scholarly journals A new navigational mechanism mediated by ant ocelli

2011 ◽  
Vol 7 (6) ◽  
pp. 856-858 ◽  
Author(s):  
Sebastian Schwarz ◽  
Antoine Wystrach ◽  
Ken Cheng
Keyword(s):  
Path Integration ◽  
Compound Eyes ◽  
Direct Path ◽  
Directional Information ◽  
Distance Information ◽  
Step Counter ◽  
Desert Ants ◽  
Celestial Compass ◽  
Path Integrator ◽  
Direction Opposite

Many animals rely on path integration for navigation and desert ants are the champions. On leaving the nest, ants continuously integrate their distance and direction of travel so that they always know their current distance and direction from the nest and can take a direct path to home. Distance information originates from a step-counter and directional information is based on a celestial compass. So far, it has been assumed that the directional information obtained from ocelli contribute to a single global path integrator, together with directional information from the dorsal rim area (DRA) of the compound eyes and distance information from the step-counter. Here, we show that ocelli mediate a distinct compass from that mediated by the compound eyes. After travelling a two-leg outbound route, untreated foragers headed towards the nest direction, showing that both legs of the route had been integrated. In contrast, foragers with covered compound eyes but uncovered ocelli steered in the direction opposite to the last leg of the outbound route. Our findings suggest that, unlike the DRA, ocelli cannot by themselves mediate path integration. Instead, ocelli mediate a distinct directional system, which buffers the most recent leg of a journey.

Multiple orientation cues in an Australian trunk-trail-forming ant, Iridomyrmex purpureus

2016 ◽  
Vol 64 (3) ◽  
pp. 227 ◽  
Author(s):  
Ashley Card ◽  
Caitlin McDermott ◽  
Ajay Narendra
Keyword(s):  
Path Integration ◽  
Trail Following ◽  
Visual Landmarks ◽  
Directional Information ◽  
Nest Location ◽  
Visual Landmark ◽  
Pheromone Trails ◽  
Orientation Cues ◽  
Celestial Compass ◽  
Path Integrator

Ants use multiple cues for navigating to a food source or nest location. Directional information is derived from pheromone trails or visual landmarks or celestial objects. Some ants use the celestial compass information along with an ‘odometer’ to determine the shortest distance home, a strategy known as path integration. Some trail-following ants utilise visual landmark information whereas few of the solitary-foraging ants rely on both path integration and visual landmark information. However, it is unknown to what degree trail-following ants use path integration and we investigated this in a trunk-trail-following ant, Iridomyrmex purpureus. Trunk-trail ants connect their nests to food sites with pheromone trails that contain long-lasting orientation information. We determined the use of visual landmarks and the ability to path integrate in a trunk-trail forming ant. We found that experienced animals switch to relying on visual landmark information, and naïve individuals rely on odour trails. Ants displaced to unfamiliar locations relied on path integration, but, surprisingly, they did not travel the entire homebound distance. We found that as the homebound distance increased, the distance ants travelled relying on the path integrator reduced.

scholarly journals Role of the pheromone for orientation in the group foraging ant, Veromessor pergandei

2020 ◽  
Author(s):  
Cody A Freas ◽  
Marcia L Spetch
Keyword(s):  
Vector State ◽  
Group Foraging ◽  
Directional Information ◽  
Desert Ant ◽  
Correct Orientation ◽  
Celestial Compass ◽  
Vector Orientation ◽  
Veromessor Pergandei ◽  
Path Integrator

Role of the pheromone for orientation in the group foraging ant, Veromessor pergandei Navigation is comprised of a variety of strategies which rely on multiple external cues to shape a navigator’s behavioral output. An additional navigational challenge is coping with forces such as wind and water currents that push navigators off-course. Here, we explore the cue interactions that dictate orientation and foragers’ ability to counter course altering rotational changes in the desert ant, Veromessor pergandei. We found a cross sensory interaction between the pheromone cue and the path integrator underlies correct orientation during the inbound journey. The celestial compass provides directional information while the presence of the trail pheromone acts as a critical context cue, triggering distinct behavioral responses (vector orientation, search and backtracking). A particularly interesting interaction occurs between the pheromone and the forager’s vector state. While exposed to the pheromone, foragers orient to the vector direction regardless of vector state, while in the pheromone’s absence the current vector triggers the switch between behaviors. Such interactions maximize the foragers’ return to the nest and inhibit movement off the trail. Finally, our manipulations continuously pushed foragers away from their desired heading, yet foragers were highly proficient at counteracting these changes, steering to maintain a correct heading even at rotational speeds of ~40°/s.

scholarly journals Flexible weighing of olfactory and vector information in the desert ant Cataglyphis fortis

