“Emlen used these funnels and inkpads on the ground. The birds would sit on ink pads and when they try to leave the cage they produced these footprints on a white paper. In our technique, developed by Wiltschko and Helbig, we used rubber paper on which the feet, and especially the nails or claws, produce small scratches. These scratches are much more easily counted and investigated. For analysing all these scratches we have developed a specific computer program, which would take all the papers with the scratches and calculate the mean value of the direction [of migration] and other necessary statistical values.”

“For the first few years after this came out, I kept count for a while. I had over 2000 requests for reprints. And this was at a time when you didn’t send PDFs. So I had to keep getting more money from my dean to pay the cost of running off, you know, another couple hundred copies every once in a while.”

“He was able to genotype 30 microsatellite loci while I did only seven allozyme markers, which was actually pretty good. The other thing he was able to do is to record and do playbacks of ultrasonic calls. That technology was not available to me. To record ultrasound you needed a high speed tape recorder, which was a great big bulky thing with big batteries and very expensive. I didn’t have one of those. Today, doing the same is still not cheap, but much cheaper than earlier. And less cumbersome.”

“Henry [Wilbur] had an enlightened and generous philosophy about authorship. This probably came from his own experience at the University of Michigan. Basically, if he wasn’t involved in the set-up, data collection, analysis, and writing, he didn’t see the point in being a coauthor. I have applied the same rationale to my own students, though you don’t see that happening very much anymore. It wasn’t unusual in 1983 to see mostly single-authored papers in Ecological Monographs or Ecology. Now it’s rare.”

“How did I draw them? I plotted them. There was a Calcomp plotter in our computer centre, and you could feed in files of numbers and, you know, there were some function calls you could make – I don’t remember how it works – and I figured out how to draw these axes and plot these figures. And they’re very crude symbols. I mean, the symbols are little squares, and then up here, it’s a rather weird looking little asterisk, in which the diagonal lines are longer than the vertical and horizontal lines. We don’t draw asterisks that way, usually. That was what the plotter produced if you gave it the figure of an asterisk, and there’s some other way you could tell it to put a square. So I had to do all that in the computer and have it computer-plotted.”

“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 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 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 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.”

“I forget what it was called, but libraries had this huge publication that listed all the literature. What I did was, every time I got a paper, I looked up and found everything that it cited. It was even more difficult because I had to find papers that may not have been on the topic but that had the relevant data. I think I still have my archives of about 3000 hard copies of different papers that went into this. The papers that had useful data were only a couple of hundred, but I had to go through the whole set of 3000 to know that. I remember going to the Royal library in Copenhagen, which is enormous and has a very good collection. Michael Rosenzweig went to Wisconsin when he was writing his book because Wisconsin was famous in the United States for being a very complete library. I went there too. I also went to Smithsonian, and spent an enormous amount of time in the Library of Congress. It took a lot of time because I needed to find everything. Even then, at the end, there were a couple of papers that I could never find.”

“I have very fond memories, you know, from graduate school days, and even in the early days of my faculty job, of going to the library. And, at that time, the library was an intellectual centre. You would look and say, oh, what journals came out this week, and you would go look at them, and flip through these different papers that, you know, much of it is serendipity, and which you wouldn’t see in the modern era. So part of it was finding those papers, but the other part of it was, I feel that there was more acceptance in those days of the appropriateness of just sitting down and reading for a few hours. My impression is, certainly in my own case, it’s very difficult to do that. But I think even among graduate students, it’s not the way it once was.”

“I know exactly how I made the figures. I had a light table and I had very good black pens. That figure was drawn by hand. In fact, looking at it now, enlarging it, I can make out that it is drawn by hand; in one place it doesn’t connect up very well. But this was just before the ability to do figures on computers became available.”

“I know that we had access to online searching, well before that paper, at our library. We didn’t necessarily do it ourselves, but we could file a search, some search terms, and see what came up. We couldn’t do what you can do today – go to Google Scholar, type in “Ecosystem Engineer*” and see what comes up.”

“I learned the basics of multivariate statistics and discriminant analysis by myself and found help in the Faculty of Engineering to run my analyses on a computer with the help of a programmer, as things were done at that time. Using a computer at that time was done through punched cards. I had to prepare my data and computer runs on special sheets of paper, which were then transcribed by a keypuncher and fed into the computer through a card reader by a certified programmer. Biologists could not get anywhere close to the computer at the time.”

“I literally dropped everything, ran to the library and started finding everything I could. I started reading everything I could. Of course, nothing was online in those days. I took out every book I could – those of interest were mostly in the social sciences at that time. And one of the books I read was the book by Larry Hedges and Ingram Olkin on the statistics of meta-analysis. And I just pored through that book and thought, “Okay, this is something we could do in ecology.” I learned everything I could about the statistics and practice of meta-analysis from the books I could find.”

“I look back on it and I see how we did things in the past, which was very different from how we do things now. That is not, necessarily, meant to criticize the paper, but rather to illustrate that we are learning as we go. I, sometimes, do that with students. I point out how we do things very differently now and how, maybe, in the past, we did some things that we now consider “wrong” – particularly in terms of statistics. But then, I emphasize the point that this was the best that we could do then. It’s good to look at papers very critically, but you should also always look at them from this more historical perspective. This is, of course, difficult if you’re a very young and naive reader; you don’t have this perspective. And that might, sometimes, make our students very critical, maybe more critical than what they should be. But, certainly, I sometimes look back at these papers, partly nostalgically, but also partly to understand how we did things in the past and how we have improved the way we do our research.”

“I made radio-transmitters with little waistbands that were designed so that when the waistband stretched the pulse rate of the radio would change. Using this I hoped to get remote data on how much the bat had fed. I made the device, put it on the bat and it worked. But, I also had to make holes in the membranes of the bat’s wing to get the waistband on and it would still slide off the bat’s belly when it fed. I eventually decided it was too intrusive. The main advantage today would be better video technology, but doing what I did would still be hard – you still need to get into the hollow, and keep the bats in view, which often requires squirming around inside the roost. So, I think what Gerald Carter did – work with a good captive population – is the way forward.”

“I made the first version of the figure which was then redrawn in ink by a departmental lab assistant, Aino Falk Wahlström, skilled at illustration work.”

“I prepared the other figures using SigmaPlot. This was one of my first times using this software and I complained about it a lot. Anurag Agrawal had to hold my hand repeatedly as I attempted to shrug off my Luddite tendencies.”

“I really didn’t start collecting data in earnest until the third field season, the third summer, after joining graduate school. Now I feel like people are much more pressured to start much earlier than that. And it was kind of nice because, you know, Bill [Hamilton] didn’t really care and it was all time well spent.”