How old do baby penguins have to be leave their parents?

Penguins don't leave their parents when they grow. Baby penguins spend up to 55% of their first 522- 881 (Emperor 959 to 1045 days) staying inside of a crèche for the first two months (or up to ten in Emperor penguins which have longer crèches and longer fledging periods in a colder environment (7, 8).