Have wings, won't fly
Over the course of time, there have been many birds who decided that flight wasn't really for them and stuck to the ground, or in the case of penguins, the water. Many of these species, however, were quickly wiped out as humans started exploring the planet, since they make easy pickings for humans and the animals that traveled with them, such as dogs, cats and rats.
Those that survived are mainly too big (like the ostrich) or too remote (such as the ocean-faring penguin) to be easy prey to new predators. And yet, there still happens to be a few more amazing flightless bird species that are hanging in there. Their ground-dwelling lives are made possible by living in areas still free of predators, or in the case of some, have had humans switch from enemy to friend just in the nick of time.
Here are 12 of the most unusual flightless birds found around the world.
Editor's note: This slideshow has been updated with new information since it was originally published in September 2015.