When it is time to sleep, the tropical butterflies of the Heliconius erato species do so in groups of four or five individuals. The objective of sharing "bed" is none other than to protect itself more effectively against its predators, according to research published in the journal Proceedings of the Royal Society B.
The results indicate that butterflies that sleep alone or in pairs suffer up to six times more attacks from birds than those that sleep in larger groups. To verify this, the researchers, from the University of California and the Smithsonian Tropical Research Center (Panama), created fake butterflies of clay and paper in which the marks of pecking and bird attacks could be identified. Later, they deposited thousands of these false insects in the usual places that butterflies choose to sleep, in the forests of Panama and Costa Rica and verified the result.
These animals have very striking colors that warn predators of their toxicity, which usually scares away their predators. By sleeping together, the signal is amplified and easier to detect, which exerts a deterrent effect that prevents bird attacks.
