Study shows butterflies bedazzle predators and escape

The female Common Mormon, which mimics the toxic Common Rose. Mimicry is an adaptive phenomenon, and in mimicry, a palatable organism resembles an unpalatable organism to deceive predators. Photo: Special Arrangement

In a five-year study, scientists of the National Centre for Biological Sciences (NCBS) have discovered secrets of a long evolutionary game through which butterflies come to warn, fool, and escape their predators using traits such as wing colour patterns and even flight behaviour.

The study conducted by NCBS PhD students Dipendra Nath Basu and Vaishali Bhaumik, along with their PhD advisor Prof. Krushnamegh Kunte, has investigated the butterfly mimetic communities of the Western Ghats.

Adaptive phenomenon

Explaining the objective of the study, which was conducted between 2017 and 2022, the PhD students said that mimicry is an adaptive phenomenon, and in mimicry, a palatable organism resembles an unpalatable organism to deceive predators.

“The unpalatable one is called models (Müllerian co-models) and the palatable one is called mimics (Batesian mimics). Interestingly, mimicry in butterflies is not limited to the resemblance in wing colour patterns alone, as some mimics have also evolved to imitate the flight behaviours of model species. In nature, multiple model and mimic butterflies could be found in the same habitat at the same time. These similar-looking co-occurring butterflies together form a mimetic community,” Mr. Basu and Ms. Bhaumik told The Hindu.

They added that these mimetic communities are generally common in tropical and sub-tropical biodiversity hotspots. The NCBS team in order to find out how these two mimetic traits (wing colour patterns and flight morphology) evolve over time, investigated the butterfly mimetic communities of the Western Ghats.

Evolution of trait

The duo said that their findings have shed light on how the rate of trait evolution helps butterflies to escape their predators.

“These (the findings) can be carried forward to investigate whether the rate of trait evolution is similar in young communities, such as in the Western Ghats versus large, old communities in NE India, SE Asia and the neotropics. We suspect that the evolutionary dynamics of functional traits depend heavily on the age, size and complexity of biological communities,” the duo said.

In this study, for the first time, evolution of multiple traits was examined in a biological community, especially in a biodiversity hotspot of the Indian subcontinent.