Fear not, no penguins were harmed in the making of this film.
Seems very difficult to explain this as food motivated
There's edible fish in the water. What other food is there on the ice?
Penguins enter the water all the time to hunt fish.
Not off cliffs.
>Every January, when the chicks are around five months old, they undergo a process known as fledging. During this process, the chicks lose their baby feathers and leave their colony for the first time — jumping from an enormous cliff into the ocean to take their first swim.
It was their first swim. Maybe the cliff was the closest shore