Amazonian Butterflies’ Brains Changing Due to Habitat Shifts

Ithomiine is a neotropical creature from the nymphalid butterfly tribe. These butterflies have 370 species which are from Mexico, Southern Brazil, Paraguay, and three Caribbean Islands. The Ithomiine have been included in research studies and served as models for biogeography, chemical ecology, and evolution. Recently, a new study has been published in an online journal called Ecology. The paper was about the relation between habitat shifts and the brain structure of those Amazonian butterflies.

Results have shown that habitat shifts can alter areas of a butterfly’s brain structure. Particularly, the part of the brain where visual information is processed. These changes are also indicated by mimicry patterns. Evidence has proven that habitat shifts are adaptive and that local adaptation to distinct light environments can occur at minimal ecological sales.

Benito Wainwright, a biologist from the University of Bristol, is the study’s lead author. The research group was supported by NERC, the Royal Society, and the Royal Commission for the Exhibition Research Fellowship. Along with his colleagues at the university’s School of Biology, he analyzed 160 samples of Amazonian butterflies. “It was known that niche partitioning in complex habitats, like tropical rainforests, might pose perceptual challenges for the animals living in them,” said Wainwright.

“Work on fish in freshwater ecosystems had previously shown that dramatic changes in light availability with depth can result in impressive visual adaptations, but little was known whether evolution could select for such adaptations in a terrestrial environment like a tropical forest,” Benito further explained. The study also highlighted the significance of visual ecology in developing groups of closely related species in complex terrestrial ecosystems.

“In other words, we want to know whether when faced with the same perceptual challenges, species evolve sensory adaptations via similar mechanisms,” Dr. Wainwright explained. “We also wish to quantify the light environment within these forests to investigate to what degree small changes in forest structure affect the sensory environment.” Furthermore, he explained the crucial role Ithomiine butterflies play in tropical ecosystems. Understanding evolutionary responses will provide precise predictions about how sudden changes in the sensory environment affect the rainforest.

“Our work shows that the way species have evolved to process the world around them plays an important role in the way entire animal communities are structured. Natural selection can lead to adaptive change in brain structure over relatively short periods of evolutionary time,” says Dr. Wainwright.