scholarly journals Hard limits to cognitive flexibility: ants can learn to ignore but not avoid pheromone trails

2021 ◽  
Author(s):  
Katharina Wenig ◽  
Richard Bach ◽  
Tomer J. Czaczkes
Keyword(s):  
Cognitive Flexibility ◽  
Negative Stimulus ◽  
Lasius Niger ◽  
Pheromone Trails ◽  
Social Signal ◽  
Y Maze ◽  
Hard Limit ◽  
Learning Flexibility ◽  
Pheromone Trail ◽  
Innate Tendency

Learning allows animals to respond to changes in their environment within their lifespan. However, many responses to the environment are innate, and need not be learned. Depending on the level of cognitive flexibility an animal shows, such responses can either be modified by learning or not. Many ants deposit pheromone trails to resources, and innately follow such trails. Here, we investigated cognitive flexibility in the ant Lasius niger by asking whether ants can overcome their innate tendency and learn to avoid conspecific pheromone trails when these predict a negative stimulus. Ants were allowed to repeatedly visit a Y-maze, one arm of which was marked with a strong but realistic pheromone trail and led to a punishment (electroshock and/or quinine solution), and the other arm of which was unmarked and led to a 1 M sucrose reward. After circa 10 trials ants stopped relying on the pheromone trail, but even after 25 exposures they failed to improve beyond chance levels. However, the ants did not choose randomly: rather, most ants begun to favour just one side of the Y-maze, a strategy which resulted in more efficient food retrieval over time, when compared to the first visits. Even when trained in a go/no-go paradigm which precludes side bias development, ants failed to learn to avoid a pheromone trail. These results show rapid learning flexibility towards an innate social signal, but also demonstrate a rarely seen hard limit to this flexibility.

Pheromone trailing in male European whip snake, Hierophis viridiflavus

2007 ◽  
Vol 28 (4) ◽  
pp. 555-559 ◽  
Author(s):  
Marco Zuffi ◽  
Elisa Bresciani ◽  
Sara Fornasiero ◽  
Federica Dendi
Keyword(s):  
Chemical Communication ◽  
Breeding Season ◽  
Chemical Cues ◽  
Adult Males ◽  
Sexual Discrimination ◽  
Pheromone Trails ◽  
Y Maze ◽  
Communication Ability ◽  
Pheromone Trail ◽  
Whip Snake

Abstract The ability of snakes to follow conspecific pheromone trails during the breeding season is of primary importance to locate potential mates, and also to elicit and maintain courtship or other reproductive behaviours, such as agonistic behaviour. Despite the recent increased knowledge on snake chemical ecology, yet little information is available on European species and nothing is known about chemical communication in European colubrid species. The aim of this study was to characterise the pheromone-mediated trailing behaviour in male European whip snake, Hierophis viridiflavus. When tested in trailing experiments using a Y-maze, male European whip snakes displayed the ability to trail both male and female pheromones when presented versus a blank arm of the maze. Moreover, adult males followed the female pheromone trail when presented simultaneously with the male trail. Our study demonstrated that male Hierophis viridiflavus rely on chemical cues for the location and the sexual discrimination of conspecifics during the breeding season. Convergence between different mating systems and chemical communication ability in distantly related species is discussed.

scholarly journals Mate-finding behaviour in Calanus marshallae Frost

1998 ◽  
Vol 353 (1369) ◽  
pp. 713-720 ◽  
Author(s):  
Atsushi Tsuda ◽  
Charles B. Miller
Keyword(s):  
Initial Contact ◽  
Mate Finding ◽  
Pheromone Trails ◽  
Spermatophore Transfer ◽  
Calanus Marshallae ◽  
Pheromone Trail

Mate-finding behaviour by Calanus marshallae Frost, 1974, was observed and video recorded in a 1 m diameter kreisel. Newly moulted females signal to males by depositing vertical pheromone trails many tens of centimetres long. Males search for trails along primarily horizontal trajectories. The orthogonality of signal trace and search trail trajectory maximizes the chance of intersection. Males often initiate a dance of rapid, tight turns upon encountering a pheromone trail, then waggle down it (chase swimming) to the signalling female. She jumps away after initial contact, and the male follows. Many successive approach, bump and jump sequences follow, with mating eventually ensuing. The actual copulatory clasp and spermatophore transfer were not observed, although a few instances of brief attachment and tandem swimming were seen. Male dances occur at times when chase swimming does not follow, and the function of dances is not yet known.

