One week after people, parrots escape from their cages from homes and zoos.
50 years after people, Tens of thousands of domestic parrots still retain the words taught to them by their former owners. These parrots pass on human speech to their chicks so parrots may still speak human words 150 years after people, but, because human speech has no impact upon parrots survival as a species, the dropoff of words between generations is more than 90%. After a few generations parrots will no longer speak human words.