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Krivoruchko K, Koblitz JC, Goldshtein A, Biljman K, Guillén-Servent A, Yovel Y. A social foraging trade-off in echolocating bats reveals that they benefit from some conspecifics but are impaired when many are around. Proc Natl Acad Sci U S A 2024; 121:e2321724121. [PMID: 39008672 DOI: 10.1073/pnas.2321724121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 05/29/2024] [Indexed: 07/17/2024] Open
Abstract
Social foraging is very common in the animal kingdom. Numerous studies have documented collective foraging in various species and many reported the attraction of various species to foraging conspecifics. It is nonetheless difficult to quantify the benefits and costs of collective foraging, especially in the wild. We examined the benefits and costs of social foraging using on-board microphones mounted on freely foraging Molossus nigricans bats. This allowed us to quantify the bats' attacks on prey and to assess their success as a function of conspecific density. We found that the bats spent most of their time foraging at low conspecific densities, during which their attacks were most successful in terms of prey items captured per time unit. Notably, their capture rate dropped when conspecific density became either too high or too low. Our findings thus demonstrate a clear social foraging trade-off in which the presence of a few conspecifics probably improves foraging success, whereas the presence of too many impairs it.
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Affiliation(s)
- Ksenia Krivoruchko
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Jens C Koblitz
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Migration, Max Planck Institute of Animal Behavior, Konstanz 78464, Germany
| | - Aya Goldshtein
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Collective Behavior, Max Planck Institute of Animal Behavior, Konstanz 78464, Germany
| | - Katarina Biljman
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Antonio Guillén-Servent
- Red de Biología y Conservación de Vertebrados, Instituto de Ecología, Xalapa 91073, Veracruz, Mexico
| | - Yossi Yovel
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- School of Mechanical Engineering, The Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
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Dietzer MT, Keicher L, Kohles JE, Hurme ER, Ruczyński I, Borowik T, Zegarek M, Choiński M, Dechmann DKN. High temporal resolution data reveal low bat and insect activity over managed meadows in central Europe. Sci Rep 2024; 14:7498. [PMID: 38553552 PMCID: PMC10980742 DOI: 10.1038/s41598-024-57915-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 03/22/2024] [Indexed: 04/02/2024] Open
Abstract
Increasing agriculture and pesticide use have led to declines in insect populations and biodiversity worldwide. In addition to insect diversity, it is also important to consider insect abundance, due to the importance of insects as food for species at higher trophic levels such as bats. We monitored spatiotemporal variation in abundance of nocturnal flying insects over meadows, a common open landscape structure in central Europe, and correlated it with bat feeding activity. Our most important result was that insect abundance was almost always extremely low. This was true regardless of management intensity of the different meadows monitored. We also found no correlation of insect abundance or the presence of insect swarms with bat feeding activity. This suggests that insect abundance over meadows was too low and insect swarms too rare for bats to risk expending energy to search for them. Meadows appeared to be poor habitat for nocturnal flying insects, and of low value as a foraging habitat for bats. Our study highlights the importance of long-term monitoring of insect abundance, especially at high temporal scales to identify and protect foraging habitats. This will become increasingly important given the rapid decline of insects.
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Affiliation(s)
- Melina T Dietzer
- Department of Biology, Universität Konstanz, Konstanz, Germany.
- Department of Migration, Max Planck Institute of Animal Behavior, Radolfzell, Germany.
- Department of Wildlife Ecology and Management, Universität Freiburg, Tennenbacherstraße 4, 79106, Freiburg, Germany.
