The subliminal pleasures of the willow warbler

Blackwater Carr, Norfolk: Soft enough to soothe the heart, willow warbler song gives a sense of summer's nonchalance
Country Diary : Willow Warbler (Phylloscopus trochilusperched in bush
Willow warbler (Phylloscopus trochilus) adult, perched in bush. Photograph: Alamy

There are five to six willow warblers singing in the bushes all around me as I write. The sound they yield seems as fresh as the flush of yellow on the sallows in which they hide. Yet in any top 10 of our summer visitors, the willow warbler probably wouldn't rank very high. The species produces an exactly repeated, gently descending cadence of what sounds like about a dozen notes. It has nothing of the force or show-stopping variety of a nightingale. Nor does it possess the eerie otherness of a grasshopper warbler's prolonged ventriloquial reel. Yet it is capable of having a large impact upon us and seems to soften the atmosphere of early spring.

My most memorable encounter with this effect occurred during my childhood. Willow warblers are Afro-Palearctic migrants, wintering in a wide belt of sub-Saharan Africa then spreading to breed across the boreal regions of Eurasia, from easternmost Siberia to the Atlantic coasts of Ireland. In the 1970s I used to intercept this momentous inter-continental wave – at one time possibly involving as many as 2 billion birds – in northern Derbyshire. When willow warblers suddenly arrived there en masse the songs of the rival males constantly overlapped, so that their collective music fell on the grim, post-winter world of those gritstone hills like a warm shower of rain. Like rain, willow warbler song is soft enough to split rock and to soothe the human heart.

Strangely, I seem to love it more when I cease to focus on its novelty and it becomes a subliminal pleasure. For then the sound is an audible analogue of that wider sense of luxury and nonchalance at the heart of summer. Alas, there is now less scope for complacency: willow warbler numbers have fallen like a stone in the last 30 years, declining possibly as a consequence of habitat loss and climate change by 60%.