QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online August 17, 2006
Journal of Experimental Biology 209, 3301-3308 (2006)
Published by The Company of Biologists 2006
doi: 10.1242/jeb.02370

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ronacher, B. Articles by Wehner, R. Search for Related Content PubMed PubMed Citation Articles by Ronacher, B. Articles by Wehner, R.

Integrating two-dimensional paths: do desert ants process distance information in the absence of celestial compass cues?

B. Ronacher^1,*, E. Westwig^1, and R. Wehner²

¹ Department of Biology, Humboldt University, Invalidenstr. 43, D 10099 Berlin, Germany
² Department of Zoology, University of Zürich, Winterthurerstrasse 190, CH 8057 Zürich, Switzerland

^* Author for correspondence (e-mail: Bernhard.Ronacher{at}rz.hu-berlin.de)

Accepted 5 June 2006

When performing foraging trips desert ants of the genus Cataglyphis continuously process and update a `home vector' that enables them to return to their nest on the shortest route. This capacity of path integration requires two types of information: (i) information about the travelling directions, and (ii) odometric information about the distances travelled in a particular direction. We have investigated how these two necessary pieces of information interact within the path integration processor. The specific question is: how do the ants process distance information if there is no simultaneous input from the sky compass available. Ants were trained to forage in a `Z'-shaped channel system, the three segments of which joined at right angles. Individual animals were transferred from the feeder to a test field where their homing paths could be observed. In the crucial tests the middle segment of the maze was covered by orange Perspex that did not transmit the UV part of the spectrum, and thus precluded the perception of polarization patterns. Changes of the ant's processing of odometric information within this channel segment directly translate into a change in homing direction on the test field. The results indicate that the odometric information about travelling distance is largely ignored for path integration if there is no simultaneous input from the sky-view-based compass. They further show that idiothetic information cannot adequately substitute for the polarization compass to infer travelling directions.

Key words: path integration, odometer, polarization compass, desert ant, Cataglyphis