“We were a bit constrained by the apparatus. The birds are in a box with a touch screen on the front of it. The touch screen and the reward mechanism that provided the birds with food pellets, those were run by beater PCs, old IBM machines, because it’s a dirty environment. I mean, you’ve got birds and bird poop and bird feathers and dust all over. I wanted equipment that was going to be tough and that, if it went soft on me, I could replace it pretty easily. So we used cheap machines. The whole thing was run with C++ programs on DOS. Very robust, very solid. Initial configurations were accessed from a Linux box in a clean location elsewhere, and the results were written back over the same network links. I could access the Linux box remotely to keep track of how experiments were going, but the individual DOS machines were totally secure – the code itself was not visible from the internet. Moth evolution occurred in stages, one generation of 100 moths per day. A new generation was produced by random breeding within the old one and downloaded each morning when the machines were started up. So, the system had to be capable of doing the evolution of the new morphs each morning when you turned it on. It didn’t take very long. I mean, it was a pretty efficient bit of code. I don’t know, it took maybe about 10 minutes or so, when you first started it. It worked okay. I showed the code to people and they said, oh my god, you did this in DOS! I had all these old DOS tricks to wedge all these great big matrices into the 512 kb memory limits. But it all worked.”

“We were camping in tents in that preserve. From there, we drove to the field sites every day. We had a jeep that could go off road because it’s a very rough terrain. In the second year, there were two more students, in addition to me. We still had tents, but we’d also rented a small trailer that we could haul around and park in that station. We did our field trips from that station. In 2001, Ian Baldwin’s lab in Max Planck, started to put more trailers there, so that more students could be there. And we also had one horse trailer, which is really funny. The trailers that transport horses are a little bit larger, and so, we turned one of those horse trailers into our scientific trailer, which had a lab in there. This was in 2000. When we saw how important plant volatile emission is, Ian Baldwin bought a gas chromatograph mass spectrometer that we put into that trailer. And then we put, I think, two four-squaremeter solar panels up, on which we ran the GCMS. [...] There’s a lot of sun light, since it is the desert, and we were able to run a GCMS off of solar panels. It was really impressive and it is still there. It grew more and more, and, now, there’s almost a little village of little trailers that facilitate the work of the researchers there.”

“We were not using Skype, and we were not on the telephone; it (the draft of the manuscript) was all by email. We didn’t have a Google doc or a working folder either. We were just passing it back and forth as attachments.”

“We were, originally, doing playback experiments with a variety of audio equipment [...] sometimes we used a public-address horn speaker, sometimes we used a whacking great cabinet speaker, of the sort you had at a rock concert. So, we were carrying these around the field. Well, that’s another area where things have improved. In order to get decent quality, we were having to carry big speakers, big amplifiers, and whopping great car batteries or lorry batteries to power them. So it was quite a major business. And I think, today, one would be able to get much better playback with much lighter hand-held equipment using lithium-ion battery technology.”

“We would do a number of things differently. So first of all, we would search much more broadly. We would not restrict the studies to a certain number of journals, we would just, you know, use scientific databases to search whatever had been published in different journals. So we would have a much wider range of studies, but then it would be too many studies to handle, so we would have to have to narrow it down in some way I guess. We used fixed effects models in that paper, which were the only statistical models that were available at that time. Now we would you use mixed effects, we would do much more complex modelling, and we would use meta-regression and not just heterogeneity tests. So we would use different statistical approaches as well as different search and inclusion approaches. We would also record and report the data differently, given the recent emphasis on reporting standards and open science.”

“We wrote the paper by hand or on a typewriter, we drew the graphs by hand, we didn’t have computers to use at that time. They were just coming into being and we were learning how to use them. So, it was all done, really, hands on.”

“We wrote the paper to get people to pay attention to this subject, and I think people are paying attention to the subject now. And so, in that regard, it’s maybe less important as a paper now, and maybe somebody would be better off reading a more updated version. But I still think that it lays out a lot of the core topics pretty well.”