Rapid up- and down-regulation of pheromone signalling due to trail crowding in the ant Lasius niger

Behaviour ◽  
2014 ◽  
Vol 151 (5) ◽  
pp. 669-682 ◽  
Author(s):  
Tomer J. Czaczkes ◽  
Christoph Grüter ◽  
Francis L.W. Ratnieks
Keyword(s):  
Cuticular Hydrocarbons ◽  
Social Insects ◽  
Glass Beads ◽  
Lasius Niger ◽  
Base Line ◽  
Baseline Levels ◽  
Line Level ◽  
Pheromone Signalling ◽  
Repeat Visits ◽  
Pheromone Trail

Social insects often respond to signals and cues from nest-mates, and these responses may include changes in the information they, in turn, transmit. During foraging, Lasius niger deposits a pheromone trail to recruit nestmates, and ants that experience trail crowding deposit pheromone less often. Less studied, however, is the time taken for signalling to revert to baseline levels after conditions have returned to baseline levels. In this paper we study the behaviour of L. niger foragers on a trail in which crowding is simulated by using dummy ants — black glass beads coated in nestmate cuticular hydrocarbons. Ants were allowed to make four repeat visits to a feeder with dummy ants, and thus crowding, being present on the trail on all visits (CCCC), none (UUUU) or only the first two (CCUU). If dummy ants were always present (CCCC), pheromone deposition probability was low in the first two visits (54% of ants deposited pheromone) and remained low in visits 3 and 4 (51%). If dummy ants were never present (UUUU) pheromone deposition probability was high in the first two visits (93%) and remained high in visits 3 and 4 (83%). If dummy ants were present on the first two visits but removed on the second two visits (CCUU) pheromone deposition probability was low in the first two visits (61%) but rose in the second two visits (69%). This demonstrates that even after pheromone deposition has been down-regulated due to crowding in the first two visits, it is rapidly up-regulated when crowding is reduced, although it does not immediately return to the base line level.

scholarly journals Irrational risk aversion in ants is driven by perceptual mechanisms

2019 ◽  
Author(s):  
Massimo De Agrò ◽  
Daniel Grimwade ◽  
Tomer J. Czaczkes
Keyword(s):  
Risk Aversion ◽  
Sucrose Solution ◽  
Risk Preference ◽  
Lasius Niger ◽  
Risk Sensitivity ◽  
Eusocial Insects ◽  
Collective Decisions ◽  
Y Maze ◽  
Equal Chance ◽  
Driving Risk

AbstractAnimals must often decide between exploiting safe options or risky options with a chance for large gains. While traditional optimal foraging theories assume rational energy maximisation, they fail to fully describe animal behaviour. A logarithmic rather than linear perception of stimuli may shape preference, causing animals to make suboptimal choices. Budget-based rules have also been used to explain risk-preference, and the relative importance of these theories is debated. Eusocial insects represent a special case of risk sensitivity, as they must often make collective decisions based on resource evaluations from many individuals. Previously, colonies of the ant Lasius niger were found to be risk-neutral, but the risk preference of individual foragers was unknown. Here, we tested individual L. niger in a risk sensitivity paradigm. Ants were trained to associate a scent with 0.55M sucrose solution and another scent with an equal chance of either 0.1 and 1.0M sucrose. Preference was tested in a Y-maze. Ants were extremely risk averse, with 91% choosing the safe option. Even when the risky option offered on average more sucrose (0.8M) than the fixed option, 75% preferred the latter. Based on the psychophysical Weber-Fechner law, we predicted that logarithmically balanced alternatives (0.3M vs 0.1M/0.9M) would be perceived as having equal value. Our prediction was supported, with ants having no preference for either feeder (53% chose the fixed option). Our results thus strongly support perceptual mechanisms driving risk-aversion in ants, and demonstrate that the behaviour of individual foragers can be a very poor predictor of colony-level behaviour.

