Scientists have recently made an exciting discovery about Heliconius butterflies. They've found that these butterflies possess the ability to learn and navigate in space, which is the first time such spatial learning has been observed in any butterfly or moth species. The research, published in Current Biology, indicates that Heliconius butterflies may even have the capacity to learn large-scale spatial information, which could be crucial for their traplining behavior, involving foraging within a specific home range.
While spatial learning is understood in certain insects like ants and bees that live in social nests, this study breaks new ground by directly demonstrating spatial learning in butterflies or moths. This suggests that insects might possess more complex learning abilities, such as using spatial information, than previously believed.
Dr. Stephen Montgomery from the University of Bristol's School of Biological Sciences, one of the study's senior authors, explains that Heliconius butterflies have developed a unique foraging habit where they feed on pollen. In the wild, these butterflies seem to learn the locations of dependable pollen sources and create lasting “traplines” to follow.
Researchers have made significant strides in understanding the spatial learning abilities of Heliconius butterflies, shedding light on their foraging strategies. These butterflies develop “traplines,” efficient foraging routes that lead to repeated visits to food sources, a behavior akin to some orchid bees and bumblebees. Surprisingly, no prior experimental testing had been done on the spatial learning capabilities of Heliconius or any butterfly.
To investigate this, the team designed experiments spanning different ecological behaviors. First, they assessed whether Heliconius could remember the position of food in a small 1 m2 grid with artificial flowers, simulating single-resource patch foraging. They then expanded the scale, testing if the butterflies could associate food with specific sides of a 3 m2 two-armed maze, mimicking multiple plants at a single location.
The researchers further stretched the distances by using large outdoor cages at the Metatron in southern France. Here, they evaluated if Heliconius could learn the location of food in a 60 m wide T-maze, mirroring foraging between different localities—similar to how wild Heliconius forage.
The team aims to compare Heliconius' spatial learning abilities with closely related species that don't feed on pollen. This comparative study could unveil how enhanced cognitive skills evolve in response to an animal's ecological niche. Additionally, the researchers intend to unravel the navigation mechanisms Heliconius employ, including potential reliance on visual cues like panoramic views or other factors such as the sun or geomagnetic compass.
Dr. Priscila Moura, co-lead author from Universidade Federal do Rio Grande do Norte, expressed excitement over providing concrete evidence of these butterflies' spatial learning. Dr. Fletcher Young, co-lead author from the University of Bristol, highlighted the butterflies' effective spatial learning over larger distances, mirroring their natural foraging behavior.
Prof. Marcio Cardoso from Universidade Federal do Rio de Janeiro added that uncovering the butterflies' memory of food sources' locations is just the tip of the iceberg in understanding their interaction with their environment.
Dr. Montgomery concluded by emphasizing the intricate behaviors these seemingly familiar butterflies exhibit as part of their natural ecological roles. Despite their small brain size, these creatures process diverse environmental information to accomplish complex tasks.
The study titled “Rapid expansion and visual specialization of learning and memory centers in the brains of Heliconiini butterflies,” authored by Antoine Couto, Stephen Montgomery, and others, has been published in Current Biology.
Source: University of Bristol