Deserted Island: Internal Navigation
Many animals have some sort of built-in global navigation system. Traveling the world and returning to the places they were born or hatched. It’s pretty amazing. Us humans are just now installing such systems in our cars. I usually have a good sense of direction but rarely remember how to get somewhere I’ve only been to once.
When young penguins finally leave the parents, little is known about where they go. However, many of them arrive back one day in Spring to the same nesting grounds to have their own family. In fact, very little is known about where adelie penguins go when they leave Antarctica in the winter too. They apparently live out in the open seas but to this day their travels go undocumented.