The Dung Beetle Dance: An Orientation Behaviour?

Emily Baird,Jochen Smolka,Eric J Warrant,Marcus J Byrne,Marie Dacke,Angela Sirigu

doi:10.1371/journal.pone.0030211

Abstract

An interesting feature of dung beetle behaviour is that once they have formed a piece of dung into a ball, they roll it along a straight path away from the dung pile. This straight-line orientation ensures that the beetles depart along the most direct route, guaranteeing that they will not return to the intense competition (from other beetles) that occurs near the dung pile. Before rolling a new ball away from the dung pile, dung beetles perform a characteristic “dance,” in which they climb on top of the ball and rotate about their vertical axis. This dance behaviour can also be observed during the beetles' straight-line departure from the dung pile. The aim of the present study is to investigate the purpose of the dung beetle dance. To do this, we explored the circumstances that elicit dance behaviour in the diurnal ball-rolling dung beetle, Scarabaeus (Kheper) nigroaeneus. Our results reveal that dances are elicited when the beetles lose control of their ball or lose contact with it altogether. We also find that dances can be elicited by both active and passive deviations of course and by changes in visual cues alone. In light of these results, we hypothesise that the dung beetle dance is a visually mediated mechanism that facilitates straight-line orientation in ball-rolling dung beetles by allowing them to 1) establish a roll bearing and 2) return to this chosen bearing after experiencing a disturbance to the roll path.

Highlights

Upon locating a suitable dung pile, a ball-rolling dung beetle cuts off a piece of dung, shapes it into a ball and rolls it away to a distant location for burial and consumption
Rolling along a straight path is crucial for dung beetles because it guarantees that they will not return to the dung pile where they risk being attacked by other beetles who, rather than making their own ball, would prefer to capitalise on the work of others [1]
We show that most beetles perform a characteristic dance – in which they climb on top of the ball and rotate about their vertical axis – before rolling away from the dung pile

Summary

Introduction

Upon locating a suitable dung pile, a ball-rolling dung beetle cuts off a piece of dung, shapes it into a ball and rolls it away to a distant location for burial and consumption. Moving along a straight line, either toward or away from a particular location, is important for survival in many different animals. At first, this does not appear to be a difficult task. Sensory and motor systems are inherently noisy This makes it is impossible for any animal (or machine) to move along a straight path without using an external reference, or ‘compass’ [2]. Such a compass could be the Earth’s magnetic field, distant landmarks, the position of the sun or the moon or the polarisation pattern they generate in the sky

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Conclusion