Delicate Butterflies Form a Colorful Ring Around the Head of a Resting Caiman in the Amazon

On September 15th, the Royal Society announced the winners of their 2016 Publishing photography competition. Among these gorgeous photos, was one that captured the sight of multiple butterflies perched in a colorful ring atop a resting caiman, gathering salt off its brow. Photographer Mark Cowan caught this amazing shot when he was on a scientific expedition in the Amazon.

The expedition was led by researchers from the Herpetology Division at the University of Michigan and included participants from Peru and Australia. A number of minerals are a scarce resource throughout Amazonia and so this behaviour allows these invertebrates access to salt, much like the clay licks that are used by a variety of vertebrates. This particular phenomenon where butterflies and bees congregate on the heads and around the eyes of caimans and turtles has been documented before but what is unique here is the simultaneous number of butterfly species and the way in which each species is associated with its own kind.

via Colossal