Study examines 104 faecal samples of the burrowing nocturnal mammals to see impact of aridification
Aardvarks share common ancestors with elephants and golden moles. Photo: iStock A warming climate is negatively impacting the chances of long-term survival of aardvarks in sub-Saharan Africa. The burrowing nocturnal mammals are affected by incredibly dry landscapes, which isolates them and leaves them vulnerable to rapid climate warming, a study from Oregon State University found.
The aridification, or drying and heating of the aardvarks’ landscape, affects aardvark distribution and movement across the landscape, the researchers found on examining faecal samples of the animals. The paper was published in the journal Diversity and Distributions.
Long-term droughts, such as the one currently affecting the Horn of Africa region, have been made 100 times more likely by climate change, according to a report by the World Weather Attribution group.
Aardvarks are found over much of the southern two-thirds of Africa and their habitat is savannah and semiarid areas. These mammals are a crucial part of the ecosystem in sub-Saharan Africa. They eat termites that can destroy human-built structures and their burrows create important habitat for many other species.
The researchers believe the species is understudied because they are nocturnal, hard to trap and exist in low densities across large and often remote landscapes.
“In the face of rapid environmental change, describing and evaluating the causes of differentiation across the range of a species are important components of informed conservation and management,” the study said.
Aardvark DNA has been examined in the past for studies on how mammals evolved, but never using wild aardvark populations.
In this study, the researchers evaluated the degree and potential causes of population differentiation in aardvarks by investigating population genetic structure at multiple spatial scales.
The researchers surveyed eight protected and four privately owned areas in South Africa, two protected areas in Eswatini (formerly Swaziland) and one location in Kenya to evaluate how landscape affected gene flow and genetic structure over local (350 kilometres) and regional (1,600 km) spatial extents.
The researchers chose to evaluate population genetic structure in South Africa and Eswatini, as the region has many accessible protected areas of varying sizes.
The study included one site from East Africa (Kenya) to provide a continental-scale comparison of genetic structure in contrast with regional investigations in South Africa and Eswatini.
From 2016 to 2018, the researchers collected 253 aardvark faecal samples and analysed 104 of the highest quality for genetic information.
At the local scale, the researchers tested hypotheses about the influences of distance and landscape on gene flow using a locally developed habitat model. At the regional scale, they tested two sets of model predictors representing hypotheses regarding the effects of landscape on genetic differentiation.
In South Africa, the genetic details collected indicated that aardvarks in the western, central and eastern regions were somewhat separated. They found individual aardvarks in multiple places up to 7.3 km apart; closely related aardvarks were separated by as much as 44 km and those within 55 km were more genetically alike.
Across South Africa and Eswatini, arid areas increased resistance to gene flow, according to the study. Individual genetic differentiation was also predicted by differences in maximum temperatures at sampling sites.
The arid areas acted as a landscape barrier to aardvark gene flow was most strongly supported, the study said. Lower rainfall likely results in less vegetation and, thus, fewer termites and ants on which aardvarks feed.
The study concluded that the genetic structure of aardvarks is strongly shaped by climate, with arid areas limiting gene flow and reflected apparent isolation by adaptation associated with temperature.
The study recommended monitoring aardvark presence as an indicator of ecosystem change associated with aridification.
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
.png)
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.