1
|
Jansen W, Steckel J. SonoNERFs: Neural Radiance Fields Applied to Biological Echolocation Systems Allow 3D Scene Reconstruction through Perceptual Prediction. Biomimetics (Basel) 2024; 9:321. [PMID: 38921202 PMCID: PMC11201853 DOI: 10.3390/biomimetics9060321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Revised: 05/24/2024] [Accepted: 05/25/2024] [Indexed: 06/27/2024] Open
Abstract
In this paper, we introduce SonoNERFs, a novel approach that adapts Neural Radiance Fields (NeRFs) to model and understand the echolocation process in bats, focusing on the challenges posed by acoustic data interpretation without phase information. Leveraging insights from the field of optical NeRFs, our model, termed SonoNERF, represents the acoustic environment through Neural Reflectivity Fields. This model allows us to reconstruct three-dimensional scenes from echolocation data, obtained by simulating how bats perceive their surroundings through sound. By integrating concepts from biological echolocation and modern computational models, we demonstrate the SonoNERF's ability to predict echo spectrograms for unseen echolocation poses and effectively reconstruct a mesh-based and energy-based representation of complex scenes. Our work bridges a gap in understanding biological echolocation and proposes a methodological framework that provides a first-order model of how scene understanding might arise in echolocating animals. We demonstrate the efficacy of the SonoNERF model on three scenes of increasing complexity, including some biologically relevant prey-predator interactions.
Collapse
Affiliation(s)
- Wouter Jansen
- Cosys-Lab, Faculty of Applied Engineering, University of Antwerp, 2020 Antwerpen, Belgium;
- Flanders Make Strategic Research Centre, 3920 Lommel, Belgium
| | - Jan Steckel
- Cosys-Lab, Faculty of Applied Engineering, University of Antwerp, 2020 Antwerpen, Belgium;
- Flanders Make Strategic Research Centre, 3920 Lommel, Belgium
| |
Collapse
|
2
|
Fritts SR, Guest EE, Weaver SP, Hale AM, Morton BP, Hein CD. Experimental trials of species-specific bat flight responses to an ultrasonic deterrent. PeerJ 2024; 12:e16718. [PMID: 38188150 PMCID: PMC10771094 DOI: 10.7717/peerj.16718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 12/04/2023] [Indexed: 01/09/2024] Open
Abstract
Unintended consequences of increasing wind energy production include bat mortalities from wind turbine blade strikes. Ultrasonic deterrents (UDs) have been developed to reduce bat mortalities at wind turbines. Our goal was to experimentally assess the species-specific effectiveness of three emission treatments from the UD developed by NRG Systems. We conducted trials in a flight cage measuring approximately 60 m × 10 m × 4.4 m (length × width × height) from July 2020 to May 2021 in San Marcos, Texas, USA. A single UD was placed at either end of the flight cage, and we randomly selected one for each night of field trials. Trials focused on a red bat species group (Lasiurus borealis and Lasiurus blossevillii; n = 46) and four species: cave myotis (Myotis velifer; n = 57), Brazilian free-tailed bats (Tadarida brasiliensis; n = 73), evening bats (Nycteceius humeralis; n = 53), and tricolored bats (Perimyotis subflavus; n = 17). The trials occurred during three treatment emissions: low (emissions from subarrays at 20, 26, and 32 kHz), high (emissions from subarrays at 38, 44, and 50 kHz), and combined (all six emission frequencies). We placed one wild-captured bat into the flight cage for each trial, which consisted of an acclimation period, a control period with the UD powered off, and the three emission treatments (order randomly selected), each interspersed with a control period. We tracked bat flight using four thermal cameras placed outside the flight cage. We quantified the effectiveness of each treatment by comparing the distances each bat flew from the UD during each treatment vs. the control period using quantile regression. Additionally, we conducted an exploratory analysis of differences between sex and season and sex within season using analysis of variance. Broadly, UDs were effective at altering the bats' flight paths as they flew farther from the UD during treatments than during controls; however, results varied by species, sex, season, and sex within season. For the red bat group, bats flew farther from the UD during all treatments than during the control period at all percentiles (p < 0.001), and treatments were comparable in effectiveness. For cave myotis, all percentile distances were farther from the UD during each of the treatments than during the control, except the 90th percentile distance during high, and low was most effective. For evening bats and Brazilian free-tailed bats, results were inconsistent, but high and low were most effective, respectively. For tricolored bats, combined and low were significant at the 10th-75th percentiles, high was significant at all percentiles, and combined was most effective. Results suggest UDs may be an effective means of reducing bat mortalities due to wind turbine blade strikes. We recommend that continued research on UDs focus on low emission treatments, which have decreased sound attenuation and demonstrated effectiveness across the bat species evaluated in this study.
