Switching perspective: Comparing ground-level and bird’s-eye views for bees navigating clutter

Abstract

AbstractAnimals navigating in three dimensions encounter different perspectives of their world, often transitioning from bird’s eye views at higher altitudes to frog’s-eye views closer to the ground. How they integrate this information to pinpoint a goal location is virtually unknown. Here we tested the ability of bumblebees to use both types of views when homing in a cluttered environment. While prior research emphasised ground-level cues, recent evidence suggests bees incorporate bird’s-eye perspectives at higher altitudes for long-distance navigation. This raises the question of whether bird’s-eye views also aid local homing, especially in environments where nest entrances are concealed by undergrowth. Our combined modelling and experimental approach examined various views for goal location in cluttered settings. Whereas, bird’s-eye views performed best in simulations of current snapshot homing models, behavioural experiments revealed that bumblebees predominantly relied on frog’s eye views when pinpointing nest entrances in cluttered environments. These findings reveal the limitations of snapshot-homing models and suggest that bumblebees use a mix of navigational tools to successfully find their way home in cluttered environments. This is not only relevant for understanding bee movements, but also for other animals and humans navigating in 3D as well as the development of technologies inspired by natural systems, such as autonomous flying robots.Significance statementNavigation in three dimensions is essential for animals especially for those that swim or fly, like fish, birds, or bees. Moving at different altitudes relative to the destination, animals undergo a range of perspectives, transitioning from aerial, bird’s eye views to goal-level perspectives as they approach their goal. We investigated if bumblebees utilise both perspectives when homing in cluttered environments. While past studies focused on ground-level cues, recent findings suggest bees incorporate bird’s-eye views for long-distance navigation. Our study explores whether these views also aid local homing, particularly for visually concealed goals. The results challenge existing models, revealing that bumblebees employ a combination of navigational strategies in cluttered settings, impacting our understanding of 3D navigation in animals and technology development.