Connect with us

Features

‘Sri Lanka is a Garden of Eden for Scientists’ – Dr. Pethiyagoda

Published

on

Hiranya Sudasinghe and Dr. Pethiyagoda. The duo has jointly published a book and more than 15 scientific papers on Sri Lankan freshwater fishes

Sri Lanka’s foremost biodiversity scientist, Dr. Rohan Pethiyagoda, describes this country as “a veritable Garden of Eden for evolutionary scientists.” Speaking to The Sunday Island, he warned that while the country remains rich in natural heritage, the threats are mounting fast.

“We now have more alien species in our waters than endemic ones. There’s no longer an ‘if’ about extinction—it’s a matter of ‘when’. And we’re doing very little about it,” he stressed.

Dr. Pethiyagoda and Hiranya Sudasinghe with Dr Maurice Kottelat, the Swiss Ichthyologist, who, in the late 1980s, mentored Pethiyagoda in the study of fishes.

Winner of the Linnean Medal and the Rolex Award, Dr. Pethiyagoda has devoted decades to documenting Sri Lanka’s freshwater fishes and other fauna. In this exclusive conversation with The Sunday Island’s Ifham Nizam, he reflects on evolution, science, and the looming challenges for conservation.

Excerpts of the interview:

Q: You describe Sri Lanka as a “veritable Garden of Eden” for evolutionary scientists. What makes the island such a unique setting for studying biodiversity and evolutionary processes?

A: Several things. First off is the rainfall regime in our biodiversity-rich south-western wet zone. This is the only region in the whole of South Asia that enjoys a perhumid climate: there are no consecutive dry months. Basically, every month receives on average 100 mm of rain. As a result, the wet zone’s rainforests support astonishing plant and animal diversity.

Second is what is referred to as ‘topographic heterogeneity’, for example, the complex landscape produced by the hill country. This results in our having 103 river basins in this small island, in addition to an elevation range that spans almost 2500 metres. Finally, we have pretty good evidence that almost all our plants and animals were wiped out in the Cretaceous-Paleogene extinction event around 66 million years ago, followed by the great volcanic eruptions that took place in the Maharashtra region of India, the so-called Deccan volcanism, which resulted in the spewing of some 700,000 cubic kilometres of basalt. An unimaginable cataclysm. But it seems to have produced on Sri Lanka a blank slate for biodiversity to flourish and, conveniently, for people like me, a definitive starting date, a ‘date of creation’ if you will, for the evolution of the incredible diversity we see today.

Q: Freshwater fish are at the heart of your lecture. Why are they particularly useful for understanding evolution, and what stories do they tell about Sri Lanka’s ecological history?

A: Freshwater fishes are arguably the best-studied vertebrate group in Sri Lanka. At least for the 50 percent of the fauna that is endemic, we have up-to-date taxonomy as well as, for almost every species, DNA sequences. The bulk of this work has been done in the past decade by Hiranya Sudasinghe, who is virtually co-presenting this lecture with me. His research has helped assess the genetic diversity of fishes, reconstruct their evolutionary relationships and history, identify the regions which served as refuges during past climatic events, such as droughts, and detect extinction events. It is a phenomenal body of work, something unparalleled for any other group of plants or animals in Sri Lanka.

Q: Could you explain how sexual selection shapes not just the behaviour of fish but also that of other animals, including humans?

A: Ever since Charles Darwin brought that phrase into vogue in 1871, this phenomenon has fascinated biologists. Let’s take an example. Dinka tribesmen are cattle herders in the plains of southern Sudan. Natural selection has adapted them to that environment by selecting traits such as tallness: they average a height of around 6 feet. In the dense rainforests of the Congo, on the other hand, a smaller stature is advantageous, and so Pigmies are around a foot and a half shorter. These differences in stature probably evolved as a result of natural selection, the Dinka and Pigmies being best ‘fitted’ to their respective environments. However, a similar result could have come about also if Dinka women preferred to mate with taller men and Pigmy women preferred to mate with shorter men. It is argued, for example, that human females have large, fatty breasts even when they are not lactating (unlike apes and monkeys), because human males ‘sexually select’ large breasts as a proxy for better ability to nourish offspring. In fish, too, we see similar processes, where males and females preferentially select mates, based on arbitrary traits. But understanding these traits can be really difficult, as I will explain.