| | - Lara Keicher
- Department of Biology, Universität Konstanz, Konstanz, Germany
- Department of Migration, Max Planck Institute of Animal Behavior, Radolfzell, Germany
| | - Jenna E Kohles
- Department of Biology, Universität Konstanz, Konstanz, Germany
- Department of Migration, Max Planck Institute of Animal Behavior, Radolfzell, Germany
| | - Edward R Hurme
- Department of Migration, Max Planck Institute of Animal Behavior, Radolfzell, Germany
- Cluster for the Advanced Study of Collective Behaviour, Universität Konstanz, Constance, Germany
| | | | | | | | - Mateusz Choiński
- Faculty of Computer Science, Bialystok University of Technology, Białystok, Poland
| | - Dina K N Dechmann
- Department of Biology, Universität Konstanz, Konstanz, Germany
- Department of Migration, Max Planck Institute of Animal Behavior, Radolfzell, Germany
- Cluster for the Advanced Study of Collective Behaviour, Universität Konstanz, Constance, Germany
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Fleming TH. Good to the Last Drop: Feeding Behavior of the Nectar Bat Leptonycteris yerbabuenae (Chiroptera, Phyllostomidae) at Hummingbird Feeders in Tucson, Arizona. ACTA CHIROPTEROLOGICA 2023. [DOI: 10.3161/15081109acc2022.24.2.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Eitan O, Taub M, Boonman A, Zviran A, Tourbabin V, Weiss AJ, Yovel Y. Echolocating bats rapidly adjust their mouth gape to control spatial acquisition when scanning a target. BMC Biol 2022; 20:282. [PMID: 36527053 PMCID: PMC9758934 DOI: 10.1186/s12915-022-01487-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 11/30/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND As well known to any photographer, controlling the "field of view" offers an extremely powerful mechanism by which to adjust target acquisition. Only a few natural sensory systems can actively control their field of view (e.g., dolphins, whales, and bats). Bats are known for their active sensing abilities and modify their echolocation signals by actively controlling their spectral and temporal characteristics. Less is known about bats' ability to actively modify their bio-sonar field of view. RESULTS We show that Pipistrellus kuhlii bats rapidly narrow their sensory field of view (i.e., their bio-sonar beam) when scanning a target. On-target vertical sonar beams were twofold narrower than off-target beams. Continuous measurements of the mouth gape of free-flying bats revealed that they control their bio-sonar beam by a ~3.6 mm widening of their mouth gape: namely, bats open their mouth to narrow the beam and vice versa. CONCLUSIONS Bats actively and rapidly control their echolocation vertical beam width by modifying their mouth gape. We hypothesize that narrowing their vertical beam narrows the zone of ensonification when estimating the elevation of a target. In other words, bats open their mouth to improve sensory localization.
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Affiliation(s)
- Ofri Eitan
- grid.12136.370000 0004 1937 0546School of Zoology, Faculty of Life Sciences, Tel Aviv University, 6997801 Tel Aviv, Israel
| | - Mor Taub
- grid.12136.370000 0004 1937 0546School of Zoology, Faculty of Life Sciences, Tel Aviv University, 6997801 Tel Aviv, Israel
| | - Arjan Boonman
- grid.12136.370000 0004 1937 0546School of Zoology, Faculty of Life Sciences, Tel Aviv University, 6997801 Tel Aviv, Israel
| | - Amir Zviran
- grid.12136.370000 0004 1937 0546School of Zoology, Faculty of Life Sciences, Tel Aviv University, 6997801 Tel Aviv, Israel ,grid.12136.370000 0004 1937 0546The School of Electrical Engineering, the Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, 6997801 Tel Aviv, Israel
| | - Vladimir Tourbabin
- grid.7489.20000 0004 1937 0511Department of Electrical and Computer Engineering, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Anthony J. Weiss
- grid.12136.370000 0004 1937 0546The School of Electrical Engineering, the Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, 6997801 Tel Aviv, Israel
| | - Yossi Yovel
- grid.12136.370000 0004 1937 0546School of Zoology, Faculty of Life Sciences, Tel Aviv University, 6997801 Tel Aviv, Israel ,grid.12136.370000 0004 1937 0546Sagol School of Neuroscience, Tel Aviv University, 6997801 Tel Aviv, Israel ,grid.12136.370000 0004 1937 0546School of Mechanical Engineering, the Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, 6997801 Tel Aviv, Israel ,grid.12136.370000 0004 1937 0546The Steinhardt Museum of Natural History, National Research Center for Biodiversity Studies, Tel-Aviv University, Tel Aviv, Israel
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Ichikawa J, Fujii K. Analysis of group behavior based on sharing heterogeneous roles in a triad using a coordinated drawing task. Front Psychol 2022; 13:890205. [DOI: 10.3389/fpsyg.2022.890205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 09/27/2022] [Indexed: 11/17/2022] Open
Abstract
Humans often share roles and aim to achieve a group goal based on sociality, which is the tendency to spontaneously involve oneself with others. Cognitive science, psychology, and neuroscience studies suggest that in such planned coordination, adjusting one’s own actions based on other roles is crucial for high task performance. However, the mechanisms of complex and dynamically planned coordination, such as non-verbal group behavior with three or more members, remain to be fully investigated. This study introduced a coordinated drawing task in a triad, quantitatively analyzed non-verbal group behavior based on sharing heterogeneous roles, and investigated an important role. Participant triads engaged in the task repeatedly by operating reels to change thread tensions and moving a pen connected to the three threads to draw an equilateral triangle. Then, the three roles (pulling, relaxing, and adjusting) had to be shared. The pulling and relaxing roles served to move the pen as if an operator pulled it closer to the hand and to support the pen’s movement, respectively. However, these roles alone could not draw a side considering the task specification. The adjusting role needed to change the tension flexibly and maintain an overall balance. In the experiment, we measured the pen positions and tensions, and established statistical models to fit the analyzed data. The results estimated that the action in the adjusting role was related to the improved performance of faster drawing on a side. This role may moderately intervene in the actions by the other roles and fine-tune without disturbing the pen’s smooth movement while avoiding great pen deviation. Our findings may suggest the crucial role as a facilitator that handles resiliently in non-verbal coordinated behavior of a triad, and contribute to our understanding of social interactions.
