The tranquil song of the Kaua'i O'o graced the high, dense forests of Kaua'i until 1987, when it was heard no more.
The voice of only one member of this family of birds, now all extinct, remains immortalized on tape.
The Macaulay Library maintains the largest collection of bird sounds in the world - more than 160,000! These recordings give voice to more than two-thirds of the world's roughly 10,000 bird species.
Some of the birds recorded are now extremely rare or perhaps even extinct - like this Bachman's Warbler, a former resident of the southeastern United States that hasn't been seen since 1988.
