Heliconius butterflies’ brains grew as they adopted a novel foraging behaviour. A region of their brain, known as the mushroom body due to its shape, is two to four times larger than those of their close relatives. 

The findings suggest that the structure and function of the nervous system are closely linked to an organism's ecological niche and behaviour. Dr Stephen Montgomery of Bristol’s School of Biological Sciences explained: “Heliconius are the only butterflies known to collect and digest pollen, which gives them an adult source of protein, when most other butterflies exclusively obtain protein as caterpillars. 

“This shift in diet allows Heliconius to live much longer lives, but they seemingly only collect pollen from specific plant species that occur at low densities. Learning the location of these plants is therefore a critical behaviour for them, but to do so they must presumably invest more in the neural structures and cells that support spatial memory.” 

Read the full University of Bristol news item

Paper: Couto A et al. (2023). Rapid expansion and visual specialisation of learning and memory centres in the brains of Heliconiini butterflies. Nature Communications.