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Charoonratana L, Thiwatwaranikul T, Paisanpan P, Suksombat S, Smith MF. Modeling the movement of Oecophylla smargandina on short-length scales in an unfamiliar environment. MOVEMENT ECOLOGY 2023; 11:64. [PMID: 37845771 PMCID: PMC10577999 DOI: 10.1186/s40462-023-00426-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 09/25/2023] [Indexed: 10/18/2023]
Abstract
The movement of individual weaver ants, of Oecophylla smargandina, was previously tracked within an unfamiliar arena. We develop an empirical model, based on Brownian motion with a linear drag and constant driving force, to explain the observed distribution of ants over position and velocity. Parameters are fixed according to the isotropic, homogeneous distribution observed near the middle of the arena. Then, with no adjustable parameters, the model accounts for all features of the measured population distribution. The tendency of ants to remain near arena edges is largely explained as a statistical property of bounded stochastic motion though evidence for active wall-following behavior appears in individual ant trajectories. Members of this ant species are capable of impressive feats of collective action and long-range navigation. But we argue that they use a simplistic algorithm, captured semi-quantitatively by the model provided, to navigate within the confined region.
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Affiliation(s)
- L Charoonratana
- School of Physics, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand
- NANOTEC-SUT Center of Excellence on Advanced Functional Nanomaterials, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand
| | - T Thiwatwaranikul
- School of Physics, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand
- NANOTEC-SUT Center of Excellence on Advanced Functional Nanomaterials, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand
| | - P Paisanpan
- School of Physics, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand
- NANOTEC-SUT Center of Excellence on Advanced Functional Nanomaterials, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand
| | - S Suksombat
- NANOTEC-SUT Center of Excellence on Advanced Functional Nanomaterials, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand
- School of Sport Science, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand
| | - M F Smith
- School of Physics, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand.
- NANOTEC-SUT Center of Excellence on Advanced Functional Nanomaterials, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand.
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Buehlmann C, Dell-Cronin S, Diyalagoda Pathirannahelage A, Goulard R, Webb B, Niven JE, Graham P. Impact of central complex lesions on innate and learnt visual navigation in ants. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023:10.1007/s00359-023-01613-1. [PMID: 36790487 DOI: 10.1007/s00359-023-01613-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/31/2022] [Accepted: 01/10/2023] [Indexed: 02/16/2023]
Abstract
Wood ants are excellent navigators, using a combination of innate and learnt navigational strategies to travel between their nest and feeding sites. Visual navigation in ants has been studied extensively, however, we have little direct evidence for the underlying neural mechanisms. Here, we perform lateralized mechanical lesions in the central complex (CX) of wood ants, a midline structure known to allow an insect to keep track of the direction of sensory cues relative to its own orientation and to control movement. We lesioned two groups of ants and observed their behaviour in an arena with a large visual landmark present. The first group of ants were naïve and when intact such ants show a clear innate attraction to the conspicuous landmark. The second group of ants were trained to aim to a food location to the side of the landmark. The general heading of naïve ants towards a visual cue was not altered by the lesions, but the heading of ants trained to a landmark adjacent food position was affected. Thus, CX lesions had a specific impact on learnt visual guidance. We also observed that lateralised lesions altered the fine details of turning with lesioned ants spending less time turning to the side ipsilateral of the lesion. The results confirm the role of the CX in turn control and highlight its important role in the implementation of learnt behaviours that rely on information from other brain regions.
