The red-billed chough, subject on one of Jane’s long term studies of effects of the environmental on the size and structure of populations (Image Credit: Jean-Jacques Boujot, CC BY-SA 2.0, Image Cropped)

Our world is changing rapidly. Yet our perception of just how much it has changed is often dulled by our inability to compare what we see around us to what was around fifty years ago with enough clarity. This is one of the reasons that long-term scientific studies are so important. They give us a tangible assessment of just how much our world has changed, whether that be in the climate, how species have evolved, our how populations fluctuate.

Jane Reid is the new International Chair Professor at the Department of Biology at the Norwegian University of Science and Technology. Jane has spent years working with several long-term studies, some of them successful, others not so much. Sam Perrin and I spoke to Jane about the importance of long term studies in ecological science.

Sam Perrin (SP): Over your career, you have worked with a lot of long term studies. Why are these important to the natural sciences, and particularly in ecology?

Professor Jane Reid (JR): The questions I am interested in are really about how ecology and the environment affect individuals’ life histories. And by life histories I primarily mean reproduction, survival, dispersal and seasonal movement. If we want to understand how populations respond to environmental change, we need to see how the environment affects all four of these things. To see that, we have to look at data from a bunch of different years and occasions. That is what gives us the variation to investigate processes and make any kind of predictions. The other aspect is evolution, and once you bring evolution into the equation you really have to look across generations.

One of the big challenges in science is that the kinds of species that have fast generation times and are therefore easier to study evolution in – lots of invertebrates for example – are fantastic to work with in the lab but more or less impossible to work with in the field. The species that are tractable to work with in the field tend to have slower generation times. They tend to be birds or some kinds of mammals or fish. So these studies take time to get answers. That is a massive challenge in science, because in biology there are a lot of funding programs that are only tailored to three or five year projects. That is simply not long enough to answer key questions. So you end up finding ways to bolt multiple projects together to generate the kind of time frame you need. There is no reason that it has to be like that.

If you look at other branches of science, they are much more used to looking at projects that take a lot longer to come to fruition. Astrophysicists are quite used to blasting a probe off and having to wait 15 years until they get any data back, because it takes that long for it to get to wherever they want to get it to. And this time frame thing is our own fault. There is no reason that is has to be like that. That is increasingly a challenge in biology.

Lara Veylit (LV): Why do you think historically projects in biology have been funded for such short periods? It is not like we have not been interested in processes that take a longer time frame to study.

JR: That is an interesting question and in some ways I can understand why the time frame is like that. It is roughly the same time frame as a PhD project, for example. I also think that having projects that are re-evaluated quite regularly is a good thing. While long term studies are absolutely an invaluable asset, the fact that a study is long term does not necessarily make it a good one. There are some pretty useless long term studies out there where either the question has been superceded, someone never really had a clear question to begin with, or the data collection has not really been particularly systematic. I think the need for regular re-evaluation and investment of resources into the right long term studies is critical rather than just investing in a study because it happens to have been started a long time ago. That’s quite a difficult situation though, because you could be threatening somebody’s pet long term project that they have probably been investing lots of personal time into.

I think what has changed recently is because research funding is more competitive in many countries than it used to be, the ability to bolt together sequences of projects has become harder. I think there is more stress on people trying to do these kinds of research projects than in the past. It was probably more likely to be the case if you were doing good work in the past, you could have some expectation of getting another project funded. I just don’t think that is the case anymore. Which in some areas of science is probably a good thing, but it adds some extra challenges when your key questions can’t be answered in the time frame of one or maybe two grants.

SP: So what makes a good long term study?

JR: I am very lucky in that I have worked with what I think are some excellent long term studies. One on song sparrows in Canada that has been going since before I was born, and that has been a fantastic dataset. One that I have had a hand in instigating in Scotland is a project on European shags and is in some ways a case in point. I realised none of the existing long term studies were really suitable to the questions that I wanted to address with regards to the ecological and evolutionary dynamics involving variable seasonal migrations. So we had to start another one. That has been going on for about ten years now, and has been fantastic. A third one I work on with red billed choughs has a much more applied context where the data collection is much more low intensity. It is basically run by local enthusiasts.