scholarly journals Same length, different shapes: ants collectively choose a straight foraging path over a bent one

2018 ◽  
Vol 14 (3) ◽  
pp. 20180070 ◽  
Author(s):  
Olivier Bles ◽  
Thibault Boehly ◽  
Jean-Louis Deneubourg ◽  
Stamatios C. Nicolis
Keyword(s):  
Food Source ◽  
Abrupt Change ◽  
Food Sources ◽  
Lasius Niger ◽  
Straight Path ◽  
Change Of Direction ◽  
Collective Decisions ◽  
Different Shapes ◽  
Theoretical Results ◽  
Pheromone Trail

In socials insects, exploration is fundamental for the discovery of food resources and determines decision-making. We investigated how the interplay between the physical characteristics of the paths leading to food sources and the way it impacts the behaviour of individual ants affects their collective decisions. Colonies of different sizes of Lasius niger had access to two equal food sources through two paths of equal length but of different geometries: one was straight between the nest and the food source, and the other involved an abrupt change of direction at the midway point (135°). Both food sources were discovered simultaneously, but the food source at the end of the straight path was preferentially exploited by ants. Based on experimental and theoretical results, we show that a significantly shorter duration of nestbound travel on the straight path, which rapidly leads to a stronger pheromone trail, is at the origin of this preference.

scholarly journals Rotating panoramic view: interaction between visual and olfactory cues in ants

2016 ◽  
Vol 3 (1) ◽  
pp. 150426 ◽  
Author(s):  
Mai Minoura ◽  
Kohei Sonoda ◽  
Tomoko Sakiyama ◽  
Yukio-Pegio Gunji
Keyword(s):  
Rotational Speed ◽  
Path Integration ◽  
Visual Input ◽  
Olfactory Cues ◽  
Lasius Niger ◽  
Panoramic View ◽  
Multiple Strategies ◽  
Rotating Table ◽  
Pheromone Trail

Insects use a navigational toolkit consisting of multiple strategies such as path integration, view-dependent recognition methods and olfactory cues. The question arises as to how directional cues afforded by a visual panorama combine with olfactory cues from a pheromone trail to guide ants towards their nest. We positioned a garden ant Lasius niger on a rotating table, whereon a segment of a pheromone trail relative to the stationary panorama was rotated while the ant walked along the trail towards its nest. The rotational speed of the table (3 r.p.m.) was set so that the table would rotate through about 90° by the time that an ant had walked from the start to the centre of the table. The ant completed a U-turn at about this point and so travelled in a nest-ward direction without leaving the trail. These results suggest that the ants persist on the pheromone trail and use visual input to determine their direction of travel along the trail.

scholarly journals The Development and Diversity of Cognitive Flexibility: Greater Cultural Variation in Early Rule Switching than Word Learning

2018 ◽  
Author(s):  
Cristine Legare ◽  
Michael T. Dale ◽  
Sarah Y. Kim ◽  
Gedeon O. Deák
Keyword(s):  
South African ◽  
Cognitive Flexibility ◽  
Language Processing ◽  
Word Learning ◽  
Population Sample ◽  
Task Demands ◽  
African Children ◽  
Age Related ◽  
Learning Flexibility ◽  
South African Children

Cognitive flexibility, the adaptation of representations and responses to new task demands, improves dramatically in early childhood. It is unclear, however, whether flexibility is a coherent, unitary cognitive trait that develops similarly across populations, or is an emergent dimension of task-specific performance that varies across populations with culturally variable experiences. Children from two populations that differ in pre-formal education experiences completed two distinct tests of cognitive flexibility, matched for complexity. Three- to 5-year-old English-speaking U.S. children and Tswana-speaking South African children completed two language-processing cognitive flexibility tests: the FIM-Animates, a word-learning test, and the 3DCCS, a rule-switching test. U.S. and South African children did not differ in word-learning flexibility, showing similar age-related increases. In contrast, only U.S. preschoolers showed an age-related increase in rule-switching flexibility; South African children did not. Working memory explained additional variance in both tests, but did not modulate the interaction between population-sample and task. The data suggest that rule-switching flexibility may be more dependent upon culturally-variable educational experience, whereas word-learning flexibility may be less dependent upon culturally-specific input.

