Voice is critical survival tool for King Penguins.
When the chick hatches, it immediately starts calling so that its parents recognize its voice.
To be fed, a chick must identify the call of its parents too.
When the chick is old enough, King Penguins put the chicks in one of the crèches, returning every several days with food. Both parents will leave at the same time. All the chicks in the rookery will stay together until their parents return. When the parents come home they recognize each other by the sound of their voices.
This picture was taken at Saint Andrew's Bay, on South Georgia, a British territory in the Southern Ocean some 1500km South-East from Falklands.