Evolution of behavioural mechanisms underpinning spatial memory

Supervisor: Professor Stephen Montgomery 

Learning can have important ecological benefits. This is of particular importance for long-lived species such as Heliconius butterflies. This genus uniquely collects and digests pollen, providing an adult source of essential amino acids, which other Heliconiini lack. This dietary innovation is accompanied by the evolution of trap-line foraging, where individuals learn routes between resources with high spatial and temporal fidelity. This suggests that they are dependent on an enhanced capacity for visually orientated spatial memory. Indeed, our recent research has shown that Heliconius are proficient spatial learners in experimental settings, and show evidence of pronounced neural specialisations to support this ability in the wild. Importantly, the transition to spatially faithful foraging in Heliconius is relatively recent, providing an unrivalled opportunity to model, test, and understand the selection regimes and mechanisms that shaped the evolution of spatial foraging. This project will uncover the behavioural mechanisms involved in the transition to spatially faithful foraging behaviours in Heliconius. It will explore the nature of cues used by Heliconius to establish spatial memories, the behavioural strategies used to capture and learn this information, and whether this involves evidence of a cognitive map, or changes in the capacity to distinguish landscape cues. By making comparisons across the Heliconiini, we aim to identify behaviours that distinguish Heliconius from their closest relatives. 

Type of work 

The student will have the opportunity to shape the project to their interests, but will likely mix fieldwork in South America with behavioural experiments in Panama and the UK. We are particularly interested in using studies in the field to understand variation in home range and dispersal behaviours across Heliconiini, and to understand the cues that Heliconius use when forming spatial memories. This may involve experiments ranging from reconstructing flight paths of wild individuals in 3D, to experiments in purpose build cages where the surrounding cues can be manipulated to test their impact on foraging behaviours, or using virtual reality flight arenas to record behaviour in tethered butterflies. 

Importance of the area of research concerned 

This project will advance our understanding of the behavioural mechanisms involved in transitions towards greater reliance on spatial memory. Understanding shifts of this nature can reveal general principles about how cognition evolves, and how behavioural complexity emerges from ancestral conditions. It can also provide inspiration for bio-robotics, helping to reveal the strategies used in nature to guide an individual’s path through complex environments.

References 

Moura PA, Corso G, Montgomery SH, Cardoso MZ. True site fidelity in pollen‐feeding butterflies. Functional Ecology. 2022 Mar;36(3):572-82. Moura PA, Cardoso MZ, Montgomery SH. Heliconius butterflies use wide-field landscape features, but not individual local landmarks, during spatial learning. Royal Society Open Science. 2024 Nov 6;11(11):241097. Moura PA, Young FJ, Monllor M, Cardoso MZ, Montgomery SH. Long-term spatial memory across large spatial scales in Heliconius butterflies. Current Biology. 2023 Aug 7;33(15):R797-8. Young FJ, Montgomery SH. Heliconiini butterflies as a case study in evolutionary cognitive ecology: behavioural innovation and mushroom body expansion. Behavioral Ecology and Sociobiology. 2023 Dec;77(12):131.