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Affiliation(s)
| | | | | | - Roman Goulard
- School of Informatics, University of Edinburgh, Edinburgh, EH8 9AB, UK.,Lund Vision Group, Department of Biology, Lund University, 223 62, Lund, Sweden
| | - Barbara Webb
- School of Informatics, University of Edinburgh, Edinburgh, EH8 9AB, UK
| | - Jeremy E Niven
- School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK
| | - Paul Graham
- School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK
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Notomi Y, Kazawa T, Maezawa S, Kanzaki R, Haupt SS. Use of Visual Information by Ant Species Occurring in Similar Urban Anthropogenic Environments. Zoolog Sci 2022; 39:529-544. [PMID: 36495488 DOI: 10.2108/zs220035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 07/27/2022] [Indexed: 12/12/2022]
Abstract
Many insects, including ants, are known to respond visually to conspicuous objects. In this study, we compared orientation in an arena containing only a black target beacon as local information in six species of ants of widely varying degree of phylogenic relatedness, foraging strategy, and eye morphology (Aphaenogaster, Brachyponera, Camponotus, Formica, and two Lasius spp.), often found associated in similar urban anthropogenic habitats. Four species of ants displayed orientation toward the beacon, with two orienting toward it directly, while the other two approached it via convoluted paths. The two remaining species did not show any orientation with respect to the beacon. The results did not correlate with morphological parameters of the visual systems and could not be fully interpreted in terms of the species' ecology, although convoluted paths are linked to higher significance of chemical signals. Beacon aiming was shown to be an innate behavior in visually naive Formica workers, which, however, were less strongly attracted to the beacon than older foragers. Thus, despite sharing the same habitats and supposedly having similar neural circuits, even a very simple stimulus-related behavior in the absence of other information can differ widely in ants but is likely an ancestral trait retained especially in species with smaller eyes. The comparative analysis of nervous systems opens the possibility of determining general features of circuits responsible for innate and possibly learned attraction toward particular stimuli.
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Affiliation(s)
- Yusuke Notomi
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda-shi, Chiba 278-8510, Japan.,Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo 153-8904, Japan
| | - Tomoki Kazawa
- Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo 153-8904, Japan
| | - So Maezawa
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda-shi, Chiba 278-8510, Japan
| | - Ryohei Kanzaki
- Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo 153-8904, Japan
| | - Stephan Shuichi Haupt
- Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo 153-8904, Japan,
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Buehlmann C, Graham P. Innate visual attraction in wood ants is a hardwired behavior seen across different motivational and ecological contexts. INSECTES SOCIAUX 2022; 69:271-277. [PMID: 35909593 PMCID: PMC9314291 DOI: 10.1007/s00040-022-00867-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/24/2022] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
UNLABELLED Ants are expert navigators combining innate and learnt navigational strategies. Whereas we know that the ants' feeding state segregates visual-navigational memories in ants navigating along a learnt route, it is an open question if the motivational state also affects the ants' innate visual preferences. Wood ant foragers show an innate attraction to conspicuous visual cues. These foragers inhabit cluttered woodland habitat and feed on honeydew from aphids on trees. Hence, the attraction to 'tree-like' objects might be an ecologically relevant behavior that is tailored to the wood ants' foraging ecology. Foragers from other ant species with different foraging ecologies show very different innate attractions. We investigated here the innate visual response of wood ant foragers with different motivational states, i.e., unfed or fed, as well as males that show no foraging activity. Our results show that ants from all three groups orient toward a prominent visual cue, i.e., this intrinsic visuomotor response is not context-dependent, but a hardwired behavior seen across different motivational and ecological contexts. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s00040-022-00867-3.
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Affiliation(s)
- C. Buehlmann
- School of Life Sciences, University of Sussex, Brighton, BN1 9QG UK
| | - P. Graham
- School of Life Sciences, University of Sussex, Brighton, BN1 9QG UK
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5
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Rapid Aversive and Memory Trace Learning during Route Navigation in Desert Ants. Curr Biol 2020; 30:1927-1933.e2. [DOI: 10.1016/j.cub.2020.02.082] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 02/03/2020] [Accepted: 02/26/2020] [Indexed: 11/19/2022]
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Abstract
Visual landmarks are important navigational aids to many animals, and when more than one is available their juxtaposition can convey valuable new information to a navigator about progress toward a goal, depending on the landmarks' comparative distinctiveness. We investigated the effect of presenting rock ant colonies (Temnothorax albipennis) with identical horizontal landmarks either side of their route, versus one horizontal landmark paired with a sloping landmark, as they navigated to a new nest site. Our findings suggest that ants can obtain more navigational information from a combination of dissimilar landmarks: the average tortuosity of the route taken between old and new nests was significantly lower when a horizontal landmark was paired with a monotonically downward sloping landmark (the paths were more direct). The impact on available navigational information from the similarity or dissimilarity of nearby landmarks is likely made through more distinctive visual panoramas, and could be an influential factor in individual and collective animal decision-making about which routes are followed. Furthermore, the effect of landmark complementarity may be relevant to a wide range of species, including other insects or birds, and highlights the possibility that there is an intrinsic difference in the informational content of natural vs. artificial environments.
