Revisiting Daniels et al. 1992

In a paper published in PNAS in 1992, RJ Ranjit Daniels, NV Joshi and Madhav Gadgil reported that bird richness declined with increasing woody plant diversity and vertical stratification in natural evergreen forests in Uttara Kannada district of the Western Ghats, India – a pattern that ran counter to what was generally believed at that time. Plantations, on the other hand, showed the expected pattern. Daniels and colleagues argued that these differences were related to differences in richness of the source faunas from which natural forest and plantation bird assemblages are drawn: the former came from an impoverished evergreen forest bird fauna while the later came from a richer dry forest fauna. Thirty years after the paper was published, I interviewed RJ Ranjit Daniels about the origins of his interest in this topic, memories of field work, and his view today about the paper’s main conclusions.

Citation: Daniels, R. J., Joshi, N. V., & Gadgil, M. (1992). On the relationship between bird and woody plant species diversity in the Uttara Kannada district of south India. Proceedings of the National Academy of Sciences, 89(12), 5311-5315.

Date of interview: 14 May 2022 (via Zoom)

Hari Sridhar: I want to talk to you about the 1992 paper published in PNAS, which came out of your PhD. What was your motivation to do this particular piece of work?

Ranjit Daniels: This goes back to 1983, when I joined the Centre for Theoretical Studies (CTS) at the Indian Institute of Science (IISc). Centre for Ecological Sciences (CES) wasn’t yet formed then; so CTS was handling all field-based research projects. I joined Professor Madhav Gadgil, and his team, who had then launched a project on human impacts on biological diversity. For various reasons they chose to do this project in Uttara Kannada, including the fact that the district, at that time, had more than 70% covered by forests. It was also one of the most forested districts of the Western Ghats. Second, it was the relative ease with which field research could be done in Karnataka. The project had three core sections: one of it was birds, the other was insects, and the third was flowering plants. Professor Raghavendra Gadagkar led the study of birds and insects and Father C J Saldanha the plant study. We wanted to look at how these three groups of organisms respond to human disturbance. At that time, there was no research on the topic in India. All that we had was what had been done in tropical American forests, mostly by American ecologists. And the general belief at that time – the dominant hypothesis – was that as soon as forests are disturbed the biological diversity drops. This was based on several publications that had emerged from the neotropical forests, and we also based on research on this premise. We selected some evergreen reserve forest sites as our “undisturbed forest”. In Karnataka, they have a category called “minor forest”, where the collection of non-timber forest produce was formally allowed, and there is cattle grazing and so on. These minor forests we selected as our representatives of disturbed forests.We also decided to sample the various kinds of plantations that were established in the area.  At that time our knowledge of field methods for study of biological diversity was very limited, and so we established one hectare plots, which in hindsight I realised were very small for birds. Anyway, we established 36 such plots across our sites and started collecting data. Even during my first visit, it was very obvious that the disturbed forests had many more species of birds than the undisturbed forests. But then nobody was willing to listen to me. The faculty at CTS who were involved in this research said that there could be methodological problems, related to the fact that in evergreen forests visibility of birds is poor, and you don’t see birds easily. All kinds of arguments were brought out. The CTS faculty said my observation is completely contrary to what is conventionally believed and found in other parts of the world.But I continued to argue that this is not a methodological problem, and I will prove this by further study taking larger samples and covering larger areas and more habitats. That was the primary motivation for this study.

HS: Did you join the project in 1983 as a PhD student?

RD: I joined as a Project Assistant. Only in 1985, I registered for my PhD. CES came into existence in 1984. In 1985, they took in the first batch of PhD students and I was among the first three students…

HS: Before I ask you more about this paper, I want to step back a bit and ask you to tell us a how you got interested in ecology and birds, and how you came to know about this project?

RD: I’m from a family of naturalists and used to have a lot of birds as pets. I also used to paint and I liked to paint birds. To paint birds, I used to observe birds closely, go into the field and look at them, and try to directly draw from field observations. That’s how I developed an interest in birdwatching and later I was also keen on doing my higher studies on areas related to nature. I graduated in agriculture,and since I wanted to be closer to nature, I did not join the agriculture department, but instead did my Master’s in Agricultural Entomology. And because I did my Master’s in Entomology and had an interest in birds, I got this opportunity to work in IISc. But I would never have come to know of this project, but for Professor NV Joshi’s younger brother who happens to be a friend of mine. I know Mr Yateendra Joshi for the past 50 years. I’d once met him after I finished my Master’s degree. At that time I was confused and really didn’t know what to do next. He too is a graduate and postgraduate in agriculture. He said, agriculture will be a dead end for you, so you should get into some kind of research institution and pursue research in ecology. I had no clue what ecology was and where in India you could do ecology, but he told me his brother works in IISc, and he will put me in touch with him.He put me in touch with his brother in 1982. In 1983, when CTS started this project and were looking for young people to work in this project, NV Joshi wrote to me saying that there is this opportunity. I went to Bangalore informally in May 1983 to meet Professor Gadgil, Professor Raghavendra Gadagkar and Father Saldanha. I talked to them and they also took me out for a birdwatching trip on IISc to check my field skills. Professor Gadgil was very impressed with my knowledge of birds and my ability to paint birds. He was particularly impressed by the latter and said he would like me to join the CTS project. So, in July 1983, after a brief interview, which was held in Sirsi, I was chosen as a Project Assistant to work in this project.

