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Wang Z, Duan P, Akamatsu T, Wang K, Wang D. Increased Yangtze finless porpoise presence in urban Wuhan waters of the Yangtze River during fishing closures. Ecol Evol 2024; 14:e11247. [PMID: 38584767 PMCID: PMC10994980 DOI: 10.1002/ece3.11247] [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: 10/16/2023] [Revised: 03/18/2024] [Accepted: 03/25/2024] [Indexed: 04/09/2024] Open
Abstract
Wuhan, a highly urbanized and rapidly growing region within China's Yangtze Economic Zone, has historically been identified as a gap area for the critically endangered Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) based on daytime visual surveys. However, there has been a noticeable increase in porpoise sightings since 2020. This study employed passive acoustic monitoring to investigate porpoise distribution in Wuhan between 2020 and 2022. Generalized linear models were used to explore the relationship between shipping, hydrological patterns, light intensity, and porpoise biosonar activity. Over 603 days of effective monitoring, the daily positive rate for porpoise biosonar detection reached 43%, with feeding-related buzz signals accounting for 55% of all porpoise biosonar signals. However, the proportion of minutes during which porpoise presence was detected was 0.18%, suggesting that while porpoises may frequent the area, their visits were brief and mainly focused on feeding. A significant temporal trend emerged, showing higher porpoise biosonar detection during winter (especially in February) and 2022. Additionally, periods without boat traffic correlated with increased porpoise activity. Hydrological conditions and light levels exhibited significant negative correlations with porpoise activity. Specifically, porpoise sonar detections were notably higher during the night, twilight, and new moon phases. It is highly conceivable that both fishing bans and COVID-19 pandemic-related lockdowns contributed to the heightened presence of porpoises in Wuhan. The rapid development of municipal transportation and shipping in Wuhan and resulting underwater noise pollution have emerged as a significant threat to the local porpoise population. Accordingly, it is imperative for regulatory bodies to effectively address this environmental stressor and formulate targeted protection measures to ensure the conservation of the finless porpoise.
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Affiliation(s)
- Zhi‐Tao Wang
- School of Marine ScienceNingbo UniversityNingboZhejiangChina
- Institute of HydrobiologyChinese Academy of SciencesWuhanChina
| | - Peng‐Xiang Duan
- Institute of HydrobiologyChinese Academy of SciencesWuhanChina
| | - Tomonari Akamatsu
- Ocean Policy Research Institutethe Sasakawa Peace FoundationMinato‐ku, TokyoJapan
| | - Ke‐Xiong Wang
- Institute of HydrobiologyChinese Academy of SciencesWuhanChina
| | - Ding Wang
- Institute of HydrobiologyChinese Academy of SciencesWuhanChina
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2
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Abildtrup Nielsen N, Dawson SM, Torres Ortiz S, Wahlberg M, Martin MJ. Hector's dolphins (Cephalorhynchus hectori) produce both narrowband high-frequency and broadband acoustic signals. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2024; 155:1437-1450. [PMID: 38364047 DOI: 10.1121/10.0024820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 01/25/2024] [Indexed: 02/18/2024]
Abstract
Odontocetes produce clicks for echolocation and communication. Most odontocetes are thought to produce either broadband (BB) or narrowband high-frequency (NBHF) clicks. Here, we show that the click repertoire of Hector's dolphin (Cephalorhynchus hectori) comprises highly stereotypical NBHF clicks and far more variable broadband clicks, with some that are intermediate between these two categories. Both NBHF and broadband clicks were made in trains, buzzes, and burst-pulses. Most clicks within click trains were typical NBHF clicks, which had a median centroid frequency of 130.3 kHz (median -10 dB bandwidth = 29.8 kHz). Some, however, while having only marginally lower centroid frequency (median = 123.8 kHz), had significant energy below 100 kHz and approximately double the bandwidth (median -10 dB bandwidth = 69.8 kHz); we refer to these as broadband. Broadband clicks in buzzes and burst-pulses had lower median centroid frequencies (120.7 and 121.8 kHz, respectively) compared to NBHF buzzes and burst-pulses (129.5 and 130.3 kHz, respectively). Source levels of NBHF clicks, estimated by using a drone to measure ranges from a single hydrophone and by computing time-of-arrival differences at a vertical hydrophone array, ranged from 116 to 171 dB re 1 μPa at 1 m, whereas source levels of broadband clicks, obtained from array data only, ranged from 138 to 184 dB re 1 μPa at 1 m. Our findings challenge the grouping of toothed whales as either NBHF or broadband species.
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Affiliation(s)
- Nicoline Abildtrup Nielsen
- Marine Biological Research Center, Department of Biology, University of Southern Denmark, 5300 Kerteminde, Denmark
| | - Stephen M Dawson
- Department of Marine Science, University of Otago, Dunedin 9054, New Zealand
| | - Sara Torres Ortiz
- Marine Biological Research Center, Department of Biology, University of Southern Denmark, 5300 Kerteminde, Denmark
| | - Magnus Wahlberg
- Marine Biological Research Center, Department of Biology, University of Southern Denmark, 5300 Kerteminde, Denmark
| | - Morgan J Martin
- Center for Marine Acoustics, Bureau of Ocean Energy Management, Sterling, Virginia 20166, USA
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Christman KA, Finneran JJ, Mulsow J, Houser DS, Gentner TQ. The effects of range and echo-phase on range resolution in bottlenose dolphins (Tursiops truncatus) performing a successive comparison taska). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2024; 155:274-283. [PMID: 38215217 DOI: 10.1121/10.0024342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 12/14/2023] [Indexed: 01/14/2024]
Abstract
Echolocating bats and dolphins use biosonar to determine target range, but differences in range discrimination thresholds have been reported for the two species. Whether these differences represent a true difference in their sensory system capability is unknown. Here, the dolphin's range discrimination threshold as a function of absolute range and echo-phase was investigated. Using phantom echoes, the dolphins were trained to echo-inspect two simulated targets and indicate the closer target by pressing a paddle. One target was presented at a time, requiring the dolphin to hold the initial range in memory as they compared it to the second target. Range was simulated by manipulating echo-delay while the received echo levels, relative to the dolphins' clicks, were held constant. Range discrimination thresholds were determined at seven different ranges from 1.75 to 20 m. In contrast to bats, range discrimination thresholds increased from 4 to 75 cm, across the entire ranges tested. To investigate the acoustic features used more directly, discrimination thresholds were determined when the echo was given a random phase shift (±180°). Results for the constant-phase versus the random-phase echo were quantitatively similar, suggesting that dolphins used the envelope of the echo waveform to determine the difference in range.
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Affiliation(s)
- Katie A Christman
- Department of Psychology, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
- Department of Biologic and Bioacoustic Research, National Marine Mammal Foundation, 3131, 2240 Shelter Island Drive, San Diego, California 92106, USA
| | - James J Finneran
- United States Navy Marine Mammal Program, Naval Information Warfare Center Pacific Code 56710, 53560 Hull Street, San Diego, California 92152, USA
| | - Jason Mulsow
- Department of Biologic and Bioacoustic Research, National Marine Mammal Foundation, 3131, 2240 Shelter Island Drive, San Diego, California 92106, USA
| | - Dorian S Houser
- Department of Biologic and Bioacoustic Research, National Marine Mammal Foundation, 3131, 2240 Shelter Island Drive, San Diego, California 92106, USA
| | - Timothy Q Gentner
- Department of Psychology, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
- Department of Neurobiology, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
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4
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Mishima Y, Matsuo I, Karasawa Y, Ishii M, Morisaka T. Directional and amplitude characteristics of pulsed call sequences in captive free-swimming Pacific white-sided dolphins (Lagenorhynchus obliquidens). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 154:2974-2987. [PMID: 37947396 DOI: 10.1121/10.0022377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 10/24/2023] [Indexed: 11/12/2023]
Abstract
We investigated the directional properties and gain control of a pulsed call sequence that functions as a contact call in Pacific white-sided dolphins (Lagenorhynchus obliquidens). The pulsed call sequences were stereotyped patterns composed of three or more pulsed call elements and were collected from two dolphins, separated into adjacent pools, and allowed to swim freely. Eight hydrophones and an overhead camera were used to determine the positions and directions of the participants. The mean peak frequency and source levels were 8.4 ± 4.4 (standard deviation)-18.7 ± 12.7 kHz and 160.8 ± 3.8 to 176.4 ± 7.9 dB re 1 μPa (peak-to-peak), respectively, depending on the element types. The elements were omnidirectional, with mean directivity index of 0.9 ± 3.4 dB. The dolphins produced sequences, regardless of their relative position and direction to the lattice, leading to the adjacent pool where the conspecific was housed. They increased the amplitude by 6.5 ± 4.6 dB as the distance from the caller to an arbitrary point in the adjacent pool doubled. These results suggest that callers broadcast pulsed call sequences in a wide direction to reach dispersed conspecifics. However, they can adjust the acoustic active space by controlling the source levels.
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Affiliation(s)
- Yuka Mishima
- Department of Marine Resources and Energy, Tokyo University of Marine Science and Technology, 4-5-7, Konan, Minato-ku, Tokyo, 108-8477, Japan
| | - Ikuo Matsuo
- Department of Information Science, Tohoku Gakuin University, 2-1-1 Tenjinzawa, Izumi-ku, Sendai, 981-3193, Japan
| | - Yuu Karasawa
- Izu Mito Sea Paradise, 3-1, Nagahama, Uchiura, Numazu-shi, Shizuoka, 410-0295, Japan
| | - Marina Ishii
- Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7, Konan, Minato-ku, Tokyo, 108-8477, Japan
| | - Tadamichi Morisaka
- Cetacean Research Center, Graduate School of Bioresources, Mie University, 1577, Kurimamachiya-cho, Tsu-shi, Mie, 514-8507, Japan
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5
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Moss CF, Ortiz ST, Wahlberg M. Adaptive echolocation behavior of bats and toothed whales in dynamic soundscapes. J Exp Biol 2023; 226:jeb245450. [PMID: 37161774 PMCID: PMC10184770 DOI: 10.1242/jeb.245450] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Journal of Experimental Biology has a long history of reporting research discoveries on animal echolocation, the subject of this Centenary Review. Echolocating animals emit intense sound pulses and process echoes to localize objects in dynamic soundscapes. More than 1100 species of bats and 70 species of toothed whales rely on echolocation to operate in aerial and aquatic environments, respectively. The need to mitigate acoustic clutter and ambient noise is common to both aerial and aquatic echolocating animals, resulting in convergence of many echolocation features, such as directional sound emission and hearing, and decreased pulse intervals and sound intensity during target approach. The physics of sound transmission in air and underwater constrains the production, detection and localization of sonar signals, resulting in differences in response times to initiate prey interception by aerial and aquatic echolocating animals. Anti-predator behavioral responses of prey pursued by echolocating animals affect behavioral foraging strategies in air and underwater. For example, many insect prey can detect and react to bat echolocation sounds, whereas most fish and squid are unresponsive to toothed whale signals, but can instead sense water movements generated by an approaching predator. These differences have implications for how bats and toothed whales hunt using echolocation. Here, we consider the behaviors used by echolocating mammals to (1) track and intercept moving prey equipped with predator detectors, (2) interrogate dynamic sonar scenes and (3) exploit visual and passive acoustic stimuli. Similarities and differences in animal sonar behaviors underwater and in air point to open research questions that are ripe for exploration.
