The Prince of Frogs - Journey of SD Biju, a Pathfinder

Joseph Antony

22 min read
Read later

From his roots as a plant taxonomist, Professor S. D. Biju (Sathyabhama Das Biju) evolved rapidly into an amphibian biologist of international repute. He is one of the only few living scientists in the world who have described more than a hundred amphibians. The scale and significance of his achievements brought him the unofficial title of 'Frogman of India'. Biju is a Senior Professor in the Department of Environmental Studies at University of Delhi and an associate of the Department of Organismic and Evolutionary Biology at Harvard University. He was recently awarded the prestigious Radcliffe Fellowship for the year 2023-2024 to work full-time at Harvard. He recieved Kerala State Government's highest civilian award Kerala Sree for 2022.

Prof. S. D. Biju. Radcliffe Fellow, Harvard University. Photo: Sonali Garg

Some people cleave history into two - before and after them. Their chosen field of activity would never be the same again after they appeared on its horizon. In the world of scientific research in India too, there are personalities like Dr. Salim Ali who, through his genius and dedication, transformed Indian Ornithology of the twentieth century.

Likewise, the scene of Indian herpetology underwent a sea change after the emergence of Professor (Dr.) S. D. Biju (Sathyabhama Das Biju). Many assess the history of Indian herpetology as 'before and after Biju'. Indian herpetology underwent a total metamorphosis after Biju came up with his first paper on the frogs of the Western Ghats in 2001 (1).

Frogs are to Biju what birds were to Salim Ali! If Salim Ali was the pre-eminent field biologist of India in the 20th century, then 21st century belongs to researchers like Biju. The media that called Salim Ali, the 'Birdman of India', now tags Biju as the 'Frogman of India!' (2, 3).

Herpetology is the study of amphibians (frogs, salamanders, and caecilians) and reptiles. The number of species of amphibians reported in India was only 206, when two decades ago Biju presented his first paper on this subject. It is more than 462 now - the credit for nearly 25 percent of the new discoveries goes to Biju (4). This includes two families of amphibians, 11 genera and 106 species (5). The Frogman of India has crossed a century and remains not out!

Every new discovery of a species is an unravelling of another great mystery of nature! Through his findings, Biju has unravelled more than a hundred mysteries hitherto unknown to humans! He is one of the only few living scientists in the world who have described more than a hundred amphibians.

Indian Purple frog (Nasikabatrachus sahyadrensis). Photo: S. D. Biju

Biju attained this rare achievement because of his decades-long arduous search in the inaccessible parts of Western Ghats and the north-eastern states of India - the result of the troubles and travails he underwent, come rain or shine. Roughly four months a year; that is, ten years in 30 years - that's how long his research took to study amphibians and impress upon the world the need for their conservation.

Biju has published his findings in over a hundred scientific papers in international journals including Nature, Science and Proceedings of National Academy of Sciences (PNAS). His discoveries have made news in influential media magazines across the world, such as National Geographic, The Economist, BBC News, New York Times and The Guardian, to name a few. On a simple Google search, over a million hits show up on 'S. D. Biju' and his work.

"Prof. Biju's work has not only given a much-needed impetus to Indian herpetology, but in general revolutionized taxonomic research across all the overlooked forms of life in the country." says Dr. Sonali Garg, Biodiversity Post-doctoral Fellow at Harvard University, and former student of Biju.

If the paper published in 2001 heralded the entry of Biju into the world of amphibians, the 2003 paper in Nature raised him to stardom. Biju and the Belgian scientist, Prof. Franky Bossuyt announced the discovery of a new family of frogs for the new genus and species Nasikabatrachus sahyadrensis in that publication (6). Using DNA, Biju and Bossuyt deciphered the evolutionary origin of this seven-centimetre-long frog to be 130 million years ago. The frog became a living proof that the Indian subcontinent was once part of the supercontinent, the Gondwanaland. Both the scientific and popular media called it a 'discovery of the century' (7), 'the living fossil' (8) and 'once-in-a-century find' (8, 9) - a thrilling episode in the recent history of global herpetology.

