The interaction, even though at times occasional, between two apex predators in habitats which overlap poses a challenge to conservation and management of species. The overlap is explained in detail in the study, Decades of leopard coexistence in the Himalayas driven by ecological dynamics, not climate change. For data, the study uses historical evidence dating back to the 1950s as well as camera trail captures made from 2016 to 2023 in Nepal’s Annapurna Conservation Area situated at an elevation of 3,100–4,696 metres.
Study author and conservation ecologist Paras B Singh had been conducting research on this coexistence between the snow leopard (Panthera uncia) and the common leopard (Panthera pardus). For the study, which was published early this year in the journal Global Ecology and Conservation, 69 cameras were made operational in the Annapurna Biosphere Reserve, mostly between 3,700 metres and 4,000 metres from the mean sea level.
“The cameras are still there as the Annapurna is an important area for the study. Here, the common leopard was spotted at an elevation of 3,800 metres in 2016. It surprised me vastly to find common leopards at this altitude,” he said over a WhatsApp call from Nepal. The southern part of the Himalayas straddling India and Nepal did not have the benefit of the use of extensive camera trappings before. “The use of camera traps in this region is a recent thing,” Singh, who contacted herders and talked to elderly people in pastoral communities, added.
Regarding coexistence, which has been attributed to a changing climate, Singh pointed out that as mammals evolve, they can change their responses to poaching and temperature changes as a safeguard measure. In this regard, he also cited the example of the musk deer which can change its diurnal as well as nocturnal activities. Even the common leopard has given birth in high altitudes in Nepal at around 3,500 metres. During a scat collection exercise in 2013, the common leopard was captured on cameras when the temperature touched -8 degrees Celsius. “I wanted to find evidence that the coexistence of the snow leopard and the common leopard is related to evolution and ecology. It is too early to point to climate change impacts for this. It cannot be directly said that climate change is the reason behind the overlap.”
The overlap is high in the winter season when the snow leopard descends to lower elevations, say at 3,000 metres. So, at 3,200 metres, both the species have been recorded, and the overlap happens more at around 3,500 metres. “In general, there is a segregation,” Singh explained. While the common leopard prefers forests, the snow leopard prefers areas above the tree line. But the common leopard, which is highly adaptive, has nearly reached the tree line. Usually, the common leopard rarely ventures far beyond the forest edge because it depends on vegetation for concealment. Snow leopards are adapted to the mountainous terrain.
The overlap points to potential conflicts when it comes to predator hierarchy between the two species. “Conflicts will take place if the natural prey base is low. Conflict with humans also cannot be ruled out, as the latter keep livestock for livelihood,” Singh pointed out. Besides ecological factors, the co-occurrence is also due to the long-term adaptation of the common leopard to sub-zero temperatures. As Singh’s study uses historical data, it shows that the common leopard has inhabited high-altitude zones of 3,100-4,300 metres.
The study also shows that while common leopards overlap 96 per cent of snow leopard habitat, snow leopards only overlap 61 per cent of common leopard habitat. But while there are an established overlap and competition for prey, especially in winters, snow leopards are not at immediate risk due to common leopards, but the situation demands conservation management.
Based in Dehradun, Ranjana Pal works for non-profit Nature Conservation Foundation as a research associate. Pal’s focus area for her PhD has been the Gangotri landscape in Uttarakhand from which the Ganga originates. “There is a transition zone from the alpine to the subalpine habitat. The snow leopard comes down to the subalpine habitat at times even though they are mostly seen in the alpine habitat. Common leopards are also found sometimes in the subalpine zone. So, it is this zone where the interaction happens between the two.”
According to Pal, both the species can extend their range a little bit for prey, and that is when, they usually overlap. Pal’s study shows that in winters when there is snow in the alpine habitat, the interaction peaks as compared to summer. However, in summers, when livestock herds move towards the towards alpine habitat, they are followed by common leopards.
Pal explained that this overlap between these two species is a cause for concern in times of climate change in Gangotri. “Driven by warmer temperatures, the sub-alpine habitat is shifting upwards. As the common leopard is bigger in size, the snow leopard tries to avoid the former’s habitat. Winters are tough for both species. As snow limits their mobility and prey diminishes in the landscape, both move towards livestock. The herders face challenges from both predators.” But Pal pointed out that the common leopard has not yet established itself in the alpine habitat.
According to Abhishek Ghoshal, manager and head of human-wildlife conflict mitigation division at the Wildlife Trust of India, the coexistence between the common leopard and the snow leopard sounds non-viable. “Simply because these are two different species having different habitats, prey preferences and behaviour. They are already partitioned by nature through evolution. However, there are indeed occasional instances of tigers and common leopards venturing into what we consider as snow leopard habitats. Snow leopards have been also rarely seen at relatively lower altitudes. It is because all these wild cat species are exploratory in nature, just like humans, and are also highly adaptable (especially the common leopard). But such occasional incidents shouldn’t be seen as a phenomenon yet, strictly ecologically speaking.”
Yashveer Bhatnagar, representative of the India country office at the International Union for Conservation of Nature, shared that changes in technology now allows researchers to understand the habitat use and distribution of species. This technological advancement makes things noticeable which went unnoticed in the past. “In Sikkim and Uttarakhand, all the three big cats have been noticed in the same landscape. A few dispersing individuals may go beyond their range during exploration of habitats. But there is a distinction between a chance occurrence or an occupation of a range by a species.”