“Well, actually, it was serendipitous. I went out to the islands to study the behavioural ecology and genetic structure of the island fox. And while I was there, I started to see some mortalities of foxes. I had worked with bald eagles in the past, and had figured that golden eagles, which were irregular visitors to the island, were taking foxes every now and then. And then I started seeing a steep decline in the foxes while I was there, so I just happened to be at the right place, at the right time, to be able to identify what was going on.”

“Well, I guess, maybe, it’s a testimony to my own lack of mental flexibility, but I guess I’d have to say that that’s pretty much the way I still think.”

“Well, I had published a paper in 2001 in Animal Conservation based on this. I had used Franck Courchamp’s model in that paper. And then – I think it was either 2000 or 2001, I have got to look back – I gave a presentation on that work at the Society for Conservation Biology meeting in Missoula. Josh came up after the talk and, you know, started rapping with me and we kind of hit it off and became friends. And then a little bit later I was talking to him over the phone about an aspect of the research that I wanted to try and get a handle on, which was to evaluate the food habits of the golden eagles. Josh said: “well, we could use stable isotopes to get at a broad-scale look at their food habits”. So then, he and I started conversing about that and felt Franck was a better modeller than either one of us, so we asked him to be involved. That’s how the team came together.”

“Well, I have always been a bird watcher and have observed and wondered about this behaviour numerous times. Tony and I first met at a conference in 1996. In fact, at that conference, when I first suggested to him that jays might have memory he was completely dismissive. He said: “I can’t think of a single reason why they would need it”. And I said “Well, what about the fact that they hide perishable food? Wouldn’t it be important for them to be able to remember when or how long ago their cached their food, in order to know when they needed to recover their caches of food?” He didn’t know anything about the caching of perishable foods and so he said: “Oh gosh, I hadn’t thought about that”. So then we went away and spent much of the rest of the conference talking and discussing. I told him what I knew about the behaviour of the birds in the wild, from my observations of them, and it was at that point that he said: “Oh well, I just made an assumption, I didn’t know about this”. And I said “Well, this is something that we could test empirically”. And he said: “Absolutely, yes”. So then we got into a collaboration designing experiments to test whether or not the birds could remember the “what, where and when” of past caching episodes.”

“Well, I probably never spent as much time writing a paper as I did with this. It took a lot of time and effort and a lot of rewriting. When I read it now it seems pretty dense. Every sentence has information in it. Nowadays, for a paper like this there would be a 100-page supplement that would have all the data and all kinds of other analyses. So that’s one difference. I think the writing style also seems somewhat different although it is hard for me to pinpoint exactly where the difference lies. It’s very natural history-focussed at the beginning, but there are three clear predictions after that, followed by the evidence in support of them. Even if I wrote it now, that would still be the way I would want to do it. You know, come up with such and such predictions and then come up with the evidence to support them. But what strikes me when I read this paper now is just how little data there really is! And how much effort went in to getting those data. It was Herculean.”

“Well, I think I would encourage him or her to read the more recent papers of my graduate student, as a way to bridge the gap between the 1984 paper and now. I was pleasantly surprised that what Gerald [Carter] found, with a lot more data, was not all that different from what I had said in the 1984 paper.”

“Well, I think the paper can be approached on its own largely because it’s so visceral. I guess what was really lacking from the paper back then was any information on the underlying mutational process. And so, I would want to draw their attention to some of the papers that have described the underlying genetics (There are, for example, a series of papers in Genetics with me as last author) so that there’s no doubt that this really is all driven by spontaneous mutation selection. In terms of caveats, it’s not a caveat really, but rather how science works. I rather like the fact that we were able to show that we had it wrong with regard to the 'fuzzy spreader'. As you investigate things, you may find what you once thought to be true, no longer the case. Some piece of information has caused you to revise a particular position. And I like very much, and get students to read, the paper by Gayle Ferguson and Frederic Bertels in Genetics in 2013, which is titled something like “A revision of the Pseudomonas radiation”. This is a good example of how science works. Again, this is not really a caveat, but something that I would emphasize. My advice to someone reading for the first time, might be to sit back and see how extraordinarily simple this piece of work is, and yet how challenging it might have been to unravel. Sometimes, just looking at the world differently can take us to unexpected places.”