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Affiliation(s)
- Edmund R Hunt
- School of Biological Sciences, University of Bristol, BS8 1TQ, UK.
| | | | - Emma Stanbury
- School of Biological Sciences, University of Bristol, BS8 1TQ, UK
| | - Ana B Sendova-Franks
- Department of Engineering Design and Mathematics, University of the West of England, BS16 1QY, UK
| | - Nigel R Franks
- School of Biological Sciences, University of Bristol, BS8 1TQ, UK
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Buehlmann C, Fernandes ASD, Graham P. The interaction of path integration and terrestrial visual cues in navigating desert ants: what can we learn from path characteristics? ACTA ACUST UNITED AC 2018; 221:jeb.167304. [PMID: 29146769 DOI: 10.1242/jeb.167304] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 11/12/2017] [Indexed: 11/20/2022]
Abstract
Ant foragers make use of multiple navigational cues to navigate through the world and the combination of innate navigational strategies and the learning of environmental information is the secret to their navigational success. We present here detailed information about the paths of Cataglyphis fortis desert ants navigating by an innate strategy, namely path integration. Firstly, we observed that the ants' walking speed decreases significantly along their homing paths, such that they slow down just before reaching the goal, and maintain a slower speed during subsequent search paths. Interestingly, this drop in walking speed is independent of absolute home-vector length and depends on the proportion of the home vector that has been completed. Secondly, we found that ants are influenced more strongly by novel or altered visual cues the further along the homing path they are. These results suggest that path integration modulates speed along the homing path in a way that might help ants search for, utilise or learn environmental information at important locations. Ants walk more slowly and sinuously when encountering novel or altered visual cues and occasionally stop and scan the world; this might indicate the re-learning of visual information.
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Affiliation(s)
- Cornelia Buehlmann
- University of Sussex, School of Life Sciences, Falmer, Brighton BN1 9QG, UK
| | | | - Paul Graham
- University of Sussex, School of Life Sciences, Falmer, Brighton BN1 9QG, UK
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8
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Altitude control in honeybees: joint vision-based learning and guidance. Sci Rep 2017; 7:9231. [PMID: 28835634 PMCID: PMC5569062 DOI: 10.1038/s41598-017-09112-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 07/24/2017] [Indexed: 11/15/2022] Open
Abstract
Studies on insects’ visual guidance systems have shed little light on how learning contributes to insects’ altitude control system. In this study, honeybees were trained to fly along a double-roofed tunnel after entering it near either the ceiling or the floor of the tunnel. The honeybees trained to hug the ceiling therefore encountered a sudden change in the tunnel configuration midways: i.e. a "dorsal ditch". Thus, the trained honeybees met a sudden increase in the distance to the ceiling, corresponding to a sudden strong change in the visual cues available in their dorsal field of view. Honeybees reacted by rising quickly and hugging the new, higher ceiling, keeping a similar forward speed, distance to the ceiling and dorsal optic flow to those observed during the training step; whereas bees trained to follow the floor kept on following the floor regardless of the change in the ceiling height. When trained honeybees entered the tunnel via the other entry (the lower or upper entry) to that used during the training step, they quickly changed their altitude and hugged the surface they had previously learned to follow. These findings clearly show that trained honeybees control their altitude based on visual cues memorized during training. The memorized visual cues generated by the surfaces followed form a complex optic flow pattern: trained honeybees may attempt to match the visual cues they perceive with this memorized optic flow pattern by controlling their altitude.
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Knaden M, Graham P. The Sensory Ecology of Ant Navigation: From Natural Environments to Neural Mechanisms. ANNUAL REVIEW OF ENTOMOLOGY 2016; 61:63-76. [PMID: 26527301 DOI: 10.1146/annurev-ento-010715-023703] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Animals moving through the world are surrounded by potential information. But the components of this rich array that they extract will depend on current behavioral requirements and the animal's own sensory apparatus. Here, we consider the types of information available to social hymenopteran insects, with a specific focus on ants. This topic has a long history and much is known about how ants and other insects use idiothetic information, sky compasses, visual cues, and odor trails. Recent research has highlighted how insects use other sensory information for navigation, such as the olfactory cues provided by the environment. These cues are harder to understand because they submit less easily to anthropomorphic analysis. Here, we take an ecological approach, considering first what information is available to insects, then how different cues might interact, and finally we discuss potential neural correlates of these behaviors.
