“I searched the literature for some species to work on for my PhD thesis. I wanted to look at how variation in calls influenced mate preference within the species, and I decided to work on red-eyed tree frogs in Panama. But they were very high up in the canopy and I was having a difficult time recording the males and a difficult time watching the matings. And when I was trying to record these males, all these Tungara frogs would be calling at my feet. They were very common and I would always be kicking the frogs to shut them out so I could hear the red-eyed tree frogs calling. That’s when I thought that since these Tungara frogs are always calling, maybe I should study them instead. That’s how I started to study them.”

“I should thank [Motoo] Kimura because he allowed me to do whatever I like in research. In my country at that time, senior professors often had big power to control junior researchers.”

“I spent the first part of my time here studying dunnock mating systems in the Botanic Garden. Our children were very young then and I wanted to have a local study, so I could spend time with them. And then gradually, as they started to grow up a bit and go to school, I felt free to go further distance – not very far, only 20 miles away. I also wanted a change of scene. I knew Wicken Fen very well and thought this would be a good place.”

“I spent the whole time – every day, all day – watching butterflies. I almost never went into town, except to get shopping at the end of the day. I would just wander around with a net and a notebook and a stopwatch. That’s all I used. The first thing I did was to mark a lot of individuals so they could be recognised. I remember being delighted how easy this was compared to trying to catch pied wagtails. I would see a butterfly in a sunny spot, capture it in a net and mark it with felt tip pen through the net. I didn’t actually have to handle the butterfly at all. This way I marked several hundred during the study. On my first day I decided to watch one individual for the whole day, just to try and get a feel for what it was like to be a speckled wood butterfly. I watched one male for six hours or so, in one little sunny patch. As the sun moved across the sky, the sunny patch moved over the woodland floor, and the male followed it faithfully, travelling something like 20 or 30 metres during the day, always staying in his little sunny spot. I noticed that he didn’t spend any time feeding there. He just perched and whenever anything came close by he would sally out and inspect it. Often it was another insect, perhaps a ladybird or another species of butterfly, and he’d then very quickly ignore it and return to his perch. But if it was another speckled wood butterfly he was very interested. If it was a male, they would have a brief spiral flight, and then one of them would retreat. It was always the owner who would come back to the territory. If it was a female he would follow and court her, but almost always she said no. She would fold her wings and depart, and he would then leave her alone. Subsequently, I discovered that these females which said ‘No’, were already mated and laying eggs. In butterflies, females can say ‘No’ and that is the end of it. There is nothing the male can do. But occasionally, a female would say ‘Yes’ and the male would then leave the territory and fly up and mate with her up in the canopy. These simple observations suggested to me that what the male was doing in these sunny spots was looking out for females. The next question I asked was whether these little chase, these little spiral flights, were territory defence. You might think, well it is obvious they must be! But there was some controversy back in the 60s and 70s about whether butterflies really did defend territories or whether these little interactions were simply a case of butterflies spacing out amongst the available habitat. So I thought it was very important to test whether these other intruding butterflies really wanted to settle in the territories. So I removed the original owners, kept them in a net, and when one of these butterflies from the canopy came down I saw what they did. I discovered that in all cases where I had removed an owner, the new comer settled in the territory and began to defend it. And that suggested to me that these spiral flights had previously kept them out, so it really was territory defence. I was very pleased with that very simple removal experiment; these other butterflies were clearly keen to get the territories when the vacancy arose.”

“I started my finch project in the summer of 1987, capturing wild birds in backyards around the area to create a captive flock in the rooftop aviary at Michigan. I didn’t take birds from the campus population because I wanted those for my field study. Once the breeding season started in March, my days were frantic. I would typically ride a bus to campus before first light, set up a mate choice trial that ran for 3 hours, then grab binoculars and head for fieldwork (out the front doors of the museum). About two days per week, I would trap and color band the local population of finches. In the second year of the field study, I used hair dyes to change the coloration of the males that I caught. That color-change experiment was the basis for my 1991 Nature paper. On other days, I would walk around campus with my binoculars recording the behavior of banded birds with a special focus on pairing. After about two and a half hours of field work, I’d run back into the museum, literally run up 5 flights of stairs to the roof, set up birds for the second mate choice trial of the morning, and then go back out for more field work. That field season kept me in great physical shape. When birds started nesting, I was often grabbing a ladder (a really big and heavy ladder) to go out and climb to nests to check contents or band chicks. This routine didn’t stop until the end of July when the finches had finished nesting.”

“I started my Ph.D. work on hummingbirds, and spent most of my first summer as a graduate student studying time and energy budgets of territorial male Broad-tailed Hummingbirds. During that time I discovered that 1) bumble bees don’t get up at 5 AM, like hummingbirds, and 2) they don’t fly in rainy weather, as hummingbirds do. Also, you don’t need permits to work with them (federal and state permits are required to capture hummingbirds), for example for marking them (with paint) or gluing tags on them. So at the end of my first summer of research I decided to switch to work on bumble bees for the next three summers.”