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Affiliation(s)
- Cynthia F. Moss
- Johns Hopkins University, Departments of Psychological and Brain Sciences, Neuroscience and Mechanical Engineering, 3400 N. Charles St., Baltimore, MD 21218, USA
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Sara Torres Ortiz
- Marine Biological Research Center, University of Southern Denmark, Hindsholmvej 11, 5300 Kerteminde, Denmark
| | - Magnus Wahlberg
- Marine Biological Research Center, University of Southern Denmark, Hindsholmvej 11, 5300 Kerteminde, Denmark
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Zhao L, Giorli G, Caruso F, Dong L, Gong Z, Lin M, Li S. Echolocation clicks of free-ranging Indo-Pacific finless porpoises (Neophocaena phocaenoides) in Hainan waters. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 153:1934. [PMID: 37002078 DOI: 10.1121/10.0017655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 03/06/2023] [Indexed: 05/18/2023]
Abstract
The echolocation clicks of free-ranging Indo-Pacific finless porpoises (IPFPs, Neophocaena phocaenoides) have been rarely studied in the wild. This paper aims at describing the echolocation-click characteristics of IPFPs and examining whether IPFPs adapt their sonar system to the habitats in Hainan waters, China. The echolocation clicks were recorded using a 13 elements star-shaped array of hydrophones. A total of 65 on-axis clicks were identified and analyzed. IPFPs use echolocation clicks with a source level (SL) of 158 ± 9 dB re: 1 μPa peak-peak, mean peak, and centroid frequency of 134 ± 3 kHz, -3 dB bandwidth of 14 ± 2 kHz and produce at inter-click intervals of 104 ± 51 ms. The results relative to other porpoises show that finless porpoises in Hainan waters produce clicks with moderate SLs and high peak frequency. These results could be useful in detecting the presence and estimating the density of IPFPs during passive acoustic monitoring in the study area and serve to shed light on the interpopulation variation of click characteristics of finless porpoises as well.
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Affiliation(s)
- Likun Zhao
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences (CAS), Sanya, 572000, China
| | - Giacomo Giorli
- National Institute of Water and Atmospheric Research, Coasts and Oceans, 301 Evans Bay Parade, Greta Point, Wellington, 6021, New Zealand
| | - Francesco Caruso
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences (CAS), Sanya, 572000, China
| | - Lijun Dong
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences (CAS), Sanya, 572000, China
| | - Zining Gong
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences (CAS), Sanya, 572000, China
| | - Mingli Lin
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences (CAS), Sanya, 572000, China
| | - Songhai Li
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences (CAS), Sanya, 572000, China
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7
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Luo J, Lu M, Luo J, Moss CF. Echo feedback mediates noise-induced vocal modifications in flying bats. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023; 209:203-214. [PMID: 36266485 DOI: 10.1007/s00359-022-01585-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 10/01/2022] [Accepted: 10/05/2022] [Indexed: 02/07/2023]
Abstract
Diverse animal taxa are capable of rapidly modifying vocalizations to mitigate interference from environmental noise. Echolocating bats, for example, must frequently perform sonar tasks in the presence of interfering sounds. Numerous studies have documented sound production flexibility in echolocating bats; however, it remains unknown whether noise-induced vocal modifications (NIVMs) mitigate interference effects on echoes or calls. In this study, we leverage echo level compensation behavior of echolocating bats to answer this question. Using a microphone array, we recorded echolocation calls of Hipposideros pratti trained to approach and land on a perch in the laboratory under quiet and noise conditions. We found that H. pratti exhibited echo level compensation behavior during approaching flights, which depended critically on distance to the landing perch. Broadcast noise delayed and affected the rate of echo level compensation in H. pratti. Moreover, H. pratti increased vocalization amplitude, i.e., exhibited the Lombard effect, while also adjusting call duration and bandwidth with increasing noise levels. Quantitative analyses of the data show that H. pratti relies on echo feedback, not vocal feedback, to adjust signals in the presence of noise. These findings provide compelling evidence that NIVMs in echolocating animals and non-echolocating animals operate through different mechanisms.
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Affiliation(s)
- Jinhong Luo
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
| | - Manman Lu
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Jie Luo
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Cynthia F Moss
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, 21218, USA.
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Castellote M, Mooney A, Andrews R, Deruiter S, Lee WJ, Ferguson M, Wade P. Beluga whale (Delphinapterus leucas) acoustic foraging behavior and applications for long term monitoring. PLoS One 2021; 16:e0260485. [PMID: 34847192 PMCID: PMC8631677 DOI: 10.1371/journal.pone.0260485] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 11/10/2021] [Indexed: 12/05/2022] Open
Abstract
Cook Inlet, Alaska, is home to an endangered and declining population of 279 belugas (Delphinapterus leucas). Recovery efforts highlight a paucity of basic ecological knowledge, impeding the correct assessment of threats and the development of recovery actions. In particular, information on diet and foraging habitat is very limited for this population. Passive acoustic monitoring has proven to be an efficient approach to monitor beluga distribution and seasonal occurrence. Identifying acoustic foraging behavior could help address the current gap in information on diet and foraging habitat. To address this conservation challenge, eight belugas from a comparative, healthy population in Bristol Bay, Alaska, were instrumented with a multi-sensor tag (DTAG), a satellite tag, and a stomach temperature transmitter in August 2014 and May 2016. DTAG deployments provided 129.6 hours of data including foraging and social behavioral states. A total of 68 echolocation click trains ending in terminal buzzes were identified during successful prey chasing and capture, as well as during social interactions. Of these, 37 click trains were successfully processed to measure inter-click intervals (ICI) and ICI trend in their buzzing section. Terminal buzzes with short ICI (minimum ICI <8.98 ms) and consistently decreasing ICI trend (ICI increment range <1.49 ms) were exclusively associated with feeding behavior. This dual metric was applied to acoustic data from one acoustic mooring within the Cook Inlet beluga critical habitat as an example of the application of detecting feeding in long-term passive acoustic monitoring data. This approach allowed description of the relationship between beluga presence, feeding occurrence, and the timing of spawning runs by different species of anadromous fish. Results reflected a clear preference for the Susitna River delta during eulachon (Thaleichthys pacificus), Chinook (Oncorhynchus tshawytscha), pink (Oncorhynchus gorbuscha), and coho (Oncorhynchus kisutch) salmon spawning run periods, with increased feeding occurrence at the peak of the Chinook and pink salmon runs.
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Affiliation(s)
- Manuel Castellote
- Cooperative Institute for Climate, Ocean and Ecosystem Studies, University of Washington, Seattle, WA, United States of America
- Marine Mammal Laboratory, Alaska Fisheries Science Center, NOAA, National Marine Fisheries Service, Seattle, WA, United States of America
- * E-mail:
| | - Aran Mooney
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, United States of America
| | - Russel Andrews
- Alaska SeaLife Center, Seward, AK, United States of America
- College of Fisheries and Ocean Sciences, University of Alaska, Fairbanks, Alaska, United States of America
| | - Stacy Deruiter
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, United States of America
- Department of Mathematics and Statistics, Calvin University, Grand Rapids, MI, United States of America
| | - Wu-Jung Lee
- Applied Physics laboratory, University of Washington, Seattle, WA, United States of America
| | - Megan Ferguson
- Marine Mammal Laboratory, Alaska Fisheries Science Center, NOAA, National Marine Fisheries Service, Seattle, WA, United States of America
| | - Paul Wade
- Marine Mammal Laboratory, Alaska Fisheries Science Center, NOAA, National Marine Fisheries Service, Seattle, WA, United States of America
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9
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Wright BM, Deecke VB, Ellis GM, Trites AW, Ford JKB. Behavioral context of echolocation and prey-handling sounds produced by killer whales ( Orcinus orca) during pursuit and capture of Pacific salmon ( Oncorhynchus spp.). MARINE MAMMAL SCIENCE 2021; 37:1428-1453. [PMID: 34690418 PMCID: PMC8519075 DOI: 10.1111/mms.12836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 04/28/2021] [Accepted: 04/30/2021] [Indexed: 06/13/2023]
Abstract
Availability of preferred salmonid prey and a sufficiently quiet acoustic environment in which to forage are critical to the survival of resident killer whales (Orcinus orca) in the northeastern Pacific. Although piscivorous killer whales rely on echolocation to locate and track prey, the relationship between echolocation, movement, and prey capture during foraging by wild individuals is poorly understood. We used acoustic biologging tags to relate echolocation behavior to prey pursuit and capture during successful feeding dives by fish-eating killer whales in coastal British Columbia, Canada. The significantly higher incidence and rate of echolocation prior to fish captures compared to afterward confirms its importance in prey detection and tracking. Extremely rapid click sequences (buzzes) were produced before or concurrent with captures of salmon at depths typically exceeding 50 m, and were likely used by killer whales for close-range prey targeting, as in other odontocetes. Distinctive crunching and tearing sounds indicative of prey-handling behavior occurred at relatively shallow depths following fish captures, matching concurrent observations that whales surfaced with fish prior to consumption and often shared prey. Buzzes and prey-handling sounds are potentially useful acoustic signals for estimating foraging efficiency and determining if resident killer whales are meeting their energetic requirements.
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Affiliation(s)
- Brianna M. Wright
- Pacific Biological StationFisheries and Oceans CanadaNanaimoBritish ColumbiaCanada
- Marine Mammal Research Unit, Institute for the Oceans and FisheriesUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- Department of ZoologyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Volker B. Deecke
- Institute of Science, Natural Resources and Outdoor StudiesUniversity of CumbriaAmblesideCumbriaUnited Kingdom
| | - Graeme M. Ellis
- Pacific Biological StationFisheries and Oceans CanadaNanaimoBritish ColumbiaCanada
| | - Andrew W. Trites
- Marine Mammal Research Unit, Institute for the Oceans and FisheriesUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- Department of ZoologyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - John K. B. Ford
- Pacific Biological StationFisheries and Oceans CanadaNanaimoBritish ColumbiaCanada
- Marine Mammal Research Unit, Institute for the Oceans and FisheriesUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- Department of ZoologyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
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10
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Zahn MJ, Laidre KL, Stilz P, Rasmussen MH, Koblitz JC. Vertical sonar beam width and scanning behavior of wild belugas (Delphinapterus leucas) in West Greenland. PLoS One 2021; 16:e0257054. [PMID: 34499678 PMCID: PMC8428689 DOI: 10.1371/journal.pone.0257054] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 08/22/2021] [Indexed: 11/18/2022] Open
Abstract
Echolocation signals of wild beluga whales (Delphinapterus leucas) were recorded in 2013 using a vertical, linear 16-hydrophone array at two locations in the pack ice of Baffin Bay, West Greenland. Individual whales were localized for 4:42 minutes of 1:04 hours of recordings. Clicks centered on the recording equipment (i.e. on-axis clicks) were isolated to calculate sonar parameters. We report the first sonar beam estimate of in situ recordings of wild belugas with an average -3 dB asymmetrical vertical beam width of 5.4°, showing a wider ventral beam. This narrow beam width is consistent with estimates from captive belugas; however, our results indicate that beluga sonar beams may not be symmetrical and may differ in wild and captive contexts. The mean apparent source level for on-axis clicks was 212 dB pp re 1 μPa and whales were shown to vertically scan the array from 120 meters distance. Our findings support the hypothesis that highly directional sonar beams and high source levels are an evolutionary adaptation for Arctic odontocetes to reduce unwanted surface echoes from sea ice (i.e., acoustic clutter) and effectively navigate through leads in the pack ice (e.g., find breathing holes). These results provide the first baseline beluga sonar metrics from free-ranging animals using a hydrophone array and are important for acoustic programs throughout the Arctic, particularly for acoustic classification between belugas and narwhals (Monodon monoceros).