Q:  You and your colleagues have discovered and named numerous species over the years. What does the process of finding and describing a new species reveal about the challenges of biodiversity science in Sri Lanka?

A: The biggest challenge to biodiversity science in this country is the low level of public appreciation of science in general. Many people seem to view science as a sort of alien, even colonial enterprise. As a result, scientists are often viewed with suspicion. Scientific interventions are, therefore, difficult to implement. Again, let’s take an extreme and controversial example: the recent introduction to the Deduru Oya of a really pernicious alien species, the Giant Snakehead, Channa micropeltes. This rapidly reproducing species is set to devastate our aquatic ecosystems. The scientifically most appropriate way of eradicating this species may have been, at least hypothetically, to use a fish-specific toxin such as rotenone to destroy all the fish in the downstream region of the river. The lower Deduru Oya has no species endemic to it, and native species would have repopulated it after the event. But such an intervention would be so controversial in Sri Lanka that no one would touch it.

As for the discovery of new species, unless we also pay attention to conservation, it is almost a waste of time. What is the point of discovering species and publishing fat ‘Red Lists” unless we actively conserve such species? Tragically for Sri Lanka, there is a huge gulf between scientists on the one side and conservation agencies on the other.

Q: How do genomic tools and modern technology enhance our understanding of evolution compared to when you began your research?

A: Well, when I began my research in the 1980s, genetics was in its infancy. And despite more than 40 years having elapsed since the PCR machine was invented, we still lack a functional DNA sequencing facility in Sri Lanka. In such a background, there’s no point talking about genomic tools and modern technology. We’re still in the Stone Age when it comes to that. Despite the electron microscope having been commercialised a century ago, we still do not have a functional scanning electron microscope in Sri Lanka. It is worth remembering that India is becoming a world leader in biodiversity science now: they are a lot friendlier to science than Sri Lankans.

Q: Your lecture hints at the looming “Sixth Extinction.” From your perspective, how vulnerable are Sri Lanka’s freshwater ecosystems, and what urgent steps need to be taken to protect them?

A: Thing is, we know from Hiranya’s research that we have suffered climate-driven extinctions in the recent geological past. At the same time, we now have more alien species in our waters than endemic species. There’s no longer an ‘if’ associated with fish extinctions in Sri Lanka: it’s ‘when’. And we’re doing very little about it. But of course, we need to appreciate the little that has been done. The Wildlife Department, for example, recently declared the stretch of stream that supports the Bandula Barb, a critically endangered species, as a sanctuary. The Zoo maintains a captive population of this fish that could be used for introductions if an extinction does happen, but they do not have the funds to do this scientifically, for example, by ensuring the genetic diversity of the captive population. It is eminently feasible to attract funds from the private sector to establish ex-situ conservation centres for all critically endangered vertebrate animals in Sri Lanka, but the prospect is likely to prove so controversial that few scientists would even mention it openly.

Q: How do you see the balance between scientific discovery and conservation advocacy in your own career?

A: Science remains for me a passion, but not so much conservation. I am not a strong advocate of conservation because I prefer to use my time productively. Sri Lankans love nature and love wildlife. Pretty much everyone is committed to protecting wildlife. But conservation is now very heavy on science, and few Sri Lankans have an appetite for that. At 70, there are other boxes to tick on my bucket list.

Q: In your experience, what role should citizens, NGOs, and government agencies play in safeguarding aquatic habitats?

A: Well, for starters, how about respecting and restoring native vegetation on all river and stream margins? These are already ‘reserves’ in law, but no one seems to be in charge. If we afforest these, every stream and river will become a biodiversity corridor, generating a huge conservation dividend. Pretty much all our endemic fishes are dependent on shade, and streamside vegetation takes care of that as well.

Q: You’ve spent decades making biodiversity research accessible to the public. Why is science communication critical for conservation, and how can Sri Lanka improve in this area?

