Recently I was watching a documentary about penguins and how a mother penguin lost its chick. Then it went looking for it, and among a horde of penguins it was able to find its chick and take it back.
What really intrigued me is that the penguins looked exactly the same. Animals don't have as many distinctive features as we humans do, such as significally different hair color, skin color, they don't really look very different. Rather animals of the same species look very similar.
How can one even differentiate between all these penguin chicks? Even the parents look very similar to me.
So how can parents spot their offspring among all of these penguins that look almost identical?