As of today I can start counting butterflies again! At least according to the protocol of the national monitoring network butterflies. The Netherlands Butterfly Foundation coordinates this network since the 1990s (and there are comparable networks across Europe). Since about 15 years I’m one of the 500-odd volunteers who from April till September every week walk a fixed route of about one kilometre to count the butterflies. All results are nationally collected and processed.
You think it’s weird, a grownup man counting butterflies? Don’t imagine an expedition with me skipping through meadows with a net and tropical hat. No, my route is in an urban environment, in the centre of the town of Tilburg, the Netherlands, where I’ve helped establish a biodiversity garden since 2010. My weekly counts allow me to see that since 2010 the number of butterflies locally has increased enormously. And thus that more natural management clearly has a positive effect on urban nature. I’ll tell you more about this another time.
Why does all this counting matter? Well, because the total of the counts gives a good indication of the status of butterflies and therefore the status of nature and biodiversity. A bit like canaries in a mine who indicate whether there’s still enough oxygen, butterflies give an impression of the health of our environment.
So what do we see, after over a quarter of a century of counts? That butterflies are doing badly in the Netherlands and Europe as a whole. And thus, that our natural environment is in a bad state. I admit, locally things go pretty well here and there, as demonstrated by my route. However, experts can convert all counts into statistics and graphs, a bit like the Dow Jones Index, but than for nature. When looking at the totals, we see for example that grassland butterflies have halved since 1990. So there are half as many butterflies now (or half as few, as in 1990 the decrease had already started).
The reasons for this are reasonably well known: disappearance of suitable habitat due to urbanisation and infrastructure works, ever increasing intensity of agriculture leaving barely any nectar in rural areas, climate change, and so on.
Let me not make this all doom and gloom. There is good news as well. The decreasing trend seems to level off a bit in the past few years, local nature restoration projects start bearing fruit, increasing numbers of farms try to work with nature, and besides the many tiled gardens there’s a growing community that make space for nature and flowers in their gardens and neighbourhoods. If now also at larger scales environmental quality improves than perhaps all will be well with butterflies someday. And therefore also with us!
Go on, go outside, start counting!