Functional diversity across space and time:trends in wader communities on British estuaries

Scientists from the BTO and the University of East Anglia have used data from WeBS to calculate the functional diversity (FD) of waders across British estuaries, and found variation in space and time over almost three decades.

FD gives a measure of the range of species traits in a community, providing an indication of the underlying characteristics and health of the ecosystem that supports the species concerned. For waders, its calculation included information about morphology and feeding ecology, which varies widely across this group (from large species like Curlew that use their long curved bill to probe deep in the intertidal mud for worms and molluscs, to small birds like Sanderling that use their short straight beaks to seize tiny crustaceans from the upper layers of sand at the tideline). This study showed that FD was lower on estuaries in the west of Britain than those on the east. There was also an increase in FD over time, which might be because waders with a greater range of characteristics can live on our estuaries as winters have become milder.

Many British waders and estuaries are protected under national and international legislation. However, understanding how these communities and ecosystems are sustained and assembled has important implications for their conservation in the face of environmental change.