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Affiliation(s)
- Markus Knaden
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany;
| | - Paul Graham
- Centre for Computational Neuroscience and Robotics, University of Sussex, Brighton, BN1 9RH, United Kingdom;
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Differt D, Möller R. Insect models of illumination-invariant skyline extraction from UV and green channels. J Theor Biol 2015; 380:444-62. [PMID: 26113191 DOI: 10.1016/j.jtbi.2015.06.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 05/27/2015] [Accepted: 06/09/2015] [Indexed: 11/28/2022]
Abstract
Experiments have shown that the skyline is an important visual cue for navigating insects. However, the comparison between two snapshots collected at different times of day is a complex task due to possible illumination changes. In this study we examine whether the information from two different color channels (UV and green, which are also available for many insects) can be used to obtain an illumination-invariant separation between the sky and ground. We collected UV and green images of seven different scenes over entire days, in which natural and artificial objects are visible in front of the sky. With the collected data we want to find answers to the following two questions: 'Does UV/green contrast vision increase the quality of separation compared to UV-only vision?' and 'What yields a better performance: separation methods based on a fixed threshold (global separation techniques) or separation methods which adapt the threshold dependent on the input image (local separation techniques)?' We implemented several linear separation techniques and found that UV/green contrast only marginally increases the quality of global separation in comparison to UV-only, and that local separation techniques are superior to global separation techniques.
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Affiliation(s)
- Dario Differt
- Computer Engineering Group, Faculty of Technology, Bielefeld University, D-33594 Bielefeld, Germany.
| | - Ralf Möller
- Computer Engineering Group, Faculty of Technology, Bielefeld University, D-33594 Bielefeld, Germany; Center of Excellence 'Cognitive Interaction Technology', Bielefeld University, D-33594 Bielefeld, Germany.
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11
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Hansen MJ, Schaerf TM, Ward AJ. The effect of hunger on the exploratory behaviour of shoals of mosquitofish Gambusia holbrooki. BEHAVIOUR 2015. [DOI: 10.1163/1568539x-00003298] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The question of how hunger affects locomotory behaviour, in particular how it affects the kinematics of movement and an animal’s interaction with the physical structures in its environment is of broad relevance in behavioural ecology. We experimentally manipulated the hunger levels of individual mosquitofish (Gambusia holbrooki) and recorded their swimming behaviour in shoals of 4 fish. We found that hungry individuals in shoals moved at greater speeds and had higher turning speeds than satiated individuals in shoals, as well as a greater variance in speed and turning speeds. We also found that hungry individuals explored more of the arena and used more of its internal space, away from the square arena’s walls and displayed less wall-following behaviour than satiated individuals. A functional explanation for this change in swimming behaviour and interaction with environmental heterogeneity is discussed in the context of social foraging, as is the consequence of these results for models of search patterns and collective movement.
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Affiliation(s)
- Matthew J. Hansen
- Animal Behaviour Lab, School of Biological Sciences, the University of Sydney, Sydney, NSW 2006, Australia
| | - Timothy M. Schaerf
- Animal Behaviour Lab, School of Biological Sciences, the University of Sydney, Sydney, NSW 2006, Australia
| | - Ashley J.W. Ward
- Animal Behaviour Lab, School of Biological Sciences, the University of Sydney, Sydney, NSW 2006, Australia
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Julle-Daniere E, Schultheiss P, Wystrach A, Schwarz S, Nooten SS, Bibost AL, Cheng K. Visual Matching in the Orientation of Desert Ants (Melophorus bagoti): The Effect of Changing Skyline Height. Ethology 2014. [DOI: 10.1111/eth.12247] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Patrick Schultheiss
- Department of Biological Sciences; Macquarie University; Sydney NSW Australia
| | | | - Sebastian Schwarz
- Department of Psychology, Neuroscience & Behaviour; McMaster University; Hamilton ON Canada
| | - Sabine S. Nooten
- Department of Biological Sciences; Macquarie University; Sydney NSW Australia
| | | | - Ken Cheng
- Department of Biological Sciences; Macquarie University; Sydney NSW Australia
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Bühlmann C, Cheng K, Wehner R. Vector-based and landmark-guided navigation in desert ants inhabiting landmark-free and landmark-rich environments. J Exp Biol 2011; 214:2845-53. [DOI: 10.1242/jeb.054601] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Two species of desert ants – the North African Cataglyphis fortis and the central Australian Melophorus bagoti – differ markedly in the visual complexity of their natural habitats: featureless salt pans and cluttered, steppe-like terrain, respectively. Here we ask whether the two species differ in their navigational repertoires, in particular, whether in homing they place different emphasis on their vector-based and landmark-based routines. In trying to answer this question, we applied the same experimental paradigms to individual foragers of either species on either continent: training and/or testing with and/or without artificial landmark arrays. We found that the open-terrain species C. fortis runs off its (path integration) home vector much more readily even in unfamiliar landmark settings than the cluttered-terrain species M. bagoti. These data support the hypothesis that C. fortis has a higher propensity to rely on vector-mediated navigation, whereas in the same experimental situations M. bagoti more easily switches to landmark-guided behaviour. In the actual navigational performances, such species-specific propensities are most likely shaped by environment-dependent individual experiences.
