Secret Songs of Birds: the Hidden Beauty of Bird Song Revealed
The British Library has selected 24 bird songs from around the world, and then slowed the recordings down to allow us to hear the detail of each note. A good example is that of Wren, which on averages take five seconds to deliver each burst of song. Here we can compare that with a slowed-down example taking almost 20 seconds! The CD demonstrates the North American race pacificus as well, so a double comparison can be made. Also included is Grasshopper Warbler. With the slow version on this CD you can hear every double note that makes up the thin reeling song.
Other British examples included are Blackcap, Redstart, Skylark and Goldcrest. The species selected are not necessarily the most beautiful in the world, but they have been chosen because they are more interesting when slowed down. For me the most bizarre sound is Grey Butcherbird from Australia – a species that actually sounds as if it has been slowed down to half speed in real life!
• Secret Songs of Birds: the Hidden Beauty of Bird Song Revealed (The British Library, London, 2010).