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Affiliation(s)
- Marie J Zahn
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, United States of America
| | - Kristin L Laidre
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, United States of America.,Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, WA, United States of America
| | - Peter Stilz
- Animal Physiology, Institute for Neurobiology, University of Tübingen, Tübingen, Germany
| | | | - Jens C Koblitz
- Max Planck Institute of Animal Behavior, Konstanz, Germany.,Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany.,Department of Biology, University of Konstanz, Konstanz, Germany
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11
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Romeu B, Machado AMS, Daura-Jorge FG, Cremer MJ, de Moraes Alves AK, Simões-Lopes PC. Low-frequency sampling rates are effective to record bottlenose dolphins. ROYAL SOCIETY OPEN SCIENCE 2021; 8:201598. [PMID: 34350008 PMCID: PMC8316790 DOI: 10.1098/rsos.201598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 07/08/2021] [Indexed: 06/13/2023]
Abstract
Acoustic monitoring in cetacean studies is an effective but expensive approach. This is partly because of the high sampling rate required by acoustic devices when recording high-frequency echolocation clicks. However, the proportion of echolocation clicks recorded at different frequencies is unknown for many species, including bottlenose dolphins. Here, we investigated the echolocation clicks of two subspecies of bottlenose dolphins in the western South Atlantic Ocean. The possibility of recording echolocation clicks at 24 and 48 kHz was assessed by two approaches. First, we considered the clicks in the frequency range up to 96 kHz. We found a loss of 0.95-13.90% of echolocation clicks in the frequency range below 24 kHz, and 0.01-0.42% below 48 kHz, to each subspecies. Then, we evaluated these recordings downsampled at 48 and 96 kHz and confirmed that echolocation clicks are recorded at these lower frequencies, with some loss. Therefore, despite reaching high frequencies, the clicks can also be recorded at lower frequencies because echolocation clicks from bottlenose dolphins are broadband. We concluded that ecological studies based on the presence-absence data are still effective for bottlenose dolphins when acoustic devices with a limited sampling rate are used.
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Affiliation(s)
- Bianca Romeu
- Laboratório de Mamíferos Aquáticos, Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
- Programa de Pós-Graduação em Ecologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Alexandre M. S. Machado
- Laboratório de Mamíferos Aquáticos, Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
- Programa de Pós-Graduação em Ecologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
- Department of Collective Behaviour, Max Planck Institute of Animal Behaviour, Konstanz, Germany
| | - Fábio G. Daura-Jorge
- Laboratório de Mamíferos Aquáticos, Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
- Programa de Pós-Graduação em Ecologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Marta J. Cremer
- Programa de Pós-Graduação em Ecologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
- Programa de Pós-Graduação em Saúde e Meio Ambiente, Universidade da Região de Joinville, Joinville, Brazil
- Laboratório de Ecologia e Conservação de Tetrápodes Marinhos e Costeiros, Universidade da Região de Joinville, Joinville, Brazil
| | - Ana Kássia de Moraes Alves
- Laboratório de Ecologia e Conservação de Tetrápodes Marinhos e Costeiros, Universidade da Região de Joinville, Joinville, Brazil
| | - Paulo C. Simões-Lopes
- Laboratório de Mamíferos Aquáticos, Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
- Programa de Pós-Graduação em Ecologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
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12
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Martin MJ, Torres Ortiz S, Reyes Reyes MV, Marino A, Iñíguez Bessega M, Wahlberg M. Commerson’s dolphins (Cephalorhynchus commersonii) can relax acoustic crypsis. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-03035-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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13
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Rimskaya-Korsakova LK, Rodionov AA, Ivanov MP. The Adjustment of Echo Pulses Reflected from Objects Located at Different Distances to the Auditory Sensitivity of Dolphins: Model Studies. Biophysics (Nagoya-shi) 2021. [DOI: 10.1134/s0006350921020172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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14
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Ming C, Haro S, Simmons AM, Simmons JA. A comprehensive computational model of animal biosonar signal processing. PLoS Comput Biol 2021; 17:e1008677. [PMID: 33596199 PMCID: PMC7888678 DOI: 10.1371/journal.pcbi.1008677] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 01/07/2021] [Indexed: 11/23/2022] Open
Abstract
Computational models of animal biosonar seek to identify critical aspects of echo processing responsible for the superior, real-time performance of echolocating bats and dolphins in target tracking and clutter rejection. The Spectrogram Correlation and Transformation (SCAT) model replicates aspects of biosonar imaging in both species by processing wideband biosonar sounds and echoes with auditory mechanisms identified from experiments with bats. The model acquires broadband biosonar broadcasts and echoes, represents them as time-frequency spectrograms using parallel bandpass filters, translates the filtered signals into ten parallel amplitude threshold levels, and then operates on the resulting time-of-occurrence values at each frequency to estimate overall echo range delay. It uses the structure of the echo spectrum by depicting it as a series of local frequency nulls arranged regularly along the frequency axis of the spectrograms after dechirping them relative to the broadcast. Computations take place entirely on the timing of threshold-crossing events for each echo relative to threshold-events for the broadcast. Threshold-crossing times take into account amplitude-latency trading, a physiological feature absent from conventional digital signal processing. Amplitude-latency trading transposes the profile of amplitudes across frequencies into a profile of time-registrations across frequencies. Target shape is extracted from the spacing of the object's individual acoustic reflecting points, or glints, using the mutual interference pattern of peaks and nulls in the echo spectrum. These are merged with the overall range-delay estimate to produce a delay-based reconstruction of the object's distance as well as its glints. Clutter echoes indiscriminately activate multiple parts in the null-detecting system, which then produces the equivalent glint-delay spacings in images, thus blurring the overall echo-delay estimates by adding spurious glint delays to the image. Blurring acts as an anticorrelation process that rejects clutter intrusion into perceptions.
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Affiliation(s)
- Chen Ming
- Department of Neuroscience and Carney Institute for Brain Science, Brown University Providence, United States of America
| | - Stephanie Haro
- Speech and Hearing Biosciences and Technology, Harvard University, Boston, United States of America
| | - Andrea Megela Simmons
- Department of Cognitive, Linguistic and Psychological Sciences and Carney Institute for Brain Science, Brown University Providence, United States of America
| | - James A. Simmons
- Department of Neuroscience and Carney Institute for Brain Science, Brown University Providence, United States of America
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15
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Dong E, Song Z, Zhang Y, Ghaffari Mosanenzadeh S, He Q, Zhao X, Fang NX. Bioinspired metagel with broadband tunable impedance matching. SCIENCE ADVANCES 2020; 6:eabb3641. [PMID: 33127672 PMCID: PMC7608802 DOI: 10.1126/sciadv.abb3641] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 09/16/2020] [Indexed: 06/01/2023]
Abstract
To maximize energy transmission from a source through a media, the concept of impedance matching has been established in electrical, acoustic, and optical engineering. However, existing design of acoustic impedance matching, which extends exactly by a quarter wavelength, sets a fundamental limit of narrowband transmission. Here, we report a previously unknown class of bioinspired metagel impedance transformers to overcome this limit. The transformer embeds a two-dimensional metamaterial matrix of steel cylinders into hydrogel. Using experimental data of the biosonar from the Indo-Pacific humpback dolphin, we demonstrate through theoretical analysis that broadband transmission is achieved when the bioinspired acoustic impedance function is introduced. Furthermore, we experimentally show that the metagel device offers efficient implementation in broadband underwater ultrasound detection with the benefit of being soft and tunable. The bioinspired two-dimensional metagel breaks the length-wavelength dependence, which paves a previously unexplored way for designing next-generation broadband impedance matching devices in diverse wave engineering.
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Affiliation(s)
- Erqian Dong
- Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, China
| | - Zhongchang Song
- Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, China
| | - Yu Zhang
- Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, China.
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Qi He
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Xuanhe Zhao
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Nicholas X Fang
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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16
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Park M, Baek Y, Dinare M, Lee D, Park KH, Ahn J, Kim D, Medina J, Choi WJ, Kim S, Zhou C, Heo J, Lee K. Hetero-integration enables fast switching time-of-flight sensors for light detection and ranging. Sci Rep 2020; 10:2764. [PMID: 32066791 PMCID: PMC7026395 DOI: 10.1038/s41598-020-59677-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 01/31/2020] [Indexed: 12/05/2022] Open
Abstract
The time-of-flight (ToF) principle is a method used to measure distance and construct three-dimensional (3D) images by detecting the time or the phase difference between emitted and back-reflected optical flux. The ToF principle has been employed for various applications including light ranging and detection (LiDAR), machine vision and biomedical engineering; however, bulky system size and slow switching speed have hindered the widespread application of ToF technology. To alleviate these issues, a demonstration of hetero-integration of GaN-based high electron mobility transistors (HEMTs) and GaAs-based vertical cavity surface emitting lasers (VCSELs) on a single platform via a cold-welding method was performed. The hetero-integrated ToF sensors show superior switching performance when compared to silicon-transistor-based systems, miniaturizing size and exhibiting stable ranging and high-resolution depth-imaging. This hetero-integrated system of dissimilar material-based high-performance devices suggests a new pathway towards enabling high-resolution 3D imaging and inspires broader range application of heterogeneously integrated electronics and optoelectronics.
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Affiliation(s)
- Minseong Park
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, 22904, USA
| | - Yongmin Baek
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, 22904, USA
| | - Mesgana Dinare
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, 22904, USA
| | - Doeon Lee
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, 22904, USA
| | - Kyung-Ho Park
- Devices Technology Division, Korea Advanced Nano Fab Center (KANC), Suwon, 16229, South Korea
| | - Jungho Ahn
- Department of Electrical and Computer Engineering, Ajou University, Suwon, 16499, South Korea
| | - Dahee Kim
- Department of Electrical and Computer Engineering, Ajou University, Suwon, 16499, South Korea
| | - Joseff Medina
- Department of Mechanical and Aerospace engineering, University of Virginia, Charlottesville, VA, 22904, USA
| | - Won-Jin Choi
- RayIR Corporation, LTD, 156 Gwanggyo-ro, Yeongtong-gu, Suwon, 16506, South Korea
| | - Sihwan Kim
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, 22904, USA
| | - Changjie Zhou
- Department of Science, Jimei university, Jimei District, Xiamen, Fujian, 361021, China
| | - Junseok Heo
- Department of Electrical and Computer Engineering, Ajou University, Suwon, 16499, South Korea
| | - Kyusang Lee
- Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, 22904, USA. .,Department of Material Science and Engineering, University of Virginia, Charlottesville, VA, 22904, USA.
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17
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Jensen FH, Keller OA, Tyack PL, Visser F. Dynamic biosonar adjustment strategies in deep-diving Risso's dolphins driven partly by prey evasion. ACTA ACUST UNITED AC 2020; 223:jeb.216283. [PMID: 31822550 DOI: 10.1242/jeb.216283] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 12/02/2019] [Indexed: 11/20/2022]
Abstract
Toothed whales have evolved flexible biosonar systems to find, track and capture prey in diverse habitats. Delphinids, phocoenids and iniids adjust inter-click intervals and source levels gradually while approaching prey. In contrast, deep-diving beaked and sperm whales maintain relatively constant inter-click intervals and apparent output levels during the approach followed by a rapid transition into the foraging buzz, presumably to maintain a long-range acoustic scene in a multi-target environment. However, it remains unknown whether this rapid biosonar adjustment strategy is shared by delphinids foraging in deep waters. To test this, we investigated biosonar adjustments of a deep-diving delphinid, the Risso's dolphin (Grampus griseus). We analyzed inter-click interval and apparent output level adjustments recorded from sound recording tags to quantify in situ sensory adjustment during prey capture attempts. Risso's dolphins did not follow typical (20logR) biosonar adjustment patterns seen in shallow-water species, but instead maintained stable repetition rates and output levels up to the foraging buzz. Our results suggest that maintaining a long-range acoustic scene to exploit complex, multi-target prey layers is a common strategy amongst deep-diving toothed whales. Risso's dolphins transitioned rapidly into the foraging buzz just like beaked whales during most foraging attempts, but employed a more gradual biosonar adjustment in a subset (19%) of prey approaches. These were characterized by higher speeds and minimum specific acceleration, indicating higher prey capture efforts associated with evasive prey. Thus, tracking and capturing evasive prey using biosonar may require a more gradual switch between multi-target echolocation and single-target tracking.
