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Wagner T, Czaczkes TJ. Corpse-associated odours elicit avoidance in invasive ants. PEST MANAGEMENT SCIENCE 2024; 80:1859-1867. [PMID: 38041619 DOI: 10.1002/ps.7916] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 11/05/2023] [Accepted: 12/02/2023] [Indexed: 12/03/2023]
Abstract
BACKGROUND Invasive ants, such as Linepithema humile (the Argentine ant), pose a global threat, necessitating a better understanding of their behaviour in order to improve management strategies. Traditional eradication methods, including baiting, have had limited success, but the causes of control failure are not always clear. This study aims to investigate whether ants form associations between food odours and corpses, and subsequently avoid areas or food sources with food odours associated with corpses. We propose that ants may learn to avoid toxic baits in part because of their association with ant corpses, which could have implications for pest control strategies. RESULTS Ants were tested on a Y-maze after exposure to scented corpses or dummies. 69% (n = 64) of ants avoided branches bearing the scent of scented corpses. Colonies neglected food with corpse-associated odours, with only 42% (n = 273) of foragers feeding from such sources. However, if corpses were produced by feeding ants scented toxicant, focal ants encountering these corpses did not avoid the corpse-associated scent on a Y-maze (53%, n = 65). In dual-feeder tests, ants did not avoid feeding at food sources scented with odours associated with conspecific corpses. CONCLUSION Conspecific corpses act as a negative stimulus for ants in a foraging situation, potentially causing avoidance of toxic baits. This study suggests adding odours to baits and cycling them to disrupt the bait-corpse association may be helpful. Interestingly, although avoidance of baits was observed, feeding preferences were not significantly affected. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Thomas Wagner
- Animal Comparative Economics Laboratory, Faculty of Biology and Preclinical Medicine, University of Regensburg, Regensburg, Germany
| | - Tomer J Czaczkes
- Animal Comparative Economics Laboratory, Faculty of Biology and Preclinical Medicine, University of Regensburg, Regensburg, Germany
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Zanola D, Czaczkes TJ, Josens R. Ants evade harmful food by active abandonment. Commun Biol 2024; 7:84. [PMID: 38216747 PMCID: PMC10786876 DOI: 10.1038/s42003-023-05729-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 12/19/2023] [Indexed: 01/14/2024] Open
Abstract
Invasive ants, such as the Argentine ant, pose a severe economic and ecological threat. Despite advancements in baiting techniques, effectively managing established ant populations remains a daunting challenge, often ending in failure. Ant colonies employ behavioural immunity against pathogens, raising the question of whether ants can collectively respond to toxic baits. This study investigates whether ant colonies actively abandon palatable but harmful food sources. We provided two sucrose feeders, each generating a new foraging trail, with one transitioning to offering toxic food. Six hours later, ant activity on that path decreases, while activity on the non-toxic food and the trunk trail remains unaffected, excluding factors like population decline or satiation as reasons for the activity decline. Laboratory experiments confirmed that ants remained alive six hours after ingesting toxic food. Ant presence remains low on the toxic food path for days, gradually decreasing along the nearest section of the trunk trail. This abandonment behaviour minimises the entry of harmful food into the nest, acting as a protective social mechanism. The evasion of toxic bait-treated areas likely contributes considerably to control failures. Understanding the behavioural response to toxic baits is essential for developing effective strategies to combat invasive ant species.
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Affiliation(s)
- Daniel Zanola
- Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE, CONICET, Ciudad Universitaria (C1428EHA), Buenos Aires, Argentina
| | - Tomer J Czaczkes
- Animal Comparative Economics Laboratory, Faculty of Biology and Preclinical Medicine, University of Regensburg, Universitaetsstrasse 31, 93053, Regensburg, Germany
| | - Roxana Josens
- Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE, CONICET, Ciudad Universitaria (C1428EHA), Buenos Aires, Argentina.