For the next, nearly, three years, I worked on that project in Uttara Kannada district. We hired a small house in Sirsi. I had a colleague called Chandrashekara, who passed away last year. We both used to stay there and work in this project.We had a good team of people including botanists and extension workers.Before starting the field work, Professor Gadagkar, me and Chandrashekara visited the museum of Bombay Natural History Society (BNHS) to go through the bird skins that were found there. At that time, Mr. Humayun Abdulali told us about a100-year old publication from Uttara Kannada district. J. Davidson, a British ornithologist, had done excellent work in the area that was then known as the North Canara district. He had documented all the birds of the district and published it as two papers (1 & 2) in the Journal of Bombay Natural History Society. There was also another paper from the early 1940s by an American ornithologist called Walter Koelz who worked in the northern parts of the Uttara Kannada district. So, we had excellent background information, which listed more than 350 species of birds from the district.

HS: When you joined the project in 1983, were you already thinking of doing a PhD?

RJ: No, it came up later. I did not have any idea of doing a PhD. I thought this was a job and I should do the job well. And, in fact, in 1985, I also thought that I could join permanently in some capacity in CES/IISc without a PhD degree. That was all that I had in mind. I did not even think of a PhD. I wanted a permanent job to pursue my career in a very prestigious institution.But Professor Gadgil felt I will be wasting my life if I didn’t do a PhD. He said, with all your talents and capabilities, and your good understanding of nature, you should do a PhD and I will be very happy to guide you. He was the one who, kind of, put the idea of a PhD into my head, and I agreed. In fact, when I went home and told my parents about it, they were also not very convinced.They felt that at my age (I was 26 then)I shouldn’t be studying more and instead should be looking for a job.That is what my mother said. She added that if opportunity arises I can pursue a PhD degree part-time with a secure job in hand. But Professor Gadgil was very firm that I should do a PhD and I agreed.There were other colleagues in IISc who also felt that if I want to continue in IISc, I should have a PhD otherwise I will regret it later in my career. So, I applied for the PhD program when it was first announced by CES.

HS: What did selection for the PhD involve at that time?

RD: Till my batch, selection was only based on interviews and Master’s degree marks, but then by that time CSIR and UGC had introduced entrance tests for PhD. At that time, Professor CNR Rao was the director of IISc. He felt that since those two organizations were insisting on entrance test, IISc should also have one. So, I was part of the first batch of students who had to take an entrance test. This test was common to all Life Sciences departments. Professor Gadgil was really worried because I was not in touch with basic sciences and mathematics for many years. He called me back from the field in Uttara Kannada, I came and stayed in Bangalore for 10 days and prepared for my exam very well. I was happy that I was able to do well; I think I scored decent marks. Professor Gadgil was also very happy. I was shortlisted for the interview. The interview was generally simple but for a question posed by Professor Gadagkar. He asked me the difference between ‘parametric and non-parametric statistics’. This I did not know. However, this did not prevent me from getting my PhD admission in CES. I must mention that Professor Sukumar, who was then a doctoral student in CTS/MCBL helped me with the preparations for the entrance test. He gave me some old textbooks and useful tips.

HS: Since you said that you were out of touch with basic sciences and mathematics at the time of the entrance exam, I wanted to ask you whether there was a long gap between when you finished your Master’s and applied for the PhD.

RD: Yes, I finished my Master’s in 1982 and then for one year I was sitting at home really not knowing what to do; I was in two minds. I was wondering whether I should go back to the university and become a teacher, which was difficult because it’s a State government institution and they had their various reservations. So, it would have been difficult to get into the Tamil Nadu Agricultural University, from where I graduated, to become a teacher. I was confused and I was sitting at home and that is when I got in touch with Professor Joshi. So that was one year, and then two years I was doing field research in the project in Uttara Kannada, which was applied work. There was hardly any basic science in my work involved except in identifying birds and some insects. So I was more or less out of touch with basic biology and mathematics.

HS: At what age did you get interested in painting birds?