Chikilidae, a new family of soil-burrowing and limbless amphibians described from Northeast India
by Biju and his student in 2012. Photo: S. D. Biju

There was no looking back for Biju after the 2003 discovery. The University of Delhi invited him to join as a professor in a suo motu decision. Currently Senior Professor with the Department of Environmental Studies at University of Delhi, Biju is also academically associated with one of the world's most prestigious universities, the Harvard. He is currently an Associate at Harvard's Department of Organismic and Evolutionary Biology ( Later this year, Biju will also officially go on to join Harvard as a Radcliffe Fellow, a competitive and prestigious interdisciplinary position for which he has been selected among a handful of leading professionals from the world over (

Biju, a native of Kadakkal, Kollam district, in Kerala, South India, is stepping into where two of the greatest biologists of the 20th century worked - Edward. O. Wilson, known as the 'Father of Biodiversity', and Ernst Mayr, the 'Second Darwin'. As he turns 60, Biju climbs a step further. To be included among the awardees of the first 'Kerala Sree' (, one of the highest civilian honors conferred by the Government of Kerala for "priceless contributions to the society", could not have come at a more appropriate moment in his life. Biju has previously been honoured with awards such as the IUCN/ASG Sabin Award (2008) and Sanctuary Asia Wildlife Service Award (2011) in recognition of his contributions to amphibian research and conservation.

"Not many researchers can be as passionate about their field as Biju. At 60, he shows the same excitement and intensity towards his research as he had when he was 35", says Dr. Ashish Thomas, Assistant Professor at Delhi University, who did his Ph.D. under Biju's guidance.

Biju's expertise spans from the field of taxonomy to evolutionary biology. With an evolutionary history of 350 million years, amphibians were the first animals to make a transition from life in water to the land. After bringing Indian amphibians and their unique evolutionary histories into limelight, Biju will expand his research at Harvard to better understand the evolutionary journeys of amphibians across the continent of Asia, using a wide array of advanced integrative approaches now available to organismic biologists.

Prof. James Hanken, former director of the Museum of Comparative Zoology at Harvard and current Curator of Herpetology, in reply to the author's query as to how a person of his stature at Harvard views Biju's research contributions, commented over email that "Prof. Biju's professional accomplishments and research record in the area of amphibian biology are, by any measure, first-rate, and he is seen as someone who can make important contributions to research efforts here and be a valuable research collaborator."

Taxonomy - A Timeless Mantra!

According to Biju, his two teachers were the ones who transformed his life: the late Prof. V.V. Sivarajan of Calicut University and Prof. Franky Bossuyt of Vrije Universiteit in Belgium. Prof. Sivarajan was a botanist who breathed a new life into plant taxonomy studies in India.

But what role would a plant taxonomist have in the life of an eminent amphibian researcher? Therein lies the twist! Biju was initially a botanist, who obtained his first Ph.D. in Plant Taxonomy from Calicut University. There, Biju had two research guides. Prof. Philip Mathew under whose guidance he was formally registered, and Prof. V. V. Sivarajan, who was Biju's true mentor. "While I am grateful to Prof. Mathew for his role and support as my guide, I must acknowledge that Prof. Sivarajan was the one who taught me the basics of taxonomy," remembers Biju. "Taxonomy can be tedious, but he showed me how to work on it with enthusiasm for a sustained period. He inspired me to find pleasure in taxonomy. Without Sivarajan Sir, I would have never seriously considered the possibility of a career as a taxonomist." Biju believes that taxonomy is not meant for everyone. "Taxonomy is an art. It is not rocket science, but it requires a special talent that cannot always be taught. When you hold a specimen in your hand, you must get a feel of life!"

In 1999, Biju was awarded his Ph.D. in Botany. Bizarre it might seem; he quit Botany the next year, but not taxonomy and systematics - only, amphibians replaced plants!

Biju had gained employment as a scientist at Jawaharlal Nehru Tropical Botanical Gardens and Research Institute (JNTBGRI) at Thiruvananthapuram, while doing his Ph.D. at Calicut University. He officially worked there from 1992 to 2004. Back then, Biju also discovered new plant species during his explorations in the Western Ghats. Stictocardia sivaranjinii is one among them; a tribute to his guru, Prof. Sivarajan.