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3
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Xu 徐焕 H, Huang 黄求应 Q, Gao 高勇勇 Y, Wu 吴佳 J, Hassan A, Liu 刘昱彤 Y. IDH knockdown alters foraging behavior in the termite Odontotermes formosanus in different social contexts. Curr Zool 2021; 67:609-620. [PMID: 34805537 PMCID: PMC8599053 DOI: 10.1093/cz/zoab032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 04/01/2021] [Indexed: 11/16/2022] Open
Abstract
Foraging, as an energy-consuming behavior, is very important for colony survival in termites. How energy metabolism related to glucose decomposition and adenosine triphosphate (ATP) production influences foraging behavior in termites is still unclear. Here, we analyzed the change in energy metabolism in the whole organism and brain after silencing the key metabolic gene isocitrate dehydrogenase (IDH) and then investigated its impact on foraging behavior in the subterranean termite Odontotermes formosanus in different social contexts. The IDH gene exhibited higher expression in the abdomen and head of O. formosanus. The knockdown of IDH resulted in metabolic disorders in the whole organism. The dsIDH-injected workers showed significantly reduced walking activity but increased foraging success. Interestingly, IDH knockdown altered brain energy metabolism, resulting in a decline in ATP levels and an increase in IDH activity. Additionally, the social context affected brain energy metabolism and, thus, altered foraging behavior in O. formosanus. We found that the presence of predator ants increased the negative influence on the foraging behavior of dsIDH-injected workers, including a decrease in foraging success. However, an increase in the number of nestmate soldiers could provide social buffering to relieve the adverse effect of predator ants on worker foraging behavior. Our orthogonal experiments further verified that the role of the IDH gene as an inherent factor was dominant in manipulating termite foraging behavior compared with external social contexts, suggesting that energy metabolism, especially brain energy metabolism, plays a crucial role in regulating termite foraging behavior.
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Affiliation(s)
- Huan Xu 徐焕
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Qiuying Huang 黄求应
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Yongyong Gao 高勇勇
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Jia Wu 吴佳
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Ali Hassan
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Yutong Liu 刘昱彤
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, Hubei 430070, China
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4
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Inhibition of serotonergic signaling induces higher consumption of both sucrose solution and toxic baits in carpenter ants. Sci Rep 2021; 11:19176. [PMID: 34584123 PMCID: PMC8478936 DOI: 10.1038/s41598-021-98030-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 09/02/2021] [Indexed: 11/08/2022] Open
Abstract
Biogenic amines play an important role in the regulation of appetitive responses in insects. Among them, serotonin (5-HT) regulates feeding-related processes in numerous insect species. In carpenter ants, 5-HT administration has been shown to depress feeding behavior, thus opening the possibility of using 5-HT modulation in control strategies against those species considered as pest. Here we studied if administration of a 5-HT antagonist, ketanserin, promotes feeding of a sucrose solution and a toxic bait in carpenter ants Camponotus mus. We found that 3 h after a single oral administration of ketanserin, the mass of sucrose solution consumed by carpenter ants increased significantly. A similar effect was found after a chronic administration that lasted 5 days. Yet, ketanserin did neither affect the intake rates nor the activity of the pharyngeal pump that mediates feeding dynamics. In addition, ketanserin promoted the consumption of a toxic bait based on boric acid. Our results thus show that feeding motivation and consumption of both sucrose solution and a toxic bait can be enhanced via prior administration of ketanserin. We discuss the possible mechanisms underlying these effects and conclude that understanding basic physiological and neural principles that underlie feeding motivation allows establishing more efficient control strategies for pest insects.
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Bytheway JP, Johnstone KC, Price CJ, Banks PB. A mechanistic understanding of prebaiting to improve interaction with wildlife management devices. PEST MANAGEMENT SCIENCE 2021; 77:3107-3115. [PMID: 33638268 DOI: 10.1002/ps.6343] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 02/10/2021] [Accepted: 02/26/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Prebaiting is a technique involving early deployment of 'unarmed' devices (e.g. baits and traps) to increase efficacy of wildlife management. Although commonly used, the mechanisms by which prebaiting works are poorly understood. We propose three mechanisms by which prebaiting may increase device interaction probabilities; (1) overcoming neophobia towards novel devices, (2) a 'trickle in' effect increasing time for animals to encounter devices; and (3) social information transfer about rewards associated with devices. We conducted a survey of 100 articles to understand how prebaiting has been used. We then tested our proposed prebaiting mechanisms using a global pest (black rats, Rattus rattus) examining how uniquely marked free-living rats responded to a common yet novel monitoring technique (tracking tunnels). RESULTS No studies in our dataset tested how prebaiting functioned. Most studies (61%) did not propose a mechanism for prebaiting, but overcoming neophobia was most commonly mentioned. We only found partial support for the overcoming neophobia hypothesis in our field test. We found the dominant mechanism operating in our system to be the 'trickle in' effect with the proportion of individuals visiting the device increasing over time. We found no support for social information transfer as a mechanism of prebaiting. CONCLUSION Applying a mechanistic understanding of how prebaiting functions will improve the efficacy of management devices. Our results suggest that prebaiting allows time for more rats to encounter a device, hence surveys in our system would benefit from long prebaiting periods. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Jenna P Bytheway
