Alumni Spotlight: Nils Christian Stenseth

Over 26 years ago, Nils Christian Stenseth led a project at CAS, 'The Mystery of the Lemming Cycle,' which he credits as pivotal in shaping his career. This project sought to deepen our understanding of regular population cycles, like those of the lemmings that peak every 3-5 years, depending on their location. NOTE: This interview is from 2019, but we share it again in light of his recent ERC Grant award.


Until a few years ago, Stenseth served as the Director of the Centre for Ecological and Evolutionary Synthesis (CEES), a distinguished Centre of Excellence. This long-bearded professor has been recognized with numerous awards throughout his career.

In collaboration with researchers from the United Kingdom and France, he was recently awarded a grant of 10 million euros to further investigate the origins and spread of the plague. Professor Stenseth, who previously led the CAS project The Mystery of the Lemming Cycle in 1996/1997, receives this funding from the European Research Council (ERC) through the ERC Synergy Grant.

NOTE: The following alumni interview with Prof. Nils Chr. Stenseth is from 2019, but we share it again in light of his recent ERC Grant award.


Could you shortly describe what The Mystery of the Lemming Cycle was about?

— The CAS project I led during the academic year 1996/97 set out to better understand regular population cycles. An example is the lemming cycle with peak abundance at regular intervals, peaking every 3-5 years depending on its location; shorter in the southern part of Fennoscandia and longer in the northern part.

It should be emphasized, though, that although we had 'lemmings' in the name of our CAS project, we worked on other similar systems as well, one of which was the hare-lynx cycle, particularly as seen in Canada. We aimed to better understand the nature of the cycle (e.g., why the regularity?), and why it differed from one place to another (e.g., why is the lemming cycle shorter in the southern part than in the northern part of its range of distribution?).


What do you remember best from your year at CAS?

— I particularly remember how well the staff took care of us. We didn’t have to ask them for help; they simply did what was needed – and much more! We could really focus on the science – which we certainly did.

Universities have much to learn from CAS. I've argued again and again that there should be more support staff for scientists where science is done. Unfortunately, at Norwegian universities, the current change goes in the opposite direction – too much administrative support centrally and too little where the science (and the scientific training of PhD students and postdocs) is done – leaving the scientist to do administrative work they are not really trained for. At CAS, the administration took care of all practical issues, which they did much more efficiently than we scientists ever could.

I look back at my stay at CAS with great pleasure. The foundation for several of the papers I'm most proud of was laid down during that year – papers that were later published in Science and Nature – as well as in more specialized literature.

I also remember the lunch breaks, not only the very good food but most of all the discussions with the other groups (psychology and linguistics when I was there).


In the abstract of your CAS project, you wrote: 'A breakthrough in understanding the small rodent fluctuations is a breakthrough in understanding the functioning of the entire arctic ecosystem.' Can you elaborate a bit? To put it in a wider societal context, can you say anything about what impact climate change has on fluctuations and lemmings?

— I am happy I wrote that – I would have done the same today. We learned a lot about regulating factors within and between populations (predation, competition for food, and other so-called biotic factors) and non-biotic factors such as climate. One such breakthrough was our understanding of how the hare-lynx cycle in Canada is structured by large-scale climate phenomena, such as the North Atlantic Oscillation, which translate to the properties of the snow – which in different ways are important for both the hare and the lynx. We had a paper in Science, which directly resulted from the CAS work of ours. Much later, we published a paper in Nature explaining how the snow conditions – not least when the snow settles in the fall – affect the regularity of the lemming cycle. Specifically, the regularity of the lemming cycle depends on the snow in the fall not melting so that a subnivean space can build up – which is important for the lemming to survive well and even reproduce during the winter.


What has happened in your career since your stay at CAS?

My period at CAS has been instrumental for much of my later career. Essentially it laid the foundation for what later became the Centre for Ecological and Evolutionary Synthesis (CEES at the University of Oslo) – a center which was a Centre of Excellence from 2007 till 2017. Although the effect of climate variation was not a key topic during my CAS period, much of my later climate-variation work has in several respects its foundation during that period – where we developed methods for analyzing how climate could affect ecology directly, and also indirectly in interaction with other biotic and abiotic factors.


What advice would you give future CAS project leaders?

— Concentrate on the work you’ll be doing during your academic year at CAS. Don’t focus on publishing papers – papers will come in due course based on the work you’ll be doing at CAS. And overall, do focus on the 'big' and 'conceptual' questions. Indeed, asking the right question is imperative: Do remember what the statistician Edwards Deming once said: 'If you do not know how to ask the right question, you discover nothing'.

Published 30 November 2023, 10:44 | Last edited 01 February 2024, 9:24