The desert ant odometer: a stride integrator that accounts for stride length and walking speed

@article{Wittlinger2007TheDA,
  title={The desert ant odometer: a stride integrator that accounts for stride length and walking speed},
  author={Matthias Wittlinger and R{\"u}diger Wehner and Harald Wolf},
  journal={Journal of Experimental Biology},
  year={2007},
  volume={210},
  pages={198 - 207}
}
SUMMARY Desert ants, Cataglyphis, use path integration as a major means of navigation. Path integration requires measurement of two parameters, namely, direction and distance of travel. Directional information is provided by a celestial compass, whereas distance measurement is accomplished by a stride integrator, or pedometer. Here we examine the recently demonstrated pedometer function in more detail. By manipulating leg lengths in foraging desert ants we could also change their stride lengths… 

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  • 2020
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A Hexapod Walking Robot Mimicking Navigation Strategies of Desert Ants Cataglyphis

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...

References

SHOWING 1-10 OF 46 REFERENCES

The Ant Odometer: Stepping on Stilts and Stumps

Desert ants, Cataglyphis, navigate in their vast desert habitat by path integration. They continuously integrate directions steered (as determined by their celestial compass) and distances traveled,

Desert ants Cataglyphis fortis use self-induced optic flow to measure distances travelled

TLDR
Even though optic flow cues are not the only ones used by the ants, the experiments show that ants are obviously able to exploit such cues for estimation of travel distance, indicating that the motion sensitive mechanism involved is different from mechanisms mediating the optomotor response.

STEPPING PATTERNS IN ANTS - INFLUENCE OF BODY MORPHOLOGY

  • Zollikofer
  • Biology
    The Journal of experimental biology
  • 1994
TLDR
Females and males show metachronal interleg coordination patterns rather than the alternating tripod coordination pattern seen in workers of the same species, which indicates that ants are 'trotting' from one tripod to the next one with intermittent aerial phases.

Desert ants compensate for navigation uncertainty

TLDR
During foraging trips, desert ants Cataglyphis fortis do not rely only on their well-studied path integration system but also use olfactory cues when approaching a familiar food source, and the results unambiguously support the second strategy.

Lateral optic flow does not influence distance estimation in the desert ant Cataglyphis fortis.

TLDR
Walking desert ants do not depend on self-induced visual flow-field cues in gauging the distance they have travelled, as do flying honeybees, but can measure locomotor distance exclusively by idiothetic means.

Honeybee navigation en route to the goal: visual flight control and odometry

TLDR
The movement-sensitive mechanisms underlying these various behaviours seem to be different, qualitatively as well as quantitatively, from those mediating the well-investigated optomotor response.

STEPPING PATTERNS IN ANTS - INFLUENCE OF SPEED AND CURVATURE

  • Zollikofer
  • Biology
    The Journal of experimental biology
  • 1994
TLDR
The locomotory behaviour of workers of 12 ant species belonging to four different genera was studied by filming individuals walking on smoked-glass plates and subsequent multivariate analyses of footfall positions and walking kinematics revealed a set of constant features characterizing ant locomotion.

Mechanics of a rapid running insect: two-, four- and six-legged locomotion.

TLDR
The mass-specific mechanical energy used to move the center of mass a given distance was similar to that measured for animals five orders of magnitude larger in mass, but was only one-hundredth of the metabolic cost.

STEPPING PATTERNS IN ANTS - INFLUENCE OF LOAD

  • Zollikofer
  • Biology
    The Journal of experimental biology
  • 1994
TLDR
Stepping pattern geometry and walking kinematics of individual foragers of Cataglyphis fortis were recorded during outward and homeward trips to and from a food source and Tripod deformation was found to be proportional to the displacement of the centre of mass induced by the load.

Mechanics of six-legged runners.

  • R. FullM. S. Tu
  • Biology, Engineering
    The Journal of experimental biology
  • 1990
TLDR
Similarities in force production, stride frequency and mechanical energy production during locomotion suggest that there may be common design constraints in terrestrial locomotion which scale with body mass and are relatively independent of body form, leg number and skeletal type.