Collapse
Affiliation(s)
| | - Emma Elizabeth Guest
- Department of Biology, Texas State University, San Marcos, Texas, United States
- Bowman, San Marcos, Texas, United States
| | | | - Amanda Marie Hale
- Department of Biology, Texas Christian University, Fort Worth, Texas, United States
- Western EcoSystems Technology, Inc., Cheyenne, Wyoming, United States
| | | | - Cris Daniel Hein
- National Renewable Energy Laboratory, Arvada, Colorado, United States
| |
Collapse
|
3
|
Vaglietti S, Villeri V, Dell’Oca M, Marchetti C, Cesano F, Rizzo F, Miller D, LaPierre L, Pelassa I, Monje FJ, Colnaghi L, Ghirardi M, Fiumara F. PolyQ length-based molecular encoding of vocalization frequency in FOXP2. iScience 2023; 26:108036. [PMID: 37860754 PMCID: PMC10582585 DOI: 10.1016/j.isci.2023.108036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 07/18/2023] [Accepted: 09/21/2023] [Indexed: 10/21/2023] Open
Abstract
The transcription factor FOXP2, a regulator of vocalization- and speech/language-related phenotypes, contains two long polyQ repeats (Q1 and Q2) displaying marked, still enigmatic length variation across mammals. We found that the Q1/Q2 length ratio quantitatively encodes vocalization frequency ranges, from the infrasonic to the ultrasonic, displaying striking convergent evolution patterns. Thus, species emitting ultrasonic vocalizations converge with bats in having a low ratio, whereas species vocalizing in the low-frequency/infrasonic range converge with elephants and whales, which have higher ratios. Similar, taxon-specific patterns were observed for the FOXP2-related protein FOXP1. At the molecular level, we observed that the FOXP2 polyQ tracts form coiled coils, assembling into condensates and fibrils, and drive liquid-liquid phase separation (LLPS). By integrating evolutionary and molecular analyses, we found that polyQ length variation related to vocalization frequency impacts FOXP2 structure, LLPS, and transcriptional activity, thus defining a novel form of polyQ length-based molecular encoding of vocalization frequency.
Collapse
Affiliation(s)
- Serena Vaglietti
- Rita Levi Montalcini Department of Neuroscience, University of Turin, 10125 Turin, Italy
| | - Veronica Villeri
- Rita Levi Montalcini Department of Neuroscience, University of Turin, 10125 Turin, Italy
| | - Marco Dell’Oca
- Rita Levi Montalcini Department of Neuroscience, University of Turin, 10125 Turin, Italy
| | - Chiara Marchetti
- Rita Levi Montalcini Department of Neuroscience, University of Turin, 10125 Turin, Italy
| | - Federico Cesano
- Department of Chemistry, University of Turin, 10125 Turin, Italy
| | - Francesca Rizzo
- Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR 518057, China
| | - Dave Miller
- Cascades Pika Watch, Oregon Zoo, Portland, OR 97221, USA
| | - Louis LaPierre
- Deptartment of Natural Science, Lower Columbia College, Longview, WA 98632, USA
| | - Ilaria Pelassa
- Rita Levi Montalcini Department of Neuroscience, University of Turin, 10125 Turin, Italy
| | - Francisco J. Monje
- Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Luca Colnaghi
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
- School of Medicine, Vita-Salute San Raffaele University, 20132 Milan, Italy
| | - Mirella Ghirardi
- Rita Levi Montalcini Department of Neuroscience, University of Turin, 10125 Turin, Italy
| | - Ferdinando Fiumara
- Rita Levi Montalcini Department of Neuroscience, University of Turin, 10125 Turin, Italy
| |
Collapse
|
4
|
Hermans C, Koblitz JC, Bartholomeus H, Stilz P, Visser ME, Spoelstra K. Combining acoustic tracking and LiDAR to study bat flight behaviour in three-dimensional space. MOVEMENT ECOLOGY 2023; 11:25. [PMID: 37101233 PMCID: PMC10131301 DOI: 10.1186/s40462-023-00387-0] [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: 10/31/2022] [Accepted: 04/16/2023] [Indexed: 06/19/2023]
Abstract
BACKGROUND Habitat structure strongly influences niche differentiation, facilitates predator avoidance, and drives species-specific foraging strategies of bats. Vegetation structure is also a strong driver of echolocation call characteristics. The fine-scale assessment of how bats utilise such structures in their natural habitat is instrumental in understanding how habitat composition shapes flight- and acoustic behaviour. However, it is notoriously difficult to study their species-habitat relationship in situ. METHODS Here, we describe a methodology combining Light Detection and Ranging (LiDAR) to characterise three-dimensional vegetation structure and acoustic tracking to map bat behaviour. This makes it possible to study fine-scale use of habitat by bats, which is essential to understand spatial niche segregation in bats. Bats were acoustically tracked with microphone arrays and bat calls were classified to bat guild using automated identification. We did this in multiple LiDAR scanned vegetation plots in forest edge habitat. The datasets were spatially aligned to calculate the distance between bats' positions and vegetation structures. RESULTS Our results are a proof of concept of combining LiDAR with acoustic tracking. Although it entails challenges with combining mass-volumes of fine-scale bat movements and vegetation information, we show the feasibility and potential of combining those two methods through two case studies. The first one shows stereotyped flight patterns of pipistrelles around tree trunks, while the second one presents the distance that bats keep to the vegetation in the presence of artificial light. CONCLUSION By combining bat guild specific spatial behaviour with precise information on vegetation structure, the bat guild specific response to habitat characteristics can be studied in great detail. This opens up the possibility to address yet unanswered questions on bat behaviour, such as niche segregation or response to abiotic factors in interaction with natural vegetation. This combination of techniques can also pave the way for other applications linking movement patterns of other vocalizing animals and 3D space reconstruction.
