They waddle, swim, and hop. Their feathers are perfect for cold temperatures and frigid water, but never for flying. And their black-and-white coloring may look like a tuxedo, but it actually helps them blend in with the sea and sky.

April 25 marks World Penguin Day, a chance to celebrate all 18 species of penguin and the quirky traits that place them among the world’s most charismatic birds.

From the southern icy wilds of Antarctica to the warm seas of the Galápagos Islands, penguins cover a wide geographic range, and each species is adapted to the remote place it calls home.

This year, celebrate with a brand-new quiz to test your penguin smarts, view a photo gallery to see the diversity of penguins living on the Antarctic Peninsula, and take our pledge to protect penguins in the Southern Ocean. The penguins are counting on you.