A: I know from my books, articles and YouTube videos that the public appetite for science is negligible. Our whole education system is focused on the arts. Only about a third of graduates are from STEM fields (Science, Technology, Engineering and Medicine). It is difficult to discuss conservation science with someone schooled in Commerce or Oriental dance. We need to invert this imbalance: that’s the first step.

Q: What do you hope the audience at this WNPS lecture will take away about evolution and biodiversity that might change how they view Sri Lanka’s wildlife?

A: I have put this lecture together with one primary goal: to inspire some girl or boy in the audience to become the next Hiranya Sudasinghe. Using our fishes as an example, I want to try and show that biology is profoundly fascinating, with so many interesting questions remaining to be studied and answered. Because of its predictive power, there’s no better intellectual platform for understanding biology than evolution. As for the rest of the audience, I hope they will be as fascinated as I am by the wonderful evolutionary processes that are moulding Sri Lanka’s biodiversity even as we watch. For this, there’s no better group of animals than fishes. They’re utterly fascinating.

Q: You’ve been awarded both the Linnean Medal and the Rolex Award for your contributions to zoology and conservation. Looking back, what are the most fulfilling aspects of your career so far?

A: In 1994, I helped Professor Sarath Kotagama to produce Siri Laka Kurullo, the first serious book on Sri Lankan ornithology, in Sinhala. It sold more than 20,000 copies, taking the hobby of birdwatching from the hallowed halls of Cinnamon Gardens to every village in Sri Lanka. It was a game-changer that democratised birdwatching and inspired ordinary Sri Lankan to take a scientific interest in biodiversity. I see kids still using tattered copies of that book even now, and when I do, my eyes well up. For me, that is fulfilment enough.

Q: What excites you most about the future of biodiversity research in Sri Lanka, especially for young scientists?

A: The antipathy to science in Sri Lanka is so deeply entrenched that I suspect that any young scientist who makes the grade will emigrate. It’s a waste of time to keep hitting your head against the wall here. Frankly, little about the future prospects for conservation science in our country excites me. Looking back at my career, now in my 70th year, I have only regrets. God knows I tried.

by Ifham Nizam  ✍️



Continue Reading
Advertisement
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

Features

Silence of the majority keeps West Asian conflict raging

Published

on

Pope Leo the XIVth / President Donald Trump

With no military quick-fix in sight to the ongoing, convoluted West Asian conflict it ought to be clear to the rationally inclined that there is no other way to a solution to the blood-letting other than through a negotiated one. Unfortunately, there are not many takers the world over for such an approach.

Consequently the war rages on incurring the gravest human costs to all relevant sides. Whereas it should be obvious to the Trump administration that Iran wouldn’t be backing down any time soon from its position of taking on the US frontally and with the required military competence in the Hormuz Strait and adjacent regions, the US demonstrates a stubbornness to persist with war strategies that are showing no quick, positive results on the ground.

Clearly, the virtual ‘lock down within a lock down’ situation in the Strait is not proving beneficial for either party. Instead, the spilling of civilian blood in particular continues with unsettling regularity along with an all-encompassing economic crisis that carries a staggering material toll for ordinary people all over the world.

From this viewpoint it is commendable for Pakistan to offer itself as a peace mediator and go ‘the extra mile’ to keep the principal parties engaged in some sort of negotiatory process. But its efforts need to win greater support from the world community. It is a time for peace-makers the world over to stand up and be counted.

It is also a time for straight-talking. To his glowing credit Pope Leo XIV is doing just that and he is the only religious head worldwide to do so. Very rightly he has called on President Trump to end the war through negotiations and described it as ‘unjust’ and ‘a scandal to humanity’.

May this crucial cause be taken up by more and more world leaders, is this columnist’s wish. Instead of speaking fatalistically about a ‘Third World War’, decision and policy makers and commentators, and these are found in plenty in Sri Lanka as well, would do better to help in drumming-up support for a peaceful solution and the latter is within the realms of the possible.

Incidentally, the commonplace definition of the phrase ‘World War’ is quite contentious and it would be premature to speak forebodingly about one right now. The fissures within the West on the Middle East conflict alone rule out the possibility of a ‘World War’ occurring any time soon.

