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Fernández Y, Dowdy NJ, Conner WE. High duty cycle moth sounds jam bat echolocation: bats counter with compensatory changes in buzz duration. J Exp Biol 2022; 225:jeb244187. [PMID: 36111562 PMCID: PMC9637272 DOI: 10.1242/jeb.244187] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 08/23/2022] [Indexed: 10/05/2023]
Abstract
Tiger moth species vary greatly in the number of clicks they produce and the resultant duty cycle. Signals with higher duty cycles are expected to more effectively interfere with bat sonar. However, little is known about the minimum duty cycle of tiger moth signals for sonar jamming. Is there a threshold that allows us to classify moths as acoustically aposematic versus sonar jammers based on their duty cycles? We performed playback experiments with three wild-caught adult male bats, Eptesicus fuscus. Bat attacks on tethered moths were challenged using acoustic signals of Bertholdia trigona with modified duty cycles ranging from 0 to 46%. We did not find evidence for a duty cycle threshold; rather, the ability to jam the bat's sonar was a continuous function of duty cycle consistent with a steady increase in the number of clicks arriving during a critical signal processing time window just prior to the arrival of an echo. The proportion of successful captures significantly decreased as the moth duty cycle increased. Our findings suggest that moths cannot be unambiguously classified as acoustically aposematic or sonar jammers based solely on duty cycle. Bats appear to compensate for sonar jamming by lengthening the duration of their terminal buzz and they are more successful in capturing moths when they do so. In contrast to previous findings for bats performing difficult spatial tasks, the number of sonar sound groups decreased in response to high duty cycles and did not affect capture success.
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Affiliation(s)
- Yohami Fernández
- Department of Biology, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, NC 27109, USA
| | - Nicolas J. Dowdy
- Department of Biology, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, NC 27109, USA
- Department of Zoology, Milwaukee Public Museum, 800 West Wells Street, Milwaukee, WI 53233, USA
| | - William E. Conner
- Department of Biology, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, NC 27109, USA
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2
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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: 13] [Impact Index Per Article: 4.3] [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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3
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Bombaci SP, Russell RE, St. Germain MJ, Dobony CA, Ford WM, Loeb SC, Jachowski DS. Context dependency of disease‐mediated competitive release in bat assemblages following white‐nose syndrome. Ecosphere 2021. [DOI: 10.1002/ecs2.3825] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Sara P. Bombaci
- Department of Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins Colorado 80523 USA
| | - Robin E. Russell
- U.S. Geological Survey National Wildlife Health Center 6006 Schroeder Road Madison Wisconsin 53711 USA
| | | | - Christopher A. Dobony
- Fort Drum Military Installation Natural Resources Branch IMNE‐DRM‐PWE Building T‐4848 Delahanty Avenue Fort Drum New York 13602 USA
| | - W. Mark Ford
- U.S. Geological Survey Virginia Cooperative Fish and Wildlife Research Unit Blacksburg Virginia 24061 USA
| | - Susan C. Loeb
- U.S. Forest Service Southern Research Station Clemson South Carolina 29634 USA
| | - David S. Jachowski
- Department of Forestry and Environmental Conservation Clemson University Clemson South Carolina 29631 USA
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4
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Alcázar-Treviño J, Johnson M, Arranz P, Warren VE, Pérez-González CJ, Marques T, Madsen PT, Aguilar de Soto N. Deep-diving beaked whales dive together but forage apart. Proc Biol Sci 2021; 288:20201905. [PMID: 33402065 DOI: 10.1098/rspb.2020.1905] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Echolocating animals that forage in social groups can potentially benefit from eavesdropping on other group members, cooperative foraging or social defence, but may also face problems of acoustic interference and intra-group competition for prey. Here, we investigate these potential trade-offs of sociality for extreme deep-diving Blainville's and Cuvier's beaked whales. These species perform highly synchronous group dives as a presumed predator-avoidance behaviour, but the benefits and costs of this on foraging have not been investigated. We show that group members could hear their companions for a median of at least 91% of the vocal foraging phase of their dives. This enables whales to coordinate their mean travel direction despite differing individual headings as they pursue prey on a minute-by-minute basis. While beaked whales coordinate their echolocation-based foraging periods tightly, individual click and buzz rates are both independent of the number of whales in the group. Thus, their foraging performance is not affected by intra-group competition or interference from group members, and they do not seem to capitalize directly on eavesdropping on the echoes produced by the echolocation clicks of their companions. We conclude that the close diving and vocal synchronization of beaked whale groups that quantitatively reduces predation risk has little impact on foraging performance.