Collapse
Affiliation(s)
- Claire Hermans
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.
| | - Jens C Koblitz
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
- Max Planck Institute of Animal Behavior, Constance, Germany
| | - Harm Bartholomeus
- Laboratory of Geo-Information Science and Remote Sensing, Wageningen University & Research, Wageningen, The Netherlands
| | - Peter Stilz
- Animal Physiology, Institute for Neurobiology, University of Tübingen, Tübingen, Germany
| | - Marcel E Visser
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Kamiel Spoelstra
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| |
Collapse
|
5
|
Hu Y, Wang X, Xu Y, Yang H, Tong Z, Tian R, Xu S, Yu L, Guo Y, Shi P, Huang S, Yang G, Shi S, Wei F. Molecular mechanisms of adaptive evolution in wild animals and plants. SCIENCE CHINA. LIFE SCIENCES 2023; 66:453-495. [PMID: 36648611 PMCID: PMC9843154 DOI: 10.1007/s11427-022-2233-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 08/30/2022] [Indexed: 01/18/2023]
Abstract
Wild animals and plants have developed a variety of adaptive traits driven by adaptive evolution, an important strategy for species survival and persistence. Uncovering the molecular mechanisms of adaptive evolution is the key to understanding species diversification, phenotypic convergence, and inter-species interaction. As the genome sequences of more and more non-model organisms are becoming available, the focus of studies on molecular mechanisms of adaptive evolution has shifted from the candidate gene method to genetic mapping based on genome-wide scanning. In this study, we reviewed the latest research advances in wild animals and plants, focusing on adaptive traits, convergent evolution, and coevolution. Firstly, we focused on the adaptive evolution of morphological, behavioral, and physiological traits. Secondly, we reviewed the phenotypic convergences of life history traits and responding to environmental pressures, and the underlying molecular convergence mechanisms. Thirdly, we summarized the advances of coevolution, including the four main types: mutualism, parasitism, predation and competition. Overall, these latest advances greatly increase our understanding of the underlying molecular mechanisms for diverse adaptive traits and species interaction, demonstrating that the development of evolutionary biology has been greatly accelerated by multi-omics technologies. Finally, we highlighted the emerging trends and future prospects around the above three aspects of adaptive evolution.
Collapse
Affiliation(s)
- Yibo Hu
- CAS Key Lab of Animal Ecology and Conservation Biology, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Xiaoping Wang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, School of Life Sciences, Yunnan University, Kunming, 650091, China
| | - Yongchao Xu
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Hui Yang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650201, China
| | - Zeyu Tong
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Ran Tian
- College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Shaohua Xu
- State Key Laboratory of Biocontrol, Guangdong Key Lab of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Li Yu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, School of Life Sciences, Yunnan University, Kunming, 650091, China.
| | - Yalong Guo
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
| | - Peng Shi
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650201, China.
| | - Shuangquan Huang
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
| | - Guang Yang
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.
- College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China.
| | - Suhua Shi
- State Key Laboratory of Biocontrol, Guangdong Key Lab of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China.
| | - Fuwen Wei
- CAS Key Lab of Animal Ecology and Conservation Biology, Chinese Academy of Sciences, Beijing, 100101, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.
| |
Collapse
|
6
|
Guo WJ, Wu Y, He K, Hu YB, Wang XY, Yu WH, Wang XY, Yu WH. Unraveling the macroevolution of horseshoe bats (Chiroptera: Rhinolophidae: Rhinolophus). Zool Res 2023; 44:169-182. [PMID: 36579403 PMCID: PMC9841180 DOI: 10.24272/j.issn.2095-8137.2022.265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Unraveling the diversification mechanisms of organisms is a fundamental and important macroevolutionary question regarding the diversity, ecological niche, and morphological divergence of life. However, many studies have only explored diversification mechanisms via isolated factors. Here, based on comparative phylogenetic analysis, we performed a macroevolutionary examination of horseshoe bats (Chiroptera: Rhinolophidae: Rhinolophus), to reveal the inter-relationships among diversification, intrinsic/extrinsic factors, and climatic ecological niche characteristics. Results showed a general slowing trajectory during diversification, with two dispersal events from Asia into Southeast Asia and Africa playing key roles in shaping regional heterogeneous diversity. Morphospace expansions of the investigated traits (e.g., body size, echolocation, and climate niche) revealed a decoupled pattern between diversification trajectory and trait divergence, suggesting that other factors (e.g., biotic interactions) potentially played a key role in recent diversification. Based on ancestral traits and pathway analyses, most Rhinolophus lineages belonging to the same region overlapped with each other geographically and were positively associated with the diversification rate, implying a competitive prelude to speciation. Overall, our study showed that multiple approaches need to be integrated to address diversification history. Rather than a single factor, the joint effects of multiple factors (biogeography, environmental drivers, and competition) are responsible for the current diversity patterns in horseshoe bats, and a corresponding multifaceted strategy is recommended to study these patterns in the future.