Instead, it would be preferable for the international community, under the aegis of the UN, to take the ‘straight and narrow’ path to a peaceful solution. As implied, this path is no easy avenue; it is cluttered with obstacles that only doughty peace makers could take on and clear.

However, the path to a negotiated peace is worth taking and no less a power than the US should know this. After all, the US ‘bled white’ in Vietnam and had to bow out of the conflict, realizing the futility of pursuing a military solution. A similar lesson should have been learned by Russia which bled futilely in Afghanistan. It too is in an unwinnable situation in Ukraine.

The Pope’s observations to President Trump on negotiating peace have earned for him some snarls and growls of criticism but with time these critics would realize that peace could come only by peaceful means and not through ‘the barrel of a gun.’

For far too long the ‘silent majority’ of the world has allowed politicians to take the sole initiative on working towards peaceful solutions to conflicts and wars. As could be seen, the results have been disastrous. The majority of politicians speak the language of Realpolitik only and this tendency runs contrary to the ways of the selfless peace maker.

Power, which is the essence of Realpolitik, and peace are generally at loggerheads in the real world. Power and self-aggrandizement have to be shelved in the pursuit of durable peace anywhere and it is a pity that the likes of Donald Trump and his team are yet to realize this.

At this juncture the ‘peace constituency’ or the silent majority would need to take centre stage and play their rightful role as the ‘Conscience of the World’. If the latter begins to take on the cause of peace in earnest everywhere, the politicians would have no choice but to pay heed to their cause and take it up, since a contrary course would earn for them public displeasure and votes.

An immediate challenge would be for the ‘peace constituency’ to come together and act as one. Right now, such a coordinating role could be played effectively by only the UN and its agencies. Practical problems are likely to get in the way but these need to be managed insightfully and resourcefully by all stakeholders to peace.

In fact the time couldn’t be more appropriate for the backers of peace to come together and work as one. Right now, economic pressures are increasing worldwide and no less a public than that in the US is beginning to feel them in a major, crushing way.

Going ahead the US public, along with other polities, would find the economic consequences of war to be intolerable. There would be no choice but for governments and peoples to champion peace. Peace makers would need to ‘strike while the iron is hot.’

The success of the above endeavours hinges on the importance humans attach to their consciences. The danger about prolonged wars is that they deaden consciences; particularly those of politicians. The latter deaden their consciences to the extent that they prove impervious to the pain and suffering wars incur.

Thus, the ‘peace constituency’ has its work cut out; it cannot rest assured that politicians would prove sensitive to their demands. The latter would need to be constantly dinned into the hearts and minds of politicians and decision-makers if peaceful solutions to conflicts are to be arrived at.

Likewise, the publics of war-torn countries would need to demand the activation and sustaining of accountability processes with regard to those sections that are suspected of committing war crimes and like atrocities. Those publics that cease to demand accountability from powerful sections among them which are faced with war-time atrocity charges are as good as condemning themselves to lives of permanent dis-empowerment and enslavement.

Continue Reading

Features

Don’t take the baby: In the quiet night, mother always returns

Published

on

Grey Slender Loris

Chaminda Jayasekara

There is a particular stillness in Sri Lanka’s forests, after dusk — a kind of hushed expectancy where shadows lengthen, cicadas soften their chorus, and the night begins to breathe in its own rhythm. It is a world that does not reveal itself easily. You have to wait for it. You have to listen.

And then, suddenly, you see them — a pair of luminous, unblinking eyes suspended in the dark.

The Grey Slender Loris, or unahapuluwa, emerges, not with drama, but with quiet precision. Small, slow-moving, and almost impossibly delicate, it is one of Sri Lanka’s most enigmatic nocturnal primates — a creature that has survived millennia by mastering the art of stillness.

Yet, during these months — from late March through July — the forests hold a more tender story. It is the breeding season of the slender loris, and with it comes a scene that is often misunderstood by those who encounter it for the first time: a tiny infant, alone on a branch, barely three inches long, its fragile body silhouetted against the night.

Grey Slender Loris with twin babies

To many, it appears to be a moment of abandonment.

To nature, it is a moment of trust.

“People often act out of compassion, but without understanding what they are seeing,” explains Chaminda Jayasekara of the University of Hertfordshire. “A baby loris left alone is not necessarily in danger. In fact, it is part of a natural process that is critical for its survival.”