“I started to work on fruits and frugivores in the Sierra de Cazorla area in the fall of 1978. In 1981, I had, for the first time, the opportunity to witness a massive spring flowering, and then an autumn fruiting event, by Phillyrea latifolia. I was absolutely amazed by the spectacular phenomenon, as all trees were in flower, and later in fruit, over countless hectares. By then I was well aware of the concept of ‘mast fruiting’ as applied to dry-fruited plants like oak or beech, but had not heard about any similar instance for fleshy-fruited plants. In principle, satiation of mutualists did not seem to me a reasonable strategy for a fruiting plant, which spurred my curiosity. In the years following 1981, I kept waiting patiently for another massive flowering event to take place, so that a study on the seed dispersal consequences of massive fruiting could be planned and undertaken. That finally happened in 1989, and we went ahead with our study that year.”

“I stayed in camps that had only ceilings, no walls and floors. We used a clay filter to filter drinking and cooking water. It lit up at night with lamps and lanterns. We slept in a hammock, bathed in “igarapé” (which in Tupi Guarani means “canoe path”) with its very cold waters, and did the physiological needs in the bush. Perishable food was stored in large izopor boxes with ice for a maximum of 3 days. A BDFFP [Biological Dynamics of Forest Fragments Project] car came to fill the pantry according to our schedule. In some cases, there was no road to the camp, so we had to use a handcart to take supplies. There was no communication radio and I used anti-ophidic serum. I was never alone. At all times during my Master’s, there was a person (called “mateiro”) who accompanied me to help in the field work – Antonio Cardoso, my faithful squire. He became a great friend too. He was always very dedicated, hardworking and very kind to me. I am very grateful for him. I stayed in the countryside for up to three weeks, without going to Manaus, where I lived. The work was very heavy because from the camp to the areas it was three kilometers walking. The path was not flat and all the time we were going up and down, crossing the “streams” and sometimes our feet were wet all day. We also had to go through areas full of “Embaúbas” (Cecropia), plants with suspended roots, which we stepped on for a long time and our feet were very painful afterwards. We returned, after a day of hard work, loaded with many bags full of branches from the litter that would later be opened in search of ant colonies. Sometimes, I arrived so tired at the camp that I didn’t have the strength to eat. I took my shower and lay in my hammock. Seu Antonio Cardoso, who prepared our meal, sometimes said “Baiana (person born in Bahia; that was my nickname in Manaus), come and eat, empty bag is not standing!” One of the incidents I remember was the day the BDFFP car got stuck in the mud of the road and was unable to climb a slope. The driver picked me up and Cardoso on foot! I rode a mule until I got to the car, but she didn’t want to walk and she stopped all the time! It was very funny! Another time, there was a poisonous snake sleeping very close to me and Mr. Cardoso saw it. If my memory serves me correctly, it was the surucucu-pico-de-jaca (Lachesis muta). In order not to frighten the snake, he started telling me to walk up to him, in front of him, slowly, slowly. There were not that many incidents but I could spend days telling you about the happy moments.”

“I struggled a lot in my first two years of graduate school on the particular questions to ask and the particular systems to study. I had many failed attempts, but in my second year, I started interacting and collaborating with Sharon Strauss. She’s currently a professor at UC Davis, was an assistant professor at the time, had been working on wild radish, and she had developed that as a system for studying plant-herbivore and plant-pollinator interactions over the previous decade. I had asked her about this as a possible study system and she was very encouraging. She and I collaborated on a project together that was published in 1999 in Evolution on the costs of induced responses to herbivory. This was the first project I had done on wild radish, but then after that study, Sharon allowed me to continue to work on it. She continued to work on radish as well, and she and I continue to collaborate in different ways, but it was a tremendous amount of generosity. After our first project together, she gave me a lot of freedom to do what I wanted with it.”

“I struggled a lot in my first two years of graduate school on the particular questions to ask and the particular systems to study. I had many failed attempts.”

“I submitted it to Nature and it was rejected. I looked at the comments and realized that what I had done was not explain exactly what I was trying to do. The reviewers were very good reviewers, but I think what they expected was a paper that was a little bit more traditional. They expected me to ask how morphological or other traits vary among populations. But what I was trying to do here was something completely different, which was ask how ecological outcomes vary among populations. I didn’t articulate that as well in that original draft. I just made the assumption that they would get that point, and they ended up focusing on other points. So, I wrote the editor and said that I realized the fault was mine, but with just a small amount of rewriting, I think I could articulate the goal and novelty in a way the reviewers would understand. I asked him to let me do that and then have them take another look at the manuscript. If they still do not think it is acceptable, then the design is my fault. The editor, who was Rory Howlett, who was a remarkable editor for Nature, looked at my comments, looked back to the original manuscript and said, I see what you’ve done and what you mean. He sent it back to the reviewers and the reviewers said, ah, I see; now I get it. This is interesting. They re-reviewed the manuscript, I made some additional changes to incorporate their suggestions, and Rory Howlett then accepted it. I was grateful for the way in which the editor and the reviewers kept an open mind throughout the process.”

