BTO: Nightingale’s song heard less often
The first of the season’s nightingales have arrived back at traditional sites across the county. This migrant songster is a familiar species, at least in name, appearing throughout some of our best poetry and nature writing.
While the song is rich and memorable, the bird itself is rather unassuming; plain brown in overall colour, but with paler underparts and a rufous-brown tail, it is easily overlooked.
Although nightingale song may be heard intermittently throughout the day, it is as its strongest at dawn and dusk, and indeed deeper into the night. Some of the most famous recordings of the bird have been of individuals singing at night, including one recorded against the throbbing drone of German bombers raiding London during World War Two. While the notion of a nightingale singing in Berkeley Square is a fanciful one, the species was certainly more common in 1939 – when the song was written by Manning Sherwin and Eric Maschwitz – than it is today. National surveys revealed a 46% fall in nightingale numbers between 1995 and 2011, but other data suggest that the decline may have exceeded 90% since the 1960s, a staggering change of fortunes.
Research strongly suggests that nightingale numbers have declined because of the changes in woodland vegetation that have come about with increasing numbers of deer, but it is likely that factors operating elsewhere have also had an influence. The nightingale is one of a suite of our summer visitors to winter in West Africa, all of which have shown pronounced population declines. If conditions on the wintering grounds are deteriorating then overwinter mortality may be contributing to the decline that we are seeing here within Suffolk.
It used to be thought that woodland, particularly coppice, was the key habitat for our breeding nightingales but recent surveys and research work suggest that scrub is now the most important habitat for the species. Scrub is an ephemeral habitat – and one that is not well-liked by many land managers – and so its availability to breeding nightingales can be somewhat limiting. Nightingales favour the most vigorous and dense patches of scrub, with bare or sparsely vegetated ground beneath them. Since scrub quickly passes through this stage, developing into young woodland, a degree of habitat management is needed to maintain the patches at a stage that is best suited to the bird. Our understanding of what are the best management approaches to adopt comes from work carried out by the British Trust for Ornithology, and the efforts of Anglian Water and local wildlife trust volunteers who have tested different methods at suitable sites. This information has just been pulled together in a free guide, Managing Scrub for Nightingales, which can be downloaded from www.bto.org. Let’s hope such efforts will increase the numbers of nightingales singing and breeding in Suffolk.