All of these studies have the attribute that data has been collected at a high standard and systematically over quite a long time frame with at least some semblance of a study question in mind. Although in some cases the questions have mutated as time has gone on. The ones that I have come across that are less useful are the ones where there is no clear purpose. Or perhaps the data that are collected are not well suited to any of the questions that we [ecologists] currently want to answer. In some long term studies, the data collection has not been standardised or collected particularly rigorously. These studies can still be useful, but then there is a trade-off between funding them and starting a new long term study that might be better designed or funding a short term study that might be really valuable. That is where the decision might go against the long term study, but it is very difficult to make that call.

Regarding the ones that work, there has always been someone at the helm who is willing to shoulder the burden of carrying it on. So if the scientific community could form a consensus on the kind of portfolio of long term studies that we should have, I do not think that would look like the portfolio we actually have. For example, there are a lot of studies on hole-nesting birds and ungulates because they are relatively tractable. This is great on the one hand, because it allows you to do comparative studies. But all of our inferences are coming from a very specific and narrow set of situations and species, which is not ideal.

SP: If you could put together a checklist for ecologists looking to start a long-term project, what would be the top three items?

JR: A good question, the right system to answer it and unending enthusiasm! And then a study system that is easy to work with. Ideally, close to where students or researchers live. Ideally, something that is logistically not too challenging such that if you go through a phase where funding is limited, you could still do the fundamental work. They’re the basics.

Actually when I started as a postdoc, I tried to take the reigns on another long term study, which was on a population of starlings on Fair Isle off the coast of Scotland. I had worked there a lot for a lot of different reasons before, so I knew the site fairly well. There was already 25 years work of data for this population but the project had been going on at a very low intensity. I spent about 6 years with 2 PhD students trying to keep it going, but in the end it was just too hard. The field work was just too time consuming. Even though the field site was in Scotland, it was a pain to get to. It was on a small island and there was no point in going there for less than a week because it took a day and a half to get there and get back. You couldn’t just maintain it. In the end, I just had to let that one go. The questions also got superceded by the shag system I mentioned before. It was quite painful to ditch it after so much investment but it just wasn’t going to work.

LV: Following up on your point that most long term studies have been on birds and ungulates, what kinds of species do you think ecologists should be branching out into?

JR: The main thing is other taxonomic groups. Even the birds I work on, some people see them as idiosyncratic because they are not hole-nesting passerines, which make up a large portion of bird studies. All of my studies are more or less on natural breeding populations, there are no artificial nesting sites used for the song sparrows or for the shags, for example. There are also no people feeding them in their gardens. There are some taxonomic groups where it would be really nice to have more long term field studies we could use in corollary to studies in the lab.

One really nice example of that is Tom Tregenza’s increasingly long term field study of crickets in Spain. It is quite a small area, basically a field as I understand it, and there are these crickets that live in burrows in the meadow which are big enough that you can mark individuals. He has these video cameras monitoring all the burrow entrances. It is basically a big capture-mark-recapture exercise to see who has gone where. Then, you can use genetic methods to identify the parents of offspring. That is really nice because crickets are also a species you can quite easily do experiments on and they have a faster generation time. But as in all field studies, it has its challenges as well. You cannot see what is going on underground. As technology improves, there will be ways to perhaps make things a bit more tractable.

SP: You would think as ecology is focused on populations in a changing world, long term studies would just be everywhere. Why do you think that is not the case?

JR: I think they’re difficult. They’re really hard. Again, it’s partly our own fault. They’re hard at a professional level because in many countries there isn’t particularly good support for them and so it really does rely on having one person or a group of people who are pretty dedicated and really have that enthusiasm to carry it on.