And then frogs discovered Biju, somewhere, sometime in one of those trips!

Biju has written that his attention was turned to frogs while attempting to take a photograph of Malabar Gliding Frog (Rhacophorus malabaricus) during a botanical expedition in the Western Ghats. Excited by the result, he started taking pictures of frogs whenever he came across one.

The Malabar gliding frog (Rhacophorus malabaricus) was the first frog
S. D. Biju photographed. Photo: S. D. Biju

As the collection of frog pictures grew, so did his interest to learn more about them. "I began to read more, going over research and review papers in depth. I realized that there were lacunae in the scientific understanding of Indian frogs. I discussed with amphibian experts in the country at that point, but in vain, as many frogs could not be satisfactorily identified. Gradually, study of amphibians became a part of my life."

In fact, Biju was beginning to understand the mission of his life. First confined to the Western Ghats of Kerala, his research on amphibians soon spread over the entire mountain chain of the Western Ghats. Over a survey of seven years, he collected frog samples from nearly 500 locations in the Western Ghats. He sought the help of experts from outside India too during this period. In 1998, Biju got in touch with Prof. Robert F. Inger of Field Museum, Chicago, who gave him very valuable guidance, and many years later, even went on to become the jury Chairman for his second Ph.D. on amphibians. Biju also interacted with several other international experts such as Prof. Alain Dubois (Museum of Natural History, Paris, France), Prof. Indraneil Das (University of Malaysia, Sarawak), Prof. Mark Wilkinson (Natural History Museum, London), and Rohan Pethiyagoda who first invited him to collectively study the Indian and Sri Lankan frogs.

Biju's first research publication on amphibians in 2001 was the outcome of a seven-year long, self-funded field work, silently studying and documenting frogs. Biju came to be noticed globally as an upcoming herpetologist with this publication. At the same time, he was awarded a Fellowship of the French government to study the techniques of amphibian research at Paris Museum with Prof. Alain Dubois. During the three-month-long stay at Paris, Biju could examine the collections of Indian specimens at various European museums including the British Museum of Natural History.

But the kind of generous appreciation of his work shown by experts outside the country was absent from within his native country. "The 2001 paper brought me utmost criticism and ridicule," remembers Biju. "How could a botanist talk authoritatively on frogs, was the critics' question."

The Resplendent Shrub Frog (Raorchestes resplendens), a unique ground-dwelling rhacophorid frog found in a
​​​​​​small region in the Anaimalai Hills of the Western Ghats, was discovered by Biju and co-researchers in 2010. Photo: S. D. Biju

In that paper Biju cautiously predicted that there can be more than a hundred species of frogs yet to be discovered in the Western Ghats and that would take the total number of frog species in Western Ghats to 200 (1). This statement irked many. Some researchers at leading institutes even published articles challenging the prediction (10). "Now, two decades later the number has crossed 200. Those critics now refer to that prediction without mentioning my name," a smile spreads across Biju's face as he talks.

While the 2001 paper was being stone-pelted by critics, Biju continued his research and turned his focus to a discovery that would stun herpetologists across the world. Biju had obtained a frog specimen split into two by a spade. It was collected by a farmer who got it while digging for a well near Thattekkad, Kerala. He preserved it in a bottle of rum and gave it to Biju!
When further search in Thattekkad for the 'Double-cut' frog bore no fruits, Biju directed his attention to Kattappana, in the Idukki district of Kerala - to the 'Double Cut' village, to be exact!

Striking Gold of Gondwana

The Purple Frog (Nasikabatrachus sahyadrensis) is distinctive with its purple-colored skin, pig-like nose, tiny blue eyes, very short limbs, and a ball-like body. They live up to six meters underground all the time, except for a week at the onset of summer showers when they emerge above ground for breeding. Shaped like a tortoise and with a call like that of a chicken, the Purple Frog is between 5 to 10 cm long.

