Data from: How to find home backwards? Locomotion and inter-leg coordination during rearward walking of Cataglyphis fortis desert ants
Pfeffer, Sarah Elisabeth, University of Ulm
Wahl, Verena Luisa
Wittlinger, Matthias, University of Ulm
Published Jul 20, 2016 on Dryad.
Cite this dataset
Pfeffer, Sarah Elisabeth; Wahl, Verena Luisa; Wittlinger, Matthias (2016). Data from: How to find home backwards? Locomotion and inter-leg coordination during rearward walking of Cataglyphis fortis desert ants [Dataset]. Dryad. https://doi.org/10.5061/dryad.7k82t
For insects, flexibility in the performance of terrestrial locomotion is a vital part of facing the challenges of their often unpredictable environment. Arthropods such as scorpions and crustaceans can switch readily from forward to backward locomotion, but in insects this behaviour seems to be less common and, therefore, is only poorly understood. Here we present an example of spontaneous and persistent backward walking in Cataglyphis desert ants that allows us to investigate rearward locomotion within a natural context. When ants find a food item that is too large to be lifted up and to be carried in a normal forward-faced orientation, they will drag the load walking backwards to their home nest. A detailed examination of this behaviour reveals a surprising flexibility of the locomotor output. Compared with forward walks with regular tripod coordination, no main coordination pattern can be assigned to rearward walks. However, we often observed leg-pair-specific stepping patterns. The front legs frequently step with small stride lengths, while the middle and the hind legs are characterized by less numerous but larger strides. But still, these specializations show no rigidly fixed leg coupling, nor are they strictly embedded within a temporal context; therefore, they do not result in a repetitive coordination pattern. The individual legs act as separate units, most likely to better maintain stability during backward dragging.
supplementary video V1 (backward walking)
Shown is an ant in backward locomotion dragging a large food item. Note that the walking pattern is irregular, without any tripod coordination.
supplementary video V2 (forward walking)
Shown is an ant walking in tripod fashion during forward locomotion. Note that three legs are coupled and are swinging in unison, while the other three legs remain on the ground.
supplementary video V3 (forward pulling)
Ants prefer to walk in forward-faced orientation, as long as the shape and weight of a food item makes this possible. Shown here is an example of an ant that has a food item that is too light-weight for backward dragging and the ant pushes the item forwards towards its home nest.
supplementary video V4 (backward tripod-like coordination)
Shown is an ant in backward locomotion. Generally, a detailed analysis of the ants’ inter-leg coordination revealed an irregular locomotion during backward walking. However, in this video we find the tendency that the legs of one tripod group are swinging more or less simultaneously. This indicates that backward tripod coordination is per se possible.