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Affiliation(s)
- Cornelia Bühlmann
- Brain Research Institute, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland
| | - Ken Cheng
- Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Rüdiger Wehner
- Brain Research Institute, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland
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15
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Basten K, Mallot HA. Simulated visual homing in desert ant natural environments: efficiency of skyline cues. BIOLOGICAL CYBERNETICS 2010; 102:413-425. [PMID: 20300942 DOI: 10.1007/s00422-010-0375-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Accepted: 02/18/2010] [Indexed: 05/29/2023]
Abstract
Desert ants, foraging in cluttered semiarid environments, are thought to be visually guided along individual, habitual routes. While other navigational mechanisms (e.g. path integration) are well studied, the question of how ants extract reliable visual features from a complex visual scene is still largely open. This paper explores the assumption that the upper outline of ground objects formed against the sky, i.e. the skyline, provides sufficient information for visual navigation. We constructed a virtual model of the ant's environment. In the virtual environment, panoramic images were recorded and adapted to the resolution of the desert ant's complex eye. From these images either a skyline code or a pixel-based intensity code were extracted. Further, two homing algorithms were implemented, a modified version of the average landmark vector (ALV) model (Lambrinos et al. Robot Auton Syst 30:39-64, 2000) and a gradient ascent method. Results show less spatial aliasing for skyline coding and best homing performance for ALV homing based on skyline codes. This supports the assumption of skyline coding in visual homing of desert ants and allows novel approaches to technical outdoor navigation.
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Affiliation(s)
- Kai Basten
- Institute of Neurobiology, University of Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany.
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Steck K, Wittlinger M, Wolf H. Estimation of homing distance in desert ants,Cataglyphis fortis, remains unaffected by disturbance of walking behaviour. J Exp Biol 2009; 212:2893-901. [DOI: 10.1242/jeb.030403] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARYDesert ants, Cataglyphis fortis, use a stride integrator as a distance gauge in their well-studied path integration system (while a skylight compass provides the direction gauge). To further scrutinize the mechanisms of the ant odometer, we tried to disturb the stride integrator by interfering with normal walking behaviour. First, legs that contribute to one of the two leg tripods alternately used in normal walking were selectively amputated. This prevented the normal tripod gait and should interfere with both the normal walking programme controlled by the central nervous system, and normal sensory feedback from the legs. Second, manipulation of the walking substrate in the form of regular corrugations was observed to interfere with normal walking behaviour, at least for corrugation wavelengths (12–25 mm) in the range of normal stride lengths. The animals fell and stumbled, or footfall patterns were entrained to the corrugation wavelength. The relationship between stride length and stride frequency was altered in several situations. Surprisingly, distance estimation and homing performance remained virtually unaffected even by the most severe interferences with walking behaviour. This demonstrates a remarkable robustness of walking behaviour and homing, and it suggests that stride length is determined by robust signals of leg sense organs.
