An unmistakable sound, echoing around the canopy of a wooded combe in Somerset’s Quantock Hills. A series of repeated, one-note calls, followed by a rapid trill often likened to a spinning coin, reveals the presence of a male wood warbler. I peer upwards, scanning the pale green foliage for a pale green bird; and finally catch sight of him, as he searches for tiny insects among the leaves.
The wood warbler is, along with the pied flycatcher and redstart, one of the “western oakwood trio”: charismatic little birds that spend the winter in sub-Saharan Africa, before travelling north to breed in “Britain’s rainforests”.
Until a couple of years ago, the wood warbler was by far the most common and easiest to see. But this year I struggled to find them at all. I’m not alone: in the past 30 years numbers have fallen by two-thirds, and if the current downward trend continues, they may soon disappear as a British breeding bird.
The BTO and RSPB recently fitted tiny geolocators to four male wood warblers, tracking them as they headed south to Africa. These revealed that the birds’ journey is far more complex than had been thought, with a long August stopover in Italy, followed by a huge leap across the Sahara to the Sahel, until they reach their final destination in west Africa. Whether this knowledge will be enough to save the wood warbler, only time will tell.
