Bumblebees locate goals in 3D with absolute height estimation from ventral optic flow

Area of Science:

• Behavioral Ecology
• Insect Navigation
• Sensory Biology

Background:

• Flying insects like bees navigate complex environments to find resources.
• Two-dimensional navigation strategies are well-understood, but three-dimensional (3D) height estimation remains largely unexplored.

Purpose of the Study:

• To investigate bumblebee strategies for height estimation during foraging.
• To determine if bumblebees use global or local cues for 3D navigation.
• To understand how bees utilize height information for goal localization.

Main Methods:

• Adapted a 2D goal localization task to a 3D environment using spherical landmarks.
• Examined bumblebee search patterns for a feeder at varying heights.
• Assessed bees' ability to estimate feeder height using ground references and local landmarks.

Main Results:

• Bumblebee search distributions in 3D were less concentrated than in 2D.
• Bees could estimate feeder height using the ground as a reference, but only when the feeder was close to the ground.
• Bumblebees demonstrated learning and recall of specific flower heights in a 3D foraging context.

Conclusions:

• Bumblebees can learn and utilize height information for navigation in 3D environments.
• The ground serves as a crucial global reference for height estimation.
• Ventral optic flow is suggested as the primary mechanism for bumblebee goal height estimation.