Himalayan black bear in Annapurna, Nepal, with DNA strands integrated into the landscape.

Ancient Secrets Unearthed: The Genetic Story of Nepal's Black Bears

Jordan Keane in Science & Nature June 2025 • 4 min read.

"Non-invasive research reveals high genetic diversity and a distinct evolutionary lineage in the Annapurna Conservation Area, challenging conservation priorities."

The Asiatic black bear (Ursus thibetanus), a vulnerable species globally, faces increasing threats from habitat loss, illegal hunting, and conflicts with humans. While conservation efforts often focus on more charismatic species, understanding the genetic health of black bear populations is crucial for their long-term survival. A population's ability to adapt to environmental changes hinges on its genetic diversity, making it a key factor in conservation strategies.

In Nepal, these bears are distributed across mid- to high-elevation mountains, yet their genetic characteristics remain poorly understood. Fragmented habitats and human settlements may impede gene flow between bear populations, further threatening their genetic diversity. Analyzing their genetics is important for conservation actions.

Recent studies indicate that wild bear populations in Nepal are undergoing rapid changes in population size, underscoring the urgent need for conservation efforts. This article will delve into a study conducted in the Annapurna Conservation Area (ACA), revealing surprising insights into the genetic diversity, population structure, and evolutionary relationships of these bears.

Genetic Diversity: A Conservation Success Story?

Himalayan black bear in Annapurna, Nepal, with DNA strands integrated into the landscape.

Researchers conducted non-invasive surveys in the ACA, collecting hair and fecal samples to analyze the DNA of black bears. They genotyped eight microsatellite loci from 147 samples, identifying 60 individual bears within a 525 km² area. This meticulous effort revealed a striking discovery: the Asiatic black bear population in the ACA has maintained high levels of genetic diversity compared to other bear populations in range countries.

Contrary to expectations, the study found no significant genetic substructure among sampling locations within the ACA. This suggests that bears move freely across the landscape, promoting gene flow and maintaining a well-connected population. Conservation efforts in the region may have played a key role in facilitating this movement, increasing habitat connectivity and supporting genetic diversity.

High genetic diversity (Hₑ = 0.76) indicates a healthy, adaptable population.
Lack of population substructure suggests free movement and gene flow within the ACA.
Community-based conservation may be contributing to the bears' genetic viability.

While the genetic diversity is encouraging, the study also revealed a moderate population size. This highlights the importance of addressing human-bear conflict to ensure the long-term viability of this expanding bear population. As bear populations recover, they may increasingly interact with human activities, requiring careful management to minimize conflict.

An Ancient Lineage: Rewriting Black Bear Evolution?

Beyond genetic diversity, the study uncovered a distinct evolutionary lineage of Himalayan black bears in Nepal. Researchers sequenced the complete mitochondrial genome from wild populations, revealing that these bears are evolutionary distinct from other known subspecies of Asiatic black bears.

This discovery challenges existing classifications and raises questions about the unique evolutionary history of these Himalayan bears. The findings suggest that the bears in Nepal represent an ancient lineage, highlighting the region's importance as a reservoir of unique genetic diversity.

The study emphasizes the need to reassess conservation priorities for Asiatic black bears, recognizing the distinctiveness of the Himalayan population. Further research across the Himalayan range is crucial to understand the distribution of this unique lineage and inform effective conservation strategies. Continued conservation efforts are needed to protect this ancient lineage.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1371/journal.pone.0207662, Alternate LINK

Title: High Genetic Diversity And Distinct Ancient Lineage Of Asiatic Black Bears Revealed By Non-Invasive Surveys In The Annapurna Conservation Area, Nepal

Subject: Multidisciplinary

Journal: PLOS ONE

Publisher: Public Library of Science (PLoS)

Authors: Rabin Kadariya, Michito Shimozuru, Jesús E. Maldonado, Mohamed Abdallah Mohamed Moustafa, Mariko Sashika, Toshio Tsubota

Published: 2018-12-05

Everything You Need To Know

What is the significance of high genetic diversity in the Asiatic black bears?

The study found that the Asiatic black bear population in the Annapurna Conservation Area (ACA) has maintained high levels of genetic diversity. High genetic diversity (Hₑ = 0.76) is a key factor for a population's ability to adapt to environmental changes. This is crucial for the long-term survival of the Ursus thibetanus, which faces threats from habitat loss, illegal hunting, and conflicts with humans. The genetic diversity allows the bear population to respond to diseases, climate change, or other environmental pressures. It also allows the population to adapt and evolve over time.

Why is genetic diversity important for the Asiatic black bears?

Genetic diversity is a measure of the variation in the genetic material within a population. It's important because it allows the Asiatic black bears to adapt to environmental changes. The Annapurna Conservation Area (ACA) showed a lack of genetic substructure. It suggests that bears move freely across the landscape, promoting gene flow and maintaining a well-connected population. This movement ensures that different genetic variations are spread throughout the population, which enhances the population's resilience to threats such as habitat fragmentation, and human-wildlife conflict.

How did the researchers study the Asiatic black bears' genetics?

Researchers collected hair and fecal samples to analyze the DNA of the Asiatic black bears in the Annapurna Conservation Area (ACA). They genotyped eight microsatellite loci from 147 samples, identifying 60 individual bears within a 525 km² area. This non-invasive method allowed scientists to study the genetic makeup of the bears without directly capturing or harming them. The analysis of these samples revealed the high genetic diversity and the evolutionary distinct lineage of these bears.

What did the study reveal about the Asiatic black bears' evolutionary lineage?

The study found a distinct evolutionary lineage of Himalayan black bears in Nepal. Researchers sequenced the complete mitochondrial genome from wild populations, revealing that these bears are evolutionary distinct from other known subspecies of Asiatic black bears. This means the Ursus thibetanus in the Annapurna Conservation Area (ACA) have unique genetic characteristics that set them apart. The discovery of this distinct lineage indicates that the bears in the ACA may have a different evolutionary history and potential adaptations compared to other populations of Asiatic black bears.

Why is the Annapurna Conservation Area (ACA) important for the Asiatic black bears?

The Annapurna Conservation Area (ACA) is significant because the study found that the Asiatic black bear population within the ACA has maintained high levels of genetic diversity. The lack of genetic substructure suggests free movement and gene flow within the ACA, meaning the bears can move throughout the area. This finding is a conservation success story, but the study also revealed a moderate population size. This highlights the importance of addressing human-bear conflict to ensure the long-term viability of this expanding bear population. The ACA provides a relatively safe habitat for the bears, the conservation efforts may play a key role in facilitating movement, increasing habitat connectivity, and supporting genetic diversity.