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Affiliation(s)
- Frants H Jensen
- Aarhus Institute of Advanced Studies, Aarhus University, 8000 Aarhus C, Denmark .,Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Onno A Keller
- Department of Coastal Systems, Royal Netherlands Institute for Sea Research and Utrecht University, P.O. Box 59, 1790 AB Den Burg Texel, The Netherlands.,Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, 1090 GE Amsterdam, The Netherlands.,Department of Animal Ecology, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Peter L Tyack
- Scottish Oceans Institute, School of Biology, University of St Andrews, East Sands, St Andrews KY16 8LB, UK
| | - Fleur Visser
- Department of Coastal Systems, Royal Netherlands Institute for Sea Research and Utrecht University, P.O. Box 59, 1790 AB Den Burg Texel, The Netherlands.,Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, 1090 GE Amsterdam, The Netherlands.,Kelp Marine Research, 1624CJ Hoorn, The Netherlands
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18
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Smith AB, Pacini AF, Nachtigall PE, Laule GE, Aragones LV, Magno C, Suarez LJA. Transmission beam pattern and dynamics of a spinner dolphin (Stenella longirostris). THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 145:3595. [PMID: 31255135 DOI: 10.1121/1.5111347] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/24/2019] [Indexed: 06/09/2023]
Abstract
Toothed whales possess a sophisticated biosonar system by which ultrasonic clicks are projected in a highly directional transmission beam. Beam directivity is an important biosonar characteristic that reduces acoustic clutter and increases the acoustic detection range. This study measured click characteristics and the transmission beam pattern from a small odontocete, the spinner dolphin (Stenella longirostis). A formerly stranded individual was rehabilitated and trained to station underwater in front of a 16-element hydrophone array. On-axis clicks showed a mean duration of 20.1 μs, with mean peak and centroid frequencies of 58 and 64 kHz [standard deviation (s.d.) ±30 and ±12 kHz], respectively. Clicks were projected in an oval, vertically compressed beam, with mean vertical and horizontal beamwidths of 14.5° (s.d. ± 3.9) and 16.3° (s.d. ± 4.6), respectively. Directivity indices ranged from 14.9 to 27.4 dB, with a mean of 21.7 dB, although this likely represents a broader beam than what is normally produced by wild individuals. A click subset with characteristics more similar to those described for wild individuals exhibited a mean directivity index of 23.3 dB. Although one of the broadest transmission beams described for a dolphin, it is similar to other small bodied odontocetes.
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Affiliation(s)
- Adam B Smith
- Marine Mammal Research Program, Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Kaneohe, Hawaii 96744, USA
| | - Aude F Pacini
- Marine Mammal Research Program, Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Kaneohe, Hawaii 96744, USA
| | - Paul E Nachtigall
- Marine Mammal Research Program, Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Kaneohe, Hawaii 96744, USA
| | - Gail E Laule
- Ocean Adventure, Camayan Wharf, West Ilanin Forest, Subic Bay Freeport Zone, Philippines
| | - Lemnuel V Aragones
- Institute of Environmental Science and Meteorology, University of the Philippines, Diliman, Quezon City, Philippines
| | - Carlo Magno
- Ocean Adventure, Camayan Wharf, West Ilanin Forest, Subic Bay Freeport Zone, Philippines
| | - Leo J A Suarez
- Ocean Adventure, Camayan Wharf, West Ilanin Forest, Subic Bay Freeport Zone, Philippines
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19
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Martin MJ, Elwen SH, Kassanjee R, Gridley T. To buzz or burst-pulse? The functional role of Heaviside's dolphin, Cephalorhynchus heavisidii, rapidly pulsed signals. Anim Behav 2019. [DOI: 10.1016/j.anbehav.2019.01.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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20
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Ladegaard M, Mulsow J, Houser DS, Jensen FH, Johnson M, Madsen PT, Finneran JJ. Dolphin echolocation behaviour during active long-range target approaches. ACTA ACUST UNITED AC 2019; 222:jeb.189217. [PMID: 30478155 DOI: 10.1242/jeb.189217] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 11/22/2018] [Indexed: 11/20/2022]
Abstract
Echolocating toothed whales generally adjust click intensity and rate according to target range to ensure that echoes from targets of interest arrive before a subsequent click is produced, presumably facilitating range estimation from the delay between clicks and returning echoes. However, this click-echo-click paradigm for the dolphin biosonar is mostly based on experiments with stationary animals echolocating fixed targets at ranges below ∼120 m. Therefore, we trained two bottlenose dolphins instrumented with a sound recording tag to approach a target from ranges up to 400 m and either touch the target (subject TRO) or detect a target orientation change (subject SAY). We show that free-swimming dolphins dynamically increase interclick interval (ICI) out to target ranges of ∼100 m. TRO consistently kept ICIs above the two-way travel time (TWTT) for target ranges shorter than ∼100 m, whereas SAY switched between clicking at ICIs above and below the TWTT for target ranges down to ∼25 m. Source levels changed on average by 17log10(target range), but with considerable variation for individual slopes (4.1 standard deviations for by-trial random effects), demonstrating that dolphins do not adopt a fixed automatic gain control matched to target range. At target ranges exceeding ∼100 m, both dolphins frequently switched to click packet production in which interpacket intervals exceeded the TWTT, but ICIs were shorter than the TWTT. We conclude that the click-echo-click paradigm is not a fixed echolocation strategy in dolphins, and we demonstrate the first use of click packets for free-swimming dolphins when solving an echolocation task.
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Affiliation(s)
- Michael Ladegaard
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus, Denmark
| | - Jason Mulsow
- National Marine Mammal Foundation, 2240 Shelter Island Drive, Suite 200, San Diego, CA 92106, USA
| | - Dorian S Houser
- National Marine Mammal Foundation, 2240 Shelter Island Drive, Suite 200, San Diego, CA 92106, USA
| | | | - Mark Johnson
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus, Denmark.,Sea Mammal Research Unit, St Andrews KY16 8LB, UK
| | - Peter Teglberg Madsen
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus, Denmark.,Aarhus Institute of Advanced Studies, Aarhus University, 8000 Aarhus, Denmark
| | - James J Finneran
- United States Navy Marine Mammal Program, Space and Naval Warfare Systems Center Pacific, Code 71510, 53560 Hull Street, San Diego, CA 92152, USA
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21
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Ladegaard M, Madsen PT. Context-dependent biosonar adjustments during active target approaches in echolocating harbour porpoises. J Exp Biol 2019; 222:jeb.206169. [DOI: 10.1242/jeb.206169] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 07/16/2019] [Indexed: 11/20/2022]
Abstract
Echolocating mammals generally target individual prey items by transitioning through the biosonar phases of search (slow-rate, high-amplitude outputs), approach (gradually increasing rate and decreasing output amplitude) and buzzing (high-rate, low-amplitude outputs). The range to the main target of interest is often considered the key or sole driver of such biosonar adjustments of acoustic gaze. However, the actively-generated auditory scene of an echolocator is invariably comprised of a large number of other reflectors and noise sources that likely also impact the biosonar strategies and source parameters implemented by an echolocating animal in time and space. In toothed whales the importance of context on biosonar adjustments is largely unknown. To address this, we trained two harbour porpoises to actively approach the same sound recording target over the same approach distance in two highly different environments; a PVC-lined pool and a semi-natural net pen in a harbour, while blind-folded and wearing a sound recording tag (DTAG-4). We show that the approaching porpoises used considerably shorter interclick intervals (ICI) in the pool than in the net pen, except during the buzz phase where slightly longer ICIs were used in the pool. We further show that average click source levels were 4-7 dB higher in the net pen. Because of the very low-level in-band ambient noise in both environments, we posit that the porpoises adapted their echolocation strategy to the different reverberation levels between the two settings. We demonstrate that harbour porpoises use different echolocation strategies and biosonar parameters in two different environments for solving an otherwise identical target approach task and thus highlight that biosonar adjustments are both range and context-dependent.
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Affiliation(s)
- Michael Ladegaard
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus, Denmark
| | - Peter Teglberg Madsen
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus, Denmark
- Aarhus Institute of Advanced Studies, Aarhus University, 8000 Aarhus, Denmark
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22
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Smith AB, Pacini AF, Nachtigall PE. Modulation rate transfer functions from four species of stranded odontocete (Stenella longirostris, Feresa attenuata, Globicephala melas, and Mesoplodon densirostris). J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2018; 204:377-389. [PMID: 29350260 DOI: 10.1007/s00359-018-1246-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 01/02/2018] [Accepted: 01/08/2018] [Indexed: 10/18/2022]
Abstract
Odontocete marine mammals explore the environment by rapidly producing echolocation signals and receiving the corresponding echoes, which likewise return at very rapid rates. Thus, it is important that the auditory system has a high temporal resolution to effectively process and extract relevant information from click echoes. This study used auditory evoked potential methods to investigate auditory temporal resolution of individuals from four different odontocete species, including a spinner dolphin (Stenella longirostris), pygmy killer whale (Feresa attenuata), long-finned pilot whale (Globicephala melas), and Blainville's beaked whale (Mesoplodon densirostris). Each individual had previously stranded and was undergoing rehabilitation. Auditory Brainstem Responses (ABRs) were elicited via acoustic stimuli consisting of a train of broadband tone pulses presented at rates between 300 and 2000 Hz. Similar to other studied species, modulation rate transfer functions (MRTFs) of the studied individuals followed the shape of a low-pass filter, with the ability to process acoustic stimuli at presentation rates up to and exceeding 1250 Hz. Auditory integration times estimated from the bandwidths of the MRTFs ranged between 250 and 333 µs. The results support the hypothesis that high temporal resolution is conserved throughout the diverse range of odontocete species.
