Why are these butterflies and bees swarming around turtle faces? In this episode of the Jungle Diaries, entomologist Phil Torres sees a rare sight in the Peruvian Amazon: Tear-drinking butterflies and bees. The behavior is driven by the same reason why some butterflies might feed on river mud or a steamy pile of jaguar poop: Sodium. From National Geographic:
Watch another video of butterflies drinking turtle tears. Plus: Catching butterflies with the longest butterfly net in the world, a night adventure to see Nicaragua’s sea turtles, and Go Into the Heart of a Kaleidoscope of Monarch Butterflies.
“Sodium and some of those other micronutrients are hard to find in nature,” said [aquatic ecologist and director of the La Selva Biological Station Carlos] de la Rosa. “Butterflies and bees consume nectar, and nectar does not have a lot of salt. But they still need salt for egg production and for their metabolism.”
To scavenge the vital mineral, insects look for tears, sweat, feces, urine, and—among hematophagous insects like mosquitos—blood. Those that drink tears are referred to as “lacryphagous,” from lacrima, the Latin word for “tear.”
A similar, and better studied, insect behavior that seems to serve a similar purpose is called “mud-puddling.” Butterflies and other species that employ this strategy will congregate around and drink from puddles containing mineral deposits.