2013 ◽  
Vol 9 (3) ◽  
pp. 20130070 ◽  
Author(s):  
Cornelia Buehlmann ◽  
Bill S. Hansson ◽  
Markus Knaden
Keyword(s):  
Path Integration ◽  
Food Sources ◽  
Feeding Site ◽  
Desert Ants ◽  
Desert Ant ◽  
Vector Information ◽  
Pass Through ◽  
Path Integrator ◽  
Odour Plumes ◽  
Cataglyphis Fortis

Desert ants, Cataglyphis fortis , are equipped with remarkable skills that enable them to navigate efficiently. When travelling between the nest and a previously visited feeding site, they perform path integration (PI), but pinpoint the nest or feeder by following odour plumes. Homing ants respond to nest plumes only when the path integrator indicates that they are near home. This is crucial, as homing ants often pass through plumes emanating from foreign nests and do not discriminate between the plume of their own and that of a foreign nest, but should absolutely avoid entering a wrong nest. Their behaviour towards food odours differs greatly. Here, we show that in ants on the way to food, olfactory information outweighs PI information. Although PI guides ants back to a learned feeder, the ants respond to food odours independently of whether or not they are close to the learned feeding site. This ability is beneficial, as new food sources—unlike foreign nests—never pose a threat but enable ants to shorten distances travelled while foraging. While it has been shown that navigating C. fortis ants rely strongly on PI, we report here that the ants retained the necessary flexibility in the use of PI.

scholarly journals Desert ants possess distinct memories for food and nest odors

2018 ◽  
Vol 115 (41) ◽  
pp. 10470-10474 ◽  
Author(s):  
Roman Huber ◽  
Markus Knaden
Keyword(s):  
Path Integration ◽  
Nest Entrance ◽  
North African ◽  
Directional Information ◽  
Distance Information ◽  
The North ◽  
Desert Ant ◽  
Odor Memory ◽  
Food Odors ◽  
Single Nest

The desert ant Cataglyphis fortis inhabits the North African saltpans where it individually forages for dead arthropods. Homing ants rely mainly on path integration, i.e., the processing of directional information from a skylight compass and distance information from an odometer. Due to the far-reaching foraging runs, path integration is error-prone and guides the ants only to the vicinity of the nest, where the ants then use learned visual and olfactory cues to locate the inconspicuous nest entrance. The learning of odors associated with the nest entrance is well established. We furthermore know that foraging Cataglyphis use the food-derived necromone linoleic acid to pinpoint dead insects. Here we show that Cataglyphis in addition can learn the association of a given odor with food. After experiencing food crumbs that were spiked with an innately neutral odor, ants were strongly attracted by the same odor during their next foraging journey. We therefore explored the characteristics of the ants’ food-odor memory and identified pronounced differences from their memory for nest-associated odors. Nest odors are learned only after repeated learning trials and become ignored as soon as the ants do not experience them at the nest anymore. In contrast, ants learn food odors after a single experience, remember at least 14 consecutively learned food odors, and do so for the rest of their lives. As an ant experiences many food items during its lifetime, but only a single nest, differentially organized memories for both contexts might be adaptive.

scholarly journals Path Integration Provides a Scaffold for Landmark Learning in Desert Ants

2010 ◽  
Vol 20 (15) ◽  
pp. 1368-1371 ◽  
Author(s):  
Martin Müller ◽  
Rüdiger Wehner
Keyword(s):  
Path Integration ◽  
Desert Ants ◽  
Landmark Learning

scholarly journals Visual Navigation in Nocturnal Insects

Physiology ◽  
2016 ◽  
Vol 31 (3) ◽  
pp. 182-192 ◽  
Author(s):  
Eric Warrant ◽  
Marie Dacke
Keyword(s):  
Visual Processing ◽  
Visual Navigation ◽  
Compound Eyes ◽  
Visual Landmarks ◽  
Processing Strategies ◽  
Straight Line ◽  
Highly Sensitive ◽  
Celestial Compass ◽  
The Brain

Despite their tiny eyes and brains, nocturnal insects have evolved a remarkable capacity to visually navigate at night. Whereas some use moonlight or the stars as celestial compass cues to maintain a straight-line course, others use visual landmarks to navigate to and from their nest. These impressive abilities rely on highly sensitive compound eyes and specialized visual processing strategies in the brain.

scholarly journals Hypergeometric Functions by Direct Path Integration

1990 ◽  
Vol 4 (3) ◽  
pp. 320 ◽  
Author(s):  
William H. Press ◽  
Saul A. Teukolsky
Keyword(s):  
Path Integration ◽  
Hypergeometric Functions ◽  
Direct Path
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