The specimen from Thattekkad Biju got in 1997 was the first inkling about this strange creature. "Most villagers around the Western Ghats region knew me; I was the crazy one looking for frogs, running around on a Yamaha scooter, shaggy and shabby. Neither did have I much money nor my family could help much."

"It was clear that the Thattekkad specimen was different from the known frog species. Though I was penniless, I spent several days searching for it but failed to get one. We didn't know then that it had a subterranean life." But Biju didn't give up hope. When Biju along with his friend and wildlife photographer Sali Palode met the locals at Kattappana, they said the frogs appeared every year and that they have seen them at a place called 'Double Cut'.

"Jayan, a local man, assisted us. I stayed at Jayan's humble house for about a month during the rainy season in June-July, watching out for the Purple Frog, but with no avail. In the following year, towards the end of the month of April, Jayan called me: 'Sir, two of them have come out! I have kept them safe in a pot!' I caught the next bus to Kattappana."

"Such a treasure it was! I cannot describe the day I saw it. Because any frog expert could see that it was no ordinary frog! Further digging at Double Cut, brought up more Purple Frogs."

Genetic studies linked with taxonomy weren't much developed in the country in those days. Those who did such studies were yet to see beyond microscopes. But Biju decided to do molecular studies on the Purple Frog. "The late Dr. J. Nagaraju, a scientist at the Centre for Cellular and Molecular Biology (CCMB), Hyderabad, helped me obtain a DNA sequence of this frog. I went to him with the samples, stayed there for five days and learned the basics."

Biju remembers: "When I decided to drop botany, I was left with two options - one, to live a life of lies for the rest of my life, pretending to study botany and do other work, or resign from my job. Giving up a job was a great risk in those days. The sole source of income would be cut off. I did not know what to do. All I knew was that I wanted to study frogs. Only my wife knew that I was planning to resign from JNTBGRI. And she supported my decision."

Biju with Professor Franky Bossuyt. Photo: K. Jayaram

It was then that Biju seriously considered taking a Ph.D. in herpetology. He had found another guru like the late Prof. V. V. Sivarjan, who changed the future course of his life - Prof. Franky Bossuyt of Vrije Universiteit in Belgium, who one fine day serendipitously contacted Biju after reading his publication from 2001.

A detailed genetic study of the Purple Frog was conducted together with Bossuyt. The study made it clear that the frog did not belong to any of the 29 families previously known. Biju and Bossuyt were enthused over the fact that they have brought to light a new family of frogs for the first time since 1929. Thus, Nasikabatrachidae became the 30th family of frogs known to the world.

There are three orders of amphibians: Anura (frogs), Caudata (salamanders), and Gymnophiona (caecilians). A large majority of species are frogs. Global databases for amphibians (4, 11) state that so far about 7600 species of frogs spread across 56 families are known globally. The number of known salamanders stands at 810 and caecilians at 221. Caecilians are limbless amphibians that look like large worms or snakes and live underground. The second amphibian family that goes to Biju's credit is the caecilian family Chikilidae that he unearthed from Northeast India in 2012 along with his PhD student (12).

It was clear from the genetic studies on Nasikabatrachidae that its evolutionary history goes back to the Gondwana period. It has no relatives in India. Biju and Bossuyt discovered that a frog living in the Seychelles Islands, about 3,000 kilometers away in the Indian Ocean, has a distant genetic resemblance - making it the only known closest relative of the Indian Purple Frog!

Further studies indicated that these Seychelles Island Frogs or Sooglossidae and Nasikabatrachus sahyadrensis had parted ways about 130 million years ago. The Nasikabatrachidae did not undergo much change since the age of Dinosaurs.

Biju and Bossuyt used phylobiogeography (study of the historical processes of geographic distributions of genealogical lineages) to trace the evolutionary path of this new family Nasikabatrachidae. "To put it in simple words - we used computer-based programs to estimate the date of origin of this frog using DNA sequences. Such a technique was in its infancy when we worked with it. It is much more advanced now. Nonetheless, it became evident that Sooglossidae and Nasikabatrachidae shared an ancestry from the Gondwana times."