RD: I don’t know. Right from my childhood, I used to draw and paint. If you look at my childhood notebooks, all the blank pages will have some drawings. Whenever I had spare time, I would draw and invariably it was a bird. At that time, I was very influenced by the National Geographic magazine, which my grandfather used to subscribe to. In fact, a lot of my interest in wildlife grew from that magazine. We had several volumes of that at home, which my grandmother had safely bound and kept in a cupboard, and I used to go through them. Those days, National Geographic used to engage artists to illustrate their articles on wildlife and nature. I was very influenced by these paintings, and used to try and copy them. I was not trained anywhere. On my own, I developed the skill, from colour pencils to watercolours and so on. At that time, I didn’t have binoculars or anything. I was doing my Master’s degree in Tamil Nadu Agricultural University campus at Madurai, which is a very vast campus with lots of wildlife. There was a wetland inside the campus and there used to be a lot of birds. During my free time, I used to go and sit in this wetland, quietly behind bushes, and observe birds that come close to me, make quick sketches in my diary, and then, later on, develop them into paintings. This gave me the idea of how to observe birds, their behaviour, their colours, their calls, and so on. I would say that this was the time I got into serious bird watching. When I came to IISc in 1983, I was able to identify about 100-150 species of birds without any difficulty.That was my starting point, when I started my career as an ecologist. I even wrote a small book, which we couldn’t publish, on the birds of the Madurai agricultural university campus. I didn’t have the resources to print it as a book, so later after I came to CTS this was typed and bound into a book with black and white drawings of the different birds. That was my first attempt at writing and illustrating a book on birds. So, basically, I had the motivation, and I was really in love with birds. That’s also the reason why I was also inclined to looking at birds in my PhD, because I had the advantage of being able to identify birds. I switched from Entomology to birds, because I felt birds are easier to identify in the field – insects are impossible to identify in the field – and since I have the background, I can use it as a means to get a headstart in my work. I come from Kanyakumari district and right from my childhood I have been exposed to the Western Ghats. My father was a graduate in Zoology and a nature lover although he later took to physical education ass his profession. He used to take us during our holidays to the nearest hills.We would spend weeks together in the hills observing birds. He would borrow Salim Ali’s Book of Indian Birds and The Birds of Travancore and Cochin from his college where he was the Physical Director and bring it home during vacation. So, I had some basic familiarity with the Western Ghats, and the Western Ghats birds, and I thought that I will use that to grow in my profession.

Interestingly, later on, I wrote to Salim Ali on two occasions. The first was when I was doing my Master’s at the agriculture college in Madurai, in 1981-82. I spotted a Pond Heron with pink legs, which was quite unusual to me. So I wrote to him to ask if this was normal. He kindly replied to my letter pointing out references in his books on such occurrence in other species of herons and egrets. He did appreciate my independent observation. The second time I wrote to him was when I was in CTS. This time I sent him a copy of my type-written and hand illustrated book on the birds of the Tamil Nadu Agricultural University campus in Madurai.

HS: When you joined the PhD in 1985 did you know right from the beginning that you were going to continue your Uttara Kannada work? Or did you also consider other possibilities?

RD: No, no, I was very adamant because nobody was willing to accept when I said there are more birds in the disturbed forest. After we did a round of field work, we are invited back to CTS for in-house seminars, where everybody presents their preliminary results and some brainstorming happened. When I spoke about this observation that there are more birds in the minor forest than in the evergreen forest everybody laughed at me and made me feel like an idiot. They said, in a dense forest you can’t see birds. This is under representation. This is methodological error. All these things they said and made me feel like a fool. But I was fully convinced because I was in the field and I was, by then, familiar with the birds. So, I was convinced that this is a point I had to validate with more data. So, I started my PhD work to validate my observation that there are more birds in the disturbed forest than in the undisturbed forest. That was my first question to answer. Second, how do you convert this into a strategy for conservation? By that time, I wanted to come up with some strategy for conserving the birds of Uttara Kannada district. In this case, when minor forests are attracting more birds, how will they be preserved? By that time, I was influenced by this subject called Landscape Ecology, which had just emerged. Professor Gadgil gave me a book by Forman and Gordon on the subject and asked me to read it. I was very much influenced by it, and I wanted to use it to come up with an integrated approach to conservation of birds in the Uttara Kannada district. It was very clear in my mind that this would be my work for the PhD. I did not consider any other ideas.

HS: Coming back to the paper,what are your memories of the period between January 1986 and April 1988 when you did the fieldwork for this study?