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Affiliation(s)
- Jesús Alcázar-Treviño
- BIOECOMAC, Departamento de Biología Animal, Edafología y Geología, Universidad de La Laguna (ULL), Avenida Astrofísico F. Sánchez, s/n. 38206, San Cristóbal de La Laguna (Tenerife), Spain
| | - Mark Johnson
- Aarhus Institute of Advanced Studies, Aarhus University, Høegh-Guldbergs Gade 6B, 8000, Aarhus C, Denmark
| | - Patricia Arranz
- BIOECOMAC, Departamento de Biología Animal, Edafología y Geología, Universidad de La Laguna (ULL), Avenida Astrofísico F. Sánchez, s/n. 38206, San Cristóbal de La Laguna (Tenerife), Spain.,Centre for Research into Ecological and Environmental Modelling, University of St Andrews, Fife, KY16 8LB, UK
| | - Victoria E Warren
- Institute of Marine Science, Leigh Marine Laboratory, University of Auckland, 160 Goat Island Road, Leigh 0985, New Zealand
| | - Carlos J Pérez-González
- Departamento de Matemáticas, Estadística e Investigación Operativa, Universidad de La Laguna (ULL), Avenida Astrofísico F. Sánchez, s/n. 38206, San Cristóbal de La Laguna (Tenerife), Spain
| | - Tiago Marques
- Centre for Research into Ecological and Environmental Modelling, University of St Andrews, Fife, KY16 8LB, UK.,Departamento de Biologia Animal, Centro de Estatística e Aplicações, Faculdade de Ciências, Universidade de Lisboa, Bloco C6 - Piso 4, Campo Grande, 1749-016 Lisboa, Portugal
| | - Peter T Madsen
- Zoophysiology, Department of Biology, Aarhus University, C.F. Moellers Allé 3, 8000, Aarhus C, Denmark
| | - Natacha Aguilar de Soto
- BIOECOMAC, Departamento de Biología Animal, Edafología y Geología, Universidad de La Laguna (ULL), Avenida Astrofísico F. Sánchez, s/n. 38206, San Cristóbal de La Laguna (Tenerife), Spain
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5
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Jones TK, Conner WE. The jamming avoidance response in echolocating bats. Commun Integr Biol 2019; 12:10-13. [PMID: 30891113 PMCID: PMC6419628 DOI: 10.1080/19420889.2019.1568818] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Accepted: 01/09/2019] [Indexed: 10/29/2022] Open
Abstract
Bats face many sources of acoustic interference in their natural environments, including other bats and potential prey items that affect their ability to interpret the returning echoes of their biosonar signals. To be able to navigate and forage successfully, bats must be able to counteract this interference and one of the ways they achieve this is by altering the various parameters of their echolocation. We describe these changes in signal design within the context of a modified definition of the jamming avoidance response originally applied to the signal changes of weakly electric fish. Both of these groups use active sensory systems that exhibit similarities in function but we take this opportunity to highlight major differences each groups' response to signal interference. These discrepancies form the basis of our need for an expanded description of the jamming avoidance response in echolocating bats.
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Affiliation(s)
- Te K Jones
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - William E Conner
- Department of Biology, Wake Forest University, Winston-Salem, NC, USA
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Kloepper LN, Branstetter BK. The effect of jamming stimuli on the echolocation behavior of the bottlenose dolphin, Tursiops truncatus. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 145:1341. [PMID: 31067932 DOI: 10.1121/1.5093636] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 02/22/2019] [Indexed: 06/09/2023]
Abstract
Echolocating bats and odontocetes face the potential challenge of acoustic interference from neighbors, or sonar jamming. To counter this, many bat species have adapted jamming avoidance strategies to improve signal detection, but any such avoidance strategies in dolphins is unknown. This study provides an investigation into whether dolphins modify echolocation behavior during jamming scenarios. Recorded echolocation clicks were projected at different click repetition rates and at different aspect angles relative to two dolphins' heads while each dolphin was performing a target detection task. Changes in the timing, amplitude, and frequency of structure of the dolphin's emitted signals were compared to determine if and how dolphins modify echolocation when faced with potentially interfering conspecific echolocation signals. The results indicate that both dolphins demonstrated different responses when faced with jamming scenarios, which may reflect optimal strategies according to individual auditory perception abilities.