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Affiliation(s)
- Kathrin Steck
- Institute of Neurobiology, University of Ulm, D-89069 Ulm, Germany
| | | | - Harald Wolf
- Institute of Neurobiology, University of Ulm, D-89069 Ulm, Germany
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17
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Merkle T, Wehner R. Landmark guidance and vector navigation in outbound desert ants. J Exp Biol 2008; 211:3370-7. [DOI: 10.1242/jeb.022715] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
This study deals with the influence landmark information has on the foraging behaviour of the desert ant, Cataglyphis fortis, especially with the interaction of such landmark information with the ants' path integration system. We show in the first experiment that desert ants that are captured immediately after leaving their nest and then transferred to a remote test area search for the nest rather than activate their previous path integration vector. In a second experiment, the ants had been trained to a landmark corridor on their way to the feeder. In the critical test situation,they were again captured immediately after they had left the nest and transferred to a test field where they faced one of the following three situations: (1) the same landmark corridor as used during the training phase,(2) no landmarks at all and (3) a landmark corridor rotated by 90 deg. as compared with the training situation. Nearly all ants in test situation (1)eventually followed the landmark corridor but most of them never reached the fictive feeder. In situation (2), the ants searched around the nest entrance. In situation (3), approximately one half of the ants searched for the nest,whereas most of the other ants followed the landmark corridor, i.e. headed in a completely wrong direction. Hence, familiar landmarks do not only influence the foraging behaviour of desert ants, e.g. in making the ants start their foraging runs but can even out-compete the ants' path integration system.
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Affiliation(s)
- Tobias Merkle
- Centre for Visual Sciences, Research School of Biological Sciences, Australian National University, Canberra ACT 2601, Australia
| | - Rüdiger Wehner
- Institute of Zoology and Brain Research Institute, University of Zürich,Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
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18
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A bee in the corridor: centering and wall-following. Naturwissenschaften 2008; 95:1181-7. [PMID: 18813898 DOI: 10.1007/s00114-008-0440-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Revised: 07/23/2008] [Accepted: 08/01/2008] [Indexed: 10/21/2022]
Abstract
In an attempt to better understand the mechanism underlying lateral collision avoidance in flying insects, we trained honeybees (Apis mellifera) to fly through a large (95-cm wide) flight tunnel. We found that, depending on the entrance and feeder positions, honeybees would either center along the corridor midline or fly along one wall. Bees kept following one wall even when a major (150-cm long) part of the opposite wall was removed. These findings cannot be accounted for by the "optic flow balance" hypothesis that has been put forward to explain the typical bees' "centering response" observed in narrower corridors. Both centering and wall-following behaviors are well accounted for, however, by a control scheme called the lateral optic flow regulator, i.e., a feedback system that strives to maintain the unilateral optic flow constant. The power of this control scheme is that it would allow the bee to guide itself visually in a corridor without having to measure its speed or distance from the walls.
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Landmark cues can change the motivational state of desert ant foragers. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2008; 194:395-403. [DOI: 10.1007/s00359-008-0315-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Revised: 01/04/2008] [Accepted: 01/06/2008] [Indexed: 10/22/2022]
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Abstract
When offered a permanent food source, central Australian desert ants, Melophorus bagoti, develop individually distinct, view-based foraging routes, which they retrace with amazing accuracy during each foraging trip. Using a particular channel setup connected to an artificial feeder, we trained M. bagoti ants to either two or three inward routes that led through different parts of their maze-like foraging grounds. Here, we show that ants are able to adopt multiple habitual paths in succession and that they preserve initially acquired route memories even after they have been trained to new routes. Individual ants differ in the consistency with which they run along habitual pathways. However, those ants that follow constant paths retain their route-specific memories for at least 5 days of suspended foraging, which suggests that even multiple route memories, once acquired, are preserved over the entire lifetime of a forager.
