An analysis of DNA from wild populations of the red panda (Ailurus fulgens) has found that there is not just one species but enough genetic differences to recognize two distinct species.
The Chinese red panda (Ailurus styani). Image credit: Yunfang Xiu, Straits (Fuzhou) Giant Panda Research and Exchange Center, China.
The red panda is an endangered mammal endemic to the Himalaya and Hengduan Mountains and is the only living member of the genus Ailurus and the family Ailuridae.
The animal was once widely distributed across Eurasia but is now restricted at the southeastern and southern edges of the Qinghai-Tibetan Plateau within an altitude range of 2,200 to 4,800 m.
On the basis of differences in morphology (skull morphology, coat color, and tail ring) and geographic distribution, red pandas are classified into two subspecies: the Himalayan red panda (A. f. fulgens) and the Chinese red panda (A. f. styani).
The Himalayan red panda is distributed in Nepal, Bhutan, northern India, northern Myanmar, and Tibet and western Yunnan Province of China, while the Chinese red panda inhabits Yunnan and Sichuan provinces of China. The Nujiang River is considered the geographic boundary between the two subspecies.
Morphologically, the Chinese subspecies has much larger skull length, more distinct tail rings, redder face coat color with less white on it, etc.
In 2010, the British-Australian taxonomist Colin Groves even proposed that the two subspecies should be updated as two distinct species: the Himalayan red panda (A. fulgens) and the Chinese red panda (A. styani).
The Himalayan red panda (Ailurus fulgens). Image credit: Arjun Thapa, Institute of Zoology, Chinese Academy of Sciences.
“In order to help clarify these questions, we used population genomics methods to analyze the genome resequencing data of 65 wild red pandas (both Himalayan and Chinese subspecies) from seven geographical populations, mitochondrial genomes of 49 red pandas, and Y chromosome single-nucleotide polymorphism (SNP) data from 49 male individuals,” said Professor Fuwen Wei, a researchers from the Institute of Zoology, the Chinese Academy of Sciences, and colleagues.
“All results from these three types of markers found substantial genetic divergence between the two species, and no sharing was found for the haplotypes of mitochondrial genome and Y chromosome SNPs.”
“These findings clearly support Colin Groves’ classification of red pandas into two phylogenetic species.”
The scientists found that the Yalu Zangbu River, rather than the Nujiang River, is most likely the geographical boundary between the two species.
They also reconstructed the demographic and divergence histories of the two species based on the genome resequencing data.
“Our results revealed clearly different demographic histories for the two species,” they said.
“The Chinese red panda had experienced two population bottlenecks and one large population expansion, whereas the Himalayan red panda had experienced three bottlenecks and one very small expansion.”
“These two species started to diverge after the serious population bottleneck caused by the Penultimate Glaciation (300,000 to 130,000 years ago).”
“In contrast to the Chinese red panda, the Himalayan red panda has less genetic diversity, higher linkage disequilibrium and a higher genetic load, thus highlighting the urgency of protecting this endangered species.”
“These findings have important conservation implications for wild red panda conservation, pedigree construction and interbreeding avoidance for captive red pandas.”
The study was published in the journal Science Advances.
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Yibo Hu et al. 2020. Genomic evidence for two phylogenetic species and long-term population bottlenecks in red pandas. Science Advances 6 (9): eaax5751; doi: 10.1126/sciadv.aax5751
