Masters of Camouflage

Leopards in Horton Plains National Park exhibit unique adaptations to their cold, mist-covered environment, including larger body size and thicker underfur, which align with Bergmann’s rule Geographic isolation and environmental pressures can lead to the formation of new subspecies through genetic divergence and reproductive isolation Despite their distinct habitats, Sri Lankan leopards do not currently meet the criteria for subspeciation.

Sri Lanka celebrates its leopards through initiatives like Sri Lankan Leopard Day on August 1 and the Multi-Regional Monitoring System, aimed at understanding and protecting the species, particularly outside protected zones.

Leopards are versatile big cats found across a diverse range of environments in both Africa and Asia, including forests, savannas, mountains, and even human-dominated landscapes. Their distinctive coat pattern provides excellent camouflage, aiding in their stealthy hunting of a wide variety of prey, from hooved mammals to smaller rodents and birds. Known for their adaptability and agile climbing abilities, leopards demonstrate a remarkable ability to thrive in various conditions and habitats.

Horton Plains in Sri Lanka’s central highlands features a unique cloud forest ecosystem. Constant low-level cloud cover creates a mystical atmosphere, essential for the region’s biodiversity. Trees capture moisture from passing mist, which condenses on leaves and branches, sustaining plants and wildlife. Mosses and epiphytes further balance moisture, supporting diverse life forms. This mist-to-water conversion not only supports ecological balance but also supplies water for the area.

Horton Plains National Park, home to the Sri Lankan leopard, illustrates how wildlife adapts to mist-covered environments, using them for camouflage and hunting advantage. This interaction highlights nature’s complexity and the park’s role in conserving biodiversity.

The leopards living in Horton Plains belong to the same biological classification as those found elsewhere on the island. However, their habitat in Horton Plains differs significantly from the lowland areas, leading to unique adaptations among these leopards.

Observing the elusive leopards of Horton Plains presents a formidable challenge. Nonetheless, years of patient observation have uncovered valuable insights into their intriguing characteristics. Male leopards typically measure between 1 to 1.5 meters in length and weigh from 37 to 90 kilograms, although larger individuals can exceed these averages. In contrast, female leopards are notably smaller, often less than half the size and weight of males

Throughout my years documenting leopards across Sri Lanka—from Yala to Wilpattu, Kumana, and notably Horton Plains—I’ve observed that highland-dwelling leopards tend to be larger. This observation aligns with Bergmann’s rule, which posits that animals in colder climates tend to have larger bodies to conserve heat. Research supports this trend among leopards in Horton Plains, where adaptations like an extra layer of body fat and thick underfur contribute to their larger appearance.

To help conserve heat, animals develop an extra layer of body fat and a thick coat of underfur, both of which help to keep out the cold. These adaptations collectively increase body mass, making the animals appear larger. This likely explains my observation that leopards in Horton Plains seem slightly bigger than their lowland counterparts

“Are the leopards in Horton Plains a newly discovered subspecies? How does the emergence of a new subspecies occur?”

New subspecies

The formation of a new subspecies, known as subspeciation or geographic isolation, typically begins with geographical isolation. This occurs when a population of a species becomes divided into different geographic areas, whether by natural barriers like mountains or rivers, or through other factors such as climate shifts or migration patterns. Once isolated, these separate populations experience distinct environmental conditions and selective pressures, leading to genetic divergence over time.

This genetic drift causes their gene pools to gradually diverge, eventually accumulating enough differences that individuals from the two groups may no longer successfully interbreed or produce fertile offspring. When reproductive isolation becomes complete and stable, the populations are classified as distinct subspecies. They exhibit recognisable differences in physical traits, behaviours, or genetic markers compared to both the original species and each other.

Over longer periods, if isolation persists and deepens, these subspecies may evolve into entirely separate species incapable of interbreeding, even if barriers to geographic movement are removed. The formation of subspecies is a nuanced process influenced by environmental changes, genetic variation, natural selection, and landscape dynamics, underscoring the complexity of evolutionary divergence beyond simple geographic separation.

India being a continent, why they have only one Leopard Subspecies?

India, despite being a continent-sized country with diverse ecosystems, has only one recognised subspecies of leopard: the Indian Leopard (Panthera pardus fusca). This subspecies is well-distributed across various habitats throughout the Indian subcontinent, including forests, grasslands, and urban areas. Despite regional variations in appearance and behavior, the Indian Leopard remains taxonomically classified as one subspecies due to genetic continuity and historical connectivity across its range.

In contrast, Sri Lanka, as an island nation with its own distinct leopard population, features the Sri Lankan Leopard (Panthera pardus kotiya). These leopards inhabit specific ecosystems such as lowland dry forests, tropical rainforests, and montane forests of Sri Lanka. Unlike continental regions like India, Sri Lanka’s isolation as an island restricts genetic interchange with other leopard populations. Despite this isolation, Sri Lankan leopards do not exhibit the level of genetic differentiation or geographic separation required to evolve into a distinct subspecies.

Geographic separation is a crucial factor in the formation of new subspecies. In the case of the Indian Leopard, despite its vast range across multiple countries, the genetic and ecological continuity across the landscape has maintained the integrity of a single subspecies. On the other hand, Sri Lanka’s leopards, though distinct in their habitat and behaviour adaptations, do not meet the criteria for subspecies differentiation because they have not been isolated long enough or separated significantly enough geographically to warrant separate taxonomic classification.

Therefore, while both India and Sri Lanka host unique populations of leopards adapted to their respective environments, the lack of substantial geographic separation in Sri Lanka means that it may not have multiple subspecies. Similarly, Africa too, being a continent spanning a large land space, has only one leopard subspecies (Panthera pardus pardus). This understanding underscores the intricate relationship between geographic isolation and subspecies differentiation in evolutionary biology.

As Sri Lankans, we should take pride in our endemic leopard species and recognise the importance of conserving their habitats. By safeguarding the future of the Sri Lankan leopard, we not only ensure the preservation of a remarkable and iconic subspecies but also uphold our responsibility to protect the natural treasures that make our country truly unique.

Sri Lanka Leopard Day

On August 1, Sri Lanka celebrates Sri Lankan Leopard Day, Sri Lanka Leopard Day, which will be celebrated annually, was declared based on a proposal put forward by The Wildlife and Nature Preservation Society of Sri Lanka (WNPS), Sri Lanka’s oldest (and the world’s third oldest) nature protection society.

The LOLC and WNPS Multi-Regional Monitoring System for the Conservation of Sri Lankan Leopard Established in early 2022 under the joint efforts of LOLC Holdings PLC and the Wildlife and Nature Protection Society. the Multi-Regional Monitoring System for the Sri Lankan Leopard project is a timely and essential intervention designed to monitor and protect the nation’s apex predator against both longstanding and emerging threats.

While many of the big cats within natural reserves and sanctuaries are identified and accounted for, there remains a pressing need to understand the distribution and behaviour of this species outside the range of protected zones. As an organization with an underlying passion for corporate sustainability, we are deeply committed towards sustaining resources for future generations, while delivering positive outcomes for the environment, as well as the communities that surround us. Even as we continue to hear reports of leopard deaths and close interactions between humans and leopards, the Multi-regional Monitoring System will rely on a collaborative research-based model to gain a deeper understanding of the core issues. We believe that this vital programme can improve our understanding of the complex dynamics that exist between humans and leopards across the island and enable us to derive the ideal solutions to mitigate the challenges faced by both parties on a daily basis.



This article first appeared in the Daily News on the 31st of July 2024.