“Well, it wasn’t that dissimilar. I mean, field work still today is based, in these sorts of studies, [on] regular samples of the observations of particular individuals, and quantitative records of their activities, in this case, the frequency of roaring, the frequency of fighting, the timing of birth, and so on. The difference is that it was all collected either on tape recorders or on check sheets in the field. So one didn’t have tablets or handheld computers, so that one had to either collect it on tape recorders and then transfer it to paper later on, or one had to collect it with check sheets in the field, both of which we did.”

“Well, now, of course, I think a lot of that has been solved, more so than it was then, but I don’t really disagree with those conclusions. In looking at it again now, I’m actually surprised at how much I got right, to be honest. Together with other people, I’ve elaborated a lot of things. And some things have changed as well. For example, we now know that some of the escalation occurred earlier in the Paleozoic. We also know that the Mesozoic revolution itself is, probably, a two or more phase process, which we didn’t realize at the time. These are important nuances, but the basic conclusions, I think, are right.”

“Well, that came about by a series of interactions that I call serendipity. Things happen, and then when you see something happening you jump on it and try to make something of it. I had taken a job as a young professor at Dartmouth College. There, I met Herb Bormann, who was a professor at Dartmouth College. Herb was interested in possibly using Hubbard Brook as a study site. He was familiar with the Coweeta Hydrologic Laboratory in North Carolina and experiments done there. I was very interested in that as well. And so we talked with Robert Pierce, who was the project manager at Hubbard Brook. And then, I recognized and became friends with Noye Johnson at a Dartmouth football game. Noye was a geologist, who had also come from the University of Wisconsin-Madison, and was a recent faculty member at Dartmouth. I introduced Noye to Herb and the four of us decided to pursue these large-scale studies.”

“Well, to be honest, I have been happily married since 1977, and we spent very little of the first decade of our marriage in the same time zone. And so, when Bill got a job at Berkeley, and I, about 6 years later, was lucky enough to get a job there, I just decided to start working in California. There was also a little bit of carbon sensitivity. I would have loved, and I still may try, to do more work in the tropics or in the Midwest where the fish are more charismatic and diverse. Salmon biologists wouldn’t like to hear me say this, but there just isn’t the fish diversity west of the Rockies that there is in the Midwest or down in the tropics. I just wanted to study something local and to invest in where I lived, and also maybe not be flying round in jets and being away from home all the time.”

“Well, when I started to work with frogs for a Master’s thesis, before I went to Cornell to do my PhD, the dogma was – most of which was true – that frog calls evolved to indicate the species [...]. And that females were under strong selection to mate with males of the same species. That’s certainly true. And then when I went to Cornell and started working with bullfrogs – I was not working with calls then; I was studying territoriality – I was struck by how variable their calls were. I mean a bullfrog call sounds like a bullfrog call, but I could clearly tell males apart. I would hear a male and know that he was on a neighbouring territory the night before. That he’d moved over. That’s how I became interested with the frog call, as it had to do with mate selection within a species.”

“What I found interesting was that I could go to any wet forest habitat on any island, and I would almost always find four species of the spiny-legged spiders: one that’s green and lives under leaves, one that’s large brown and lives on tree trunks, one little brown that lives on twigs and one maroon that lives on mosses. It was just so striking that you almost always get the same set of forms, or “ecomorphs”, on each island. The green ecomorphs on one island look just like the green ones on every other island, and likewise the large brown, little brown, and maroon. So, at the meeting in Australia, I talked about the close affinities of the green ones across islands - surely the green ecomorphs must either be the same species or be very closely related (and likewise the large brown, little brown, and maroon). But then, you know, we got a hold of the molecular data and it told us a totally different story, that the different green ecomorphs are not their own group (and likewise maroon ones and the brown ones). Rather, they have independently or semi-independently evolved the same set of ecomorphs on each of the different islands. So it was really this kind of incredible realization that these things that looked as if they were so similar and then to find that actually they were not that closely related. That was fairly mind-blowing to me.”