Collapse
Affiliation(s)
- Wei-Jian Guo
- Key Laboratory of Conservation and Application in Biodiversity of South China, School of Life Sciences, Guangzhou University, Guangzhou, Guangdong 510000, China
| | - Yi Wu
- Key Laboratory of Conservation and Application in Biodiversity of South China, School of Life Sciences, Guangzhou University, Guangzhou, Guangdong 510000, China
| | - Kai He
- Key Laboratory of Conservation and Application in Biodiversity of South China, School of Life Sciences, Guangzhou University, Guangzhou, Guangdong 510000, China
| | - Yi-Bo Hu
- CAS Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiao-Yun Wang
- Key Laboratory of Conservation and Application in Biodiversity of South China, School of Life Sciences, Guangzhou University, Guangzhou, Guangdong 510000, China,E-mail:
| | - Wen-Hua Yu
- Key Laboratory of Conservation and Application in Biodiversity of South China, School of Life Sciences, Guangzhou University, Guangzhou, Guangdong 510000, China,
| | | | | | | | | |
Collapse
|
7
|
Brualla NLM, Wilson LAB, Doube M, Carter RT, McElligott AG, Koyabu D. The vocal apparatus: An understudied tool to reconstruct the evolutionary history of echolocation in bats? J MAMM EVOL 2023. [DOI: 10.1007/s10914-022-09647-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
8
|
Håkansson J, Mikkelsen C, Jakobsen L, Elemans CPH. Bats expand their vocal range by recruiting different laryngeal structures for echolocation and social communication. PLoS Biol 2022; 20:e3001881. [PMID: 36445872 PMCID: PMC9707786 DOI: 10.1371/journal.pbio.3001881] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 10/19/2022] [Indexed: 12/03/2022] Open
Abstract
Echolocating bats produce very diverse vocal signals for echolocation and social communication that span an impressive frequency range of 1 to 120 kHz or 7 octaves. This tremendous vocal range is unparalleled in mammalian sound production and thought to be produced by specialized laryngeal vocal membranes on top of vocal folds. However, their function in vocal production remains untested. By filming vocal membranes in excised bat larynges (Myotis daubentonii) in vitro with ultra-high-speed video (up to 250,000 fps) and using deep learning networks to extract their motion, we provide the first direct observations that vocal membranes exhibit flow-induced self-sustained vibrations to produce 10 to 95 kHz echolocation and social communication calls in bats. The vocal membranes achieve the highest fundamental frequencies (fo's) of any mammal, but their vocal range is with 3 to 4 octaves comparable to most mammals. We evaluate the currently outstanding hypotheses for vocal membrane function and propose that most laryngeal adaptations in echolocating bats result from selection for producing high-frequency, rapid echolocation calls to catch fast-moving prey. Furthermore, we show that bats extend their lower vocal range by recruiting their ventricular folds-as in death metal growls-that vibrate at distinctly lower frequencies of 1 to 5 kHz for producing agonistic social calls. The different selection pressures for echolocation and social communication facilitated the evolution of separate laryngeal structures that together vastly expanded the vocal range in bats.
Collapse
Affiliation(s)
- Jonas Håkansson
- Sound Communication and Behavior Group, Department of Biology, University of Southern Denmark, Odense M, Denmark,* E-mail: (JH); (CPHE)
| | - Cathrine Mikkelsen
- Sound Communication and Behavior Group, Department of Biology, University of Southern Denmark, Odense M, Denmark
| | - Lasse Jakobsen
- Sound Communication and Behavior Group, Department of Biology, University of Southern Denmark, Odense M, Denmark
| | - Coen P. H. Elemans
- Sound Communication and Behavior Group, Department of Biology, University of Southern Denmark, Odense M, Denmark,* E-mail: (JH); (CPHE)
| |
Collapse
|
9
|
Collins MN, Mesce KA. A review of the bioeffects of low-intensity focused ultrasound and the benefits of a cellular approach. Front Physiol 2022; 13:1047324. [PMID: 36439246 PMCID: PMC9685663 DOI: 10.3389/fphys.2022.1047324] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 10/25/2022] [Indexed: 10/28/2023] Open
Abstract
This review article highlights the historical developments and current state of knowledge of an important neuromodulation technology: low-intensity focused ultrasound. Because compelling studies have shown that focused ultrasound can modulate neuronal activity non-invasively, especially in deep brain structures with high spatial specificity, there has been a renewed interest in attempting to understand the specific bioeffects of focused ultrasound at the cellular level. Such information is needed to facilitate the safe and effective use of focused ultrasound to treat a number of brain and nervous system disorders in humans. Unfortunately, to date, there appears to be no singular biological mechanism to account for the actions of focused ultrasound, and it is becoming increasingly clear that different types of nerve cells will respond to focused ultrasound differentially based on the complement of their ion channels, other membrane biophysical properties, and arrangement of synaptic connections. Furthermore, neurons are apparently not equally susceptible to the mechanical, thermal and cavitation-related consequences of focused ultrasound application-to complicate matters further, many studies often use distinctly different focused ultrasound stimulus parameters to achieve a reliable response in neural activity. In this review, we consider the benefits of studying more experimentally tractable invertebrate preparations, with an emphasis on the medicinal leech, where neurons can be studied as unique individual cells and be synaptically isolated from the indirect effects of focused ultrasound stimulation on mechanosensitive afferents. In the leech, we have concluded that heat is the primary effector of focused ultrasound neuromodulation, especially on motoneurons in which we observed a focused ultrasound-mediated blockade of action potentials. We discuss that the mechanical bioeffects of focused ultrasound, which are frequently described in the literature, are less reliably achieved as compared to thermal ones, and that observations ascribed to mechanical responses may be confounded by activation of synaptically-coupled sensory structures or artifacts associated with electrode resonance. Ultimately, both the mechanical and thermal components of focused ultrasound have significant potential to contribute to the sculpting of specific neural outcomes. Because focused ultrasound can generate significant modulation at a temperature <5°C, which is believed to be safe for moderate durations, we support the idea that focused ultrasound should be considered as a thermal neuromodulation technology for clinical use, especially targeting neural pathways in the peripheral nervous system.
