Deep in the western Amazon rainforest, live butterflies that drink turtle tears. That sounds like a line straight out of a fantasy novel, but it’s one hundred percent real life! It’s an unusual sight – swarms of butterflies flocking at the eyes of yellow-spotted river turtles, trying to get a sip. The poor turtles keep ducking or swatting, but the butterflies persist until they’ve had their fill.
According to Phil Torres, a scientist at the Tambopata Research Center in Peru, the butterflies are attracted to turtle tears because the drops of liquid contain sodium, a mineral that is scarce in the western Amazon region. While turtles get plenty of sodium through their carnivorous diet, the herbivore butterflies need an extra mineral source.
Torres explained that the western Amazon rainforest is over 1,000 miles away from the Atlantic Ocean – a prime source of salt. The region is also cut off from the mineral particles blown towards the west from the Andes Mountains. Most of these windblown minerals are removed from the air by the rain before they have a chance to reach the western Amazon. These factors contribute to the extremely low levels of sodium. So the butterflies have to turn to the best source available to them, and that include turtle tears, animal urine, muddy river banks, puddles, and sweaty clothes.