Pheromone Trail-Following Studies of Typhlopid, Leptotyphlopid, and Colubrid Snakes

Behaviour ◽  
1971 ◽  
Vol 40 (3-4) ◽  
pp. 282-294 ◽  
Author(s):  
James C. Kroll ◽  
Frederick R. Gehlbach ◽  
Julian F. Watkins
Keyword(s):  
Temperature Fluctuations ◽  
Trail Following ◽  
Same Sex ◽  
Army Ant ◽  
Pheromone Trails ◽  
Opposite Sex ◽  
Pheromone Trail

AbstractThe blind snakes, Leptotyphlops dulcis and Typhlops pusillus, readily follow pheromone trails of various ants and termites and their own trails plus those made by conspecific individuals. Conversely, the colubrid snakes, Sonora episcopa, Tantilla gracilis, and Virginia striatula, do not follow insect and snake trails as readily, although the latter two species follow army ant and earthworm trails, respectively. Army ant trails are followed much further by the blind snakes than trails of other ants. This behavior is selectively advantageous, since these trails can lead to both army ant and captured ant brood as food for the snakes. Blind snakes and colubrids follow the trails of individuals of the opposite sex further than their own trails or those of other members of the same sex. This behavior is selectively advantageous for reproduction. Also, snake trail-following may effect aggregations that conserve moisture and reduce temperature fluctuations. Pheromone trail-following in general is advantageous, as it reduces the energy spent foraging for food, shelter, and mates.

scholarly journals Negative feedback: ants choose unoccupied over occupied food sources and lay more pheromone to them

2020 ◽  
Vol 17 (163) ◽  
pp. 20190661 ◽  
Author(s):  
Stephanie Wendt ◽  
Nico Kleinhoelting ◽  
Tomer J. Czaczkes
Keyword(s):  
Food Intake ◽  
Negative Feedback ◽  
Visual Cues ◽  
Food Source ◽  
Mate Recognition ◽  
Food Sources ◽  
Lasius Niger ◽  
Surface Lipid ◽  
Feedback Systems ◽  
Pheromone Trails

In order to make effective collective decisions, ants lay pheromone trails to lead nest-mates to acceptable food sources. The strength of a trail informs other ants about the quality of a food source, allowing colonies to exploit the most profitable resources. However, recruiting too many ants to a single food source can lead to over-exploitation, queuing, and thus decreased food intake for the colony. The nonlinear nature of pheromonal recruitment can also lead colonies to become trapped in suboptimal decisions, if the environment changes. Negative feedback systems can ameliorate these problems. We investigated a potential source of negative feedback: whether the presence of nest-mates makes food sources more or less attractive. Lasius niger workers were trained to food sources of identical quality, scented with different odours. Ants fed alone at one odour. At the other odour ants fed either with other feeding nest-mates, or with dummy ants (black surface lipid-coated glass beads). Ants tended to avoid food sources at which other nest-mates were present. They also deposited less pheromone to occupied food sources, suggesting an active avoidance behaviour, and potentiating negative feedback. This effect may prevent crowding at a single food source when other profitable food sources are available elsewhere, leading to a higher collective food intake. It could also potentially protect colonies from becoming trapped in local feeding optima. However, ants did not avoid the food associated with dummy ants, suggesting that surface lipids and static visual cues alone may not be sufficient for nest-mate recognition in this context.

Combined use of pheromone trails and visual landmarks by the common garden ant Lasius niger

2008 ◽  
Vol 63 (2) ◽  
pp. 261-267 ◽  
Author(s):  
Sophie E. F. Evison ◽  
Owen L. Petchey ◽  
Andrew P. Beckerman ◽  
Francis L. W. Ratnieks
Keyword(s):  
Common Garden ◽  
Lasius Niger ◽  
Visual Landmarks ◽  
Pheromone Trails ◽  
Combined Use ◽  
The Common
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