Collapse
Affiliation(s)
- Morgan N. Collins
- Graduate Program in Neuroscience, University of Minnesota, Saint Paul, MN, United States
| | - Karen A. Mesce
- Department of Entomology and Graduate Program in Neuroscience, University of Minnesota, Saint Paul, MN, United States
| |
Collapse
|
10
|
Fernández Y, Dowdy NJ, Conner WE. High duty cycle moth sounds jam bat echolocation: bats counter with compensatory changes in buzz duration. J Exp Biol 2022; 225:jeb244187. [PMID: 36111562 PMCID: PMC9637272 DOI: 10.1242/jeb.244187] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 08/23/2022] [Indexed: 10/05/2023]
Abstract
Tiger moth species vary greatly in the number of clicks they produce and the resultant duty cycle. Signals with higher duty cycles are expected to more effectively interfere with bat sonar. However, little is known about the minimum duty cycle of tiger moth signals for sonar jamming. Is there a threshold that allows us to classify moths as acoustically aposematic versus sonar jammers based on their duty cycles? We performed playback experiments with three wild-caught adult male bats, Eptesicus fuscus. Bat attacks on tethered moths were challenged using acoustic signals of Bertholdia trigona with modified duty cycles ranging from 0 to 46%. We did not find evidence for a duty cycle threshold; rather, the ability to jam the bat's sonar was a continuous function of duty cycle consistent with a steady increase in the number of clicks arriving during a critical signal processing time window just prior to the arrival of an echo. The proportion of successful captures significantly decreased as the moth duty cycle increased. Our findings suggest that moths cannot be unambiguously classified as acoustically aposematic or sonar jammers based solely on duty cycle. Bats appear to compensate for sonar jamming by lengthening the duration of their terminal buzz and they are more successful in capturing moths when they do so. In contrast to previous findings for bats performing difficult spatial tasks, the number of sonar sound groups decreased in response to high duty cycles and did not affect capture success.
Collapse
Affiliation(s)
- Yohami Fernández
- Department of Biology, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, NC 27109, USA
| | - Nicolas J. Dowdy
- Department of Biology, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, NC 27109, USA
- Department of Zoology, Milwaukee Public Museum, 800 West Wells Street, Milwaukee, WI 53233, USA
| | - William E. Conner
- Department of Biology, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, NC 27109, USA
| |
Collapse
|
11
|
Kotila M, Helle S, Lehto HJ, Rojas D, Vesterinen EJ, Lilley TM. Atmospheric humidity affects global variation of bat echolocation via indirect effects. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.934876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The peak frequency of bat echolocation is a species-specific functional trait linked to foraging ecology. It is tailored via evolution to suit conditions within the distribution range of each species, but the evolutionary drivers are not yet well-understood. Global patterns of humidity correlate with many aspects of bat ecology. We hypothesized that atmospheric absolute humidity could explain global peak frequency variation directly and indirectly via increasing species body size and bat species richness. These hypotheses were tested using Bayesian phylogenetic path analysis on 226 tropical and subtropical bat species. In line with our predictions, we found a positive total effect of humidity on peak frequency, which was dominated by the positive indirect effects via body size and bat species richness. We did not observe the negative direct effect of humidity on peak frequency, which was hypothesized based on atmospheric attenuation of sound. In line with our expectations, excluding the predominantly clutter foraging bat families from our dataset downplayed the importance of the richness-mediated route. To conclude, our findings suggest that indirect effects, owing to ecology and biogeography of bat taxa, play a major role in the global relationship between peak frequency and atmospheric humidity.
