If you are ever lucky enough to travel down the Peruvian Amazon, you may see a rather magical sight. Amongst all the incredible animal species that the area is home to, butterflies have been filmed doing something rather incredible: drinking the tears of the turtles that live there.
Tropical entomologist and science communicator Phil Torres posted a video to his YouTube channel showing the remarkable behavior of these butterfly species. He explains that the butterflies, around eight different species, are all seeking one thing: sodium.
This area is lacking in salt because of the distance from the open sea. The Atlantic Ocean is more than 1,600 kilometers (1,000 miles) away, and the Andes Mountains are blocking the wind from carrying important mineral particles to this region. This causes the animals that live here to get a bit creative to find salt.
Typically butterflies feast on the nectar of flowers, slurping up the sugary goodness with their long proboscis. These insects also need salt, and while they can’t get it from plants, poop, mud, and turtle tears provide them with a good source. This is likely because the diet of the turtles contains meat and therefore a higher salt content. The turtles don’t seem to get much out of the experience, however.
"They definitely don't seem to enjoy it," Peter told LiveScience in 2018. "This is a fairly colorful example of commensalism — a species partnership where one species benefits and the other species doesn't really get affected, positively or negatively."
Butterflies aren’t the only animal to seek an unusual source to get the salt content they need – the Kitum cave elephants are known to mine dirt from these caves to access calcium, magnesium, and sodium.