Multi-species habitat suitability and gap analysis in the Central Western Ghats, India

In the vast, green expanse of the Western Ghats, a mountain range running down the western edge of India, nature operates on a scale that often defies human boundaries. This region is a global treasure, a hotspot where the air is thick with humidity and the forests teem with life, including some of the world's most elusive large mammals. For decades, the primary strategy to protect these animals has been the creation of protected areas, or reserves, where human activity is strictly limited. The logic is straightforward: if we fence off the best land, the animals will be safe. However, nature does not respect fences. Large animals like tigers, leopards, and wild pigs require vast territories to hunt, breed, and find water. Their paths often wind far beyond the official borders of a reserve, crossing through private lands, villages, and other forests that lack formal protection. If these surrounding areas are degraded or blocked by roads and development, the animals inside the reserves can become isolated, leading to a slow decline in their populations. Conservationists have long suspected that the land outside the fences is just as critical as the land inside, but proving exactly where these animals go and how well they survive in unprotected zones has been difficult without a clear map.

A team of researchers from the Wildlife Institute of India set out to draw that map for the central part of the Western Ghats, specifically in the Uttara Kannada district of Karnataka. They focused on seven key species that represent the health of the entire ecosystem: the tiger, the common leopard, the dhole (a type of wild dog), the gaur (a massive wild bovine), the sambar deer, the spotted deer, and the wild pig. Instead of relying on old data or broad guesses, the team went into the field between March and June 2024. They set up a grid of 87 camera traps across a landscape of over 800 square kilometers, capturing images of animals as they moved through the forest. This area included the Kali Tiger Reserve, a well-known protected zone, as well as two neighboring forest divisions, Karwar and Yellapur, which are not officially protected reserves. By analyzing thousands of photos, the researchers built a detailed picture of where each animal was found and what kind of environment they preferred. They then used computer models to predict habitat suitability, essentially asking the data to show where the conditions were right for these animals to thrive, based on factors like how much food was available, how close they were to water, how rough the terrain was, and how much human activity was nearby.

The results painted a picture that challenges the idea that conservation success is confined to the boundaries of a tiger reserve. The computer models, which combined data from six different statistical approaches to ensure accuracy, showed that the animals were not just surviving in the protected Kali Tiger Reserve; they were also thriving in the adjacent, unprotected forests. For the dhole, a social predator that travels in packs, the models predicted that nearly 60 percent of the habitat in the Kali Tiger Reserve was suitable, but an almost identical 58.5 percent of the habitat in the neighboring Karwar division was also suitable. Similarly, the gaur, a massive herbivore, was found to have the highest suitability in the Yellapur division, an area without formal protection, where over 93 percent of the land was deemed ideal for them. Even the tiger, the apex predator that requires the most space and the least human disturbance, showed a strong presence in the unprotected Yellapur division, with over 65 percent of that area predicted to be suitable habitat. This was a significant finding because it meant that the forests outside the reserve were not just empty buffers; they were active, high-quality homes for these animals.

When the researchers combined the data for all seven species to look at the overall richness of the landscape, they found that the protected area did have a slight edge, with an average of about 4.6 species per location compared to 4.1 in the unprotected areas. However, the difference was not as large as one might expect, and the statistical analysis confirmed that the unprotected forests were holding their own. In fact, many specific spots in the unprotected Karwar and Yellapur divisions showed high levels of species richness, comparable to the best parts of the tiger reserve. The study highlighted that while the reserve offers a layer of safety, the surrounding forests are essential for maintaining the connectivity that allows these animals to move freely. The models revealed that vegetation productivity, or how lush and green the plants were, and the proximity to water were the most important factors for most species. Interestingly, the presence of humans, measured by how close settlements and roads were, was a major negative factor, particularly for tigers, who avoided areas with high human activity. Yet, species like the leopard and the wild pig showed a greater ability to adapt, finding suitable habitats even in areas with some human presence, often utilizing the edges where the forest meets open land.

The implications of these findings are profound for how we think about protecting wildlife in India and around the world. The research suggests that the current focus on protecting only the land inside reserve boundaries is insufficient. If the forests in Karwar and Yellapur are allowed to be degraded by infrastructure projects or land conversion, the animals that rely on them will lose critical corridors needed to move between populations. The study points out that the dhole, for instance, relies on these unprotected areas to connect with the main reserve, and losing this link could threaten the entire local population. The authors argue that conservation efforts must expand to include a landscape-level approach, where the management of protected and unprotected lands is coordinated. This means that decisions about building roads, expanding agriculture, or approving new development projects must take into account the habitat needs of these large mammals, even if the land is not officially a reserve. The data provides a clear, evidence-based argument that the health of the Kali Tiger Reserve is inextricably linked to the health of the forests surrounding it.

Ultimately, this study serves as a reminder that nature is a continuous system, not a collection of isolated islands. The forests of the central Western Ghats are a complex web where the fate of a tiger in a reserve is tied to the condition of a forest patch miles away. By identifying exactly where these animals are and what they need, the researchers have provided a roadmap for a more effective conservation strategy. The message is clear: to save these magnificent creatures, we must look beyond the fences. The land outside the protected areas is not merely a backdrop; it is a vital, functioning part of the ecosystem that requires active management and protection. If the goal is to ensure that tigers, leopards, and their prey continue to roam freely in this biodiversity hotspot, then the conservation network must be woven together across both protected and unprotected landscapes, ensuring that the corridors between them remain open and intact.