Collapse
|
12
|
Wray AK, Gratton C, Jusino MA, Wang JJ, Kochanski JM, Palmer JM, Banik MT, Lindner DL, Peery MZ. Disease‐related population declines in bats demonstrate non‐exchangeability in generalist predators. Ecol Evol 2022; 12:e8978. [PMID: 35784069 PMCID: PMC9170538 DOI: 10.1002/ece3.8978] [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] [Received: 12/21/2021] [Revised: 05/04/2022] [Accepted: 05/09/2022] [Indexed: 11/15/2022] Open
Abstract
The extent to which persisting species may fill the functional role of extirpated or declining species has profound implications for the structure of biological communities and ecosystem functioning. In North America, arthropodivorous bats are threatened on a continent‐wide scale by the spread of white‐nose syndrome (WNS), a disease caused by the fungus Pseudogymnoascus destructans. We tested whether bat species that display lower mortality from this disease can partially fill the functional role of other bat species experiencing population declines. Specifically, we performed high‐throughput amplicon sequencing of guano from two generalist predators: the little brown bat (Myotis lucifugus) and big brown bat (Eptesicus fuscus). We then compared changes in prey consumption before versus after population declines related to WNS. Dietary niches contracted for both species after large and abrupt declines in little brown bats and smaller declines in big brown bats, but interspecific dietary overlap did not change. Furthermore, the incidence and taxonomic richness of agricultural pest taxa detected in diet samples decreased following bat population declines. Our results suggest that persisting generalist predators do not necessarily expand their dietary niches following population declines in other predators, providing further evidence that the functional roles of different generalist predators are ecologically distinct.
Collapse
Affiliation(s)
- Amy K. Wray
- Department of Forest & Wildlife Ecology University of Wisconsin‐Madison Madison Wisconsin USA
| | - Claudio Gratton
- Department of Entomology University of Wisconsin‐Madison Madison Wisconsin USA
| | - Michelle A. Jusino
- Center for Forest Mycology Research Northern Research Station USDA Forest Service Madison Wisconsin USA
| | - Jing Jamie Wang
- Department of Forest & Wildlife Ecology University of Wisconsin‐Madison Madison Wisconsin USA
| | - Jade M. Kochanski
- Department of Entomology University of Wisconsin‐Madison Madison Wisconsin USA
- Department of Integrative Biology University of Wisconsin‐Madison Madison Wisconsin USA
| | - Jonathan M. Palmer
- Center for Forest Mycology Research Northern Research Station USDA Forest Service Madison Wisconsin USA
| | - Mark T. Banik
- Center for Forest Mycology Research Northern Research Station USDA Forest Service Madison Wisconsin USA
| | - Daniel L. Lindner
- Center for Forest Mycology Research Northern Research Station USDA Forest Service Madison Wisconsin USA
| | - M. Zachariah Peery
- Department of Forest & Wildlife Ecology University of Wisconsin‐Madison Madison Wisconsin USA
| |
Collapse
|
13
|
Branstetter BK, Brietenstein R, Goya G, Tormey M, Wu T, Finneran JJ. Spatial acuity of the bottlenose dolphin (Tursiops truncatus) biosonar system with a bat and human comparison. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2022; 151:3847. [PMID: 35778192 DOI: 10.1121/10.0011676] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Horizontal angular resolution was measured in two bottlenose dolphins using a two-alternative forced-choice, biosonar target discrimination paradigm. The task required a stationary dolphin positioned in a hoop to discriminate two physical targets at a range of 4 m. The angle separating the targets was manipulated to estimate an angular discrimination threshold of 1.5°. In a second experiment, a similar two-target biosonar discrimination task was conducted with one free-swimming dolphin, to test whether its emission beam was a critical factor in discriminating the targets. The spatial separation between two targets was manipulated to measure a discrimination threshold of 6.7 cm. There was a relationship between differences in acoustic signals received at each target and the dolphin's performance. The results of the angular resolution experiment were in good agreement with measures of the minimum audible angle of both dolphins and humans and remarkably similar to measures of angular difference discrimination in echolocating dolphins, bats, and humans. The results suggest that horizontal auditory spatial acuity may be a common feature of the mammalian auditory system rather than a specialized feature exclusive to echolocating auditory predators.
