A single volcanic crater lake in Madagascar contains the world’s rarest duck species. Scientists thought them extinct for decades until they rediscovered a few dozen birds in 2006.

MSN: The 10 rarest birds by region you'll be lucky to see

During Indiana’s early statehood, the northern cardinal was far less common than it is today. The species favored warmer climates farther south and appeared only sporadically in parts of the Midwest.

AnimalWised shares the 18 rarest animals in the world. While not all are rare due to human influence, most are because of anthropocentric activities. By highlighting the preciousness of these animals, we might be able to create awareness of their precariousness. It's one of the best ways we can help ensure they stop being so rare in the future.

From the rarest minerals to the largest, stinkiest flower, there are tons of incredible things that people have discovered. Keep reading for a list of the most unique and precious items on earth (and maybe even some beyond).

What Is the Rarest Thing in the World? 19 Awesome Finds - wikiHow

Here are nine of the rarest things in the world, spanning natural wonders, precious materials, and unique phenomena:

The Hainan gibbon is the rarest ape on the planet. Thanks to poaching and ongoing habitat degradation, these animals account for one of the most threatened species in the world.