It's 40 years since Radio New Zealand's bird calls were first broadcast.
They started on 6 February in 1974 and are now a mainstay of morning programming.
They were recorded by conservationist John Kendrick, who died last year.
Former broadcaster Robert Taylor says the first bird call which aired was a fake morepork call which he recorded with a technician by making noises with their hands cupped over their mouths.
He says no-one noticed for about two months until Mr Kendrick picked it up and offered his own recordings.
The Royal Forest and Bird Protection Society of New Zealand says the bird calls are now part of New Zealand's culture and identity