25. The greylag goose, the memory of nature and the usefulness of economic history (13-4-2020)
The greylag goose, the memory of nature and the usefulness of economic history (13-4-2020)
Written by: Jan Luiten van Zanden
This morning we woke up by the chatter of a group of greylag geese that had landed in the ditch close to our house. Chatter is perhaps too nice a word for the loud noises they make – the Dutch ‘gakken’ describes it better. There are two geese trying to nest in another ditch nearby, and they often let it be known that they are still alive and kicking. At times they are joined by a larger group, and they clearly have a lot of goose-gossip to share. At 6 in the morning.
It is a more general problem: there are simply far too many greylag geese (and other geese) in the Netherlands. They are crowding out other, more special ‘meadow birds’ (weidevogels), such as lapwing (kievit), black-tailed godwits (grutto), and redshanks (tuureluur), and they are a problem for air traffic around Schiphol. There are now over a 100.000 breeding couples, and much effort is put into limiting their enormous growth – some nature lovers of course disagree with any interventions to control the ever expanding population.
In a way, this is a success story: 50 years ago the greylag goose was a very rare bird, due to persecution by men – both here and abroad – and probably water pollution. Some time ago I read in a diary of a birdwatcher from the 1940s that he had been at a meeting in Utrecht, which suddenly was broken off as they heard a flight of greylag goose coming over the city; they all went out to enjoy the sight. That is how special the bird was back then, when it came close to extinction.
We have all but forgotten this now, and only complain about the overpopulation of geese. It is an example of a more general problem which handicaps ecological research: to assess the changes in the richness of nature, scholars tend to compare with the state of nature they knew when they started their career. They tend to believe that this was the ‘pristine state’ – the baseline – that preceded the big changes they are interested in. From one generation to another, this ‘pristine’ baseline changes, but the long-term trend is not sufficiently noticed as the next generation takes another – less rich – baseline as its comparator. This is called the hypothesis of the ‘shifting baseline syndrome’, which was first developed in marine research, and has now become ‘popular’ in a broad range of ecological research.
For a historian this is a fascinating idea. What ecologists are telling us that they lack the institutional, ‘permanent’ memory to make valid comparisons of historical change, and in fact rely on their memories, on rather ‘impressionistic’ ideas and notions taken from their youth. They tell us that they lack the skills and the tools to do this in a more or less ‘objective’, standardized way. The result is that a large part of the real historical changes in biodiversity remain unnoticed as the ideas about the baseline of one generation is gradually replaced by the next one. Consequently, we probably seriously underestimate biodiversity decline in the long run (the example of the greylag goose is not really representative as it works in the opposite direction – the gain in biodiversity due to the recovery of the geese population is now forgotten).
In a way the good news for us as economic and social historians is that it demonstrates the value of the research we are doing. No economist or social scientist (as far as I know) is complaining that we do not know what happened during the 1970s, or the 1930s, or what the ‘social question’ was, or how poor we were before the Industrial Revolution. It is the first task of historians to maintain the collective memory of society, and we apparently do this in a satisfactory way, at least in such a way that we do not have to rely on our memories to chart changes (you may even argue that we now know and understand what happened to the economy of the 1930s or of the 16th century more fully than people did at the time – but this is another issue to which I hope to return soon).
The problem of the shifting baseline results from the fact that ecological historians, or historical ecologists still do not play a similar role, and that the ecologists that do ‘historical’ research into the development of eco-systems, have not conceptualized a systematic framework for studying the biological past, as, for example, economic historians have developed to study growth. The syndrome points to a gap in the academic distribution of labour – in the difficult terrain where ecology/biology ‘meets’ history. By their nature these two fields are not close, but I am not sure if the academic gap is wider than, for example, between economics and history, or sociology and history. It is clear, however, that we do have a framework to study economic change which produces the Maddison-type synthesis of what happened in the world economy in the past 1000 years, whereas nothing comparable exists in ecological history – and we, therefore, are left in the dark about similar changes in nature. A gap, however, also means that there is a potential for academic innovation as well.
I thank Marc Argeloo, biologist and birdwatcher, for introducing me to the literature about the shifting baseline syndrome. He is currently finishing a book on the topic, and hopes to defend it as a dissertation in the coming year (he will perhaps be the last Ph D that I supervise!)
Continue reading: Are we smarter than Colijn, or Charles V? (14-4-2020)