Stellar performance: Mechanisms underlying milky way orientation in dung beetles

Research output: Contribution to journalArticle

Abstract

Nocturnal dung beetles (Scarabaeus satyrus) are currently the only animals that have been demonstrated to use the Milky Way for reliable orientation. In this study, we tested the capacity of S. satyrus to orient under a range of artificial celestial cues, and compared the properties of these cues with images of the Milky Way simulated for a beetle’s visual system. We find that the mechanism that permits accurate stellar orientation under the Milky Way is based on an intensity comparison between different regions of the Milky Way. We determined the beetles’ contrast sensitivity for this task in behavioural experiments in the laboratory, and found that the resulting threshold of 13% is sufficient to detect the contrast between the southern and northern arms of the Milky Way under natural conditions. This mechanism should be effective under extremely dim conditions and on nights when the Milky Way forms a near symmetrical band that crosses the zenith. These findings are discussed in the context of studies of stellar orientation in migratory birds and itinerant seals.

Details

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

Subject classification (UKÄ) – MANDATORY

  • Zoology

Keywords

  • Sky compass, Star, Straight-line orientation, Vision
Original languageEnglish
Article number20160079
JournalRoyal Society of London. Philosophical Transactions B. Biological Sciences
Volume372
Issue number1717
Publication statusPublished - 2017 Apr 5
Publication categoryResearch
Peer-reviewedYes