• The power of our endemic species and why they must be protected

Sri Lanka, often celebrated as a treasure trove of biodiversity, holds a unique position in the world as an island nation with a remarkable array of endemic species. But beneath the layers of rich flora and fauna, there lies a delicate balance that makes the country’s biodiversity both a source of pride and a growing concern. 

Sri Lanka is recognised as one of the world’s 34 biodiversity hotspots, boasting the highest biodiversity per unit area among Asian countries. The island’s rich ecosystems include diverse rainforests, wetlands, and coastal areas, which together support an impressive array of flora and fauna. Approximately 75% of the country’s endemic animals reside within its wet zone rainforests, which are also home to nearly all of its woody endemic plants. 

Notably, Sri Lanka is home to over 3,000 varieties of rice, showcasing remarkable genetic diversity in agricultural crops. The country’s biodiversity contributes significantly to ecosystem services, providing fresh water, regulating climate, and supporting agriculture and fisheries, which are vital for the livelihoods of millions.

Despite its rich natural resources, Sri Lanka faces significant conservation challenges. The primary threat to its biodiversity stems from habitat loss due to urbanisation, agricultural expansion, and infrastructure development. Other critical issues include pollution, invasive species, and climate change, which exacerbate the decline of endemic species. 

A recent report highlighted that over 100 species were at risk, with freshwater fish particularly vulnerable due to river diversions. The economic crisis currently gripping the nation has further strained conservation efforts, limiting funding for environmental initiatives and increasing pressures on wildlife and habitats. To address these challenges effectively, experts advocate for a coordinated approach that integrates conservation with sustainable development practices. 

Endemic species are not just a part of Sri Lanka’s natural heritage – they are vital to the country’s cultural identity and economic stability, particularly through tourism. Yet, these same species are increasingly threatened by habitat destruction, climate change, and human activities. Understanding the power of our endemic species and the pressing need to protect them is key to preserving Sri Lanka’s rich biodiversity for future generations.

University of Colombo (UOC) Faculty of Science Department of Zoology and Environment Sciences Professor in Zoology Prof. Sampath Seneviratne recently highlighted just how crucial Sri Lanka’s endemism was to both its identity and its future at the National Trust Sri Lanka’s September lecture. 

The Sunday Morning Brunch sat down with Prof. Seneviratne for more on our island paradise’s endemism and what we can do to protect it. 

The island nature of Sri Lanka

Sri Lanka’s biodiversity is deeply intertwined with its geographical history. The adage ‘no man is an island’ would really seem not to apply in the context of Sri Lanka. 

“We’re not just a simple island; we’re kind of an island within an island within an island,” said Prof. Seneviratne. This multi-layered ‘islandness’ is what makes Sri Lanka so unique, both in terms of its ecological and cultural landscape.

To begin with, Sri Lanka’s isolation as an island has deep geological roots. Around 150 million years ago, the landmass that is now Sri Lanka was part of Antarctica. Over millions of years, it broke away and drifted towards its current position, near India. 

During this journey, Sri Lanka spent most of its time as an isolated island, although there have been intermittent connections with the Indian mainland. This long-standing isolation has allowed the evolution of species that are found nowhere else on earth, making Sri Lanka one of the world’s biodiversity hotspots.

Geographically, Sri Lanka is separated from India by the Palk Strait, which has limited the movement of plants, animals, and even human cultures between the two regions. This separation has created a unique evolutionary pathway for species in Sri Lanka. 

Prof. Seneviratne pointed out that this geographical isolation was crucial: “We’re geographically an island – surrounded by ocean, with the Palk Strait separating us from India. Animal, plant, and human movement is restricted, which has allowed evolution to take place independently.”

Climatically too, Sri Lanka is an island. The country is home to one of the wettest regions in the world, with the southwest receiving the highest rainfall, creating isolated pockets of ecosystems. 

In addition, Sri Lanka’s mountainous regions further contribute to its ‘island within an island’ status. These mountains create isolated habitats for many species, particularly in the montane forests, which are home to several endemic plants and animals.

Endemism: A source of national pride

Endemism, the phenomenon where species are found only in a specific location, is one of Sri Lanka’s greatest ecological assets. The island boasts an impressively high level of endemism – around 30% of its plants and animals are unique to Sri Lanka. 

“About 30% of our 4,500 plant species and about 30% of our 5,000 animal species are endemic to Sri Lanka,” said Prof. Seneviratne, emphasising the island’s significance in global biodiversity.

To put this into perspective, Sri Lanka’s level of endemism is far higher than that of much larger landmasses. For example, India’s endemism rate is around 7%, while in Europe, it is even lower, hovering between 0% and 1%. 

While other islands like the Philippines have a slightly higher endemism rate of around 50-60%, Sri Lanka’s 30% stands out because of the sheer number of species it supports – around 10,000 documented large plants and animals. This places Sri Lanka among the most biodiverse regions in the world. 

It’s also worth noting that despite Sri Lanka’s size, approximately 95% of our endemic species live in our wet zone (about a quarter of Sri Lanka’s landmass is located in the southwestern portion of the island). Incidentally, this is also where a huge part of our population lives. 