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Affiliation(s)
- Adam B Smith
- Department of Biology, University of Hawai'i at Mānoa, 2538 McCarthy Mall, Edmondson Hall Room 216, Honolulu, HI, 96822, USA. .,Hawai'i Institute of Marine Biology, 46-007 Lilipuna Road, Kāne'ohe, HI, 96744, USA.
| | - Aude F Pacini
- Department of Biology, University of Hawai'i at Mānoa, 2538 McCarthy Mall, Edmondson Hall Room 216, Honolulu, HI, 96822, USA.,Hawai'i Institute of Marine Biology, 46-007 Lilipuna Road, Kāne'ohe, HI, 96744, USA
| | - Paul E Nachtigall
- Department of Biology, University of Hawai'i at Mānoa, 2538 McCarthy Mall, Edmondson Hall Room 216, Honolulu, HI, 96822, USA.,Hawai'i Institute of Marine Biology, 46-007 Lilipuna Road, Kāne'ohe, HI, 96744, USA
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23
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Frasier KE, Roch MA, Soldevilla MS, Wiggins SM, Garrison LP, Hildebrand JA. Automated classification of dolphin echolocation click types from the Gulf of Mexico. PLoS Comput Biol 2017; 13:e1005823. [PMID: 29216184 PMCID: PMC5720518 DOI: 10.1371/journal.pcbi.1005823] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 10/17/2017] [Indexed: 11/18/2022] Open
Abstract
Delphinids produce large numbers of short duration, broadband echolocation clicks which may be useful for species classification in passive acoustic monitoring efforts. A challenge in echolocation click classification is to overcome the many sources of variability to recognize underlying patterns across many detections. An automated unsupervised network-based classification method was developed to simulate the approach a human analyst uses when categorizing click types: Clusters of similar clicks were identified by incorporating multiple click characteristics (spectral shape and inter-click interval distributions) to distinguish within-type from between-type variation, and identify distinct, persistent click types. Once click types were established, an algorithm for classifying novel detections using existing clusters was tested. The automated classification method was applied to a dataset of 52 million clicks detected across five monitoring sites over two years in the Gulf of Mexico (GOM). Seven distinct click types were identified, one of which is known to be associated with an acoustically identifiable delphinid (Risso’s dolphin) and six of which are not yet identified. All types occurred at multiple monitoring locations, but the relative occurrence of types varied, particularly between continental shelf and slope locations. Automatically-identified click types from autonomous seafloor recorders without verifiable species identification were compared with clicks detected on sea-surface towed hydrophone arrays in the presence of visually identified delphinid species. These comparisons suggest potential species identities for the animals producing some echolocation click types. The network-based classification method presented here is effective for rapid, unsupervised delphinid click classification across large datasets in which the click types may not be known a priori. Health of marine mammal populations is often considered an indicator of overall marine ecosystem health and resilience, particularly in highly-impacted regions such as the Gulf of Mexico. Marine mammal populations are difficult to monitor given the many challenges of observing animals at sea (e.g. weather, limited daylight, ocean conditions, and expense). An increasingly common approach is the use of underwater acoustic sensors capable of recording marine mammal calls at remote locations for months at a time. Acoustic sensors generate large datasets in which dolphin echolocation clicks are commonly present. Dolphins are the most diverse family of marine mammals, and distinguishing click characteristics have only been described for a small subset of species. We developed a workflow to automatically identify distinct dolphin click types within large datasets without prior knowledge of their distinguishing features. Our algorithm then recognizes these click types in novel recording data across a range of monitoring locations. Known species-specific click types emerge from the data using this approach, as well as new click types potentially associated with additional species. This technique is a key step toward determining species identification for passive acoustic monitoring of offshore populations of dolphins and other toothed whales under a big data paradigm.
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Affiliation(s)
- Kaitlin E. Frasier
- Scripps Institution of Oceanography, La Jolla, California, United States of America
- * E-mail:
| | - Marie A. Roch
- San Diego State University, San Diego, California, United States of America
| | - Melissa S. Soldevilla
- NOAA NMFS Southeast Fisheries Science Center, Protected Resources and Biodiversity Division, Miami, Florida, United States of America
| | - Sean M. Wiggins
- Scripps Institution of Oceanography, La Jolla, California, United States of America
| | - Lance P. Garrison
- NOAA NMFS Southeast Fisheries Science Center, Protected Resources and Biodiversity Division, Miami, Florida, United States of America
| | - John A. Hildebrand
- Scripps Institution of Oceanography, La Jolla, California, United States of America
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24
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Schrøder AEM, Beedholm K, Madsen PT. Time-varying auditory gain control in response to double-pulse stimuli in harbour porpoises is not mediated by a stapedial reflex. Biol Open 2017; 6:525-529. [PMID: 28202466 PMCID: PMC5399549 DOI: 10.1242/bio.021469] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Echolocating animals reduce their output level and hearing sensitivity with decreasing echo delays, presumably to stabilize the perceived echo intensity during target approaches. In bats, this variation in hearing sensitivity is formed by a call-induced stapedial reflex that tapers off over time after the call. Here, we test the hypothesis that a similar mechanism exists in toothed whales by subjecting a trained harbour porpoise to a series of double sound pulses varying in delay and frequency, while measuring the magnitudes of the evoked auditory brainstem responses (ABRs). We find that the recovery of the ABR to the second pulse is frequency dependent, and that a stapedial reflex therefore cannot account for the reduced hearing sensitivity at short pulse delays. We propose that toothed whale auditory time-varying gain control during echolocation is not enabled by the middle ear as in bats, but rather by frequency-dependent mechanisms such as forward masking and perhaps higher-order control of efferent feedback to the outer hair cells.
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Affiliation(s)
| | - Kristian Beedholm
- Zoophysiology, Bioscience, Aarhus University, C. F. Moellers Allé 3, Aarhus C 8000, Denmark
| | - Peter Teglberg Madsen
- Zoophysiology, Bioscience, Aarhus University, C. F. Moellers Allé 3, Aarhus C 8000, Denmark .,Murdoch University Cetacean Research Unit, Murdoch University, South Street, Murdoch, Western Australia 6150, Australia
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Pesek M, Leonardis A, Marolt M. Robust Real-Time Music Transcription with a Compositional Hierarchical Model. PLoS One 2017; 12:e0169411. [PMID: 28046074 PMCID: PMC5207709 DOI: 10.1371/journal.pone.0169411] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 12/17/2016] [Indexed: 11/19/2022] Open
Abstract
The paper presents a new compositional hierarchical model for robust music transcription. Its main features are unsupervised learning of a hierarchical representation of input data, transparency, which enables insights into the learned representation, as well as robustness and speed which make it suitable for real-world and real-time use. The model consists of multiple layers, each composed of a number of parts. The hierarchical nature of the model corresponds well to hierarchical structures in music. The parts in lower layers correspond to low-level concepts (e.g. tone partials), while the parts in higher layers combine lower-level representations into more complex concepts (tones, chords). The layers are learned in an unsupervised manner from music signals. Parts in each layer are compositions of parts from previous layers based on statistical co-occurrences as the driving force of the learning process. In the paper, we present the model's structure and compare it to other hierarchical approaches in the field of music information retrieval. We evaluate the model's performance for the multiple fundamental frequency estimation. Finally, we elaborate on extensions of the model towards other music information retrieval tasks.
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Affiliation(s)
- Matevž Pesek
- University of Ljubljana, Faculty of Computer and Information Science, Laboratory for computer graphics and multimedia, Ljubljana, Slovenia
- * E-mail:
| | - Aleš Leonardis
- University of Ljubljana, Faculty of Computer and Information Science, Laboratory for computer graphics and multimedia, Ljubljana, Slovenia
- University of Birmingham, School of Computer Science, Centre for Computational Neuroscience and Cognitive Robotics, Birmingham, United Kingdom of Great Britain and Northern Ireland
| | - Matija Marolt
- University of Ljubljana, Faculty of Computer and Information Science, Laboratory for computer graphics and multimedia, Ljubljana, Slovenia
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26
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Ladegaard M, Jensen FH, Beedholm K, da Silva VMF, Madsen PT. Amazon river dolphins (Inia geoffrensis) modify biosonar output level and directivity during prey interception in the wild. J Exp Biol 2017; 220:2654-2665. [DOI: 10.1242/jeb.159913] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 05/08/2017] [Indexed: 11/20/2022]
Abstract
Toothed whales have evolved to live in extremely different habitats and yet they all rely strongly on echolocation for finding and catching prey. Such biosonar based foraging involves distinct phases of searching for, approaching, and capturing prey, where echolocating animals gradually adjust sonar output to actively shape the flow of sensory information. Measuring those outputs in absolute levels requires hydrophone arrays centred on the biosonar beam axis, but this has never been done for wild toothed whales approaching and capturing prey. Rather, field studies make the assumption that toothed whales will adjust their biosonar in the same manner to arrays as they will when approaching prey. To test this assumption, we recorded wild botos (Inia geoffrensis) as they approached and captured dead fish tethered to a hydrophone in front of a star-shaped seven-hydrophone array. We demonstrate that botos gradually decrease interclick intervals and output levels during prey approaches, using stronger adjustment magnitudes than extrapolated from previous boto array data. Prey interceptions are characterised by high click rates, but although botos buzz during prey capture, they do so at lower click rates than marine toothed whales, resulting in a much more gradual transition from approach phase to buzzing. We also demonstrate for the first time that wild toothed whales broaden biosonar beamwidth when closing in on prey, as it is also seen in captive toothed whales and in bats, thus resulting in a larger ensonified volume around the prey, likely aiding prey tracking by decreasing the risk of prey evading ensonification.
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Affiliation(s)
- Michael Ladegaard
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus, Denmark
| | | | - Kristian Beedholm
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus, Denmark
| | | | - Peter Teglberg Madsen
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus, Denmark
- Murdoch University Cetacean Research Unit, School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch, Western Australia 6150, Australia
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27
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Koblitz JC, Stilz P, Rasmussen MH, Laidre KL. Highly Directional Sonar Beam of Narwhals (Monodon monoceros) Measured with a Vertical 16 Hydrophone Array. PLoS One 2016; 11:e0162069. [PMID: 27828956 PMCID: PMC5102362 DOI: 10.1371/journal.pone.0162069] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 08/17/2016] [Indexed: 11/19/2022] Open
Abstract
Recordings of narwhal (Monodon monoceros) echolocation signals were made using a linear 16 hydrophone array in the pack ice of Baffin Bay, West Greenland in 2013 at eleven sites. An average -3 dB beam width of 5.0° makes the narwhal click the most directional biosonar signal reported for any species to date. The beam shows a dorsal-ventral asymmetry with a narrower beam above the beam axis. This may be an evolutionary advantage for toothed whales to reduce echoes from the water surface or sea ice surface. Source level measurements show narwhal click intensities of up to 222 dB pp re 1 μPa, with a mean apparent source level of 215 dB pp re 1 μPa. During ascents and descents the narwhals perform scanning in the vertical plane with their sonar beam. This study provides valuable information for reference sonar parameters of narwhals and for the use of acoustic monitoring in the Arctic.
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Affiliation(s)
| | | | | | - Kristin L. Laidre
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, United States of America
- * E-mail: (JCK); (KLL)
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28
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Macías S, Hechavarría JC. Short delays and low pulse amplitudes produce widespread activation in the target-distance processing area of auditory cortex of the mustached bat. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 140:917. [PMID: 27586724 DOI: 10.1121/1.4960547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
While approaching an object, echolocating bats decrease the amplitude of their vocalizations. This behavior is known as "echo-level compensation." Here, the activation pattern of the cortical FM-FM (frequency modulated) area of the mustached bat is assessed by using acoustic stimuli that correspond to sonar signals and their echoes emitted during echo-level compensation behavior. Activation maps were calculated from the delay response areas of 86 cortical neurons, and these maps were used to explore the topography of cortical activation during echolocation and its relation to the bats' cortical "chronotopy." Chronotopy predicts short echo-delays to be represented by rostral auditory cortex neurons while caudal neurons represent long echo-delays. The results show that a chronotopic activation of the cortex is evident only at loud pulse amplitudes [80-90 dB sound pressure level (SPL)]. In response to fainter pulse levels (60-70 dB SPL), as those produced as the animals zoom-in on targets, chronotopic activation of the cortex becomes less clear because units throughout the FM-FM area start firing, especially in response to short echo-delays. The fact that cortical activity is more widespread in response to combinations of short echo-delays and faint pulse amplitudes could represent an adaptation that enhances cortical activity in the late stages of echo-level compensation.
