“Butterflies drinking a turtle’s tears” sounds like the theme of a Lisa Frank Trapper Keeper, but it’s also something that happens in real life in the Amazon basin (and, as far as we know, nowhere else on earth).
The region’s plants are sodium-deficient — it’s too far from the ocean to get salt from seawater, the mountains block winds that might blow essential minerals in from a westward direction, and the rainforest precipitation clears out the stuff that blows in from the east. So plant-eaters like butterflies suffer. Turtles get sufficient sodium from eating meat, though — which means butterflies can sometimes depend on turtles for salt. Specifically, as this photo shows, they get it from drinking a turtle’s tears. (No word on why the turtle was crying; perhaps it feels guilty about eating all that meat.)
Turtle tears are of course rare and precious — turtles are notoriously emotionally stalwart — but luckily, resourceful butterflies know how to branch out.
Other sources of salt for the Amazonian butterflies (that are not nearly as interesting or picturesque) include urine, river banks, puddles of water, and human sweat.
We are DEFINITELY not buying those Trapper Keepers.
Thirsting for turtle tears, Life Lines.