According to Jayasekara, when a baby loris is about a month old, the mother begins a remarkable routine. As darkness settles, she gently places her infant on a secure branch and moves off into the forest to forage. Her journey can take her hundreds of metres away — sometimes close to 800 metres — as she searches for insects and other small prey.

In those hours of solitude, the infant is not abandoned. It is learning.

Clinging to the branch, it begins to explore its immediate surroundings. Tentatively, almost hesitantly, it reaches out — testing balance, grip, and instinct. It may attempt to catch tiny insects, mimicking behaviours it will one day rely on entirely. This is its first classroom, and the forest its only teacher.

“Those early nights are crucial,” Jayasekara says. “The baby is developing motor skills, coordination, and the ability to interact with its environment. These are things that cannot be replicated in captivity.”

And yet, this is precisely where human intervention often disrupts the process.

Across rural and even semi-urban Sri Lanka, stories circulate of well-meaning individuals who come across a lone baby loris and assume the worst. Driven by concern, they pick it up, take it home, or attempt to hand-rear it — believing they are saving a life.

Grey Slender Loris

But the reality is far more complex — and far more tragic.

“When a baby is removed unnecessarily, it loses something fundamental,” Jayasekara emphasises. “It loses the chance to learn how to survive in the wild. Without that, even if it survives in the short term, its long-term prospects are extremely poor.”

The forest, after all, is not just a habitat. It is a living, evolving system of lessons — how to detect predators, how to navigate branches, how to hunt silently, how to recognise territory. These are not instincts alone; they are behaviours refined through experience.

And the mother, contrary to assumption, is rarely far away.

“If people simply waited — even for several hours — they would often see the mother return,” Jayasekara explains. “She knows exactly where she left her baby. Her absence is temporary, purposeful.”

The advice from conservationists is clear and consistent: observe, but do not interfere.

If you encounter a baby loris, watch quietly from a distance. Avoid using bright lights or making noise. Give it time — at least 10 to 12 hours — before drawing conclusions. In most cases, the situation will resolve itself, just as nature intended.

35 days old Grey Slender Loris

Only if the animal is clearly injured, or if there is strong evidence of abandonment after prolonged observation, should intervention be considered — and even then, it must be done through the proper channels, particularly the Department of Wildlife Conservation.

Attempting to care for such a delicate animal at home is not only ineffective but often fatal.

Sri Lanka is home to two species of slender loris — the Grey Slender Loris and the Red Slender Loris — each adapted to specific ecological zones across the island. Both are protected under national legislation and recognised internationally as species requiring urgent conservation attention.

Their threats are many: habitat loss, road mortality, illegal pet trade, and, increasingly, human misunderstanding.

Yet, in the midst of these challenges, there are also signs of hope.

In recent years, the slender loris has become the focus of a unique form of wildlife tourism — one that values patience over spectacle. Night walks, conducted with trained naturalists and strict ethical guidelines, offer visitors a chance to witness the loris in its natural environment without disturbing its behaviour.

At places like Jetwing Vil Uyana, this approach has been refined into a model of responsible eco-tourism. Over more than a decade, the property has developed a dedicated Loris Conservation Project, recording thousands of sightings while educating visitors and supporting local communities.

Here, the loris is not handled, chased, or exploited. It is simply observed — a quiet presence in a carefully protected landscape.

“The success of such initiatives shows that conservation and tourism do not have to be at odds,” Jayasekara reflects. “When done responsibly, tourism can actually support conservation by creating awareness and value for these species.”

There is something profoundly moving about encountering a loris in the wild. It does not roar or charge. It does not demand attention. Instead, it exists — quietly, deliberately — as it has for millions of years.

And perhaps that is why it is so easily misunderstood.

In a world that often equates visibility with importance, the loris reminds us that some of the most extraordinary lives unfold beyond the spotlight.

It also reminds us of something else — something simpler, yet harder to practice.

Restraint.

Because conservation is not always about stepping in. Sometimes, it is about stepping back. About recognising when nature does not need our help, but our patience.