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Affiliation(s)
- Silvio Macías
- Institut für Zellbiologie und Neurowissenschaft, J. W. Goethe Universität Frankfurt, Max-von-Laue-Strausse 13, 60439 Frankfurt am Main, Germany
| | - Julio C Hechavarría
- Institut für Zellbiologie und Neurowissenschaft, J. W. Goethe Universität Frankfurt, Max-von-Laue-Strausse 13, 60439 Frankfurt am Main, Germany
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29
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Arranz P, DeRuiter SL, Stimpert AK, Neves S, Friedlaender AS, Goldbogen JA, Visser F, Calambokidis J, Southall BL, Tyack PL. Discrimination of fast click-series produced by tagged Risso's dolphins (Grampus griseus) for echolocation or communication. ACTA ACUST UNITED AC 2016; 219:2898-2907. [PMID: 27401759 DOI: 10.1242/jeb.144295] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 07/05/2016] [Indexed: 11/20/2022]
Abstract
Early studies that categorized odontocete pulsed sounds had few means of discriminating signals used for biosonar-based foraging from those used for communication. This capability to identify the function of sounds is important for understanding and interpreting behavior; it is also essential for monitoring and mitigating potential disturbance from human activities. Archival tags were placed on free-ranging Grampus griseus to quantify and discriminate between pulsed sounds used for echolocation-based foraging and those used for communication. Two types of rapid click-series pulsed sounds, buzzes and burst pulses, were identified as produced by the tagged dolphins and classified using a Gaussian mixture model based on their duration, association with jerk (i.e. rapid change of acceleration) and temporal association with click trains. Buzzes followed regular echolocation clicks and coincided with a strong jerk signal from accelerometers on the tag. They consisted of series averaging 359±210 clicks (mean±s.d.) with an increasing repetition rate and relatively low amplitude. Burst pulses consisted of relatively short click series averaging 45±54 clicks with decreasing repetition rate and longer inter-click interval that were less likely to be associated with regular echolocation and the jerk signal. These results suggest that the longer, relatively lower amplitude, jerk-associated buzzes are used in this species to capture prey, mostly during the bottom phase of foraging dives, as seen in other odontocetes. In contrast, the shorter, isolated burst pulses that are generally emitted by the dolphins while at or near the surface are used outside of a direct, known foraging context.
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Affiliation(s)
- P Arranz
- Sea Mammal Research Unit, School of Biology, University of St Andrews, St Andrews KY16 8LB, UK
| | - S L DeRuiter
- Centre for Research into Ecological and Environmental Modelling, School of Mathematics and Statistics, University of St Andrews, St Andrews KY16 9LZ, UK Department of Mathematics and Statistics, Calvin College, Grand Rapids, MI 49546, USA
| | - A K Stimpert
- Vertebrate Ecology Lab, Moss Landing Marine Laboratories, Moss Landing, CA 95039, USA
| | - S Neves
- Sea Mammal Research Unit, School of Biology, University of St Andrews, St Andrews KY16 8LB, UK
| | - A S Friedlaender
- Department of Fisheries and Wildlife, Mammal Institute, Hatfield Marine Science Center, Oregon State University, Newport, OR 97635, USA
| | - J A Goldbogen
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - F Visser
- Kelp Marine Research, Hoorn 1624 CJ, The Netherlands Institute of Biology, Leiden University, Leiden 2311, The Netherlands
| | | | - B L Southall
- Southall Environmental Associates, Aptos, CA 95003, USA University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - P L Tyack
- Sea Mammal Research Unit, School of Biology, University of St Andrews, St Andrews KY16 8LB, UK
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30
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Abstract
Ultrasonic emissions of bats are directional and delimit the echo-acoustic space. Directionality is quantified by the aperture of the sonar beam. Recent work has shown that bats often widen their sonar beam when approaching movable prey or sharpen their sonar beam when navigating through cluttered habitats. Here we report how nose-emitting bats, Phyllostomus discolor, adjust their sonar beam to object distance. First, we show that the height and width of the bats sonar beam, as imprinted on a parabolic 45 channel microphone array, varies even within each animal and this variation is unrelated to changes in call level or spectral content. Second, we show that these animals are able to systematically decrease height and width of their sonar beam while focusing on the approaching object. Thus it appears that sonar beam sharpening is a further, facultative means of reducing search volume, likely to be employed by stationary animals when the object position is close and unambiguous. As only half of our individuals sharpened their beam onto the approaching object we suggest that this strategy is facultative, under voluntary control, and that beam formation is likely mediated by muscular control of the acoustic aperture of the bats' nose leaf.
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31
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Finneran JJ, Echon R, Mulsow J, Houser DS. Short-term enhancement and suppression of dolphin auditory evoked responses following echolocation click emission. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 140:296. [PMID: 27475154 DOI: 10.1121/1.4955093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Biosonar gain control mechanisms in a bottlenose dolphin were investigated by measuring the auditory steady-state response (ASSR) to an external tone while the animal echolocated. The dolphin performed an echo change-detection task that utilized electronically synthesized echoes with echo delays corresponding to 25- and 50-m target range. During the task, amplitude modulated tones with carrier frequencies from 25 to 125 kHz were continuously presented and the instantaneous electroencephalogram stored for later analysis. ASSRs were extracted from the electroencephalogram by synchronously averaging time epochs temporally aligned with the onset of the external tone modulation cycle nearest to each of the dolphin's echolocation clicks. Results showed an overall suppression of the ASSR amplitude for tones with frequencies near the click center frequencies. A larger, temporary suppression of the ASSR amplitude was also measured at frequencies above 40-50 kHz, while a temporary enhancement was observed at lower frequencies. Temporal patterns for ASSR enhancement or suppression were frequency-, level-, and range-dependent, with recovery to pre-click values occurring within the two-way travel time. Suppressive effects fit the patterns expected from forward masking by the emitted biosonar pulse, while the specific mechanisms responsible for the frequency-dependent enhancement are unknown.
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Affiliation(s)
- James J Finneran
- U.S. Navy Marine Mammal Program, Space and Naval Warfare Systems Center Pacific, Code 71510, 53560 Hull Street, San Diego, California 92152, USA
| | - Roxanne Echon
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106, USA
| | - Jason Mulsow
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106, USA
| | - Dorian S Houser
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106, USA
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32
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Heiler J, Elwen S, Kriesell H, Gridley T. Changes in bottlenose dolphin whistle parameters related to vessel presence, surface behaviour and group composition. Anim Behav 2016. [DOI: 10.1016/j.anbehav.2016.04.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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33
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Fais A, Johnson M, Wilson M, Aguilar Soto N, Madsen PT. Sperm whale predator-prey interactions involve chasing and buzzing, but no acoustic stunning. Sci Rep 2016; 6:28562. [PMID: 27340122 PMCID: PMC4919788 DOI: 10.1038/srep28562] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 06/07/2016] [Indexed: 11/09/2022] Open
Abstract
The sperm whale carries a hypertrophied nose that generates powerful clicks for long-range echolocation. However, it remains a conundrum how this bizarrely shaped apex predator catches its prey. Several hypotheses have been advanced to propose both active and passive means to acquire prey, including acoustic debilitation of prey with very powerful clicks. Here we test these hypotheses by using sound and movement recording tags in a fine-scale study of buzz sequences to relate the acoustic behaviour of sperm whales with changes in acceleration in their head region during prey capture attempts. We show that in the terminal buzz phase, sperm whales reduce inter-click intervals and estimated source levels by 1-2 orders of magnitude. As a result, received levels at the prey are more than an order of magnitude below levels required for debilitation, precluding acoustic stunning to facilitate prey capture. Rather, buzzing involves high-frequency, low amplitude clicks well suited to provide high-resolution biosonar updates during the last stages of capture. The high temporal resolution helps to guide motor patterns during occasionally prolonged chases in which prey are eventually subdued with the aid of fast jaw movements and/or buccal suction as indicated by acceleration transients (jerks) near the end of buzzes.
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Affiliation(s)
- A Fais
- BIOECOMAC. Dept. of Animal Biology, La Laguna University, Spain.,Zoophysiology, Department of Bioscience, Aarhus University, Denmark
| | - M Johnson
- Scottish Ocean Institute, University of St. Andrews, Scotland
| | - M Wilson
- Zoophysiology, Department of Bioscience, Aarhus University, Denmark.,Institute of Biology, University of Southern Denmark, Denmark
| | - N Aguilar Soto
- BIOECOMAC. Dept. of Animal Biology, La Laguna University, Spain.,CREEM, University of St. Andrews, Scotland
| | - P T Madsen
- Zoophysiology, Department of Bioscience, Aarhus University, Denmark.,Murdoch University Cetacean Research Unit, Murdoch University, South Street, Murdoch, Western Australia 6150, Australia
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34
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Kugler K, Greiter W, Luksch H, Firzlaff U, Wiegrebe L. Echo-acoustic flow affects flight in bats. ACTA ACUST UNITED AC 2016; 219:1793-7. [PMID: 27045094 DOI: 10.1242/jeb.139345] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 03/21/2016] [Indexed: 11/20/2022]
Abstract
Flying animals need to react fast to rapid changes in their environment. Visually guided animals use optic flow, generated by their movement through structured environments. Nocturnal bats cannot make use of optic flow, but rely mostly on echolocation. Here, we show that bats exploit echo-acoustic flow to negotiate flight through narrow passages. Specifically, bats' flight between lateral structures is significantly affected by the echo-acoustic salience of those structures, independent of their physical distance. This is true even though echolocation, unlike vision, provides explicit distance cues. Moreover, the bats reduced the echolocation sound levels in stronger flow, probably to compensate for the increased summary target strength of the lateral reflectors. However, bats did not reduce flight velocity under stronger echo-acoustic flow. Our results demonstrate that sensory flow is a ubiquitous principle for flight guidance, independent of the fundamentally different peripheral representation of flow across the senses of vision and echolocation.
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Affiliation(s)
- Kathrin Kugler
- Division of Neurobiology, Department Biology II, LMU Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany
| | - Wolfgang Greiter
- Lehrstuhl für Zoologie, Technische Universität München, Liesel-Beckmann-Str. 4, 85354 Freising, Germany
| | - Harald Luksch
- Lehrstuhl für Zoologie, Technische Universität München, Liesel-Beckmann-Str. 4, 85354 Freising, Germany
| | - Uwe Firzlaff
- Lehrstuhl für Zoologie, Technische Universität München, Liesel-Beckmann-Str. 4, 85354 Freising, Germany
| | - Lutz Wiegrebe
- Division of Neurobiology, Department Biology II, LMU Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany
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35
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Wang ZT, W L Au W, Rendell L, Wang KX, Wu HP, Wu YP, Liu JC, Duan GQ, Cao HJ, Wang D. Apparent source levels and active communication space of whistles of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis) in the Pearl River Estuary and Beibu Gulf, China. PeerJ 2016; 4:e1695. [PMID: 26893973 PMCID: PMC4756734 DOI: 10.7717/peerj.1695] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 01/26/2016] [Indexed: 11/20/2022] Open
Abstract
Background. Knowledge of species-specific vocalization characteristics and their associated active communication space, the effective range over which a communication signal can be detected by a conspecific, is critical for understanding the impacts of underwater acoustic pollution, as well as other threats. Methods. We used a two-dimensional cross-shaped hydrophone array system to record the whistles of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis) in shallow-water environments of the Pearl River Estuary (PRE) and Beibu Gulf (BG), China. Using hyperbolic position fixing, which exploits time differences of arrival of a signal between pairs of hydrophone receivers, we obtained source location estimates for whistles with good signal-to-noise ratio (SNR ≥10 dB) and not polluted by other sounds and back-calculated their apparent source levels (ASL). Combining with the masking levels (including simultaneous noise levels, masking tonal threshold, and the Sousa auditory threshold) and the custom made site-specific sound propagation models, we further estimated their active communication space (ACS). Results. Humpback dolphins produced whistles with average root-mean-square ASL of 138.5 ± 6.8 (mean ± standard deviation) and 137.2 ± 7.0 dB re 1 µPa in PRE (N = 33) and BG (N = 209), respectively. We found statistically significant differences in ASLs among different whistle contour types. The mean and maximum ACS of whistles were estimated to be 14.7 ± 2.6 (median ± quartile deviation) and 17.1± 3.5 m in PRE, and 34.2 ± 9.5 and 43.5 ± 12.2 m in BG. Using just the auditory threshold as the masking level produced the mean and maximum ACSat of 24.3 ± 4.8 and 35.7 ± 4.6 m for PRE, and 60.7 ± 18.1 and 74.3 ± 25.3 m for BG. The small ACSs were due to the high ambient noise level. Significant differences in ACSs were also observed among different whistle contour types. Discussion. Besides shedding some light for evaluating appropriate noise exposure levels and information for the regulation of underwater acoustic pollution, these baseline data can also be used for aiding the passive acoustic monitoring of dolphin populations, defining the boundaries of separate groups in a more biologically meaningful way during field surveys, and guiding the appropriate approach distance for local dolphin-watching boats and research boat during focal group following.
