The Madagascar Pochard is a critically endangered diving duck and the world's rarest waterfowl, rediscovered in 2006 after being feared extinct for 15 years.
Generally silent, but males produce a soft, wheezy 'whirr' whistle during courtship, while females emit a harsh 'gaaaa' croak.
Open Birdsong, tap record, and identify the bird singing near you in seconds — then collect it in your field journal.
Identify a bird by its song