KATHMANDU — Researchers have discovered brown bears in a part of Nepal not previously known to host the species, prompting a call to protect this area as a bear “stronghold.”
The finding, based on camera-trap images, also expands the known range of the brown bear (Ursus arctos) in Asia. It could also mark out the Limi Valley, in northwestern Nepal, as a “contact zone” between two subspecies of this apex predator, the researchers write in a newly published study.
“The bears weren’t the species we primarily set up the camera traps for,” study lead author Naresh Kusi, from the Himalayan Wolves Project, told Mongabay.
As part of their research, Kusi and his project team have since 2021 run a network of 61 camera traps across an area in the Limi Valley that’s half the size of London. Since then, they’ve recorded images of species never before confirmed outside Nepal’s protected areas, such as the steppe polecat (Mustela eversmanii), Pallas’s cat (Otocolobus manul) and Eurasian lynx (Lynx lynx).
This time around, it’s the brown bear — a species found throughout the Northern Hemisphere, but which is so vanishingly rare in Nepal, at an estimated 20 individuals, that it’s considered critically endangered here. Yet Kusi’s team managed to capture dozens of independent images of brown bears in their camera-trapping surveys.
“Although we didn’t estimate the size of the population in Limi Valley, based on our study and other studies on brown bears, we can say that the number we currently have looks like an underestimate,” Kusi said.
They snapped a higher number of images in their 2022-2023 survey than in 2021, likely because of the season, he added.
“In 2021, we were there in the summer season. But the next year we went there during spring,” Kusi said, adding that brown bears are known to be more active in the spring, when the snow hasn’t completely melted yet and people don’t frequent the rangelands.
The researchers say the finding is significant, as it comes from a region situated between the known ranges of two brown bear subspecies: the Himalayan brown bear (U. a. isabellinus), found farther west in India and Pakistan, and the Tibetan brown bear (U. a. pruinosus), found further north and east up to Tibet.
“This suggests that the area may be a ‘contact zone’ between the two subspecies,” Kusi said.
The researchers write in their study that the discovery points to “the significance of Limi Valley as a stronghold for brown bears in Nepal and underscore[s] the importance of formally protecting the currently unprotected wildlife habitats in Limi Valley.”
They add that the photographed bears appeared to have the physical characteristics of the Tibetan brown bear, including a white “collar” (also described by some researchers as a yellow “scarf”) around its neck, and black ears. But a genetic analysis would be needed to confirm which subspecies they belong to — or whether they’re a hybrid of the Tibetan and Himalayan subspecies if indeed the “contact zone” hypothesis is correct.
Rajan Paudel, co-author of a recent study on potential bear habitats under a changing climate in Nepal, agreed on the need for more research into that hypothesis.
“Another interesting aspect to investigate is whether there are any barriers in the Limi Valley and its surroundings that could have isolated brown bear populations to the east [Tibetan] and west [Himalayan] of the valley, leading to the development of two separate subspecies,” he added.
While Kusi and his team posit that their finding expands the known range of brown bears in Nepal, research by Paudel and his team suggests that in a warming world, the overall range for the animals is likely to shrink. Their study found that if the average global temperature rises on a trajectory to hit by 2.7° Celsius (4.9° Fahrenheit) by the end of the century, brown bears in Nepal will lose more than two-thirds of their current suitable habitat by 2050, and 82% by 2070.
“Our study further shows the importance of saving the brown bears in Limi,” Paudel said, echoing Kusi’s team’s call to protect the area. “If we manage to do so, we could potentially be saving both the Himalayan and the Tibetan brown bears.”
The presence of brown bears in Nepal is as mythical as the beliefs surrounding them. Until recently, the Tibetan subspecies had never been recorded in the country. (Yet again, it was a camera-trap survey that confirmed their presence in 2022.) Bears have also been pegged as the possible origin for the enduring Yeti myth.
Their presence in the Limi Valley adds to the wealth of wildlife still being uncovered in the area. The valley is located in the trans-Himalayan region, only a small portion of which lies in Nepal, a country largely situated south of the Himalayas. Research into the flora and fauna of Nepal’s trans-Himalayan region, home to iconic species such as snow leopards (Panthera uncia) and wild yaks (Bos mutus), has been limited compared to the lower-elevation hills and plains, where better-known species such as greater one-horned rhinos (Rhinoceros unicornis) and Bengal tigers (Panthera tigris) are found.
Abhaya Raj Joshi is a staff writer for Nepal at Mongabay. Find him on @arj272.
Banner Image: A captive Tibetan brown bear with the trademark yellowish scarf-like ‘collar’ around its neck. Image by Aardwolf6886 via Flickr (CC BY-ND 2.0).
Citations:
Kusi, N., Gurung, S., Lama, D. T., Pathak, S., Pant, G., Timalsina, K., & Werhahn, G. (2024). New insights into the geographical distribution of brown bears Ursus arctos in Nepal. Oryx, 1-5. doi:10.1017/S0030605324000796
Baral, R., Adhikari, B., Paudel, R. P., Kadariya, R., Subedi, N., Dhakal, B. K., … Tsubota, T. (2024). Predicting the potential habitat of bears under a changing climate in Nepal. Environmental Monitoring and Assessment, 196(11). doi:10.1007/s10661-024-13253-2
This article by Abhaya Raj Joshi was first published by Mongabay.com on 31 October 2024. Lead Image: A captive Tibetan brown bear with the trademark yellowish scarf-like ‘collar’ around its neck. Image by Aardwolf6886 via Flickr (CC BY-ND 2.0).
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