In 2003, Biju became a star overnight when the Nasikabatrachus discovery was finally published in the journal Nature. But his detractors didn't rest. "They said this was not my work!" Biju recollects. It was an achievement that many holding authority in the field could not make. "I take it as a blessing in disguise that made me only work harder. And as I look back, maybe there wouldn't exist the Biju of today if the saga of Nasikabatrachus hadn't happened in my life. The Biju minus Nasikabatrachus would not have been me. Unknown, uninteresting, I would have been around somewhere. But not this Biju!"

The Borderless World of Research

Biju joined Vrije Universiteit in Belgium for Ph.D. under Prof. Franky Bossuyt after resigning from JNTBGRI in 2004. His research focused on the systematics and conservation of amphibians; the degree was awarded in 2007.

But even before that, in 2005, an unexpected phone call was received at the office of his then Ph.D. guide. The person on the line wished to speak to Biju. Personal mobile phones were not common back then, and even if they were, Biju didn't own one. "The Delhi University authorities invited me to join as a faculty member when I was still working in Belgium." Biju recalls. "The then Vice-Chancellor of Delhi University, Prof. Deepak Nayyar and Pro-Vice Chancellor, Prof. C. R. Babu had taken the initiative. I was skeptical but Dr. M. Sanjappa, the former Director of Botanical Survey of India, who was familiar with my work from my early plant days, greatly encouraged me to join. I wouldn't be here if it wasn't for him!"

Biju had certain requirements: one, that he wouldn't start work in Delhi until the submission of his Ph.D. thesis at Vrije Universiteit, Brussels. So, "I was appointed as Reader at Delhi University in 2005, but I came to Delhi only in 2006". After completing three years as an Associate Professor, and another ten as Professor, Biju is currently a Senior Professor at the University, and has served as the Head of his Department and the Dean of the Faculty of Science.

Second, "I needed a laboratory space in Delhi as well as funds for setting it up." Both were readily offered. An excellent molecular lab and related paraphernalia came next. That was the beginning of the Systematics Lab ( at Delhi University for the study of amphibians. His lab studies anything and everything about amphibians, but primarily systematics, that includes nomenclature and classification and deciphering systematic relationships using morphological, molecular and various other integrative approaches, as well as evolution, biogeography, reproduction, vocalization and conservation.

Forest expeditions typically lasting several weeks and sometimes months are necessary to search for amphibians and are an integral part of field-based research. Photo: Systematics Lab

But a well-equipped lab alone would not serve the purpose; samples of amphibians must be collected. For that one must take to the forests. "I am not in Delhi for about four months in a year, but in the field," stated Biju.

Prof. Deepak Pental had replaced Deepak Nayyar as the Vice Chancellor. He didn't know Biju, but it took him no time to understand the importance of Biju's work. He extended his unconditional support towards his scientific mission. "Prof. Pental was the reason I continued to work at Delhi University. He took pride in the work we produced here in our small lab and always warmly referred to me as a colleague!" In gratitude, one of the frogs discovered by Biju is named after Pental.

The two-month summer vacation period at the University coincides with the monsoon in the Western Ghats and Northeast India, where it rains mainly in June, July, and August. "To that I add my eligible leaves, altogether giving me four months for field work." He adds, "I also often try to maintain a fitness regime - not for a longer life, but to keep my health for hard field work in the jungles." For the rest of the year, he and his students work on the samples collected during the field season.

A series of high-quality papers on amphibians began flowing out of Biju's lab from 2006 itself. Soon, the Systematics Lab became one of the most active research centers of herpetology in the world. 'Delhi University' was frequently mentioned in international media. Students from foreign nations sought research possibilities at Biju's Lab. He had guided students from countries such as Ireland and Belgium at his lab.

India's smallest frog (Miniature Night Frog, Nyctibatrachus minimus) sitting comfortably on an Indian five rupee coin, was another species discovered by Biju and co-researchers. Photo: S. D. Biju

Though he joined Delhi University, Biju did not forget his role model, Franky Bossuyt. Like the plant he named after Prof. Sivarajan, Bossuyt's name was given for two frogs - Frankixalus jerdonii discovered from the Northeast and Mysticellus franki from the Western Ghats.