RD: I was basically given a lot of independence. There was a team which was continuing to work on plants, insects etc. in that area but Professor Gadgil felt I should be independent. I should not be bogged down by their routine. For example, people who study plants go to the field at a later time, but I had to go early in the morning. So, he bought me a motorbike and he gave me a field assistant – one Mr. Harikantra – and said, you both should independently do your research without being bogged down by the others’ schedule. I was given a letter of permission to travel throughout Uttara Kannada by the forest department. I and my field assistant, with the help of Survey of India topo-sheets, systematically covered the entire district, mainly because Davidson had recorded birds from different parts of Uttara Kannada and had mentioned where he had seen them. I wanted to go and see whether these birds are still there. Davidson had recorded the Wayanad Laughingthrush from Castle Rock in the 1898 paper. He had mentioned there was a small flock of these birds in Castle Rock. Now, throughout my travel in Uttara Kannada district I had never seen this bird anywhere. So, as a last chance, I wanted to go to Castle Rock and see whether this bird is still there. Castle Rock is very far away from Sirsi, which was my base. It was a long drive of more than 200 kilometres on forested roads to Castle Rock. We rode all the way on the motor bike, checked in at the forest guesthouse and that evening when I went for a walk, to my surprise, I saw a flock of Wayanad Laughingthrushes right next to the bungalow. This is exactly where Davidson had mentioned he had seen the birds. So, 100 years later, that bird which is highly sedentary had persisted. This was one of my most exciting moments.

The other bird that I really searched for was the Long-billed Vulture. Davidson had recorded it from Jog Falls and surrounding areas, because it’s more of a cliff-dwelling species unlike the White-backed Vulture. I never found it during my studies, but later when I was doing my postdoctoral work, I was travelling to Jog Falls for some other purpose I found it. Some of these surprising discoveries were very motivating. And I wanted to travel throughout Uttara Kannada district.By that time the French Institute had produced excellent vegetation maps of parts of the Western Ghats including Uttara Kannada. Using that, I was able to identify 21 different kinds of habitats, including wetlands, coastal habitats, cultivation, forests, plantations and so on. I wanted to visit each one of these 21 different habitats and see how the birds were in them. So, I planned my field visits accordingly and travelled to all these places from the coast to Haliyal, which is the easternmost part of Uttara Kannada district, close to Hubli and Dharwad. I worked every day except during the rainy season. During the rainy season, it’s very, very wet in Uttara Kannada. You can’t do any field work, you can’t travel, the roads are bad, you can’t even stand inside the forest. At that time, I used to come back to Bangalore and process my data. In fact, that was the time when we were just beginning to use personal computers. Before that we had a centralized system in IISc, a huge computer department with a huge computer. We had only limited access to the terminals, we had to go there and punch cards, etc. It was a very cumbersome process. I did most of my work using that facility. Whenever I came to Bangalore, I used to go and punch in my data. I had a huge set of data. In fact, it took me nearly one year to process my entire data and computerize them.My fieldwork ended in April 1988 and till 1989 I was sitting and processing my data. I had data on vegetation, data on birds, data on habitats and so on. So this was something I used to do. The rest of the time, during the non-rainy season, I was in Uttara Kannada.

HS: Can you tell me a little about the contributions of Professor Gadgil and Professor Joshi in the making of this paper?

RD: Professor Gadgil was my research supervisor, and he was responsible for my overall motivation to do research. As I told you, he has always been supportive of my doing a PhD. He was the one who encouraged me to work on birds. Other people, particularly Professor Raghavendra Gadagkar felt that a lot of work has already been done on birds and there is nothing new that you can find on birds. In fact, he even suggested that if I was serious about pursuing a career in birds, CES would not be the best place. But Professor Gadgil accepted my ideas and said, yeah, why not? You try. He was behind me in all possible ways, he visited me in the field and was very supportive. He was also the one who gave me the idea that this paper should be published in PNAS. By that time, he had been elected as a fellow of the National Academy of Sciences in the US, and he said, I have access to PNAS and we can actually publish it in PNAS. Before that, in 1989, after I submitted my thesis, I had a short-term fellowship from the Smithsonian Tropical Research Institution (STRI) to visit the Barro Colorado Island in Panama. I was very curious about why the birds of the Western Ghats are different from neotropical birds. All these publications on birds of the tropics are all saying that with disturbance bird diversity comes down. What is different about the Western Ghats? I was fortunate enough to visit neotropical rainforests in Panama. And I saw that there was quite a lot of difference between their birds and Western Ghats’ birds. Their forests were much richer in understory birds. And then, mainly, I gave a seminar to the scientists of the Smithsonian Tropical Research Institution, who in Panama have done excellent work on birds of the rainforests. One of the scientists, Joe Wright, who has published extensively on birds said the birds of India are bizarre. He said, it cannot be possible that disturbed forests have more birds; it’s impossible. It is a bizarre observation, he said. But then the other senior scientists felt that I have substantial data to support my findings and that I should go ahead and publish this. And they suggested that I should publish this in a top American journal, because the American scientists have been convincing the world with their findings that all that they have found so far in tropical South America is the last word on bird community ecology. They told me that I have got something completely different from what they have been saying. After I came back to India, when I told Professor Gadgil that this is the kind of feedback I got in Panama, he said, PNAS would be the best journal to publish this. He was the one who gave me the idea of how to write the paper, according to their guidelines. He was the one who overall shaped the paper; the contents and the idea were mine. Regarding Professor Joshi: Although I had undergone courses in computer science and mathematics and statistics as a PhD student, it was not very easy for me to handle my data. I had such a huge volume of data. And those days, we did not have personal computers, and had only Fortran as the program. There were no ready-made software like now.  Joshi was the only expert in CES at that time, who could really handle this. And Joshi was a friend, and so he told me, whatever help you want I will do it for you. So, I used to put all the data into the computer and give it to him and then he would sit and write programs and analyze it and ask me whether the trends that are emerging are correct. Right from the beginning of my PhD work, Joshi was helping me with my mathematics and statistics and that is why I involved him, as a co-author on this paper. It was he who did the mathematical analysis for the paper. It was a perfect team – me, Joshi and Professor Gadgil – and we worked together very well. Each one of them has really contributed equally – except that I did the field work – but the contribution towards this paper would be more or less equal.

