“I actually did not go there wanting to do this experiment. I had no idea that this is what I would do for my postdoc. I had done a bunch of chemical ecology as a graduate student. One of these invasive species that Bob [Whitlatch] and Rick [Osman] were studying didn’t seem to get eaten very much by any of the native predators, and they were wondering whether there were any chemical defenses that this invasive were producing. And so, that’s one of the things that I went there thinking I would do. But when I got there and saw this other thing that they had going on, that I could be involved in, I thought that’s just way more interesting.”

“I applied to several graduate programs, got into all but one of them, and decided to study at Duke with Henry Wilbur, who was a rising star in the field. Henry mostly worked with amphibians then, so that led me to work on amphibians too.”

“I basically go by what’s available and I’m interested in just about any behaviour. Whatever catches my eye, that’s what I go for. I don’t care if it’s bees or beetles or birds.”

“I believe it is my best paper because it is short and informative, reporting a fairly clear outcome of a controlled, interesting experiment. It demonstrated, in the wild, female choice of mate based on a conspicuous ornament, one of Darwin’s most controversial ideas. Another often cited sexual selection paper is a model (Evolution 40: 804-816) showing that a genetic indicator process of mate choice can work, taking to higher frequencies a female preference and a preferred male ornament that reflects genetic viability. This, together with similar results from other researchers, may have helped generate more interest and more sophisticated modeling and empirical testing of such processes in sexual selection.”

“I came to the University of Michigan determined to “figure out” coloration in birds and by extension ornamentation in animals generally. I decided to focus on carotenoid coloration, which was almost unstudied in birds at the time, because of an obscure statement in an Ornithology text by Joel Welty: “Canaries will, in successive molts, gradually change from yellow to intense orange if fed red peppers.” Condition dependent sexual signaling was a new and exciting topic in behavioral ecology when I read that statement about canary coloration in the early 1980s. The prospect of diet-dependent coloration sounded intriguing to me. Then, when I went to the literature to find out more about carotenoid coloration in birds, I found a paper published in 1976 in The Auk on pigmentation in House Finches. In that paper, Alan Brush and Dennis Power used thin layer chromatography to identify the carotenoid pigments in house finches, one of the first characterizations of carotenoid pigments in feathers in any bird. House finches were an invasive species in Michigan, having just colonized the area a few years before I arrived in Ann Arbor, and they seemed to be a perfect study bird. So, in 1987, I started capturing wild house finches and visually quantifying their feather coloration.”

“I can remember sitting there and going through – of course, again, at that time you couldn’t do anything online - these big back-issues of journals in Parasitology and deciding which data sets are going to have a more complete set of birds that I’m gonna be able to rank.”

“I can understand now that it did fit at a certain moment in time. I think that Steve Hubbell’s work had, in some ways, set the expectation fairly low for the contribution of niche differences to community structure. Going to, at this point, one of the most diverse communities that we had information for, and exploring and finding patterns that were consistent with that, was exciting, in part, because of what Steve had written. I don’t know if that result had been, for instance, submitted in 1998, two years before Steve’s book was out, it would have been as exciting to the field. It really only worked in that format because of the dialogue with the ideas that Steve was putting out at that time. At the same time, I think that the framework we used to interpret the patterns was far too simple. That is something that we really have come to understand in the years after this paper had come out. If I wrote this paper now, I would write a different discussion of the potential drivers of the pattern that we found. It would be more nuanced.”

“I conducted this research with the assistance of six undergraduates. They were students in a class that I taught, Field Studies in Animal Behavior, the duration of which coincided with the elephant seal breeding season. I trained them to read tags (from a blind) and observe the behaviors under study (who dominates whom, who fights and wins and loses, who mates, etc.). With this crew, we made observations every day during the breeding season. I spent every weekend on the island study site (Thursday or Friday to Monday) and lectured during the week. We had bunk beds and cooking space in two buildings on the former, abandoned lighthouse on the island. We carried in our own water and food. We used an outdoor privy (with a great view). We crossed the dangerous and harrowing channel in an Avon inflatable raft powered by a 15 hp outboard motor engine. We got to the launching site in an old 4-wheel former military truck that John Wayne might have used.”

“I did have a look at the paper again recently, in response to your questions, and it does seem like something from a different era, where natural history and simple field observations were considered to be important. Times have changed enormously in academia, and it is now extremely difficult to obtain money to do this sort of work. This is a shame, to say the least, as there is so much that we don’t know about the natural world.”