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21
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Wittlinger M, Wolf H, Wehner R. Hair plate mechanoreceptors associated with body segments are not necessary for three-dimensional path integration in desert ants, Cataglyphis fortis. ACTA ACUST UNITED AC 2007; 210:375-82. [PMID: 17234606 DOI: 10.1242/jeb.02674] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In formicine ants, the hair fields associated with the neck and the petiole (alitrunk-petiole and petiole-gaster joints) have long been established to function in graviception. Here, we examine a possible role of these hair receptors in three-dimensional (3-D) path integration of the (formicine) desert ant, Cataglyphis fortis. Cataglyphis judge the ground distance when travelling over hills, allowing correct homing even in (unpredictably) uneven terrain. We eliminated the function of these hair sensors in graviception either by shaving the hairs or by immobilising the joints monitored by the hair plates. With that major component of their sense of graviception eliminated, one would expect the ants to disregard, or at least misgauge, the ascents and descents performed across hills during outbound journey. The ants should thus consider the (much longer) actual walking trajectory, instead of the base distance, when calculating their homing distance. Surprisingly, neither shaving nor immobilisation of the hair sensillae affected correct path integration, across both uneven terrain (3-D) and level surface. If anything, the ants underestimated homing distance, which may reflect a general, safety-oriented navigation strategy. Animals that had performed the outbound journey with their gaster fixed in a horizontal position underestimated their homing so dramatically that this latter explanation cannot hold.
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Affiliation(s)
- Matthias Wittlinger
- Department of Neurobiology, University of Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany.
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22
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Müller M, Wehner R. Wind and sky as compass cues in desert ant navigation. Naturwissenschaften 2007; 94:589-94. [PMID: 17361400 DOI: 10.1007/s00114-007-0232-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Revised: 12/19/2006] [Accepted: 02/20/2007] [Indexed: 11/30/2022]
Abstract
While integrating their foraging and homing paths, desert ants, Cataglyphis fortis, depend on external compass cues. Whereas recent research in bees and ants has focused nearly exclusively on the polarization compass, two other compass systems--the sun compass and the wind (anemo) compass--as well as the mutual interactions of all these compass systems have received little attention. In this study, we show that of the two visual compass systems, it is only the polarization compass that invariably outcompetes the wind compass, while the sun compass does so only under certain conditions. If the ants are experimentally deprived of their polarization compass system, but have access simultaneously to both their sun compass and their wind compass, they steer intermediate courses. The intermediate courses shift the more towards the wind compass course, the higher the elevation of the sun is in the sky.
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Affiliation(s)
- Martin Müller
- Institute of Zoology, University of Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
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23
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Dussutour A, Deneubourg JL, Fourcassié V. Amplification of individual preferences in a social context: the case of wall-following in ants. Proc Biol Sci 2005; 272:705-14. [PMID: 15870033 PMCID: PMC1602045 DOI: 10.1098/rspb.2004.2990] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Amplification processes are an essential component of the collective phenomena observed in social and gregarious species. In this paper, we tested the hypothesis that a weak individual wall-following tendency in ants can be amplified by communication through chemical trails, leading to a response to the spatial heterogeneities at the collective level. In our experiments, ants had to cross a diamond-shaped bridge along either of two branches of equal length to get from their nest to a food source. Two types of bridge were used: control bridges without a wall, and experimental bridges equipped with a wall along the inner edge of one of their branches. On the control bridges, ants collectively chose either branch of the bridge in most experiments, whereas on the experimental bridges, the branch with the wall was selected almost systematically. A mathematical model is proposed to assess, in various conditions, the importance of the amplification effect of the chemical trail on the wall-following tendency observed at the individual level. The model highlights the fact that the amplification process can lead to an overestimation of individual capabilities and, thus, that the results of experiments investigating individual preferences at group level in animals must be interpreted with caution.
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Affiliation(s)
- Audrey Dussutour
- Centre de Recherches sur la Cognition Animale, UMR CNRS 5169, Université Paul Sabatier118 route de Narbonne, F-31062 Toulouse cedex 4, France
| | - Jean-Louis Deneubourg
- Service d'Ecologie Sociale, Université Libre de BruxellesCP231, Boulevard du Triomphe, B-1050 Bruxelles, Belgium
| | - Vincent Fourcassié
- Centre de Recherches sur la Cognition Animale, UMR CNRS 5169, Université Paul Sabatier118 route de Narbonne, F-31062 Toulouse cedex 4, France
- Author for correspondence ()
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24
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Thiélin-Bescond M, Beugnon G. Vision-independent odometry in the ant Cataglyphis cursor. Naturwissenschaften 2005; 92:193-7. [PMID: 15772808 DOI: 10.1007/s00114-005-0609-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2004] [Accepted: 01/13/2005] [Indexed: 10/25/2022]
Abstract
In contrast to flying insects, in which distance estimation is visually mediated, self-induced image motion and use of familiar landmarks are known to play a minor role in ants. Here we show that strictly diurnal Cataglyphis cursor ants can gauge with accuracy the distance they have travelled even in complete darkness in the absence of any other cues, i.e. chemical or protocounting information. Thus, an ant's odometer is a vision-independent system based on proprioceptive cues, implicating some form of step counting, which remain to be elucidated.