Dr. M. Sanjappa, the former Director of Botanical Survey of India (BSI) and INSA Senior Scientist, has known Biju since his Calicut University days. "He does his research work with total dedication" - says Sanjappa in an email communication. "At JNTBGRI, Biju did floristic and ecological works in Silent Valley National Park, Eravikulam National Park, and other such protected areas of Kerala State. It is here that he developed his fascination for working on the taxonomy and the biology of frogs for which he literally spent whatever salary he was getting from JNTBGRI and any available family funds. His dedication was such that he would use his holidays for field study and rear and breed frogs at his residence in his makeshift laboratory."

Biju extends the same care he has about his gurus to his students as well. "Biju Sir leads us on our field trips as if we are on an army expedition. He might seem very strict from afar, but actually he is very considerate of his students," says his former student, Dr. Ashish Thomas.

Former masters and PhD students of Biju and members of his lab (Systematics lab, at Univer_sity of Delhi along with Prof. Darrel Frost (AMNH, USA), Romulus Whitaker (Madras Crocodile Bank Trust and Centre for Herpetology), and Prof. Franky Bossuyt (VUB, Belgium). Photo: Gopinath Sricandane

Biju has two exceptional qualities as a researcher, says Ashish - "extraordinary memory and ability to foresee the future. He can correctly recollect when and where he saw a particular frog even after years. He is always on the alert for probable changes in the existing conditions. He has the farsightedness to predict what aspect of frog studies would be relevant, what technology would be more applicable in the forthcoming years. What took him to Bossuyt's lab in Belgium is his correct anticipation that molecular studies of amphibians would take centerstage in the near future." Ashish Thomas spent six years from 2008 onwards in Kattappana, studying the Purple Frogs under Biju's supervision.

"As a teacher and mentor, Biju Sir leads by example! His passion, determination, and persuasion are contagious. His contributions to my professional life are far more than those of my parents," says Dr. Sonali Garg, also his former student. "He inspires and supports his students in every possible way. He spends most of his personal earnings on research, be it for field work or lab facilities. Our work never stops as long as there is salary remaining in his bank account. He even helps students during their personal financial difficulties. He always recalls that many people helped him during his early and difficult days, so he knows how much a single meal or a small contribution matter." Sonali has worked with Biju for over 12 years, right from being his Master's and PhD student, to their continued scientific collaboration for her postdoctoral studies.

Sonali adds, "His work is his life - and he works with all his heart; and anyone who knows him closely has seen his heart of gold," as a sense of deep respect rings in her voice. "Biju Sir is a rare specimen. From where he came, to what he has achieved, his contributions to frogs, science, and society will remain unparalleled. History will be kind to him and stand testimony, whether people choose to say it out aloud or not!"

Frog Kamasutra

The way Biju was once introduced by an American colleague was rather unexpected. "The only frog herpetologist ever to appear on a Stephen Colbert's Late-Night Show! Only then did I realize the importance of this TV show. Our research had made it to the drawing rooms of common US homes." laughs Biju.

Stephen Colbert's Late-Night Show is a popular program in the US TV channel, the CBS. The late-night show in June 2016 talked about the discovery of a peculiar reproductive behavior in Bombay Night Frogs (Nyctibatrachus humayuni) that was published in the journal Peer J by Biju and his colleagues (13).

Until the publication of that paper, researchers had observed that the then 6650 frog species in the world mated in six different positions. But Biju and fellow researchers found that there was a seventh amplexus position, unique for the Bombay Night Frogs! They named it 'Dorsal straddle'! (14).

The seventh 'sex' or amplexus position in frogs - Dorsal straddle - was discovered in Bombay Night Frog by Biju and co-researchers. Photo: S. D. Biju

While disgorging sperm, male frogs position themselves to ensure that the sperm reach the maximum number of eggs. But in the case of Bombay Night Frogs, the male deposits sperm while in an embrace from behind and removes himself as soon as the female spawns eggs. Spermatozoa trickle down the female's back to join the eggs and fertilize them.

If frogs have a Kamasutra, this study added a new chapter to it!