So if, on some future night, you find yourself walking beneath the trees, and your light catches a tiny figure sitting alone on a branch — do not rush forward.

Pause.
Watch.
Let the moment unfold.

Because somewhere, moving silently through the darkness, guided by instinct and memory, a mother is already on her way back.

And by morning, the forest will be whole again.

 

By Ifham Nizam

Continue Reading

Features

Kumar de Silva: 40 years of fame and flair

Published

on

Kumar de Silva: The four-decade journey

We first saw him on the small screen in January 1986 – a relatively raw, totally untrained and a very nervous 24-year-old presenting ‘Bonsoir’ on ITN.

And now, 40 years later, and as one looks back, one realises what a multi-dimensional journey Kumar de Silva has navigated across the small screen yes, from your television screens to your laptops, and iPads, tabs, and mobile phones.

Says Kumar: “It is the French language I speak that opened the world of television to me, 40 years ago. It was ‘Bonsoir’ alone, and so to my French teacher at Wesley College, Mrs. BA Fernando, to ‘Bonsoir’, and to the Embassy of France in Sri Lanka, I am eternally grateful”.

Promoting the French language, and culture, in Sri Lanka, in a big way

Kumar went on to say that on the heels of ‘Bonsoir” came ‘Fanclub’, on ITN, describing it as yet another resounding success story which saw him as a music DJ on TV.

His inherent talent saw him handle a range of contrasting programmes across ITN, TNL, Prime TV and SLRC with consummate ease – from News Reading, Business Talk Shows, Celebrity Chats, to Dhamma discussions, on Poya Days, to name a few.

Kumar – the 1986 look

Trained in Paris in television production and presentation, the Government of France, in 2012, conferred on him the title of ‘Chevalier dans l’Ordre des Arts et Lettres’ (Chevalier in the Order of Arts and Letters) in recognition of his contribution to promoting the French language, and culture, in Sri Lanka.

In celebration of his four decades on the small screen, Kumar recently launched ‘Bonsoir Katha’, the Sinhala translation (by Ciara Mendis) of his English book ‘Bonsoir Diaries’ (2013), at a gala soiree. at the Alliance Francaise de Colombo, under the distinguished patronage of the French Ambassador in Sri Lanka, Remi Lambert, and francophone President Chandrika Kumaratunga.

He’s now excited about launching the French version of this book, ‘Les Coulisses de Bonsoir’, in Paris, in autumn this year. It is currently being translated by Guilhem Beugnon, a former Deputy Director of the Alliance Francaise de Colombo. This will, co-incidentally, also be Kumar’s 30th visit to Paris.

Chief Guest French Ambassador in Sri
Lanka Remi Lambert

Says Kumar: “The word GRATITUDE means a lot to me and so I always make it a point to spend time with two very special French people every time I go to France. One is Madame Josiane Thureau, formerly of the French Foreign Ministry, who began ‘Bonsoir’ in Sri Lanka. way back in the mid-1980s. The other is Madame Aline Berengier, the lady who designed the ‘Bonsoir’ logo – the Sri Lankan elephant in the colours of the French national flag”.

Kumar is also a much-sought-after Personal Development and Corporate Etiquette Coach in Colombo’s corporate world. Over the past 15 years, tens of thousands of corporates, have been through the different modules of his interactive training sessions. There have also been thousands of school leavers and undergraduates from national and private universities, many of whom will constitute the corporates of tomorrow.

Guest of Honour francophone President Chandrika Kumaratunga at the gala soiree
at the Alliance Francaise de Colombo

The multi-talented Kumar turns 65 next year, and his journey on the small screen still continues – you see him on the (monthly) ‘Rendez-Vous with Yasmin and Kumar’ on the French Embassy’s YouTube Channel, and (every Friday) on ‘Fame Game with Rozanne and Kumar’ on Daily Mirror Online, Hi Online and The Sun Online.

There’s yet another podcast in the pipeline, he indicated, but diplomatically declined to give us details. All he said, with a glint in his eye, was, “It will hit your screens soon.”

Whatever he has in mind, one can be certain that the new programme will continue to showcase Kumar de Silva’s enduring presence in Sri Lanka’s entertainment scene.

Continue Reading

Trending