Microhabitats enhance butterfly diversity in nature's imitation game

Typography

The spectacular variety of colours and patterns that butterflies use to ward off potential predators may result from highly localised environmental conditions known as “microhabitats”, researchers have found.

The spectacular variety of colours and patterns that butterflies use to ward off potential predators may result from highly localised environmental conditions known as “microhabitats”, researchers have found.

The study, by an international team of researchers, attempts to explain why, even though butterfly species have evolved to mimic one another’s wing patterns to more efficiently signal their toxicity, they nevertheless maintain a kaleidoscopic array of patterns overall.

This paradox applies not just to butterflies, but to a wide range of species, and addresses broader questions about how many different defensive strategies can be optimal in one place. Although many species have evolved warning colour patterns that signal to predators that they are bad to eat, there is still a remarkable diversity of these patterns. Scientists predict that all species should converge on the same pattern, but this has clearly not happened. 

In the new study, the researchers focused on an area of Ecuadorian rainforest where butterfly species copy each other’s markings to deter insect-eating birds. The birds have learned that butterflies which exhibit certain patterns are toxic. There are, however, numerous different examples of these so-called “mimicry rings”, with the butterflies using a wide range of different colours and patterns to achieve the same result.

Read more at St John's College, University of Cambridge

Image: Left: Ceratinia tutia -- one of numerous examples of clearwing butterfly species which have mimicked the warning colour patterns of others to deter predators. Right: Chris Jiggins collecting data about butterfly flying habits from a tree. (Credit: Kim Garwood / Julia Robinson Willmott)