This 2016 study shows how difficult and exciting amphibian research can be and that it is more than discovering new species. Biju first noticed the mating behavior of Bombay Night Frogs in 2002 at the Koyna Wildlife Sanctuary in Maharashtra. But it took him years to study it.

A three-hour walk through dense forests from Humberli village in Koyna Sanctuary takes you to a forest stream that gushes out from cracks in laterite rocks. That was the area selected for the detailed study of Bombay Night Frogs. A team of four spent 40 nights continuously in the heavy rainy season. "We made our observations using photographs and video recordings. We shot nearly 200 hours of video footage using multiple cameras. Most events were recorded with the help of infrared cameras, without the use of flash, to avoid disturbance to frogs during the entire mating process," says Biju.

The researchers did not focus only on the mating. They noted several other peculiarities that opened the doors to the secret life of these frogs. One was that the females also called to catch the attention of the male frogs! According to the study, only in less than 0.5 per cent of all known species of frogs were the females calls ever documented. Among the rest, it is solely the male's duty to advertise himself through calls.

This tiny colourful Shrub Frog (Raorchestes beddomii) belongs to the most speciose amphibian genera found in India. Photo: Sandeep Das

Behind each of the 104 species of amphibians that Biju has formally discovered and described there are such stories and more - 104 amphibians mean 104 stories, 104 reasons for nature conservation.

Not only is Biju the first frog expert to appear in a popular late night TV show, but also the first of his kind to appear on the cover of 'The Economist' published from London! Emma Duncan, one of the editors of The Economist spent days and nights with Biju and his team in the forests of Agasthyamalai region in southern Kerala for the cover story of 2011 Christmas special!

Biju is also an accomplished photographer and scientific illustrator. Prominent scientific journals and popular magazines like BBC, National Geographic, New Scientist, Outdoor Photographer, and The Economist have published more than 300 photographs and 200 scientific illustrations drawn by Biju!

Sathyabhama, Das and Biju

Biju is world-famous today, a top scientist in his field of research. But when looking at his childhood, one wonders if someone who grew up in meagre financial circumstances could thus evolve into a world-renowned researcher. The bittersweet truth is that today's Biju is the creation of his combat with the adverse conditions and penury in his younger days.

Of the amphibian species described by Biju, 40 are named after persons who helped Biju in this journey. Two frogs described by other researchers have been given Biju's name - Beddomixalus bijui, discovered in 2011 from Kerala by herpetologist Dr. Anil Zachariah and team, and Bijurana nicobarensis, described from Nicobar Islands by a joint team of Indian and Indonesian researchers in 2020.

Frog species named after S. D. Biju: Beddomixalus bijui by Anil Zachariah and co-researchers in 2011 (left) and Bijurana nicobariensis by S. R. Chandramouli and co-researchers in 2020 (right). Photos: S. D. Biju

"Many have asked me why I haven't named a frog after my parents. I reply that my parents hold a much higher place," says Biju. "I even take their name before mine!", he laughingly adds pointing that his name is literally that. His parents are no more.

Biju was born in 1963 as one of three children of Sathyabhama and Krishnan Das of Idakkaryatthu Puthen Veedu in Kadakkal. He has two sisters - Mini the elder, and Biji the younger. His father was a local political leader. "He would often compete and fail in Panchayat ward and co-operative society elections," Biju laughs. This left his father little time to be involved in household affairs, and it all fell on his mother's shoulders. As a child, Biju shared the burden of caring for the family with his mother. His main occupation was to assist his mother. Going to school was secondary to keeping hunger at bay. "My mother struggled a lot to raise and educate me."

S. D. Biju with family, an old Picture

Biju's early education suffered because of the lack of sufficient resources at home. His proper education started much later in life. But he ended up doing his Pre-Degree at NSS College, studying in the IInd group (Biology). After completing his B.Sc. at University College, Thiruvananthapuram, in Botany in 1985, he did his Master's at Sree Narayana College, Kollam in 1987.

