Michael Walter, the former Warden of the Reserve, has written the following piece about willow warblers:
It always turns rather quiet in the wood at this time of year as birdsong fades away, but this season there is another reason for the stillness – there are fewer birds about. This is presumably largely to do with the cold, wet weather early last year, and the exceptionally long, cold spring this year, resulting in fewer young birds being reared and, in the case of migrants, some birds simply failing to turn up.
But there are other underlying problems for many species, probably relating to climate change and farming practices, and this is well-illustrated by the willow warbler, once an abundant species to be heard singing its delicate little song from almost any scrap of young coppice. As the graph of numbers on my monitored plot (see below) shows, my arrival at Blean in 1982 more or less coincided with the onset of the willow warbler’s decline and, despite brief upturns, the tale has been one of a relentless downward trend. There still appears to be masses of suitable habitat at Blean, and it is more likely that the birds are struggling to find enough food in their winter quarters, due to a combination of drought and the spread of agriculture into the semi-natural habitats that they favour.
Willow warblers have now become relatively scarce birds in Kent, and it remains to be seen whether Blean will remain as a last bastion of the species, or if they will disappear from here as well.