TIL: Why Do These Birds Eat Dirt? | Today I Learned

chips, but macaws, they grab a big old hunk of dirt.

All animals need salt, badly, for

basic biological function.

Animals in the western Amazon are really deprived of salt

because the Andes actually block the weather from the Pacific. So that means that all of

the weather comes from the Atlantic. By the time that salty air gets all the way to the

western Amazon, most of that salt has already fallen.

So animals in the western Amazon are

really desperate for salt, and they’ll go to great lengths to get it. Macaws, in particular,

which are specialized for fruit in the very highest part of the canopy will come all the

way down and they’ll eat the dirt. They’re selecting these very specific layers of soil

that were formed over geological time during periods where conditions were a little bit

saltier than in the other times. It’s like a vitamin, but it’s especially salty.