The Kashmir Langur's Identity Crisis

The Kashmir gray langur is dealing with an identity crisis as Indian primate scientists are still looking for clear answers to looming questions — Is it truly a distinct species? How does it differ from the Himalayan langur that it is often confused with?

Given the ongoing uncertainty about the taxonomy of the species, the latest population estimate and the genetic study on the Kashmir gray langur  (Semnopithecus ajax), that is endemic to the northwestern Himalayas, take on added significance.

“Ambiguity around the taxonomy of this species has always existed. However, we disagree with the conclusion by Arekar et al., who suggest that the Kashmir gray langur is the same as the Himalayan langur. Their study relied on a single, small fragment of mitochondrial DNA, which isn’t sufficient to determine the taxonomy of a species,” explains Tawqir Bashir, an assistant professor at the Centre of Research for Development, University of Kashmir. Bashir co-authored recent papers on the population and genetic diversity of the Kashmir gray langur, published in 2024.

Lead author of the papers, Shahid Hameed informs Mongabay India that the lack of understanding surrounding the species prompted him to take up the study. “The langur was first reported by Walter (Roper) Lawrence in his book Valley of Kashmir published in 1895. Even after a century, we don’t have enough data on the species,” he says. Its endemicity to the northwestern Himalayas and its endangered status assigned by the IUCN further encouraged him to turn the lens on the species.

The Kashmir gray langur is often confused with the Himalayan langur (Semnopithecus schistaceus), with some studies, including a 2020 paper on the integrative taxonomy of the Himalayan langur, supporting this claim. The Himalayan langur — already a relatively understudied species — was once considered a subspecies of the plain-dwelling Hanuman langur (Semnopithecus entellus). This study distinguished the Himalayan langur from the more widely distributed Hanuman langur using mitochondrial DNA (mt-DNA). However, the study concluded that all langurs in the Himalayas belong to a single species despite clear morphological differences such as size, coat colour, and facial features.

In their current studies, the researchers emphasise the genetic distinctiveness of the Kashmir gray langur. Bashir explains that they are maintaining the species’ taxonomic identity for two key reasons: the IUCN recognises it as a separate species, and the genetic study that questioned its identity lacks sufficient detail.

Hameed adds that the previous genetic study failed to account for female philopatry in the species. Female philopatry is a behaviour pattern seen in many animal species, where females remain in or return to the area where they form close-knit bonds with relatives, such as mothers, sisters, and aunts. This social structure can enhance the survival and well-being of offspring. In contrast, adult males typically disperse from their natal groups to mate with females from different groups, which promotes genetic diversity. “Since mt-DNA is maternally inherited, studies using it don’t capture the movement of males between groups, and how that might connect the populations genetically,” Hameed explains.

However, Mehreen Khaleel, a Kashmir-based independent researcher and founder of the Wildlife Research and Conservation Foundation, remains unconvinced about the genetic distinctiveness of the Kashmir gray langur. “There’s still no clarity on its taxonomy; we don’t have enough evidence to definitively say it’s a separate species,” she says. Khaleel argues that more genetic research is needed to properly classify the species.

Additionally, she points out the limited understanding of its ecology, which complicates efforts to ascertain its identity. “Genetics alone can’t define a species without studies into its behaviour and ecology,” Khaleel asserts, urging primate researchers to broaden their research to gain a more comprehensive understanding of the langur.

Counting heads

Using a double-observer method, where two observers independently record sightings, the research team led by Hameed estimated that there are approximately 1,496 Kashmir gray langurs in the northwestern Himalayas, with a density of 3.64 individuals per square km. The team surveyed a total area of 411 square km across 31 survey blocks spanning all three regions of Kashmir — north, central, and south — walking 1,284 km in the process. This estimate did not include the Chamba district of Himachal Pradesh, where the species also occurs, Hameed notes.

Bashir highlights the importance of these population estimates for conservation, especially as climate change threatens the survival of this high-altitude species.

“Climate change is likely to impact temperate deciduous forests, which are the primary habitat for the Kashmir gray langur,” Bashir explains. As temperatures rise, the growth of broad-leaved forests slows, reducing their ability to sequester carbon. This accelerates warming, which further disrupts the species’ habitat. Other threats to the langur include pressure from predators and humans, driven by agricultural expansion and forest degradation. “Unlike macaques, langurs are not easily adapted to human-modified landscapes,” he adds, emphasising the critical role of population estimates in shaping effective conservation strategies and monitoring protocols. 

It’s all in the genes

Understanding the genetic diversity of the Kashmir gray langur was another key objective of the study, says Hameed, as the long-term survival of a species is closely linked to its genetic diversity. This is particularly important for an endangered species like the langur. For the population genetics study, researchers sampled 15 langur groups using non-invasive methods, such as scat collection, and also obtained a tissue sample from a deceased langur for whole-genome sequencing, according to the paper.

Hameed explains that the population estimation revealed the species’ distribution is very patchy, with populations separated across the landscape. “The objective of the study was to understand how the species was doing genetically and to assess its overall genetic diversity,” he says. The findings were concerning: the langur exhibits very low genetic diversity, even lower than other critically endangered primates in India. “The subpopulations were found to be genetically isolated and do not share much genetic material,” he highlights. This is a critical issue, as low genetic diversity, compounded by other threats like climate change, threatens the species’ long-term survival in the absence of targeted conservation efforts. “With reduced genetic diversity, the species may not have enough genetic resilience to adapt to environmental or evolutionary changes,” Hameed warns.

He says he believes that while the species does not face significant threats from human activities, restoring forests and improving connectivity between fragmented forest patches could play a key role in ensuring the langur’s long-term survival.

 This story was first published on Mongabay India