African lions are losing their genetic diversity and resilience

A new study led by researchers at the Zoological Society of London is warning that the genetic diversity of African lions has declined substantially since the late 19th century, leaving the animals more susceptible to reduced fitness and resilience. In the KAZA region, up to 17 percent of genetic variation has been lost among lions since 1895.

“The dramatic population decline of the African lion has made the protection of the remaining populations and the improvement of gene flow between populations of the utmost importance and has led to a number of transboundary conservation initiatives, such as the Kavango–Zambezi transfrontier conservation area (KAZA),” wrote the study authors.

“The size of the KAZA region and its ability to support a large number of lion prides, results in it being considered one of the few remaining strongholds for the lion population.”

A drop in genetic diversity means that the lions will be less capable of handling changes in their environment.

“If you lose some of those populations, or they’re not mixing, you’re going to lose the overall population’s ability to withstand change. It could be climate change, it could be disease. It’s the ability to withstand the unknown,” study lead author Simon Dures told New Scientist.

Many of the lions that were killed in the KAZA region by a 19th-century British hunter, Frederick Selous, ended up at the Natural History Museum in London. The team used 27 of these samples to compare the DNA to modern lions.

“The rapid decline observed in allelic richness and the highest levels of genetic differentiation coincide with the arrival of the first western settlers in 1890 and the subsequent rise of the colonial presence in the region after the end of the Matabele Wars in 1897,” said Dures.

“Furthermore, modern firearms became more prevalent following European settlement and predators were often persecuted as vermin, which likely contributed to the earlier decline of lions in the study region.’

“While the timing of genetic decline and colonial settlement is compelling enough to suggest causation, the evidence is not conclusive.”

According to the study authors, the findings emphasize the need for improved connectivity between protected areas in order to prevent further loss of genetic diversity in the region.

The research is published in the journal Diversity and Distributions.
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By Chrissy Sexton, Earth.com Staff Writer