Parrots at an exposed cliff in Peru, where they gather to eat clay, which is richer in sodium than plants in the area. Frans Lemmens/Getty Images

Thanks to Carolyn Beans and the salt colleagues at National Public Radio (USA) for this:

Why Do Parrots (And People) Eat Clay?

The parrots of Southeastern Peru crave an earthy delicacy: dirt. At the Colorado clay lick, a cliff face rising above the Tambopata River in the western Amazon Basin, parrots — often hundreds at a time from up to 18 species — gather each day to feast on sun-hardened clay. Continue reading →