title: Naturalistic path integration ofCataglyphisdesert ants on an air-cushioned lightweight spherical treadmill.
abstract: Air-cushioned spheres are widely used as treadmills to study behavioural and neurophysiological questions in numerous species. We describe an improved spherical treadmill design that reliably registers the path and walking behaviour of an animal walking on top of the sphere. The simple and robust set-up consists of a very light hollowed styrofoam ball supported by an air stream in a hollow half sphere and can be used indoors and outdoors. Two optical mouse sensors provided with lenses of 4.6 mm focal length detect the motion of the sphere with a temporal resolution of more than 200 frames s-1and a spatial resolution of less than 0.2 mm. The treadmill can be used in an open- or closed-loop configuration with respect to yaw of the animal. The tethering allows animals to freely adjust their body posture and in the closed-loop configuration to quickly rotate around their yaw axis with their own moment of inertia. In this account, we present the first evidence of naturalistic homing navigation on a spherical treadmill for two species ofCataglyphisdesert ants. We were able to evaluate with good precision the walking speed and angular orientation at any time. During homing the ants showed a significant difference in walking speed between the approach and search phases; moreover, they slowed down significantly as soon as they reached zero vector state, the fictive nest position.
authors.affiliation: Department of Biology, University of Tübingen, Auf der Morgenstelle 28, Tübingen 72076, Germany Hansjuergen.dahmen@uni-tuebingen.de matthias.wittlinger@biologie.uni-freiburg.de.
authors.forename: Hansjürgen
authors.initials: H
authors.lastname: Dahmen
authors.affiliation: Institute of Neurobiology, Ulm University, Helmholtzstrasse 10/1, Ulm 89081, Germany.
authors.forename: Verena L
authors.initials: VL
authors.lastname: Wahl
authors.affiliation: Institute of Neurobiology, Ulm University, Helmholtzstrasse 10/1, Ulm 89081, Germany.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Pfeffer
authors.affiliation: Department of Biology, University of Tübingen, Auf der Morgenstelle 28, Tübingen 72076, Germany.
authors.forename: Hanspeter A
authors.initials: HA
authors.lastname: Mallot
authors.affiliation: Institute of Neurobiology, Ulm University, Helmholtzstrasse 10/1, Ulm 89081, Germany Hansjuergen.dahmen@uni-tuebingen.de matthias.wittlinger@biologie.uni-freiburg.de.|Institute of Biology I, Albert-Ludwigs University of Freiburg, Hauptstrasse 1, Freiburg 70104, Germany.
authors.forename: Matthias
authors.identifier: 0000-0002-9484-0179
authors.initials: M
authors.lastname: Wittlinger
mesh_terms: D000818:Animals; D001000:Ants / Q000502:physiology*; D001070:Appetitive Behavior; D003889:Desert Climate; D006702:Homing Behavior; D009949:Orientation; D016138:Walking; D015046:Zoology / Q000379:methods
keywords: Ant navigation; Fast response treadmill; Homing; Optical mouse motion sensors; Orientation behaviour