A stream of brightly-coloured butterflies was pictured smothering the heads of turtles as they bizarrely tried to drink their tears in the Peruvian Amazon.
The strange phenomenon occurs because the orange Julia butterflies and yellow Sulphur butterflies require the nutritional benefits of sodium.
Being far from any source of salt, the butterflies take advantage of the turtles' salt-rich tears by surrounding their heads looking for a drink.
The photos capturing the unique event were taken in Tambopata, Peru, in the Amazon jungle.
Travel photographer Jeff Cremer and biologist Phil Torres had never seen so many butterflies gather at once.
Cremer, 35, from Colorado, America, said: "We're used to one or two butterflies on a turtle but these ones seem to be absolutely smothered in butterflies.
"I would say there were about 15 turtles in all up and down the river but there were loads of butterflies."
The turtles were seen basking in the sun to collect heat and energy for the day.
Much like humans, their sweat is rich in salt and insects in the region have to drink their tears because they are nowhere near an ocean.
Phil, 27, said: "As you go further from the Atlantic Ocean, the general availability of salt decreases in the environment because there is less of it in the rain.
"So, in the western Amazon region far from the Atlantic, odd behaviours pop up to account for this - including drinking the tears of turtles and caiman.
"The butterflies tend to attract each other - so if one butterfly is feeding, its bright colours invite other butterflies to that site to feed as well."
The turtles appeared undisturbed by the butterflies.
Phil added: "Butterflies in this area will do anything for salt - including drinking from your sweaty skin or backpack.
"I bet that if you laid out with your skin covered and your eyes open, you may eventually have a swarm of colourful butterflies imbibing on your tears, too."
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