Since 2014, 49,520 registered volunteers have classified penguins, chicks, and eggs in Antarctic photos; more than 6 million classifications helped build a colony dataset

Somewhere in Antarctica, a camera snaps another picture of a crowded penguin colony. Far away, a person at home clicks on every bird in it. In 2018, Oxford researchers published a study in Scientific Data showing that more than six million images had been classified on a project called Penguin Watch by 49,520 registered volunteers and many anonymous participants. This created a dataset scientists could compare with expert counts.

Why counting penguins in Antarctica is so hard