“I think editors today might ask us to split it into three papers: one on egg mimicry, one on recognition errors and one on the absence of chick rejection. But I’m pleased that we put it all in one package, because I think comparing the eggs and the chicks in the same paper makes it more complete. Subsequent studies have done more detailed analysis of each of these topics. I’m also really grateful for the old style editors who allowed us to be chatty and put some long quotes from Darwin, Wallace and Aristotle. I think it’s lovely to pay tribute to these great naturalists. Lots of early cuckoo discoveries were really hard won, by Edgar Chance, for example. We’re so lucky to have this natural history to build on. As I said earlier, the hardest bit is doing the watching before you do the wondering.”

“I think I was in the field over 60% of the 5 years I was in graduate school. The outer coast sites were rainy and difficult to get to, but very rewarding and fascinating for their high diversity and all of the fascinating interactions. The tides were often in the middle of the night, and I spent the day fishing for Salmon from Bob Paine’s tiny boat. I slept and ate in my small 4-wheel drive vehicle. The San Juan Island sites were much dryer and more difficult to work because the rock was so hard. I struggled to maintain the cages. But there I had the luxury of a house to stay in and I was better able to work up data and get caught up. I spent my free time solo diving, looking at sea star foraging biology. At the time, I think I was stressed trying to keep up with all the driving and fieldwork and keeping up with the data, but in hindsight those were absolutely the best times of my life. Bob Paine was a wonderful warm friend as well as a mentor and he kept reminding me how lucky I was, and he sure was right.”

“I think I would tell the student to read this as one of the early studies trying to understand how coevolving interactions may diversify ecologically across landscapes, knowing that it doesn’t have everything that you would want in a full study of this sort. To really understand that, you need to read the subsequent studies from our lab and from other labs for what you need for true tests of geographic mosaic. This study, though, helped to show that coevolving interactions vary ecologically and evolutionarily among ecosystems, and it helped to show that, with hard work, it is possible to study these mosaics in nature, which are the fuel for the relentlessness of evolutionary and coevolutionary change.”

“I think if I did it today, I will record all the roars given. Instead of just counting roars, I think I’d be going in for looking at qualitative aspects of the roars during the roaring exchanges. And I would be using computer-based techniques to identify changes in roar structure during roaring interactions, which would have given a totally new perspective on that. But that would have been impossibly time consuming with the methods that were available to looking at the structure of vocalizations at that stage. Now, it would be okay because you could get the computer to run through thousands of roars and parameterize them, But at that stage, there was nothing like that.”

“I think it [the paper] stood up pretty well. I’d say I definitely had a fondness for optimal foraging theory at the time, that I’m a little less enthralled with now; but only a little! We didn’t really engage that much in some of the evolutionary causes of this as much as I might now. I think thinking about things like gene flow and other forms of negative frequency dependence – there’s a variety of things that could generate and sustain this individual variation, some of which are adaptive, some of which are non adaptive. I think I would have expanded on that. It’s a long paper already, but I certainly could envision writing more on that at the time.”

“I think it has stood the test of time and other people who have done similar things have found similar patterns. So yes, the main conclusion still stands.”

“I think it is very difficult to think back what it was like before we had smart phones, or before there was PCR. Nowadays, everybody lives life as if we’ve always had smart phones or email or internet. And I think it is difficult for them to see what science was like 30 years ago. I know, because these methods aren’t used anymore, it’s hard for them to imagine that you can sequence DNA with radioactivity. Why would you do that? You can do it with fluorescence now. So, I view this a little bit as a lesson of how –Avery or Watson or Crick or whoever – how they worked in a generation or two before me, to try to imagine what that was like and what the data were like and how cumbersome it was to get only a little bit of new information. I think this is maybe a lesson in that, that it’s difficult to understand, from a young student’s perspective, in particular, how these kinds of technical advances really contributed to progress in science generally and to better understanding the patterns and processes that describe and shaped biological diversity on our planet.”

“I think it was motivating, not only because it was intellectually quite exciting, but also because it was such a wonderful experience of working together with somebody where the collaboration actually started when I was thinking, Oh, dear, I need to criticize this person, and that he took it so wonderfully. I think it’s just a great example of the way science should work, when people are open-minded and generous and all that. So that sort of creates a positive feeling as well.”

“I think it was the year 2000 when there was the ISBE (International Society for Behavioral Ecology) conference in Zurich [...] and that’s where I first met Rob Brooks, who then was giving a talk about his very fancy result on guppies, where basically he was saying that his results favor the ‘Fisherian’ rather than the ‘good genes’ process, when it comes to explaining why females are preferring this trait. I had never met him before, but I remember sitting in the audience and thinking, hey, but hang on [...] maybe the better males are actually intrinsically better, but they can get so much benefit out of putting that all allocation-wise into attractiveness, rather than into survival traits, assuming that there’s a trade off. He hasn’t actually shown that it’s this process as opposed to that other process. And of course, when you’re a young scientist – I was much younger then – you’re kind of nervous about criticizing somebody, so I didn’t dare to do that during the conference. I thought that I need to write up my thoughts. [...] That critique I wrote became an Ecology Letters paper.”