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Affiliation(s)
- Zhi-Tao Wang
- The Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology of the Chinese Academy of Sciences, Wuhan, Hubei, China; University of Chinese Academy of Sciences, Beijing, China; Marine Mammal Research Program, Hawaii Institute of Marine Biology, University of Hawaii, Hawaii, HI, United States of America; Current affiliation: Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University, Beaufort, NC, United States of America
| | - Whitlow W L Au
- Marine Mammal Research Program, Hawaii Institute of Marine Biology, University of Hawaii , Hawaii, HI , United States of America
| | - Luke Rendell
- Sea Mammal Research Unit, School of Biology, University of St. Andrews , Fife , United Kingdom
| | - Ke-Xiong Wang
- The Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology of the Chinese Academy of Sciences , Wuhan, Hubei , China
| | - Hai-Ping Wu
- School of Marine Sciences, Qinzhou University , Guangxi , China
| | - Yu-Ping Wu
- School of Marine Sciences, Sun Yat-Sen University , Guangzhou , China
| | - Jian-Chang Liu
- Transport Planning and Research Institute, Ministry of Transport , Guangzhou , China
| | - Guo-Qin Duan
- Hongkong-Zhuhai-Macao Bridge Authority , Guangzhou , China
| | - Han-Jiang Cao
- Hongkong-Zhuhai-Macao Bridge Authority , Guangzhou , China
| | - Ding Wang
- The Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology of the Chinese Academy of Sciences , Wuhan, Hubei , China
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36
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Zheng K, Fan X, Mao Y, Lin J, Dai W, Zhang J, Cheng J. The well-designed hierarchical structure of Musa basjoo for supercapacitors. Sci Rep 2016; 6:20306. [PMID: 26842714 PMCID: PMC4740865 DOI: 10.1038/srep20306] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 12/30/2015] [Indexed: 11/12/2022] Open
Abstract
Application of biological structure is one of the hottest topics in the field of science and technology. The unimaginable and excellent architectures of living beings supporting their vital activities have attracted the interests of worldwide researchers. An intriguing example is Musa basjoo which belongs to the herb, while appears like a tree. The profound mystery of structure and potential application of Musa basjoo have not been probed. Here we show the finding of the hierarchical structure of Musa basjoo and the outstanding electrochemical performance of the super-capacitors fabricated through the simple carbonization of Musa basjoo followed by KOH activation. Musa basjoo has three layers of structure: nanometer-level, micrometer-level and millimeter-level. The nanometer-level structure constructs the micrometer-level structure, while the micrometer-level structure constructs the millimeter-level structure. Based on this hierarchical structure, Musa basjoo reduces the unnecessary weight and therefore supports its huge body. The super-capacitors derived from Musa basjoo display a high specific capacitance and a good cycling stability. This enlightening work opens a window for the applications of the natural structure and we hope that more and more people could pay attention to the bio-inspired materials.
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Affiliation(s)
- Kaiwen Zheng
- Key Laboratory of Carbon Fiber and Functional Polymers (Beijing University of Chemical Technology), Ministry of Education, Beijing 100029, China
| | - Xiaorong Fan
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
| | - Yingzhu Mao
- College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China
| | - Jingkai Lin
- College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China
| | - Wenxuan Dai
- Joint Research Centre for Biomedical Engineering, Department of Electronic Engineering, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Junying Zhang
- Key Laboratory of Carbon Fiber and Functional Polymers (Beijing University of Chemical Technology), Ministry of Education, Beijing 100029, China
| | - Jue Cheng
- Key Laboratory of Carbon Fiber and Functional Polymers (Beijing University of Chemical Technology), Ministry of Education, Beijing 100029, China
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37
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King S. Marine mammal observer and passive acoustic monitoring handbook. BIOACOUSTICS 2015. [DOI: 10.1080/09524622.2015.1079448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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38
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Fang L, Li S, Wang K, Wang Z, Shi W, Wang D. Echolocation signals of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis) in Sanniang Bay, China. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 138:1346-1352. [PMID: 26428773 DOI: 10.1121/1.4929492] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
While the low-frequency communication sounds of Indo-Pacific humpback dolphins (Sousa chinensis) have been reported in a number of papers, the high-frequency echolocation signals of Sousa chinensis, especially those living in the wild, have been less studied. In the current study, echolocation signals of humpback dolphins were recorded in Sanniang Bay, Guangxi Province, China, using a cross-type hydrophone array with five elements. In total, 77 candidate on-axis clicks from 77 scans were selected for analysis. The results showed that the varied peak-to-peak source levels ranged from 177.1 to 207.3 dB, with an average of 187.7 dB re: 1 μPa. The mean peak frequency was 109.0 kHz with a -3-dB bandwidth of 50.3 kHz and 95% energy duration of 22 μs. The -3-dB bandwidth was much broader than the root mean square bandwidth and exhibited a bimodal distribution. The center frequency exhibited a positive relationship with the peak-to-peak source level. The clicks of the wild Indo-Pacific humpback dolphins were short-duration, broadband, ultrasonic pulses, similar to those produced by other whistling dolphins of similar body size. However, the click source levels of the Indo-Pacific humpback dolphin appear to be lower than those of other whistling dolphins.
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Affiliation(s)
- Liang Fang
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
| | - Songhai Li
- Sanya Key Laboratory of Marine Mammal and Marine Bioacoustics, Sanya Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, People's Republic of China
| | - Kexiong Wang
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
| | - Zhitao Wang
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
| | - Wenjing Shi
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
| | - Ding Wang
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
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The Source Parameters of Echolocation Clicks from Captive and Free-Ranging Yangtze Finless Porpoises (Neophocaena asiaeorientalis asiaeorientalis). PLoS One 2015; 10:e0129143. [PMID: 26053758 PMCID: PMC4459872 DOI: 10.1371/journal.pone.0129143] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 05/04/2015] [Indexed: 11/19/2022] Open
Abstract
The clicks of Yangtze finless porpoises (Neophocaena asiaeorientalis asiaeorientalis) from 7 individuals in the tank of Baiji aquarium, 2 individuals in a netted pen at Shishou Tian-e-zhou Reserve and 4 free-ranging individuals at Tianxingzhou were recorded using a broadband digital recording system with four element hydrophones. The peak-to-peak apparent source level (ASL_pp) of clicks from individuals at the Baiji aquarium was 167 dB re 1 μPa with mean center frequency of 133 kHz, -3dB bandwidth of 18 kHz and -10 dB duration of 58 μs. The ASL_pp of clicks from individuals at the Shishou Tian-e-zhou Reserve was 180 dB re 1 μPa with mean center frequency of 128 kHz, -3dB bandwidth of 20 kHz and -10 dB duration of 39 μs. The ASL_pp of clicks from individuals at Tianxingzhou was 176 dB re 1 μPa with mean center frequency of 129 kHz, -3dB bandwidth of 15 kHz and -10 dB duration of 48 μs. Differences between the source parameters of clicks among the three groups of finless porpoises suggest these animals adapt to their echolocation signals depending on their surroundings.
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de Freitas M, Jensen FH, Tyne J, Bejder L, Madsen PT. Echolocation parameters of Australian humpback dolphins (Sousa sahulensis) and Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the wild. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 137:3033-41. [PMID: 26093395 DOI: 10.1121/1.4921277] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Echolocation is a key sensory modality for toothed whale orientation, navigation, and foraging. However, a more comparative understanding of the biosonar properties of toothed whales is necessary to understand behavioral and evolutionary adaptions. To address this, two free-ranging sympatric delphinid species, Australian humpback dolphins (Sousa sahulensis) and Indo-Pacific bottlenose dolphins (Tursiops aduncus), were studied. Biosonar clicks from both species were recorded within the same stretch of coastal habitat in Exmouth Gulf, Western Australia, using a vertical seven element hydrophone array. S. sahulensis used biosonar clicks with a mean source level of 199 ± 3 dB re 1 μPa peak-peak (pp), mean centroid frequency of 106 ± 11 kHz, and emitted at interclick intervals (ICIs) of 79 ± 33 ms. These parameters were similar to click parameters of sympatric T. aduncus, characterized by mean source levels of 204 ± 4 dB re 1 μPa pp, centroid frequency of 112 ± 9 kHz, and ICIs of 73 ± 29 ms. These properties are comparable to those of other similar sized delphinids and suggest that biosonar parameters are independent of sympatric delphinids and possibly driven by body size. The dynamic biosonar behavior of these delphinids may have, consequently, allowed for adaptations to local environments through high levels of control over sonar beam properties.
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Affiliation(s)
- Mafalda de Freitas
- Zoophysiology, Department of Bioscience, Aarhus University, Building 1131, C.F. Moellers Alle 3, DK-8000 Aarhus C, Denmark
| | - Frants H Jensen
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey 08544, USA
| | - Julian Tyne
- Murdoch University Cetacean Research Unit, School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch, Western Australia 6150, Australia
| | - Lars Bejder
- Murdoch University Cetacean Research Unit, School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch, Western Australia 6150, Australia
| | - Peter T Madsen
- Zoophysiology, Department of Bioscience, Aarhus University, Building 1131, C.F. Moellers Alle 3, DK-8000 Aarhus C, Denmark
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Supin AY, Popov VV. Evoked-potential recovery during double click stimulation in a beluga whale: implications for biosonar gain control. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 137:2512-2521. [PMID: 25994684 DOI: 10.1121/1.4919300] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Auditory evoked potentials (AEPs) were recorded in a beluga whale Delphinapterus leucas using a double-pulse stimulation paradigm, specifically measuring the recovery (release from masking) of the second (test) response as a function of delay after the first (conditioning) pulse at various levels of the conditioning and test stimuli. The conditioning/test stimulus level ratio influenced the recovery time (the higher the ratio, the longer the recovery). This interrelation was used to evaluate the intensity/time trade in release from forward masking. Trade was evaluated as 32.2 dB per time decade. Data were considered as simulating interactions between the transmitted pulse and echo during echolocation, assuming that a transmitted sonar pulse produces forward masking of the echo response. With increased target distance, the attenuation of the echo may be compensated by the release from masking. According to the model, the compensation results in substantial stabilization of the echo response even if the intensity/time trade of release from masking is not precisely equal to the rate of echo attenuation with distance.
