Indicators provide warnings that risks may be about to materialise so you can act to avoid them..
Having too many indicators can obscure what is going on. Having just one – a bellwether indicator – can be very helpful.
For example when housing starts begin to fall, it is usually the sign of an imminent recession and you may want to prepare your business for its onset.
If chosen well, single bellwether indicators can provide information on complex systems or scenarios without having to analyse them in detail. However, such indicators do need to be tested for validity, to see if they are telling us what we think they are telling us.
Dung beetles have been monitored for years as indicators of the health of complex eco-systems. Their numbers can provide an indicator of the impact of activities such as logging, grazing and road building. When there are abundant species of dung beetle around and animal faeces disappear rapidly, then the eco-system is in good health; otherwise, something is wrong. Oxford University zoologist, Elizabeth Raine, has shown that these monitoring methods, and thus the indicators reported, may be flawed.
Sampling is generally done by attracting dung beetles with faeces, and researchers have usually used their own as bait. Dr Raine realised that this method had never been tested, so she set up a study in the Brazilian tropical forest comparing the results using both the dung of various forest animals (jaguars, ocelots, capuchin monkeys) versus human faeces, her own. The results using human faeces indicated twice the number of dung beetles and a much greater diversity of species. Human faeces are so much more alluring to insects that it creates the illusion that they are present in greater numbers and are consuming far more dung than they actually are. The indicator may thus have been overstating the numbers of wild animals and the health of the eco-systems they were measuring.
In case you were wondering, no-one yet knows why dung beetles seem to prefer human faeces…
Data Source: The Economist magazine