The wood warbler is one of my signature birds, a highlight of schooldays when a pair bred annually in Lightwood five minutes from my house. They were also widespread at other local sites and while we took them in our stride, they were always special too. Seeing the bird was less frequent than hearing its song, which comes down from the high canopy as a hard, brittle repeat note delivered with increased pace and volume, until it swells to a final exhilarating trill.
Yet the full impact of the species cannot truly be understood without observing the song’s delivery. His head is thrown back. His pink bill is agape and points skywards, often translucent against the sunlight, rather like the brilliant green of the beech leaves, to which he brings an unfathomable synaesthetic effect. His lemon breast is thrust forward and the long wings shiver as the sounds emerge, and with each climactic trill, the bird pauses, his wood is given back to silence, the warbler shifts location, and – way above your head – the song builds again.
Until last week, I hadn’t encountered this magic here since 1979, fitting a pattern of British decline that has seen its range withdraw northwards and numbers collapse by 82%. (We should note that Poland’s 9m hectares of woodland, three times our own paltry total, holds a million pairs.) Even so, for an individual to return to this exact place aroused all sorts of questions, as well as a melancholy joy.
The likelihood is that such a late‑singing bird, whose kind normally arrives in early May, failed to find a mate at a previous location in, say, Herefordshire or Wales. It then moved, probably at night, flying across unknown terrain, almost all of it treeless and chemically controlled, and unsuitable for a wood-dwelling bird. It passed over possibly at a kilometre above the ground, until some mysterious cue brought it down to the precise place where other wood warblers had sung and bred 50 years before. That feat alone by a bird weighing 10g, having already arrived from west Africa, speaks at once of extraordinary resilience and deep vulnerability.
• Under the Changing Skies: The Best of the Guardian’s Country Diary, 2018-2024, is available now at guardianbookshop.com