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Affiliation(s)
- Alexander Ya Supin
- Institute of Ecology and Evolution, Russian Academy of Sciences., 33 Leninsky Prospect, 119071 Moscow, Russia
| | - Vladimir V Popov
- Institute of Ecology and Evolution, Russian Academy of Sciences., 33 Leninsky Prospect, 119071 Moscow, Russia
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Tyack P. Clicking for supper. eLife 2015; 4:e07690. [PMID: 25922991 PMCID: PMC4413020 DOI: 10.7554/elife.07690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
When close to prey, porpoises actively widen their sonar beam, which may make it harder for the prey to escape.
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Affiliation(s)
- Peter Tyack
- School of Biology, University of St. Andrews, St. Andrews, United Kingdom
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Wisniewska DM, Ratcliffe JM, Beedholm K, Christensen CB, Johnson M, Koblitz JC, Wahlberg M, Madsen PT. Range-dependent flexibility in the acoustic field of view of echolocating porpoises (Phocoena phocoena). eLife 2015; 4:e05651. [PMID: 25793440 PMCID: PMC4413254 DOI: 10.7554/elife.05651] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 03/19/2015] [Indexed: 12/03/2022] Open
Abstract
Toothed whales use sonar to detect, locate, and track prey. They adjust emitted sound intensity, auditory sensitivity and click rate to target range, and terminate prey pursuits with high-repetition-rate, low-intensity buzzes. However, their narrow acoustic field of view (FOV) is considered stable throughout target approach, which could facilitate prey escape at close-range. Here, we show that, like some bats, harbour porpoises can broaden their biosonar beam during the terminal phase of attack but, unlike bats, maintain the ability to change beamwidth within this phase. Based on video, MRI, and acoustic-tag recordings, we propose this flexibility is modulated by the melon and implemented to accommodate dynamic spatial relationships with prey and acoustic complexity of surroundings. Despite independent evolution and different means of sound generation and transmission, whales and bats adaptively change their FOV, suggesting that beamwidth flexibility has been an important driver in the evolution of echolocation for prey tracking. DOI:http://dx.doi.org/10.7554/eLife.05651.001 Bats and toothed whales such as porpoises have independently evolved the same solution for hunting prey when it is hard to see. Bats hunt in the dark with little light to allow them to see the insects they chase. Porpoises hunt in murky water where different ocean environments can quickly obscure fish from view. So, both bats and porpoises evolved to emit a beam of sound and then track their prey based on the echoes of that sound bouncing off the prey and other objects. This process is called echolocation. A narrow beam of sound can help a porpoise or bat track distant prey. But as either animal closes in on its prey such a narrow sound beam can be a disadvantage because prey can easily escape to one side. Scientists recently found that bats can widen their sound beam as they close in on prey by changing the frequency—or pitch—of the signal they emit or by adjusting how they open their mouth. Porpoises, by contrast, create their echolocation clicks by forcing air through a structure in their blowhole called the phonic lips. The sound is transmitted through a fatty structure on the front of their head known as the melon, which gives these animals their characteristic round-headed look, before being transmitted into the sea. Porpoises would also likely benefit from widening their echolocation beam as they approach prey, but it was not clear if and how they could do this. Wisniewska et al. used 48 tightly spaced underwater microphones to record the clicks emitted by three captive porpoises as they approached a target or a fish. This revealed that in the last stage of their approach, the porpoises could triple the area their sound beam covered, giving them a ‘wide angle view’ as they closed in. This widening of the sound beam occurred during a very rapid series of echolocation signals called a buzz, which porpoises and bats perform at the end of a pursuit. Unlike bats, porpoises are able to continue to change the width of their sound beam throughout the buzz. Wisniewska et al. also present a video that shows that the shape of the porpoise's melon changes rapidly during a buzz, which may explain the widening beam. Furthermore, images obtained using a technique called magnetic resonance imaging (MRI) revealed that a porpoise has a network of facial muscles that are capable of producing these beam-widening melon distortions. As both bats and porpoises have evolved the capability to adjust the width of their sound beam, this ability is likely to be crucial for hunting effectively using echolocation. DOI:http://dx.doi.org/10.7554/eLife.05651.002
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Affiliation(s)
| | - John M Ratcliffe
- Sound and Behaviour Group, Institute of Biology, University of Southern Denmark, Odense, Denmark
| | - Kristian Beedholm
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | | | - Mark Johnson
- Scottish Oceans Institute, University of St Andrews, St Andrews, Scotland
| | - Jens C Koblitz
- Animal Physiology, Institute for Neurobiology, University of Tübingen, Tübingen, Germany
| | - Magnus Wahlberg
- Sound and Behaviour Group, Institute of Biology, University of Southern Denmark, Odense, Denmark
| | - Peter T Madsen
- Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
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Sperm whale echolocation behaviour reveals a directed, prior-based search strategy informed by prey distribution. Behav Ecol Sociobiol 2015. [DOI: 10.1007/s00265-015-1877-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Wisniewska DM, Johnson M, Nachtigall PE, Madsen PT. Buzzing during biosonar-based interception of prey in the delphinids Tursiops truncatus and Pseudorca crassidens. ACTA ACUST UNITED AC 2014; 217:4279-82. [PMID: 25394631 DOI: 10.1242/jeb.113415] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Echolocating bats and toothed whales probe their environment with ultrasonic sound pulses, using returning echoes to navigate and find prey in a process that appears to have resulted from a remarkable convergence of the two taxa. Here, we report the first detailed quantification of echolocation behaviour during prey capture in the most studied delphinid species, a false killer whale and a bottlenose dolphin. Using acoustic DTAGs, we demonstrate that just prior to prey interception these delphinids change their acoustic gaze dramatically by reducing inter-click intervals and output >10-fold in a high repetition rate, low output buzz. Buzz click rates of 250-500 Hz for large but agile animals suggest that sampling rates during capture are scaled with the whale's manoeuvrability. These observations support the growing notion that fast sonar sampling accompanied by a low output level is critical for high rate feedback to inform motor patterns during prey interception in all echolocating toothed whales.
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Affiliation(s)
- Danuta M Wisniewska
- Marine Mammal Research, Bioscience, Aarhus University, Roskilde DK-4000, Denmark. Zoophysiology, Bioscience, Aarhus University, Aarhus DK-8000, Denmark.
| | - Mark Johnson
- Scottish Oceans Institute, University of St Andrews, St Andrews KY16 8LB, UK
| | | | - Peter T Madsen
- Zoophysiology, Bioscience, Aarhus University, Aarhus DK-8000, Denmark
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Finneran JJ, Branstetter BK, Houser DS, Moore PW, Mulsow J, Martin C, Perisho S. High-resolution measurement of a bottlenose dolphin's (Tursiops truncatus) biosonar transmission beam pattern in the horizontal plane. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2014; 136:2025-2038. [PMID: 25324101 DOI: 10.1121/1.4895682] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Previous measurements of toothed whale echolocation transmission beam patterns have utilized few hydrophones and have therefore been limited to fine angular resolution only near the principal axis or poor resolution over larger azimuthal ranges. In this study, a circular, horizontal planar array of 35 hydrophones was used to measure a dolphin's transmission beam pattern with 5° to 10° resolution at azimuths from -150° to +150°. Beam patterns and directivity indices were calculated from both the peak-peak sound pressure and the energy flux density. The emitted pulse became smaller in amplitude and progressively distorted as it was recorded farther off the principal axis. Beyond ±30° to 40°, the off-axis signal consisted of two distinct pulses whose difference in time of arrival increased with the absolute value of the azimuthal angle. A simple model suggests that the second pulse is best explained as a reflection from internal structures in the dolphin's head, and does not implicate the use of a second sound source. Click energy was also more directional at the higher source levels utilized at longer ranges, where the center frequency was elevated compared to that of the lower amplitude clicks used at shorter range.
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Affiliation(s)
- James J Finneran
- U.S. Navy Marine Mammal Program, Space and Naval Warfare Systems Center Pacific, Code 71510, 53560 Hull Street, San Diego, California 92152
| | - Brian K Branstetter
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106
| | - Dorian S Houser
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106
| | - Patrick W Moore
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106
| | - Jason Mulsow
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106
| | - Cameron Martin
- Naval Research Enterprise Internship Program (NREIP), 1818 N Street Northwest, Suite 600, Washington, DC 20036
| | - Shaun Perisho
- Department of Psychology, University of Southern Mississippi, 118 College Drive, #5025, Hattiesburg, Mississippi 39406
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Kloepper LN, Smith AB, Nachtigall PE, Buck JR, Simmons JA, Pacini AF. Cognitive adaptation of sonar gain control in the bottlenose dolphin. PLoS One 2014; 9:e105938. [PMID: 25153530 PMCID: PMC4143348 DOI: 10.1371/journal.pone.0105938] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 07/30/2014] [Indexed: 11/19/2022] Open
Abstract
Echolocating animals adjust the transmit intensity and receive sensitivity of their sonar in order to regulate the sensation level of their echoes; this process is often termed automatic gain control. Gain control is considered not to be under the animal's cognitive control, but previous investigations studied animals ensonifying targets or hydrophone arrays at predictable distances. To test whether animals maintain gain control at a fixed level in uncertain conditions, we measured changes in signal intensity for a bottlenose dolphin (Tursiops truncatus) detecting a target at three target distances (2.5, 4 and 7 m) in two types of sessions: predictable and unpredictable. Predictable sessions presented the target at a constant distance; unpredictable sessions moved the target randomly between the three target positions. In the predictable sessions the dolphin demonstrated intensity distance compensation, increasing the emitted click intensity as the target distance increased. Additionally, as trials within sessions progressed, the animal adjusted its click intensity even from the first click in a click train, which is consistent with the animal expecting a target at a certain range. In the unpredictable sessions there was no significant difference of intensity with target distance until after the 7th click in a click train. Together, these results demonstrate that the bottlenose dolphin uses learning and expectation for sonar gain control.
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Affiliation(s)
- Laura N. Kloepper
- Department of Neuroscience, Brown University, Providence, Rhode Island, United States of America
- Electrical and Computer Engineering, University of Massachusetts Dartmouth, Dartmouth, Massachusetts, United States of America
| | - Adam B. Smith
- Department of Zoology, University of Hawaii, Honolulu, Hawaii, United States of America
| | - Paul E. Nachtigall
- Department of Zoology, University of Hawaii, Honolulu, Hawaii, United States of America
| | - John R. Buck
- Electrical and Computer Engineering, University of Massachusetts Dartmouth, Dartmouth, Massachusetts, United States of America
| | - James A. Simmons
- Department of Neuroscience, Brown University, Providence, Rhode Island, United States of America
| | - Aude F. Pacini
- Department of Zoology, University of Hawaii, Honolulu, Hawaii, United States of America
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Macías S, Hechavarría JC, Cobo A, Mora EC. Narrow sound pressure level tuning in the auditory cortex of the bats Molossus molossus and Macrotus waterhousii. Hear Res 2014; 309:36-43. [DOI: 10.1016/j.heares.2013.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 11/09/2013] [Accepted: 11/13/2013] [Indexed: 11/26/2022]
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50
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Fenton B, Jensen FH, Kalko EKV, Tyack PL. Sonar Signals of Bats and Toothed Whales. BIOSONAR 2014. [DOI: 10.1007/978-1-4614-9146-0_2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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