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Affiliation(s)
- Mary Thiélin-Bescond
- Centre de Recherches sur la Cognition Animale, UMR-CNRS 5169, Université Paul-Sabatier, 31062 Toulouse Cedex 4, France
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25
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Kohler M, Wehner R. Idiosyncratic route-based memories in desert ants, Melophorus bagoti: How do they interact with path-integration vectors? Neurobiol Learn Mem 2005; 83:1-12. [PMID: 15607683 DOI: 10.1016/j.nlm.2004.05.011] [Citation(s) in RCA: 167] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2003] [Revised: 05/10/2004] [Accepted: 05/25/2004] [Indexed: 10/26/2022]
Abstract
Individually foraging desert ants of central Australia, Melophorus bagoti, exhibit amazingly precise mechanisms of visual landmark guidance when navigating through cluttered environments. If trained to shuttle back and forth between the nest and a feeder, they establish habitual outbound and inbound routes, which guide them idiosyncratically across the natural maze of extended arrays of grass tussocks covering their foraging areas. The route-based memories that usually differ between outbound and inbound runs are acquired already during the first runs to the nest and feeder. If the ants are displaced sideways of their habitual routes, they can enter their stereotyped routes at any place and then follow these routes with the same accuracy as if they had started at the usual point of departure. Furthermore, the accuracy of maintaining a route does not depend on whether homebound ants have been captured at the feeder shortly before starting their home run and, hence, with their home vector still fully available (full-vector ants), or whether they have been captured at the nest after they had already completed their home run (zero-vector ants). Hence, individual landmark memories can be retrieved independently of the state of the path-integration vector with which they have been associated during the acquisition phase of learning. However, the ants display their path-integration vector when displaced from the feeder to unfamiliar territory.
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Affiliation(s)
- Martin Kohler
- Institute of Zoology, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
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26
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Fukushi T, Wehner R. Navigation in wood ants Formica japonica: context dependent use of landmarks. J Exp Biol 2004; 207:3431-9. [PMID: 15326219 DOI: 10.1242/jeb.01159] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Wood ants Formica japonica can steer their outbound (foraging) and inbound (homing) courses without using celestial compass information, by relying exclusively on landmark cues. This is shown by training ants to run back and forth between the nest and an artificial feeder, and later displacing the trained ants either from the nest (when starting their foraging runs:outbound full-vector ants) or from the feeder (when starting their home runs:inbound full-vector ants) to various nearby release sites. In addition, ants that have already completed their foraging and homing runs are displaced after arrival either at the feeder (outbound zero-vector ants) or at the nest(inbound zero-vector ants), respectively, to the very same release sites. Upon release, the full-vector ants steer their straight courses by referring to panoramic landmark cues, while the zero-vector ants presented with the very same visual scenery immediately search for local landmark cues defining their final goal. Hence, it depends on the context, in this case on the state of the forager's round-trip cycle, what visual cues are picked out from a given set of landmarks and used for navigation.
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Affiliation(s)
- Tsukasa Fukushi
- Department of Biology, Miyagi University of Education, Aramaki-aza-Aoba, Aoba-ku, Sendai 980-0845, Japan.
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27
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Abstract
The navigational strategies that are used by foraging ants and bees to reach a goal are similar to those of birds and mammals. Species from all these groups use path integration and memories of visual landmarks to navigate through familiar terrain. Insects have far fewer neural resources than vertebrates, so data from insects might be useful in revealing the essential components of efficient navigation. Recent work on ants and bees has uncovered a major role for associative links between long-term memories. We emphasize the roles of these associations in the reliable recognition of visual landmarks and the reliable performance of learnt routes. It is unknown whether such associations also provide insects with a map-like representation of familiar terrain. We suggest, however, that landmarks act primarily as signposts that tell insects what particular action they need to perform, rather than telling them where they are.
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Affiliation(s)
- Thomas S Collett
- School of Biological Sciences, University of Sussex, Brighton BN1 9QG, UK.
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