The cognitive capabilities of insects, often dismissed due to their diminutive size and simple brains, are gaining newfound respect within the scientific community. Recent research from the University of Bristol has showcased that Heliconius butterflies, contrary to previous underestimations, exhibit remarkable spatial learning abilities. This study, as published in Current Biology, provides the first experimental evidence of such cognitive prowess in any butterfly or moth species, previously only well-documented in social insects like ants and bees.
Dr. Stephen Montgomery, the senior author of the study from the University of Bristol’s School of Biological Sciences, emphasizes the complexity of behaviors these familiar creatures can exhibit. “These species are extracting and processing diverse information from their environment and using them to perform complex tasks—all with brains a couple of millimeters wide,” he notes.
The research involved a series of spatial learning experiments set up across three different scales, each designed to mimic ecologically relevant behaviors. Initially, butterflies were tested for their ability to locate a food reward among 16 artificial flowers within a one-square meter area, simulating foraging within a single resource patch. Subsequently, the experiment’s complexity increased to a three-square meter two-armed maze and eventually to a 60-meter-wide T-maze using large outdoor cages, where the butterflies continued to succeed in locating food.
This capability suggests that Heliconius butterflies not only learn but remember and utilize complex spatial information to form “traplines”—efficient foraging routes similar to those used by some orchid bees and bumblebees. This insight into their cognitive abilities opens up new questions about the evolutionary pressures that enhance such capacities.
The research team plans to further explore the relative proficiency at spatial learning of Heliconius compared to closely related non-pollen feeding species, aiming to understand how ecological factors shape cognitive evolution. They are also interested in the specific navigational cues used by these butterflies, which are thought to include visual landmarks and potentially astronomical or geomagnetic cues.
Dr. Priscila Moura from Universidade Federal do Rio Grande do Norte, a co-lead author of the study, reflects on the significance of these findings. “It’s been almost a century since the publication of the first anecdotal story on the spatial capabilities of these butterflies,” she says. “Now we are able to provide actual evidence on their fascinating spatial learning. And this is just the beginning.”
This research not only challenges the conventional view of insect intelligence but also underscores the intricate and sophisticated nature of butterfly cognition, promising exciting new directions for future studies in the field.