While the DNA of Namibian desert elephants is the same as that of African savanna elephants, the former species has learned how to adapt to its environment and that unique knowledge makes it worthy of species protection, according to new research published online Wednesday.
Writing in the journal Ecology and Evolution, Alfred Roca, a professor of animal sciences and a member of the Carl R. Woese Institute for Genomic Biology at the University of Illinois, and his colleagues explain that Namibian desert-dwelling elephants have learned to cover their bodies in sand wetter by their urine or water regurgitated from a pouch under their tongue to stay cool.
Furthermore, this group of pachyderms are able to remember the location of limited amounts of water and food in their habitats, which are considerably larger than those of other elephants, and help shape their ecosystems by creating paths and digging watering holes. In order to ensure that these elephants are able to continue passing on their wisdom and survival skills, steps need to be taken to protect them from potential threats, the study authors explained.
“The ability of species such as elephants to learn and change their behavior means that genetic changes are not critical for them to adapt to a new environment,” Roca said in a statement. “The behavioral changes can allow species to expand their range to novel marginal habitats that differ sharply from the core habitat.”
Surviving in the Namibian Desert is difficult– so elephants pass their knowledge through generations. (Credit: Thinkstock)
Survival skills ‘crucial’ to survival of elephants in arid regions
As part of their research, Roca’s team analyzed both the nuclear and the mitochondrial DNA of both desert-dwelling and non-desert-dwelling elephant populations located throughout Namibia. They found that there were no significant genetic differences between the two populations, with one exception – those living in the Caprivi Strip region of the African nation.
Since female elephants live in close matrilineal family groups, mutations in mitochondrial DNA (mtDNA), which are passed from mothers to offspring, are linked to geographic populations. So it should not come as a surprise that the mtDNA of elephants living in the Caprivi Strip is similar to that of elephants from the bordering countries of Botswana and Zimbabwe, the authors said.
Aside from Caprivi Strip elephants, however, there is an overall lack of genetic differentiation, which the researchers said is consistent with historical movements of the populations during the Namibian War of Independence. Their analysis also revealed other migration patterns, including the fact that elephants living in the Ugab River region shared mtDNA with those living near the Huab River, a group from which the Ugab River elephants are believed to have migrated.
Furthermore, by analyzing their mtDNA, Roca’s group found that the lack genetic differences in these elephants was most likely due to the long distances they traveled, their large ranges, recent increases in population size and range, and/or gene flow (the transfer of alleles or genes from one population to another) resulting from male elephants breeding with different groups of females.
Despite their genetic similarities, desert-dwelling elephants “should be conserved,” Roca said. “Their knowledge of how to live in the desert is crucial to the survival of future generations of elephants in the arid habitat, and pressure from hunting and climate change may only increase in the coming decades. The desert elephants are also rumored to be larger, which may put them at greater risk for trophy game hunting.”
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Image credit: Andrew Schaefer
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