HS: In the paper you say “Bird species richness is inversely related to woody plant species diversity and vertical stratification in the natural vegetation of Uttara Kannada, the district with the largest contiguous tract of humid tropical forest in peninsular India. This inverse relationship may be explained by the fact that although the peninsular Indian evergreen forests are rich in woody plant species when compared with the drier vegetation, they harbour an impoverished bird fauna due to their smaller overall extent and greater isolation. Much of this impoverishment is accounted for by the absence of many species of understory timaliids characteristic of the humid evergreen forests of the Eastern Himalayas and Southeast Asia. The plantations of Uttara Kannada largely derive their bird fauna from the drier vegetation and exhibit the commoner trend of a positive correlation between bird species richness and vertical stratification of the vegetation.”

How did you arrive at this interpretation of the results, i.e. in terms of the source faunas from which the bird communities are derived?

RD: The idea first emerged from a paper by David Pearson. He was the one who said there may be a lot of history involved in the composition of birds in tropical forests. He had written a paper – if I am correct the title could be ‘A pantropical comparison of birds…’ which was published in 1977 in the journal Condor. In this paper, he talks about how the previous history of a landscape would affect the bird species composition. He based his analysis on data from tropical America, Africa and Southeast Asia. It was a very convincing paper. Pearson said that immediate changes in a landscape will not be reflected in the bird community. This was something that I had in mind, and so I too started looking at the history of the Uttara Kannada district. In fact, as I told you, Davidson had earlier identified 343 different species of birds from the district during the five years that he stayed there. And during the five years that I spent there I had also identified 343, but then there were some 15 or 16 species that were different from what Davidson had seen. So we wrote about how the fauna had changed in 100 years in relation to land-use changes, in a paper in Biological Conservation. That was my first paper, in 1991. We found that many more wetland birds had come up in the district, which Davidson had not seen and I did not record many of the forest birds that he had seen.  I felt one that the mismatch could be related to the fact that Davidson was a hunter. Every bird that he recorded he shot. Those days, that was how British ornithologists worked – they shot the bird, skinned the bird, and took it to the museum to confirm the identity. So, some groups like quails I probably recorded less than Davidson because I didn’t capture them. Quails are difficult to identify or even spot in the field. So, I thought I could have missed some of these birds because I didn’t collect them. But then there were wetland birds that were obviously absent during Davidson’s time and came into existence during my time. In 100 years, there were many irrigation projects that brought water into the Uttara Kannada district including the eastern drier parts. All this made me feel that, apart from the habitats themselves, there must be some history behind this whole chain. Therefore, I was trying to look at the history of the landscape and it occurred to me that, maybe, certain groups of birds are poorly represented in the Western Ghats. That is what led me to kind of look at what the faunal composition of Western Ghats is in comparison to the rest of the fauna of India. That was the idea behind doing this analysis.

HS: When did you come across David Pearson’s paper?

RD: He published it in the late 70s. So, when I was still doing my work, I was looking through literature, and I found this paper.  I also met David Pearson later when he came to Bangalore to give a talk, but by then he had switched to studying tiger beetles. I was hoping he would give some insights into his bird paper, but he talked about his experiences in India. So, I couldn’t really interact with him to get more feedback.

HS: Earlier, you said that what really motivated you to do this study was the preliminary finding that disturbed forests had higher diversity. That was, in a sense, the primary hypothesis you wanted to test in your PhD. At what point during your PhD did you start realizing that your hunch was correct. Was it only after you came back and analyzed your data or did you have a sense of that even as you were collecting the data?