- School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
| | - Kyla C Johnstone
- School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
| | - Catherine J Price
- School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
| | - Peter B Banks
- School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
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Rossi N, Pereyra M, Moauro MA, Giurfa M, d'Ettorre P, Josens R. Trail pheromone modulates subjective reward evaluation in Argentine ants. J Exp Biol 2020; 223:jeb230532. [PMID: 32680904 DOI: 10.1242/jeb.230532] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 07/15/2020] [Indexed: 12/13/2022]
Abstract
The Argentine ant, Linepithema humile, is native to South America but has become one of the most invasive species in the world. These ants heavily rely on trail pheromones for foraging, and previous studies have focused on such signals to develop a strategy for chemical control. Here, we studied the effects of pre-exposure to the trail pheromone on sugar acceptance and olfactory learning in Argentine ants. We used the synthetic trail pheromone component (Z)-9-hexadecenal, which triggers the same attraction and trail-following behavior as the natural trail pheromone. We found that pre-exposure to (Z)-9-hexadecenal increases the acceptance of sucrose solutions of different concentrations, thus changing the ants' subjective evaluation of a food reward. However, although ants learned to associate an odor with a sucrose reward, pheromone pre-exposure affected neither the learning nor the mid-term memory of the odor-reward association. Taking into account the importance of the Argentine ant as a pest and invasive organism, our results highlight the importance of pheromonal cues in resource evaluation, a fact that could be useful in control strategies implemented for this species.
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Affiliation(s)
- Natacha Rossi
- Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE, CONICET, Ciudad Universitaria Pab. II. (C1428 EHA), Buenos Aires, Argentina
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, F-31062 Toulouse Cedex 09, France
| | - Muriel Pereyra
- Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE, CONICET, Ciudad Universitaria Pab. II. (C1428 EHA), Buenos Aires, Argentina
| | - Mariel A Moauro
- Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE, CONICET, Ciudad Universitaria Pab. II. (C1428 EHA), Buenos Aires, Argentina
| | - Martin Giurfa
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, F-31062 Toulouse Cedex 09, France
- Institut Universitaire de France (IUF), Paris, France
| | - Patrizia d'Ettorre
- Laboratory of Experimental and Comparative Ethology, UR4443, University Sorbonne Paris Nord, Villetaneuse, France
- Institut Universitaire de France (IUF), Paris, France
| | - Roxana Josens
- Laboratorio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IFIBYNE, CONICET, Ciudad Universitaria Pab. II. (C1428 EHA), Buenos Aires, Argentina
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Czaczkes TJ, Beckwith JJ, Horsch AL, Hartig F. The multi-dimensional nature of information drives prioritization of private over social information in ants. Proc Biol Sci 2019; 286:20191136. [PMID: 31431163 DOI: 10.1098/rspb.2019.1136] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
When personally gathered and socially acquired information conflict, animals often prioritize private information. We propose that this is because private information often contains details that social information lacks. We test this idea in an ant model. Ants using a food source learn its location and quality rapidly (private information), whereas pheromone trails (social information) provide good directional information, but lack reliable information about food quality. If this lack is indeed responsible for the choice of memory over pheromone trails, adding information that better food is available should cause foragers to switch their priority to social information. We show it does: while ants follow memory rather than pheromones when they conflict, adding unambiguous information about a better potential food source (a 2 µl droplet of good food) reverses this pattern, from 60% of ants following their memory to 75% following the pheromone trail. Using fluorescence microscopy, we demonstrate that food (and thus information) flows from fed workers to outgoing foragers, explaining the frequent contacts of ants on trails. Ants trained to poor food that contact nest-mates fed with good food are more likely to follow a trail than ants which received information about poor food. We conclude that social information may often be ignored because it lacks certain crucial dimensions, suggesting that information content is crucial for understanding how and when animals prioritize social and private information.
