Birds in a changing world
Yesterday, I shared my impressions from the first day of the BirdNumbers 2016 conference and some first insights into the health of our continent emerging from the impressive body of data being put together by EBCC scientists and the thousands of volunteers counting birds around Europe.
My first thought, at the end of a long day of presentations, is that the EBCC (just like BirdLife) truly represents the Europe we believe in. What a great group of passionate and diverse people that work together, across borders, to build a better world. At a moment when Europe risks descending into a dystopia of nationalist sentiments, egoism, closed borders and conflicts, it’s heartening to see scientists from across the continent working together, including setting standards and procedures to make the data they gather compatible so that it can be compiled and analyzed at a higher level. And in a historic phase, where fact-free politics seems to be the rule, sound science is all the more important in helping us chart a sane future.
As to the content, many of today’s studies show that climate change is already deeply affecting the living world. From the Alps to the UK and from Mediterranean wetlands to the Czech Republic, birds are on the move. Species are disappearing from the southern end of their range and colonizing new areas at the northern end of their distribution. In the mountains, species are moving to ever higher altitudes. And the change is on a grand scale. Waterbird communities have apparently moved their “thermal affinity”, a clever indicator that measures the proportion of warm climate versus cold loving species, by over 300 km northwards in the last 22 years.
While climate change is starting to appear in the bird data, most of the (rapid and sometimes catastrophic) changes observed are the product of more direct human impact.
Starlings have collapsed across northern Europe and research in Denmark shows that much of the decline is down to cows being moved off the grasslands and into indoor stables. In just 12 years, the proportion of free grazing cows has gone down from 75% to 25%, and the starlings have disappeared with the grazing in one more indictment of factory farming. A happier study, from the Schorfheide-Chorin biosphere reserve in eastern Germany, offers a rare ray of hope for farmland birds. The area has heavily invested in sustainable farming, with some areas going 95% organic, and large scale deployment of well-designed agri-environment schemes to provide flower strips, field margins and fallow plots. And farmland birds do show distinctly better trends than the German average (and by the way, so do the farmers!). More disappointing is the news from Sweden, where much hyped improvements to the sustainability of forest management seem to have basically stalled since 2000, and have had hardly any effect on forest birds. Leaving the odd tree standing in the clear cuts earns sustainability certification labels, without really restoring the forest ecology. Outright horrifying is the news from European Russia and Siberia where Rustic and Yellow breasted bunting populations are crashing. The latter, once distributed right across Eurasia has seen its range shrink by thousands of km! While the causes are still being investigated, massive industrial trapping in China during migration might be playing a key role. This beautiful song bird used to be a European bird. The upcoming European atlas might not feature it any more; a sad fate we hope to spare other species that share our continent with us, and its uncertain future.