this work. They want to perform genomic analysis on new samples and do field work across a wider range of sub-Saharan Africa.

“Our initial findings suggest that climate change will increase habitat fragmentation and limit gene flow for aardvarks, particularly where precipitation is expected to decrease and temperature increase,” Epps said. “With aridity expected to increase in southern-most Africa under most climate change scenarios, the need for further research is clear.”

Although Epps conducted this research, he has not yet seen an aardvark in the wild.

Spaan and Matt Weldy of Oregon State and Hannah Tavalire of the University of Oregon also co-authored this paper.