Collapse
Affiliation(s)
- Brian K Branstetter
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106, USA
| | - Rachel Brietenstein
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106, USA
| | - Gavin Goya
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106, USA
| | - Megan Tormey
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106, USA
| | - Teri Wu
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106, USA
| | - James J Finneran
- United States Navy Marine Mammal Program, Naval Information Warfare Center Pacific, San Diego, California 92152, USA
| |
Collapse
|
14
|
de Aguiar Silva C, Machado RB, Silveira M, Aguiar LMS. Listening in the dark: acoustics indices reveal bat species diversity in a tropical savannah. BIOACOUSTICS 2022. [DOI: 10.1080/09524622.2022.2053741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Claysson de Aguiar Silva
- Department of Zoology, Laboratory of Biology and Conservation of Bats, University of Brasília, Brasília, Brazil
| | - Ricardo B. Machado
- Department of Zoology, Laboratory of Biodiversity Conservation Planning, University of Brasília, Brasília, Brazil
| | - Mauricio Silveira
- Department of Zoology, Laboratory of Biology and Conservation of Bats, University of Brasília, Brasília, Brazil
| | - Ludmilla M. S. Aguiar
- Department of Zoology, Laboratory of Biology and Conservation of Bats, University of Brasília, Brasília, Brazil
| |
Collapse
|
15
|
Rydell J, Russo D, Sewell P, Seamark ECJ, Francis CM, Fenton SL, Fenton MB. Bat selfies: photographic surveys of flying bats. Mamm Biol 2022; 102:793-809. [PMID: 35411207 PMCID: PMC8988114 DOI: 10.1007/s42991-022-00233-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 01/16/2022] [Indexed: 01/31/2023]
Abstract
The recent pandemic and other environmental concerns have resulted in restrictions on research and surveys involving capture and handling bats. While acoustic surveys have been widely used as an alternative survey method, in this study, we show how photographic surveys can offer an important contribution to study and survey bats. We outline approaches, using high speed flash and automated trip beams to obtain photos of flying bats of sufficient quality for reliable identification of species. We show, through a series of examples of setups and photographs, that photography is effective for surveying bats at a variety of sites, where bats roost, drink, and forage. We note, however, that photographic surveys cannot replace capture in all situations. In addition, although photographing bats is less invasive than capturing them, it can involve disturbance, so we stress the importance of minimizing the impact of such operations on bats. Supplementary Information The online version contains supplementary material available at 10.1007/s42991-022-00233-7.
Collapse
Affiliation(s)
- Jens Rydell
- Department of Biology, Lund University, 22362 Lund, Sweden
| | - Danilo Russo
- Wildlife Research Unit, Dipartimento di Agraria, Università degli Studi di Napoli Federico II, via Università 100, Portici, 80055 Naples, Italy
| | - Price Sewell
- Copperhead Environmental Consulting, 471 Main Street, Richmond, KY USA
| | | | - Charles M. Francis
- Canadian Wildlife Service, Environment and Climate Change Canada, Ottawa, ON Canada
| | - Sherri L. Fenton
- Department of Biology, University of Western Ontario, London, ON Canada
| | - M. Brock Fenton
- Department of Biology, University of Western Ontario, London, ON Canada
| |
Collapse
|
16
|
Bermant PC. BioCPPNet: automatic bioacoustic source separation with deep neural networks. Sci Rep 2021; 11:23502. [PMID: 34873197 PMCID: PMC8648737 DOI: 10.1038/s41598-021-02790-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 11/16/2021] [Indexed: 11/09/2022] Open
Abstract
We introduce the Bioacoustic Cocktail Party Problem Network (BioCPPNet), a lightweight, modular, and robust U-Net-based machine learning architecture optimized for bioacoustic source separation across diverse biological taxa. Employing learnable or handcrafted encoders, BioCPPNet operates directly on the raw acoustic mixture waveform containing overlapping vocalizations and separates the input waveform into estimates corresponding to the sources in the mixture. Predictions are compared to the reference ground truth waveforms by searching over the space of (output, target) source order permutations, and we train using an objective function motivated by perceptual audio quality. We apply BioCPPNet to several species with unique vocal behavior, including macaques, bottlenose dolphins, and Egyptian fruit bats, and we evaluate reconstruction quality of separated waveforms using the scale-invariant signal-to-distortion ratio (SI-SDR) and downstream identity classification accuracy. We consider mixtures with two or three concurrent conspecific vocalizers, and we examine separation performance in open and closed speaker scenarios. To our knowledge, this paper redefines the state-of-the-art in end-to-end single-channel bioacoustic source separation in a permutation-invariant regime across a heterogeneous set of non-human species. This study serves as a major step toward the deployment of bioacoustic source separation systems for processing substantial volumes of previously unusable data containing overlapping bioacoustic signals.