"It was at the fag end of my M.Sc. days that I met Prof. Sivarajan of Calicut University. It became my cherished dream to study under him. I already knew that I would work in taxonomy." We now know the life of Biju after arriving in Calicut University for his Ph.D. in Botany; and like they say, the rest is history.

Biju married Anitha, who was a co-researcher in Calicut University, pursuing her Ph.D. While Biju's Ph.D. was in Plant Taxonomy, Anitha's was in Plant Breeding and Genetics. The couple has two children - Anju Parvathy pursuing her doctorate in English Literature from Pennsylvania University in USA, and Kalyani Biju, third year student of BDS at Amritha Institute of Medical Sciences at Kochi.

* Roots and Rise of a 'Frogman'- Interview with S.D. Biju

Additional Reading -

1. Biju S. D. 2001. A Synopsis to the Frog Fauna of the Western Ghats, India, The Occasional publication of Indian Society for Conservation Biology, ISCB 1: 1-24.
2. Emma Duncan (2011). Frog hunters of the Western Ghats, The Economist (December 17).
3. Soutik Biswas (2016). India's Maverick 'Frogman', BBC News (January 22).
4. Frost D.R. (2023) "Amphibian Species of the World: An Online Reference." Version 6.0. American Museum of Natural History, New York, USA. ( Retrieved from: (accessed 30 March 2023).
5. Amphibians of India (2023).
6. Biju S.D. and Bossuyt F. (2003). New Frog Family from India Reveals an Ancient Biogeographical Link with Seychelles, Nature 425: 711-714.
7. Hedges S. B. (2003). The Coelacanth of Frogs, Nature 425: 669-670.
8. Ian Sample (2003). New Frog Species is 'Living Fossil', The Guardian (October 15).
9. Sarah Graham (2003). Scientists Discover New Frog Family, Scientific American (October 16)
10. Chaitra M.S., Vasudevan K., and Shanker K. (2004). The Biodiversity Bandwagon: The Splitters Have It, Current Science 86(7): 897-899.
11. AmphibiaWeb (2023). Information on amphibian biology and conservation. Berkeley: University of California. (accessed 30 March 2023.
12. Kamei et al. (2022). Discovery of a New Family of Amphibians from Northeast India with Ancient links to Africa, Proceedings of the Royal Society B: Biological Sciences 279: 2396-2401.
13. Willaert B. et al. (2016). A unique mating strategy without physical contact during fertilization in Bombay Night Frogs (Nyctibatrachus humayuni) with the description of a new form of amplexus and female call, Peer J 4:e2117.
14. "Thavalakalude Kamasutrayil puthiya adhaayam kandetthi malayali gaveshakan." June15, 2016.
15. Wikipedia contributors. (2023, March 18). Sathyabhama Das Biju. In Wikipedia, The Free Encyclopedia. (accessed April 30,2023).
16. John R. P. (2014). (May 12, 2014).

Author's statement: I first contacted Biju in 2003 when he published his discovery of the Indian Purple Frog. I wanted to cover a story for Mathrubhumi. Ever since, I have closely followed his research and reports on his various discoveries and contributions. This interview was conducted through a zoom meeting on 22 November 2022 and follow up communication. An abridged version of this article and interview appeared as a cover story in Mathrubhumi Weekly on 15 January 2023.

Acknowledgements: Prof. James Hanken (Harvard University), Dr. M. Sanjappa (INSA Senior Scientist); Dr. Sonali Garg (Harvard University), Dr. Ashish Thomas (University of Delhi), and Dr. A. J. Thomas, and P Venugopal for content editing and suggestions.

Translation: Balachandran V

Add Comment
Related Topics

Get daily updates from

Disclaimer: Kindly avoid objectionable, derogatory, unlawful and lewd comments, while responding to reports. Such comments are punishable under cyber laws. Please keep away from personal attacks. The opinions expressed here are the personal opinions of readers and not that of Mathrubhumi.

Representative Image | Photo: Canva

3 min

Retired bureaucrats and their insipid memoirs

Sep 27, 2023


8 min

Chandrakant Jha : The Butcher of Delhi

Sep 26, 2023

drug abuse

6 min

Drug dependence and abuse among Kerala school children 

Oct 6, 2022