The effect of step size on straight-line orientation

Research output: Contribution to journalArticle

Abstract

Moving along a straight path is a surprisingly difficult task. This is because, with each ensuing step, noise is generated in the motor and sensory systems, causing the animal to deviate from its intended route. When relying solely on internal sensory information to correct for this noise, the directional error generated with each stride accumulates, ultimately leading to a curved path. In contrast, external compass cues effectively allow the animal to correct for errors in its bearing. Here, we studied straight-line orientation in two different sized dung beetles. This allowed us to characterize and model the size of the directional error generated with each step, in the absence of external visual compass cues (motor error) as well as in the presence of these cues (compass and motor errors). In addition, we model how dung beetles balance the influence of internal and external orientation cues as they orient along straight paths under the open sky. We conclude that the directional error that unavoidably accumulates as the beetle travels is inversely proportional to the step size of the insect, and that both beetle species weigh the two sources of directional information in a similar fashion.

Details

Authors
Organisations
External organisations
  • University of Colorado
  • University of the Witwatersrand
  • Harvard University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Evolutionary Biology

Keywords

  • compass, dung beetle, navigation, orientation, random walk, step size
Original languageEnglish
Article number20190181
JournalJournal of the Royal Society, Interface
Volume16
Issue number157
Publication statusPublished - 2019
Publication categoryResearch
Peer-reviewedYes