New findings challenge study from 2020 about the classification of Red Pandas.
In 2020, a groundbreaking study by a Chinese research team classified the Ailurus fulgens (the Red Panda found in Nepal, Bhutan, India, and Tibet) and Ailurus styani (the Red Panda found China’s Sichuan and Yunnan provinces) as two distinct species.
In the new study, Dr. Mukesh Thakur, scientist from the Zoological Survey of India, and his colleagues Dr. Supriyo Dalui and Dr. Lalit Kumar Sharma challenge these findings. The researchers offer a new perspective on the genetic and morphological variations within Red Panda populations.
Dr. Thakur explains in an email interview why this study came to different conclusions and what impact the classification of Red Pandas has on species conservation.
Red Pandazine: How do the studies differ in their approach, and why are the results so different?
Dr. Mukesh Thakur: The key difference lies in sampling design and geographic scope. Earlier studies, particularly Hu et al. (2020), focused on Red Panda populations from China and Nepal, leaving a critical sampling gap in the trans-Himalayan region, especially India and Bhutan.
From Our Archives (2020):
Our study fills this gap by analyzing samples collected on both sides of the Siang River in Arunachal Pradesh, India, a potential contact zone between the two lineages.
Additionally, we used both mitochondrial (mtDNA) and nuclear (microsatellite) markers (see fact box below, note), along with photographic assessment, whereas previous studies largely relied on genomic SNP (“Single Nucleotide Polymorphism”, variation of DNA building blocks, note) data from geographically distant populations.
These methodological and spatial differences explain the contrasting results: earlier findings supported two distinct species, while our data show ongoing gene flow and lack of clear morphological divergence, supporting a subspecies classification.
Fact box: The genetic markers used in the study
For the study, mitochondrial D-loop sequences and nuclear microsatellites were used. Both are widely accepted markers for studying population structure and recent gene flow.
Mitochondrial D-Loop Sequence:
A region of DNA found in mitochondria, the “powerhouses” of cells. It helps regulate mitochondrial genes and plays an important role in copying this DNA. This sequence is passed down from generation to generation and is often used in genetic research to study relationships and origins of populations.
Nuclear Microsatellites:
Short, repeating sequences of DNA found in the cell nucleus. They consist of small units of base pairs that repeat several times. These microsatellites vary widely among individuals of the same species, making them useful for genetic studies like determining relationships and analyzing genetic diversity. They are commonly studied in population biology, forensics, and species tracking.
What distinguishes the two approaches—two species versus two subspecies—in the practice of nature conservation?
Dr. Mukesh Thakur: Classifying lineages as distinct species often leads to separate management and breeding programs, while the subspecies approach promotes genetic connectivity and integrated conservation strategies. If the populations are reproductively compatible, treating them as subspecies enables genetic rescue, avoids inbreeding depression, and enhances long-term viability of both wild and captive populations. The subspecies model acknowledges divergence while maintaining evolutionary and ecological cohesion, which is particularly crucial for wide-ranging species like the Red Panda.
“Continuing to treat Red Pandas as two distinct species could lead to artificial genetic isolation”
Dr. mukesh thakur
What would happen if the two groups continued to be treated as different species—would this have negative consequences?
Dr. Mukesh Thakur: Yes, continuing to treat them as two distinct species could lead to artificial genetic isolation, especially in captive breeding programs where inter-lineage breeding is discouraged. This could reduce genetic diversity, especially in small, fragmented populations, and limit the adaptive potential of future generations. Misguided species-level separation might also skew conservation priorities, diverting resources away from integrated landscape-level management, which is essential for wide-ranging Himalayan fauna.
Some Impressions From the Field
How do you explain that earlier studies reported clear external differences in the (sub)species, but your study was unable to confirm such differences?
Dr. Mukesh Thakur: Earlier reports likely overstated morphological divergence due to limited and geographically skewed samples. Our study examined 22 Red Panda skins and numerous field photographs from the entire contact zone across Arunachal Pradesh. We found no consistent external differences in coat color, tail ring pattern, or facial features. This suggests that supposed diagnostic traits may fall within natural phenotypic variation or may be influenced by environmental and age-related factors, rather than representing fixed species-level distinctions.
Photo: Jürgen Breitenbaumer
What would need to be done to definitively determine whether Ailurus fulgens and Ailurus styani are two species or two subspecies?
Dr. Mukesh Thakur: A definitive answer would require an integrated approach involving genome-wide sequencing of individuals across the entire distribution range, especially India and Bhutan, ecological niche modeling to test for habitat separation, reproductive compatibility tests, especially in captive populations, and long-term monitoring of gene flow in natural populations. Combining genomic data, field ecology, and morphological variation within a landscape context will offer the most reliable basis for taxonomic resolution and conservation planning.
Read more
Red Panda Phylogenetic Conundrum: Are There Two Distinct Species?
Supriyo Dalui, Lalit Kumar Sharma, Mukesh Thakur
Wiley, 2025
https://doi.org/10.1111/jbi.15175