The slow-moving river surface reflects the blue sky and the patches of white and gunmetal-coloured clouds passing overhead. The trees and long, damp grass rustle in the breeze.
Familiar summer-morning bird song rises from the trees, reeds and bushes – song thrush, wren, reed bunting and the rhythmic, steady, repeated “chit-chit-chit” of a reed warbler. A nearby sedge warbler competes, blaring out its more hurried, chaotic whirrs, chatters and whistles from the top of a small tree.
There’s another sound, barely perceptible among the rustling of the trees in the breeze and the other birds, but it gradually becomes clearer – a continuous metallic whirr, like a fishing reel spinning. It’s the song of a grasshopper warbler – a small, brown, streaky bird, similar to a sedge or reed warbler. But there’s not much chance of finding it. Notoriously hard to see, the grasshopper warbler tends to throw its voice over long distances, while it stays out of sight. Gilbert White described the bird as “the most artful creature, skulking in the thickest part of a bush”. I scan the vegetation carefully, but this one is skulking as well.
A strong birdwatcher’s urge compels me to follow the sound and to try to see the warbler, but there’s no public footpath towards it, across the marsh and dense grass, and I know from experience that it will stay hidden. So I try to triangulate its position, about 200 metres away, and make a note to record the location later with the BirdTrack app. I’m content just to listen to the bird’s remarkable song. The sound recedes, then grows louder again, as the breeze that carries it changes direction, or the warbler’s head moves.
Grasshopper warblers are rare in Britain, but they can be heard in West Sussex in this sort of riverside, marshy habitat, usually from mid-April, when the birds first return for the summer. They rarely stay to breed – most seem to move on somewhere else. I haven’t heard one here this year before today, so has this male bred elsewhere, and is now already passing through on its way south again?
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