In doing so they have also countered a Chinese study published in February 2020 which claimed that the CRP is not present in India.
Indian scientists, in this breakthrough study based on the DNA from faecal samples collected over a span of three years, have said that two phylogenetic (sub-species) of HRP and CRP exist in the country.
The study was published in Nature (Scientific Reports) as well as in German Society of Mammalian Biology last week.
The Indian scientists have also contradicted China claims, saying it is the Siang river in Arunachal Pradesh that is the potential boundary or geographic that divides the two sub-species after examining the DNA samples from the Indian Himalayan Region.
A Himalayan red panda. The faecal samples of this species was found to be in north west Bengal and confirmed by DNA study by Indian scholars of Zoological Survey of India.
The Chinese study, by scientist Yibo Hu, had claimed that Yalu Zangbu river near Tibet was the geographic barrier that led to divergence of red panda species into two varieties.
“We collected 132 faecal samples — 29 from north-west Bengal, 28 from Sikkim and 75 from Arunachal Pradesh. Genomic DNA was extracted…sequencing was performed…We also downloaded 44 complementary sequences of red panda available in the public domain,” said Dr Mukesh Thakur, scientist, ZSI. In contrast, the Chinese study analysed only 18 samples from Nepal. Indian scientists found that DNA samples of red pandas in Dibang Valley in Arunachal Pradesh matched with those of CRP.
“Samples collected from Dibang valley were actually located on the east of Siang river, indicating this same river in Arunachal Pradesh has been the potential barrier of species divergence in red panda,” the study noted.
“A few studies reported that large rivers often function as barrier in the distribution and gene flow of the arboreal and small mammals. Thus, occurrence of a Chinese Red Panda in Dibang in AP that lies on the east of Siang river was in accordance to the fact that Siang river is a potential geographic barrier in several species including Hoolock Gibbon, Stump tailed macaque, Pigtailed macaque..” the study points out.
“Further, Yalu Zangbu river descends from 4500 to 3000 m and surrounding vegetation changes from cold desert to arid steppe to deciduous scrub vegetation and this further changes into a conifer and rhododendron forest when enter to Arunachal Pradesh, India32. Thus, changes in the mentioned topographic features and habitat types often influence the distribution and movement of animals across the river. Hence, it is imperative to mention the Siang River, the regional stretch of Yalu Zangbu River in western Arunachal Pradesh, India is responsible to hinder the movement of red panda across the range….” it notes
The Himalyan Red Panda was found to be active largely on the west of Siang river as established from samples collected from Darjeeling, Sikkim, south Tibet, western and central Arunachal Pradesh and “concludes that we have presence of both sub-species,” Thakur told TOI. (Also map shows distribution of both sub species of red pandas..)
Their research paper in Nature, titled Geological and Pleistocene glaciations further explains the demography and disjunct distribution of red panda in eastern Himalayas.
The paper that has been jointly authored by ZSI’s director Dr Kailash Chandra along with seven other Indian scholars also makes a startling revelation that the red panda actually diverged into Chinese and Himalyan species at about 0.3 million years ago.
“That corresponds to the middle-late Pleistocene transition (ice age)…”it states.
The study in the Nature journal also takes a swipe at the Chinese claim that the Chinese red panda had low genetic variations.
In their work, the Indian scientists found that the population of CRPs in Dibang Valley has genetically diverged thrice and the HRP had also diverged twice at 0.17 million years ago and 0.12 million years ago.
“Recently, Hu (Chinese scientist), demonstrated the presence of two phylogenetic species, the Himalayan red panda (Ailurus fulgens ) and Chinese red panda (Ailurus styani) and proposed that Yalu Zangbu river has been the potential boundary of species divergence27. Their study sequenced 18 samples from Nepal, and inferred that it sufered from three historic bottlenecks (followed by a small expansion consequently imparting low genetic diversity) …… In contrast, we did not observe a low genetic variation in control region of DNA,” the Nature study by Indian scientists states.
Indian scientists state that Dibang population of panda, being in the eastern edge of Siang river evolved with CRP species and further diverged into three diferent lineages.
They also say that even Himalyan Red Panda diverged about 0.17 million years ago (mya) during the Penultimate glaciation and interestingly the individuals of KL population emerged independently about 0.12 mya.
The scientists further stated that their study also found that the HRP population in Kanchenjunga landscape-India (KL) had declined abruptly in the last 5-10 thousand years due to environmental changes.
The red panda has lost 50% of its population in the last 20 years and now only 2500 individuals survive in the wild in India, China, Tibet, Nepal, Myanmar and Bhutan.
“Red panda conservation requires the involvement of multi-agency coordination and countries,” said Chandra.