“I did much of this study in the laboratory back at the University of California, Berkeley, but in order to carry out the experiment, I had to collect litter and soils from Toolik Lake, Alaska. Collecting litter and soils in Arctic tundra is very different from collecting them in any other sort of ecosystem. The plants I was collecting were tiny, and I needed to collect dead stems, recently senesced leaf litter, and roots. I had to devise different methods of collecting material for each species. The species I remember best was Vaccinium vitis-idaea, or lingonberry, a dwarf shrub. Its leaves are tiny, about half a centimeter long. The species is evergreen and when the leaves senesce, which happens throughout the summer, they remain on the tiny branches. To collect them, I had to lie on the tundra and use a tweezers to gently tug at senesced leaves, one by one. I only collected those that had clearly abscised, so that they easily came free from the branch. Often they would fall at the touch of my tweezers, so I would try to retrieve the fallen leaves from in between the mosses and lichens. I remember spending days lying on the ground collecting leaf litter. I think I listened to a Walkman to pass the time. Much of the time I wore bright yellow rain gear, because the ground is very wet in the tundra since the permafrost impedes drainage. I recall that the folks in camp at the Toolik Research Station could see me across the lake, essentially motionless on the ground, and they couldn’t figure out why I appeared to be lying still in the tundra for hours on end. I had to use tiny scissors to trim dead branch tips for the same species. I collected senesced leaf litter of the sedge species the same way, since these species’ leaves senesce from the tips of the blades downward to the base. I felt like I was giving the Eriophorum vaginatum tussocks a haircut, as I trimmed individual blades to separate senesced from live tissue. Separating roots from peat is a pain in the neck because the only way to do it is to carefully pull the peat away from the roots. The Ericaceous species have such fine roots that it took a long time to get sufficient mass to carry out the experiment. So all in all, it was a pretty tedious process.”

“I did not have a laboratory set up there. I stayed there much of the time, but I would periodically go back to Harvard, to deal with all the data, to deal with identifications, and in one case course work, and then I would fly back again. I had rented a house, and the house was my laboratory. Every morning when I was down there, when the weather wasn’t too bad, I would go to a particular marina depending on which island I was planning to work on, go to the island for the whole day and come back. I learnt a lot about using small motors navigating them. That’s what I did. It was very intensive fieldwork.”

“I did that [draw the figures], and I did it by hand. I didn’t have a program then. I ruled paper, and then I typed in the labels. Yes, it was pretty time-consuming. You have to realise that in the 1960s there wasn’t software to do this kind of thing. There was no other way.”

“I did the study near Ottawa simply because that is where I was living.”

“I do encourage students to think about turning their PhD proposals into review papers, and some of them have done so. In that sense, it continues to serve as a useful model, although it is not the only one. And I continue to recommend the process that produced it – an extensive period of reading and reflection during which one tries to identify the leading ideas, and the major deficiencies, of the field in which one is interested and then summarize them in a clearly written document that can be critiqued by others. But if one wants to get an introduction to life history evolution today, it is better to read the books by Charlesworth, Roff, Charnov, and myself, than to read this paper, which I think is now mostly of historical interest.”

“I do remember arguing against Apparency Theory, probably like an annoying yappy dog, but I felt initially as if no one were listening. At the time, Paul Feeny, who was a famous professor at Cornell, could have squashed me and my career. Instead, he welcomed discussions, treated me with respect, and was a perfect gentleman and true scientist. He liked challenges and cared about the ideas and not his ego. He even wrote me letters of recommendation. I have tried to follow his example ever since.”

“I do think that there is good evidence for these statements from the data that we collected at that time. Whether it is ‘true’ for all peafowl everywhere is a different question, and whilst some studies have found the same positive relationship between train morphology and mating success, at least one Japanese study claims that no such relationship exists (although, they did find a non-significant positive correlation). Of course, if females do not prefer peacocks with elaborate trains it does raise the question of why the peacock’s train has evolved, and I haven’t seen any good data that support any alternative hypothesis.”

“I don’t even remember why he was in the vehicle with me, but we stopped by the site where the exclosures were and I said, “Hey, I want to show you this experiment. It’s pretty cool.” And that’s when he said, “Wow, the amount of nitrogen in this plot is probably incredible; you should measure that.””

“I don’t see anything wrong with the major ideas expressed in the 1970 paper, though they have certainly developed enormously since then. By now many books and vast numbers of papers (both empirical and theoretical) have been written on sperm competition and its resultant adaptations. Sperm competition and cryptic female choice have been amalgamated to form the growing field of ‘post-copulatory sexual selection’, which for some reason was not discussed by Darwin, who confined his treatise to pre-copulatory processes.”

“I don’t think I would have wanted to make that initial paper more complex [...]. Nature papers are very short, so you need quite a simple design. And I think the trick to Nature papers, from what I have seen, is, really, to have a couple of really solid experiments that provide the firm footing in other journals. Then if you do a really exciting experiment and it works, then you can publish a short paper in Nature with this body of other evidence in other journals to substantiate your claim. I think a lot of people have done that.”

“I don’t think we did a very good job of getting this into the media. People didn’t do that much, you know, in 2000. There was no social network, I mean it was sort of vaguely there, but no Facebook or Twitter or any of that stuff. But in those days, there was an incredible demand for hard copy reprints, and we quickly ran out.”