The richness of Sri Lanka’s biodiversity is not just a scientific statistic – it is also an integral part of the country’s cultural and economic fabric. Biodiversity plays a vital role in tourism, which is one of Sri Lanka’s key industries. Visitors are drawn not only to the island’s natural beauty but also to its unique species, from elephants and leopards to the wide array of endemic birds, reptiles, and plants. 

“Tourism is rooted primarily in biodiversity – people come for the uniqueness of our species, culture, food, and even traditional medicine like Ayurveda,” noted Prof. Seneviratne.

Our endemism is at risk

While Sri Lanka’s rich biodiversity is a source of pride, it also makes the island’s ecosystems particularly fragile. Due to their small geographic ranges, many endemic species have small populations, making them more susceptible to environmental changes, diseases, and human activities. 

“Life on islands is quite different. Most island species have evolved to live in simpler, more isolated systems, making them either giants or dwarfs compared to their mainland relatives,” Prof. Seneviratne highlighted. This phenomenon, known as island gigantism and dwarfism, reflects the unique evolutionary pressures faced by species on islands.

However, this long-term adaptation to stable and simple ecosystems has a downside: it leaves island species vulnerable to rapid changes. Island ecosystems typically have fewer predators and competitors, meaning that many species have not developed the resilience needed to cope with the environmental pressures brought about by human activities. 

“Our biodiversity is unique, but it is also, in a sense, weak,” said Prof. Seneviratne. “Too adapted to this small, comfortable pocket of the world, species here struggle when faced with rapid environmental changes.”

In fact, islands globally are hotspots for extinction. While islands make up only about 6% of the world’s landmass, they are home to 50% of the world’s endangered species and account for 75% of known extinctions. 

Sri Lanka is no exception. Habitat destruction, climate change, and the introduction of invasive species have all contributed to the decline of the island’s endemic species. 

Prof. Seneviratne highlighted the critical nature of the situation: “We have about 413 species of Sri Lankan endemics that are critically endangered, most of them plants and small animals like insects and shrews. If we don’t act now, we risk losing them forever.”

Conserving our endemic species

Given the vulnerability of Sri Lanka’s endemic species, conservation efforts are more important than ever. One of the most effective strategies for protecting endangered species is habitat preservation. “If you save the habitat, you save everything within it,” said Prof. Seneviratne, emphasising the need to protect critical ecosystems like rainforests, mountains, wetlands, and coral reefs.

One successful initiative in Sri Lanka is the Preserving Land and Nature Trust (PLANT) movement spearheaded by the Wildlife and Nature Protection Society (WNPS) – the oldest conservation society in Sri Lanka and the third oldest in the world. 

PLANT focuses on encouraging private landowners to commit to dedicating land to reforestation and connecting isolated forest patches through narrow corridors to increase the population size of endangered species. By linking these habitats, species are able to move between areas, which reduces their risk of extinction. 

“By connecting forest patches, you can double the available population size of any animal species and halve the extinction risk,” Prof. Seneviratne shared. This approach has already shown promise in reducing extinction risks for several of Sri Lanka’s endemic species.

However, habitat preservation alone may not be enough. Some species require more direct intervention, such as captive breeding programmes and habitat restoration. 

Prof. Seneviratne pointed to the success of the captive breeding programme for the Bandula barb, a critically endangered freshwater fish found only in one small area in Sri Lanka. Thanks to conservation efforts, the population of this species has increased from just a few to over 1,500. Similar efforts could help prevent the extinction of other critically endangered species in Sri Lanka.

Endemic vs. non-endemic 

One of the challenges in conservation is deciding whether to prioritise endemic species over non-endemic ones. 

In many cases, non-endemic species can pose a threat to endemics, especially in human-altered environments. Non-endemic species are often more adaptable to changing conditions, such as variations in humidity, light, and temperature, which gives them a competitive edge over more specialised endemic species. 

“In human-altered landscapes, non-endemic species are better at adapting, while endemic species, which are more sedentary and have less capacity for change, can be wiped out,” explained Prof. Seneviratne.

This is particularly true in Sri Lanka’s rainforests and mountain peaks, where many endemic species have evolved over millions of years in stable, untouched environments. As deforestation and habitat destruction continue, these specialised species are finding it harder to survive, while non-endemic species, which are better at coping with environmental changes, are thriving. 

However, Prof. Seneviratne stressed that endemic species should still be a priority for conservation efforts: “Endemics are our own, and in that way, conservation agencies pay more attention to them.”

The protection of habitats, such as rainforests, wetlands, and coral reefs, is the most effective way to safeguard Sri Lanka’s biodiversity. This approach benefits not only wildlife but also human communities that rely on these ecosystems for their livelihoods. For example, turtle hatcheries in Sri Lanka have transformed local economies by attracting tourists and creating jobs, demonstrating the symbiotic relationship between conservation and economic development.

Sri Lanka’s biodiversity is not just an environmental issue – it is a part of the island’s identity, its economy, and its future. As Prof. Seneviratne put it: “Our biodiversity is part of our brand.” 

Protecting Sri Lanka’s endemic species is not only about preserving the uniqueness of the island – it is about ensuring the survival of entire ecosystems, which in turn supports tourism, local communities, and the economy.