RD: On the very first day when I entered the field, I immediately was able to see that there were fewer birds in the undisturbed forest. This was my immediate impression even before I started recording any data in my data book. Later when I started entering data from the 36 permanent plots we had marked, it started becoming more and more evident. In 1991, I published a paper on the birds of man-made ecosystems in the Proceedings of the Indian Academy of Sciences, after I found that plantations have equal diversity. This was something I found based on the 36 plots we studied, that plantations can have equal amount of bird diversity as the undisturbed forest. So, that was something that I had seen even before I started my PhD. In my PhD, I wanted to also give some clear explanation as to why this could happen. To just report a new finding, and say that this is different from what has been found in other parts of the world is one thing, but to kind of reach out and say this is the actual cause for this was another challenge. And that is where I had been inspired by this paper by David Pearson. I did some more thinking about it and also spoke to Professor Gadgil, and he also felt that’s a good idea. I had Salim Ali’s book Birds of the Eastern Himalayas and I was able to look at the bird fauna of Eastern Himalayas and compare it to the Western Ghats. That is how I was able to find out that there is a pool of birds that the Western Ghats is supplied from, which is less diverse than the pool of the Eastern Himalayas. The bird fauna was more influenced by the drier peninsular India. I thought that was one of the explanations that could be put forward for this anomaly.

HS: What do you remember about the peer review of this paper?

RD: I don’t remember exactly, because it’s 30 years ago, but I remember Jared Diamond pointed out that, in rainforests, one has to rely more on calls than on sightings when counting and identifying birds. He asked me if I had taken this into consideration. I had. In the paper you’ll see that I’ve put birds in three categories: birds directly sighted, birds that were only heard and birds flying overhead. So, I explained to him that I had taken this into consideration. Also, in every transect I sampled, on the day before proper sampling, I would visit this site and do a background assessment of the birds present. That is how I was able to say that my samples actually represented about 30% of the birds that are actually found there. I would spend a lot of time on the day before sampling and record all the birds and compare it with what I actually see in my transects. This is something I did for all the transects. From that, I got a fair amount of confidence in saying that this is fairly representative of the habitat.

HS: Was John Terborgh, who you acknowledge, also a reviewer of the paper?

RD: Yeah, he was another reviewer of the paper. He didn’t have any major comments. He said it’s a good observation. In fact, I’d corresponded with John Terborgh earlier. For a while, I had in mind that I will go and do a postdoc under him, but at that time he was shifting from, I think, Princeton University to Duke University  and so he was not able to accommodate a postdoctoral student. So I decided, instead, to go to STRI in Panama for post-doctoral work.

HS: I’m surprised that this paper hasn’t been cited much, considering how counter-intuitive the results are. Do you have a sense of why it hasn’t attracted more attention? Could it, in fact, be because it runs counter to the dominant narrative?

RD: It could be. But I also feel that during that time, not many people, at least in India, were reading PNAS. People would refer to Nature and Proceedings of the Royal Society of London and others; those were familiar, but PNAS was not so popular amongst the researchers, at least bird researchers in India. Later in 2002, I had gone to China for an International Ornithological Congress, where I saw people from Ecuador or another South American country, presenting very similar results. They also found that disturbed open habitats that were adjacent to farmlands having greater bird species richness, and native forests not having as many species of birds and so on. I was very impressed by their work, and I had a brief interaction with them. But, as you said, I did not get any feedback on this paper. In 1992, I left IISc and have not been in an academic institution after that. I have been in NGOs and haven’t had access to libraries and seminars. So, I’ve never really followed up on that paper after we published it. But otherwise, I really do not know if, as you said, the lack of attention is because it is contrary to conventional thinking.

HS: Today, looking back, what do you feel about the paper’s findings and its interpretations?

RD: They are still very relevant. In fact, last week, after you wrote to me, I read the paper again. I have been working in the Western Ghats, although not directly on birds. I’ve started working on other vertebrates. My main focus today is conservation. To come up with conservation strategies, we need to understand two things: diversity in different habitats and the factors that lead to diversity in different habitats. If you understand these two you can come up with conservation strategies. And as I told you, I was influenced by Landscape Ecology theory by which you can integrate various kinds of habitats and develop a holistic conservation approach. I worked in the Nilgiris for a while after I finished my PhD. In 1986, the Nilgiris were declared a Biosphere Reserve. A team headed by Father Saldanha, which included me, did some work in the Nilgiris related to the state of the biosphere reserve. Similar to my PhD work, I did some transects in the shola forests of the Nilgiris. The results were not any different. My general feeling is that, not just in Uttara Kannada, but in Western Ghats as a whole, this anomaly prevails. Therefore, this is what I continue to believe, and I don’t think I have seen any major difference in what I had concluded 30 years ago. However, recently – 2013-2015 – I did some work on the bird communities of the Eastern Ghats in Tamil Nadu, where the pattern is different. The dense forests have more diversity. I wrote about it in Current Science, sometime in 2015 or 16. So, this anomaly seems to be true only in the Western Ghats.

HS: You were also involved in a more recent bird community study, also published in PNAS, led by Jai Ranganathan. How did that come about and how did you get involved?

