Sometimes nature is so poetic, and sometimes it is so damn strange that I feel like sitting back and taking a minute simply to applaud. David Attenborough knows what I’m talking about. Learning that butterflies drink turtle tears is one of these times.
Symbiotic relationships between animals are the most amazing systems nature has to offer. Some are pretty macabre, such as the African Oxpecker that sucks blood out of open wounds on the backs of zebras, elephants and other African animals (they eat ticks too, which why this works). Some are unlikely, as the small cleaner fish that eat parasites and dead tissue from the skins of their much larger (and sometimes otherwise predatory) client. Some are commonplace, such as bees and flowers. But the special relationship between butterflies and river turtles has to be one of the coolest, and one of the most picturesque.
In the western Amazon rainforest, sodium is a scarce commodity. Butterflies have figured out a great fix for their salt cravings: turtle tears. Because turtles are carnivores, they get plenty of sodium, unlike the vegetarian butterflies. So the butterflies like to hang out on turtles and lick up their tears. It definitely beats other sources of salt, like urine, muddy rivers, and human sweat. Good call, butterflies. Turtle tears also may have other useful minerals, even possibly amino acids. Scientists plan to conduct further research to see what other treasures are in these tears. I’m sure these reptiles will love having their eyeballs swabbed by scientists.
What do the turtles get out of this? Comfort, I guess. It’s always nice when something beautiful dries your eyes, right? Other than that, researchers don’t think the butterfly kisses have much effect. The process isn’t painful—the butterflies “drink” the tears by absorbing the salt through a proboscis, rather than sucking or extracting anything. And they don’t bite. The butterflies also don’t deplete the turtles’ sodium levels because they take very little and there’s more than enough to go around. Researchers do concede it’s possible that the turtles would be more visible to predators with their colorful halos, and perhaps slightly less able to see and maneuver. But really, who’s going to mess with a turtle escorted by a gang of butterflies? No one would dare.
One benefit—for us anyway, and for attention-starved turtles—is that they’re easier to photograph when surrounded by butterflies. Maybe a symbiotic relationship can develop between photographers, turtles, and butterflies? Bees also drink turtle tears for the same reason, but that doesn’t sound quite as pleasant. I doubt the bees would sting their shelled salt lick, but their buzzing understandably appears to irritate the turtles.
The lack of salt in the western Amazon has pushed other animals to look for sodium in strange places. Macaws lick clay and monkeys eat dirt. Butterflies definitely made a wise, and hauntingly poetic, choice.