Climate-driven changes in winter abundance of a migratory waterbird in relation to EU protected areas

Many bird species are showing distributional change in response to global warming. New research using data collected by volunteers taking part in the Wetland Bird Survey shows that Europe's winter population of Smew has redistributed north-eastwards due to milder winter conditions in the last 25 years. In the UK, a small population of typically less than 200 Smew (and in mild winters just a few dozen birds) can be found in winter at favoured gravel pits and reservoirs in lowland England. This UK population has approximately halved since the late 1990s.  This study, compiled by scientists in 16 countries (including BTO staff) shows that Special Protection Areas (SPAs) scheduled under the EU Birds Directive, facilitate such distribution change across a species’ entire range. Currently, one third of the total population winters in north-eastern Europe, compared to 6% two decades ago. Furthermore, population growth rate in this region was also twice as fast inside EU Birds Directive’s SPAs compared to those outside over the last 25 years.

Thus, well designed protected area networks can mitigate the effects of climate change on biodiversity by safeguarding high quality habitat as species adopt new distributions. These findings confirm that the existence of Special Protection Areas assists species to cope with climate change.  However, the results also highlighted severe gaps in the EU Special protection Area network, especially in northern parts of the wintering range. Many countries designated their SPAs more than 20 years ago, when no account was taken of the rapid environmental changes now occurring. More than eight out of ten Smew wintering in Latvia and Sweden do so in currently unprotected areas, and in Finland nearly all individuals winter outside the SPA network. Despite this range shift, it is still important to maintain the network at the southern end of the birds’ range, so that they have somewhere to retreat during particularly harsh winters. Studies such as this can help policy makers review protected area networks to ensure they keep pace with the conservation needs of Smew and other species.