RD: Jai Ranganathan first approached me in 1996-97- I was at the MS Swaminathan Research Foundation then – and asked if he could work under me and get some training in ecology. He had a Master’s degree in Geology but was keen on shifting to ecology. In the US, I think they insist that you should have some practical training – do some internship or a course  – before you can jump disciplines. So he wanted to come and get trained in ecology. I asked him if he could work on bird ecology, and he was happy to do that. So, for nearly a year, he worked with me in Kolli Hills in the Eastern Ghats of Tamil Nadu and trained himself on the study of birds. He did some good work, learned how to count and identify birds. He then went back to the US. One day he suddenly called me and said, I have registered for my PhD in Stanford University and want to work on bird community ecology in the Western Ghats. He asked me to help him with the location of the study. I immediately suggested Uttara Kannada because there is enough background data,  I’d already published quite a few papers on the birds of the region, and I was familiar with that area. I asked Jai to read all my papers, which he did. Jai had only a short time to do his fieldwork. And considering the questions that he had in mind we chose to work primarily in Areca nut plantations. In Uttara Kannada, they have what are called ‘betta’ and ‘bena’ lands which are privately managed forests associated with the Areca plantations. I suggested to Jai that he could work in these privately managed forests also.  Jai agreed and wanted me to join him in the field work. In 2004, I spent 15 days in the field in Uttara Kannada with him to get him started on the fieldwork. The first round of data collection was all done by me. We were working parallelly because he had a very short time to stay in India. Since he was not familiar with the Western Ghats birds, as much as I was, I asked him to carry a tape recorder with him to the field and keep it on while he was doing the sampling so that all the bird calls, including those in the background, get recorded. He then transferred all these calls onto CDs and sent them to me.  I went through all the CDs and identified all the calls, to help him get an idea of the species that he missed, or misidentified. These were my contributions to that work. Later on, when he wrote up the work, he had put me as the second author of the paper. 

HS: Tell us about how you came up with the field methods to measure vertical stratification and canopy cover, which have since been used in a number of other studies.

RD: The inspiration came from MacArthur’s paper, where he had looked at foliage density. Now, I had no idea about how to measure foliage density because MacArthur said he’d used the graduated sticks for the purpose. Our foliage is too high for that method, so I wanted to come up with a simpler method. From my experience, I felt that the forests in Uttara Kannada are quite well-stratified. So, I decided to use a visual method but I assigned them into classes in a geometric series to reduce the likelihood of error. It is easy to tell the difference between one metre and two metres close to the ground but as we go higher it becomes more and more challenging. So, I increased the sizes of classes as we went higher. But before that, I had this one privilege. When I was doing my PhD coursework, I was given an additional course by Professor Gadgil, an exclusive course for me, which I could even register for three credits. I’d earlier told him that one-hectare plots won’t work for birds. We need larger areas. One-hectare plots was the standard procedure used in tropical Americas. Professor Gadgil said that if I wanted to come up with a different method I have to prove that it works. I spent three months in the field doing this, and during that time I developed this method. I tested it, collected data and came back and gave a seminar in CES and showed how it works. Based on that, I was given a grade and was able to clear that course. So I had this privilege, which not many other students had, to do pilots of my methods as a credited course. Also, in 1983, the transect method has just emerged, and I was the first to really talk about using transects for studying birds. I tested it and came up with this 600 meter length based on my trial and error. The entire methodology for my field sampling, I developed over a period of three months, which was given to me as a credited course. Therefore, I didn’t waste any time. From day one, I was able to start collecting my data for my PhD work. I also developed a simple method for estimating canopy cover. This I did by standing at a point and look straight upwards and assess the canopy. I gave a score of ‘0’ if the sky was visible, 1 if it was partly covered, 2 if it was sparsely visible and 3 if the sky was not visible. This I did every 5 meters along the transect (120 points in all). Using these measures I was able to calculate the habitat heterogeneity in my study areas.

HS: You earlier said that immediately after your PhD, you moved away from academia. Was that a conscious decision you took, because you wanted to get involved in conservation work?

