“Whole-ecosystem experiments were unfamiliar back in those days. Ecologists wanted experiments to be done in tiny containers with lots of replicates, but it is impossible to study trophic cascades realistically in tiny jars. When I look at the paper today, I think the amount of statistical detail we included is rather ridiculous. But we had to include it to placate the referees.”

“Working in growth chambers is much more difficult than working in the field. Three in the morning, something would breakdown and you have to run in there. The rain would go off at the wrong time and we had to figure out why. Or there would be a power surge and the lights would blow. I slept at the station many nights just nursing the thing through. We had set “the sun to go down” in the middle of the day, so if I wanted to get there at “sunrise” that would be two a.m. So, I just slept in the office most of the time.”

“Yes and no. It has actually been a fascinating example of how science works. Yes, because many of the observations have been confirmed in later studies on different populations of the same (and other) species. For example, there is little doubt now that females play an active role in seeking extra-pair copulations, and it has also been confirmed in blue tits that extra-pair males are larger. However, the conclusion that females seek extra-pair copulations to obtain good genes benefits was probably premature. Initially, we found additional support for this hypothesis. We could show that extra-pair offspring were in better condition and were more likely to survive than their within-pair half-sibs. Most of my colleagues and I were convinced that this was good evidence for genetic effects, because we thought that within- and extra-pair offspring only differed in paternal genes. These offspring indeed share the same environment because they grow up in the same nest and they have the same maternal genes. At the time, there was some discussion about whether males would treat within- and extra-pair offspring differently, but we thought that this was highly unlikely. Another possibility was that extra-pair offspring would do better because the eggs from which they came hatched a bit earlier, and thus the extra-pair young would have a head start in life. I had actually rejected this idea after looking into it during my post-doc at Queen’s University where I worked on extra-pair paternity in tree swallows and eastern bluebirds. However, when it comes to blue tits, who lay large clutches of up to 15 eggs, it turned out I was wrong. Colleagues from the University in Groningen showed in 2009 in a paper published in Current Biology that extra-pair young are much more likely to be among the first laid eggs and because first laid eggs hatch first and generally do better, this alone might explain the extra-pair young’s superior performance. It’s really great work and I am still shaking my head that we did not do it ourselves.”

“Yes, (I wrote the paper) right there in my room, longhand, and for a fee it was typed by some kind secretary. No computers!”

“Yes, at least in the old days, it was important, if you were trying to publish in Nature or Science, to be as lucid as possible. Things have changed now. If you read the average Nature or Science paper nowadays, it’s so highly specialised, so technical; it’s very hard to follow. And there is a lot more material too; you are expected to put a lot more into it. A small idea, a small result, is no longer something that Nature or Science will even think about, unless it’s something really profound. And most often, nowadays, you need to have a strong molecular biology component, otherwise journals don’t even look at it. I think, if I submitted something like this now, it probably won’t get accepted.”

“Yes, I still remember that day in an ash tree! Butterflies defending sunspot territories sat on low perches, often on brambles or other leaves in the ground layer. Butterflies that were intruding came down from the canopy. I noticed that the canopy males searched for females in a different way. Whereas the sun spot males perched in the sunshine and waited to inspect things that passed by, the ones up in the canopy were patrolling. The canopy was more or less completely in the sun, so perhaps the best thing to do was to just patrol around and try and find females by active search. On days that were cloudy, but still warm enough for the butterflies to be active, I noticed that all the butterflies were in the canopy patrolling. These different tactics for searching for females were fascinating. What I wanted to test was why patrolling males were so keen to get sun spot vacancies that arose. Was the woodland floor the best place to look for females? This is why I sat up in a tree all day! I simply scored the number of females that visited sun spot territories below, and the number of females that I saw being harassed by patrolling males above in the canopy where I was sitting. I found that the sun spot males encountered many more females than the canopy ones. Though statistically the evidence wasn’t very strong, together with the behaviour of the males, it convinced me that the males were competing for best places to look for females. Another very important finding was that because territory vacancies arose frequently, most of my canopy males got a sunspot territory in the end. This suggested to me that a sun spot wasn’t an incredibly valuable resource, unlike my pied wagtails where only a small proportion of the population held territories. Here, it was almost like seats on a bus – everybody had a turn, if only they waited patiently for a little bit.”

“Yes, I think we did share drafts over snail mail.”

“Yes, I would delete the parenthesis saying “a group of compounds” because we now know it is cyclic AMP, one small molecule [...] the substance was identified as cyclic AMP by David Barkley and Theo Konijn in my laboratory in 1947.”

“Yes, I would say that the conclusions regarding changes in plant composition hold true, and that our confidence in those conclusions has grown.”

“Yes, it [literature search] was challenging, but on the other hand, there were many fewer papers in the literature back then than there are now. During my BSc, I learned how to use BioAbstracts (on paper) to do a search, so I used the same approach for my literature searches during my MSc. I was lucky to be in Ottawa, because I could go to the National Research Council library which had virtually every journal I could hope to find. They also had nice quiet research rooms. I could select a room, take in a pile of journal volumes, and if I didn’t finish with them that day, I could leave them there until the next day when I could go back and continue my search. This made the literature search very efficient.”

“Yes, the main conclusions still hold true, and that’s why it keeps being cited. And if I were to redo it today I can’t think of anything that I would change. Of course, nowadays, we can add lots of interesting genome methods.”

“Yes, today I would use sequences of several hundred genomes, representing more clades of endosymbionts, instead of a handful of single genes from just a couple of groups. One can get >1000x data for less effort today.”

“You know, at the beginning I was not sure exactly what I was going to find. I just knew I needed to be systematic, be quantitative. I knew I wanted to study food sharing but I didn’t know how often I would see it, so it was done with some level of hope. The information from these focal animal samples was mainly used in a subsequent paper where I report on social grooming. The food-sharing was so infrequent that I recorded it whenever I saw it. It was so rare that if I had done it only on focal animals I would have had no data. In fact, in the first six months, I think I had seen it only a couple of times. At that point I was starting to think that the whole project was doomed. I think part of the issue was that – and this is not mentioned in any paper –in order to see the animals and identify them, I used coloured reflecting bands – bird bands, basically – on the wings of the bats. And to see the bands inside the tree I had to shine lights on them. Initially, the bats would always hide from the lights and so I couldn’t make any observations. In order to overcome that, I would, every single day, take a miner light into the tree and shine it on the bats continuously. These would last for 12 hours with rechargeable batteries, and the bats had nowhere to go, so in some time they got habituated to the lights. I could confirm this with a night vision scope which I could use with infra-red light. Infra-red light is invisible to bats. So when I compared their behaviour with the night vision scope and with the lights I couldn’t tell any difference. But it took months.”

“You know, my most favourite paper was rejected so many times I gave up on it. It hasn’t been published. I had used a method called angular statistics, on predator-prey cycles, and was able to show that they really weren’t cycles. I thought it was neat and nobody had ever done that before. But it’s been rejected and rejected and rejected. So my favourite paper is only mine!”

“You know, right now I’m working on a project where we’re trying to get rid of the four paradigms. I think they were really useful for a while. But now they are kind of getting in the way because they are highly idealized and not really likely to actually apply to more realistic situations.”