Desert elephants pass on survival skills to their offspring

New York, Aug 4 (IANS) Desert elephants pass on their unique knowledge and survival skills to future generations to help them adapt to extreme environmental conditions, says an interesting study conducted on Namibian elephants.

The findings showed that the ability of species such as elephants to learn and change their behaviour means that genetic changes are not critical for them to adapt to a new environment.

"The behavioural changes can allow species to expand their range to novel marginal habitats that differ sharply from the core habitat," said lead author Alfred Roca, Professor at the University of Illinois in the US.

Female elephants were found to live in tight-knit matrilineal family groups, so mutations in mitochondrial DNA, which is passed from mothers to offspring, are closely tied to geographic groups.

For the study, the team evaluated the nuclear DNA and mitochondrial DNA (mtDNA) of both desert-dwelling and non-desert-dwelling elephant groups throughout Namibia.

Despite reported differences in appearance and behaviour, DNA evidence has found that Namibian desert elephants share the same DNA as African Savanna elephants.

The lack of genetic differentiation is consistent with historical evidence of elephant movements during the Namibian War of Independence, which increased hunting pressures.

In addition, it could also be attributed to their long distance migrations, large home ranges, recent increases in population size and range, or gene flow provided by male elephants breeding with different groups of female elephants, the researchers said.

"Our results and the historical record suggest that a high learning capacity and long distance migrations enabled Namibian elephants to shift their ranges to survive against high variability in climate and in hunting pressure," added Yasuko Ishida, research scientist at the University of Illinois.

The desert-dwelling elephants in Namibia play a critical role in this arid ecosystem by creating paths and digging watering holes.

According to researchers, they have figured out how to prevent overheating in triple-digit temperatures by covering their bodies with sand wetted by their urine or regurgitated water from a specialised pouch beneath their tongue that holds many gallons of water.

They also remember the location of scarce water and food resources across their home ranges, which are unusually large compared to those of other elephants.

These desert elephants are also rumoured to be larger, putting them at greater risk for trophy game hunting, the researchers noted adding "these elephants should be conserved".