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Affiliation(s)
- Tomer J Czaczkes
- Institute of Zoology, University of Regensburg, 93053 Regensburg, Germany
| | - John J Beckwith
- Institute of Zoology, University of Regensburg, 93053 Regensburg, Germany.,Department of Zoology, University of Oxford, Oxford OX13PS, UK
| | - Anna-Lena Horsch
- Institute of Zoology, University of Regensburg, 93053 Regensburg, Germany
| | - Florian Hartig
- Theoretical Ecology, University of Regensburg, 93053 Regensburg, Germany
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Wendt S, Strunk KS, Heinze J, Roider A, Czaczkes TJ. Positive and negative incentive contrasts lead to relative value perception in ants. eLife 2019; 8:e45450. [PMID: 31262401 PMCID: PMC6606023 DOI: 10.7554/elife.45450] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 05/30/2019] [Indexed: 11/30/2022] Open
Abstract
Humans usually assess things not according to their absolute value, but relative to reference points - a main tenant of Prospect Theory. For example, people rate a new salary relative to previous salaries and salaries of their peers, rather than absolute income. We demonstrate a similar effect in an insect: ants expecting to find low-quality food showed higher acceptance of medium-quality food than ants expecting medium quality, and vice versa for high expectations. Further experiments demonstrate that these contrast effects arise from cognitive rather than mere sensory or pre-cognitive perceptual causes. Social information gained inside the nest can also serve as a reference point: the quality of food received from other ants affected the perceived value of food found later. Value judgement is a key element in decision making, and thus relative value perception strongly influences which option is chosen and ultimately how all animals make decisions.
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Affiliation(s)
- Stephanie Wendt
- Animal Comparative Economics Laboratory, Institute of Zoology and Evolutionary BiologyUniversity of RegensburgRegensburgGermany
| | - Kim S Strunk
- School of Business, Economics and Information Systems, Chair of Management, People and InformationUniversity of PassauPassauGermany
| | - Jürgen Heinze
- Institute of Zoology and Evolutionary BiologyUniversity of RegensburgRegensburgGermany
| | - Andreas Roider
- Department of EconomicsUniversity of RegensburgRegensburgGermany
| | - Tomer J Czaczkes
- Animal Comparative Economics Laboratory, Institute of Zoology and Evolutionary BiologyUniversity of RegensburgRegensburgGermany
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Lim H, Choi J, Song W, Lee SI, Jablonski PG. Collecting, discarding, and re-collecting of protein-rich food in a natural colony of Camponotus japonicus. J ETHOL 2019. [DOI: 10.1007/s10164-019-00607-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Oberhauser FB, Czaczkes TJ. Tasting the unexpected: disconfirmation of expectations leads to lower perceived food value in an invertebrate. Biol Lett 2018; 14:20180440. [PMID: 30185610 PMCID: PMC6170749 DOI: 10.1098/rsbl.2018.0440] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 08/07/2018] [Indexed: 11/12/2022] Open
Abstract
To make sensible decisions, both humans and other animals must compare the available options against a reference point-either other options or previous experience. Options of higher quality than the reference are considered good value. However, many perceptible attributes of options are value-neutral, such as flower scent. Nonetheless, such value-neutral differences may be part of an expectation. Can a mismatch between the expectation and experience of value-neutral attributes affect perceived value? Consumer psychology theory and results suggest it can. To test this in a non-human animal, we manipulated a value-neutral aspect of a food source-its taste-while keeping its absolute value-its sweetness-the same. Individual ants (Lasius niger) were allowed to drink either lemon- or rosemary-flavoured 1 M sucrose. After three successive visits to the food, we switched the taste in the last, fourth, visit to induce a disconfirmation of expectations. In control trials, ants received the same taste on all four visits. Disconfirmed ants showed lower food acceptance and laid less pheromone on the way back to the nest, even though the molarity of the food was unchanged. As ants recruit nest-mates via pheromone depositions, fewer depositions indicate that the ants valued the food less. Thus, an expectation of value-neutral attributes can influence the perceived value of a resource. Such influences of value-neutral variables on value perception may affect how animals interact with and exploit their environment, and may contribute to phenomena such as flower constancy.
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Affiliation(s)
- F B Oberhauser
- Animal Comparative Economics Laboratory, Department of Zoology and Evolutionary Biology, University of Regensburg, Regensburg 93053, Germany
| | - T J Czaczkes
- Animal Comparative Economics Laboratory, Department of Zoology and Evolutionary Biology, University of Regensburg, Regensburg 93053, Germany
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Abstract
Decision-making in uncertain environments requires animals to evaluate, contrast and integrate various information sources to choose appropriate actions. In consensus-making groups, quorum responses are commonly used to combine private and social information, leading to both robust and flexible decisions. Here we show that in house-hunting ant colonies, individuals fine-tune the parameters of their quorum responses depending on their private knowledge: informed ants evaluating a familiar new nest rely relatively more on social than private information when the certainty of their private information is low, and vice versa. This indicates that the ants follow a highly sophisticated ‘copy-when-uncertain’ social learning strategy similar to that observed in a few vertebrate species. Using simulations, we further show that this strategy improves colony performance during emigrations and confers well-informed individuals more weight in the decision process, thus representing a novel mechanism for the emergence of leadership in collective decision-making.
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