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Affiliation(s)
- Laura N Kloepper
- Department of Biology, Saint Mary's College, Notre Dame, Indiana 46556, USA
| | - Brian K Branstetter
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106, USA
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Song S, Lin A, Jiang T, Zhao X, Metzner W, Feng J. Bats adjust temporal parameters of echolocation pulses but not those of communication calls in response to traffic noise. Integr Zool 2019; 14:576-588. [PMID: 30811841 PMCID: PMC6900015 DOI: 10.1111/1749-4877.12387] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Many studies based on acute short‐term noise exposure have demonstrated that animals can adjust their vocalizations in response to ambient noise. However, the effects of chronic noise over a relatively long time scale of multiple days remain largely unclear. Bats rely mainly on acoustic signals for perception of environmental and social communication. Nearly all previous studies on noise‐induced vocal adjustments have focused on echolocation pulse sounds. Relatively little is known regarding the effects of noise on social communication calls. Here, we examined the dynamic changes in the temporal parameters of echolocation and communication vocalizations of Vespertilio sinensis when exposed to traffic noise over multiple days. We found that the bats started to modify their echolocation vocalizations on the fourth day of noise exposure, with an increase of 42–91% in the total number of pulse sequences per day. Under noisy conditions, the number of pulses within a pulse sequence decreased by an average of 17.2%, resulting in a significantly slower number of pulses/sequence (P < 0.001). However, there was little change in the duration of a pulse sequence. These parameters were not significantly adjusted in most communication vocalizations under the noise condition (all P > 0.05), except that the duration decreased and the number of syllables/sequences increased in 1 type of communicative vocalization (P < 0.05). This study suggests that bats routinely adjust temporal parameters of echolocation but rarely of communication vocalizations in response to noise condition.
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Affiliation(s)
- Shengjing Song
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, Jilin, China
| | - Aiqing Lin
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, Jilin, China
| | - Tinglei Jiang
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, Jilin, China
| | - Xin Zhao
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, Jilin, China
| | - Walter Metzner
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, Jilin, China.,Department of Integrative Biology and Physiology, University of California, Los Angeles, California, USA
| | - Jiang Feng
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, Jilin, China.,College of Life Science, Jilin Agricultural University, Changchun, Jilin, China
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Affiliation(s)
- Yann Gager
- Department of Migration and Immuno‐ecologyMax Planck Institute for Ornithology Am Obstberg 1 Radolfzell 78315 Germany
- Department of BiologyUniversity of Konstanz Konstanz 78457 Germany
- International Max Planck Research School for Organismal BiologyUniversity of Konstanz Konstanz 78457 Germany
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9
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Maitani Y, Hase K, Kobayasi KI, Hiryu S. Adaptive frequency shifts of echolocation sounds in Miniopterus fuliginosus according to the frequency-modulated pattern of jamming sounds. ACTA ACUST UNITED AC 2018; 221:jeb.188565. [PMID: 30322982 DOI: 10.1242/jeb.188565] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 10/09/2018] [Indexed: 11/20/2022]
Abstract
When flying in a group, echolocating bats have to separate their own echoes from pulses and echoes belonging to other individuals to extract only the information necessary for their own navigation. Previous studies have demonstrated that frequency-modulated (FM) bats change the terminal frequencies (TFs) of downward FM pulses under acoustic interference. However, it is not yet clear which acoustic characteristics of the jamming signals induce the TF shift according to the degree of acoustic interference. In this study, we examined changes in the acoustic characteristics of pulses emitted by Miniopterus fuliginosus while presenting jamming stimuli with different FM patterns to the bat flying alone. Bats significantly altered their TFs when responding to downward (dExp) and upward (uExp) exponential FM sounds as well as to a constant-frequency (CF) stimulus, by approximately 1-2 kHz (dExp: 2.1±0.9 kHz; uExp: 1.7±0.3 kHz; CF: 1.3±0.4 kHz) but not for linear FM sounds. The feature common to the spectra of these three jamming stimuli is a spectrum peak near the TF frequency, demonstrating that the bats shift the TF to avoid masking of jamming sounds on the TF frequency range. These results suggest that direct frequency masking near the TF frequency range induces the TF shift, which simultaneously decreases the similarity between their own echolocation sounds and jamming signals.
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Affiliation(s)
- Yosuke Maitani
- Faculty of Life and Medical Sciences, Doshisha University, 1-3 Tatara miyakodani, Kyotanabe, Kyoto 610-0321, Japan
| | - Kazuma Hase
- Faculty of Life and Medical Sciences, Doshisha University, 1-3 Tatara miyakodani, Kyotanabe, Kyoto 610-0321, Japan .,Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083, Japan
| | - Kohta I Kobayasi
- Faculty of Life and Medical Sciences, Doshisha University, 1-3 Tatara miyakodani, Kyotanabe, Kyoto 610-0321, Japan
| | - Shizuko Hiryu
- Faculty of Life and Medical Sciences, Doshisha University, 1-3 Tatara miyakodani, Kyotanabe, Kyoto 610-0321, Japan .,JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
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