RD: Actually, I was very keen on continuing in CES as a faculty mainly to teach. I come from a family of teachers and I love teaching too. Professor CNR Rao was then the director. He, for some reason not clear to me, announced a moratorium on fresh faculty appointments for two years starting 1992. At this time Professor Gadgil suggested that I sought a job elsewhere and come back to CES when the situation is more favourable. While I took his suggestion and left CES in 1992, I did not feel like returning to it later. As I mentioned earlier, in 1989, when I submitted my PhD thesis, I was fortunate to get a fellowship to go to Panama. I went there wanting to look at the bird communities, but it was September, which is the rainy season in Panama. It was raining all day and it was impossible to do any field work on birds. So I switched to working on amphibians, and that is why a lot of my postdoctoral work was on amphibians. As I told you, my idea was to look at vertebrates, their distribution and their diversity and come up with an integrated approach to conservation. Ultimately, my goal is to conserve. I’m not very keen on academics, scientific publications and so on. So, after birds, I wanted to look at whether amphibians also show the same pattern. I had this opportunity to start my research on amphibians in Panama. I then came back to the Western Ghats and had some good publications on amphibians, including one in Journal of Biogeography. I tried to find out whether all vertebrates have similar patterns or they differ. I found that amphibians are much more diverse in the denser undisturbed forests than in the open forests. It is a pattern completely different from birds but very similar to plants. It broadened my understanding of vertebrate ecology. I was very keen to continue this work in CES but it didn’t happen because of the circumstances. I got an opportunity to move to Chennai, which seemed suitable for various practical reasons. I first got a job at the Madras Crocodile Bank. And then from there, I moved to the MS Swaminathan Research Foundation, and the Chennai Snake Park. These were all non-academic institutions, so pursuing research became very difficult after that. I was more and more focused on conservation approaches, based more on reading and guiding younger people than doing fieldwork personally. I came to a point where I couldn’t actually go to the field and collect data. But I used to read and understand and based on that come up with strategies for conservation and restoration. These two have been my focus for the last several years. I have been helping with restoration of the campuses of IIT Madras and IIT Mandi. I’m no longer a person who does fundamental research. We don’t have the means: the funds, labs, access to libraries, seminars and so on. I miss that, what I enjoyed so much in CES. But then this is a different challenge altogether, where you come up with practical solutions to real problems. You are faced with real-life issues, and have to come up with solutions based on your own knowledge and experience. That is my present commitment. Since 2000 I have been with Care Earth in Chennai; a NGO that I co-founded. We do practical conservation work and I also get opportunities to teach. I am happy.

HS: What relevance does this paper have for you today? 

RD: It does have relevance. After that study, in the last 30 years, I have been able to travel, not only in India but also in other parts of the world: Indonesia, Bangladesh and so on. I also had the opportunity to work in the Western Himalayas and the Great Nicobar Islands and other tropical forests. The challenge is that different areas show different patterns in terms of their vertebrate species composition, diversity and distribution. This makes it difficult for conservation. You can’t have one model. This was, in a sense, my finding then too, which is very relevant today.  Each habitat and each community has to be dealt with separately. This was not the understanding earlier. In the 1980s, they had one simple yardstick: dense forests had more birds and open forests had less birds, so let’s preserve the dense forest. That idea I have completely dropped. We have to integrate, by using various methods including Landscape Ecology, open forests, degraded forests, plantations etc. Many plantations are very rich in birds and other groups. In fact, amphibians are very rich in Areca nut plantations. I have now looked at birds, amphibians, mammals,   reptiles and even fishes, and it’s a major challenge because different groups have different requirements. One common conservation strategy, or one simple straightforward solution in the form of declaring a place a protected area or  sanctuary to take care of all taxa is a myth. That is my understanding over the last 30 years, after I finished my PhD. Conservation is very complex, and that is why I feel Landscape Ecology is very relevant, because different kinds of habitats will have to be integrated into a conservation area or that is how you can make conservation effective. You should be able to integrate certain amount of human disturbance, because that also helps in some cases. That is what I was trying to look for 30 years ago. I wanted to come up with clear directions on how we conserve biodiversity. Today, after having worked on birds, woody plants, amphibians, fishes, reptiles and mammals, I have a much clearer idea about how to evolve conservation strategies. That is, basically, the sum of what I would like to say.

HS: What would you say to a student or a young researcher who is about to read this paper today? Would you guide the reading in any way? Would you add any caveats they should keep in mind as they’re reading this paper?

RD: I don’t think there is any caveat as such, but they should read this paper carefully. Today, there are better tools to analyze the data that we didn’t have 30 years ago – GIS, habitat models, niche models, and all kinds of things that I’m not familiar with. I only keep reading about them. The same data people can put to better analysis, and they may be able to come up with more relevant interpretation. I would tell students that more rigorous data analysis would help them in getting more out of this data. It is a huge dataset! Most of all students should not hesitate in questioning prevailing notions in ecology. Science is open to questions and students should be ready to do so. They should also take courage in exploring newer avenues of ecological research. Ecology is fascinating. This paper should be a source of inspiration to younger students.

HS: Would you count this paper as one of your favourites, among all the papers you have published?

RD: It is certainly one of my favourites. There are two papers that were really original work, which I’d completely conceptualised and executed. This is one and the other is a paper published in 1991 in Conservation Biology on assigning conservation values. Earlier, people were using ranks and votes but I wanted something that is more objective, where you could attribute values to species, and then value habitats, communities, and so on. That’s exactly what the Conservation Biology paper does. These two I feel are my best papers, and the best contributions I made in my doctoral work.