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Insectivorous bats form mobile sensory networks to optimize prey localization: The case of the common noctule bat. Proc Natl Acad Sci U S A 2022; 119:e2203663119. [PMID: 35939677 PMCID: PMC9388074 DOI: 10.1073/pnas.2203663119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Animals that depend on ephemeral, patchily distributed prey often use public information to locate resource patches. The use of public information can lead to the aggregation of foragers at prey patches, a mechanism known as local enhancement. However, when ephemeral resources are distributed over large areas, foragers may also need to increase search efficiency, and thus apply social strategies when sampling the landscape. While sensory networks of visually oriented animals have already been confirmed, we lack an understanding of how acoustic eavesdropping adds to the formation of sensory networks. Here we radio-tracked a total of 81 aerial-hawking bats at very high spatiotemporal resolution during five sessions over 3 y, recording up to 19 individuals simultaneously. Analyses of interactive flight behavior provide conclusive evidence that bats form temporary mobile sensory networks by adjusting their movements to neighboring conspecifics while probing the airspace for prey. Complementary agent-based simulations confirmed that the observed movement patterns can lead to the formation of mobile sensory networks, and that bats located prey faster when networking than when relying only on local enhancement or searching solitarily. However, the benefit of networking diminished with decreasing group size. The combination of empirical analyses and simulations elucidates how animal groups use acoustic information to efficiently locate unpredictable and ephemeral food patches. Our results highlight that declining local populations of social foragers may thus suffer from Allee effects that increase the risk of collapses under global change scenarios, like insect decline and habitat degradation.
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Jones TK, Allen KM, Moss CF. Communication with self, friends and foes in active-sensing animals. J Exp Biol 2021; 224:273391. [PMID: 34752625 DOI: 10.1242/jeb.242637] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Animals that rely on electrolocation and echolocation for navigation and prey detection benefit from sensory systems that can operate in the dark, allowing them to exploit sensory niches with few competitors. Active sensing has been characterized as a highly specialized form of communication, whereby an echolocating or electrolocating animal serves as both the sender and receiver of sensory information. This characterization inspires a framework to explore the functions of sensory channels that communicate information with the self and with others. Overlapping communication functions create challenges for signal privacy and fidelity by leaving active-sensing animals vulnerable to eavesdropping, jamming and masking. Here, we present an overview of active-sensing systems used by weakly electric fish, bats and odontocetes, and consider their susceptibility to heterospecific and conspecific jamming signals and eavesdropping. Susceptibility to interference from signals produced by both conspecifics and prey animals reduces the fidelity of electrolocation and echolocation for prey capture and foraging. Likewise, active-sensing signals may be eavesdropped, increasing the risk of alerting prey to the threat of predation or the risk of predation to the sender, or drawing competition to productive foraging sites. The evolutionary success of electrolocating and echolocating animals suggests that they effectively counter the costs of active sensing through rich and diverse adaptive behaviors that allow them to mitigate the effects of competition for signal space and the exploitation of their signals.
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Affiliation(s)
- Te K Jones
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Kathryne M Allen
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Cynthia F Moss
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
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