Collapse
|
17
|
Starik N, Göttert T, Zeller U. Spatial Behavior and Habitat Use of Two Sympatric Bat Species. Animals (Basel) 2021; 11:ani11123460. [PMID: 34944237 PMCID: PMC8697949 DOI: 10.3390/ani11123460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 11/27/2021] [Accepted: 12/02/2021] [Indexed: 11/19/2022] Open
Abstract
Simple Summary Few studies refer to ecological differences of genetically close and morphologically almost identical insectivorous bat species. However, this information is indispensable for effective and sustainable nature conservation strategies. This study aims at investigating differences in the spatial ecology of the long-eared bat species Plecotus auritus and Plecotus austriacus in a typical cultural landscape of Brandenburg, where the two species occur sympatrically. The reconstruction of the prey spectrum revealed that P. auritus and P. austriacus strongly overlapped in their diet. Our results suggest that resource partitioning is based on using different foraging habitats. While radio-tracked females of P. auritus were strongly associated with woodland patches resulting in small-scale activity areas of only few square kilometers, activity areas of P. austriacus encompassed a large-scale matrix of grassland habitats in the magnitude of a small town. Based on these results, we identify priority conservation needs for the two species to ensure that these differences in the spatial behavior and habitat use can be adequately taken into account for future nature conservation efforts. Abstract Movement behavior and habitat use of the long-eared bat species Plecotus auritus and Plecotus austriacus were studied in the Havelland region in Brandenburg (Germany). Data collection included mist-netting, radiotelemetry, reconstruction of prey items, and monitoring of roosting sites. Body measurements confirm a high degree of phenotypic similarity between the two species. Total activity areas (100% Minimum Convex Polygons, MCPS) of Plecotus austriacus (2828.3 ± 1269.43 ha) were up to five-fold larger compared to Plecotus auritus (544.54 ± 295.89 ha). The activity areas of Plecotus austriacus contained up to 11 distinct core areas, and their mean total size (149.7 ± 0.07 ha) was approximately three-fold larger compared to core areas of Plecotus auritus (49.2 ± 25.6 ha). The mean distance between consecutive fixes per night was 12.72 ± 3.7 km for Plecotus austriacus and 4.23 ± 2.8 km for Plecotus auritus. While Plecotus austriacus was located most frequently over pastures (>40%) and meadows (>20%), P. auritus was located mostly within deciduous (>50%) and mixed forests (>30%) in close vicinity to its roosts. Roost site monitoring indicates that the activity of P. austriacus is delayed relative to P. auritus in spring and declined earlier in autumn. These phenological differences are probably related to the species’ respective diets. Levins’ measure of trophic niche breadth suggests that the prey spectrum for P. auritus is more diverse during spring (B = 2.86) and autumn (B = 2.82) compared to P. austriacus (spring: B = 1.7; autumn: B = 2.1). Our results give reason to consider these interspecific ecological variations and species-specific requirements of P. auritus and P. austriacus to develop adapted and improved conservation measures.
Collapse
Affiliation(s)
- Nicole Starik
- Albrecht Daniel Thaer-Institute of Agricultural and Horticultural Sciences, Faculty of Life Sciences, Humboldt-Universität zu Berlin, 10115 Berlin, Germany;
- Correspondence: ; Tel.: +49-(0)30-2093 46923
| | - Thomas Göttert
- Research Center [Sustainability–Transformation–Transfer], Eberswalde University for Sustainable Development, Schicklerstr. 5, 16225 Eberswalde, Germany;
| | - Ulrich Zeller
- Albrecht Daniel Thaer-Institute of Agricultural and Horticultural Sciences, Faculty of Life Sciences, Humboldt-Universität zu Berlin, 10115 Berlin, Germany;
| |
Collapse
|
18
|
Roemer C, Julien J, Bas Y. An automatic classifier of bat sonotypes around the world. Methods Ecol Evol 2021. [DOI: 10.1111/2041-210x.13721] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Charlotte Roemer
- Centre d’Ecologie et des Sciences de la Conservation (Muséum national d’Histoire naturelle, CNRS, Sorbonne Université) Paris France
- CEFEUniversité de MontpellierCNRSEPHEIRDUniversité Paul Valéry Montpellier 3 Montpellier France
| | - Jean‐François Julien
- Centre d’Ecologie et des Sciences de la Conservation (Muséum national d’Histoire naturelle, CNRS, Sorbonne Université) Paris France
| | - Yves Bas
- Centre d’Ecologie et des Sciences de la Conservation (Muséum national d’Histoire naturelle, CNRS, Sorbonne Université) Paris France
- CEFEUniversité de MontpellierCNRSEPHEIRDUniversité Paul Valéry Montpellier 3 Montpellier France
| |
Collapse
|
19
|
Wang R, Müller R. Bioinspired solution to finding passageways in foliage with sonar. BIOINSPIRATION & BIOMIMETICS 2021; 16:066022. [PMID: 34584027 DOI: 10.1088/1748-3190/ac2aff] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 09/28/2021] [Indexed: 06/13/2023]
Abstract
Finding narrow gaps in foliage is an important component skill for autonomous navigation in densely vegetated environments. Traditional approaches are based on collecting large amounts of data with high spatial resolution. However, the biosonar systems of bats that live in dense habitats demonstrate that finding gaps is possible based on sensors with angular resolutions that are poor compared to technologies such as man-made sonar and lidar. To investigate these capabilities, we have used a biomimetic sonar head to ensonify artificial hedges in the laboratory. We found that a conventional approach based on echo energy performed poorly on detecting gaps with the area under the receiver operating characteristic (ROC) curve ranging from 0.69 to 0.75 depending on the distance to the hedge and gap width. A deep-learning approach based on a convolutional neural network (CNN) operating on the echo spectrograms achieved area under the ROC curve (AUC) values between 0.94 and 0.97. Class activation mapping indicated that the rising flank of the echoes was critical for detecting the gaps. As a consequence, a simple code consisting of first threshold-crossing times was able to almost reproduce the performance of the CNN classifier (AUC 0.9 to 0.95). This demonstrates that the echo waveforms contained patterns that were indicative of a gap in the foliage but did not suffer from the comparatively large beamwidth used.
Collapse
Affiliation(s)
- Ruihao Wang
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, United States of America
| | - Rolf Müller
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, United States of America
| |
Collapse
|
20
|
Leiser‐Miller LB, Santana SE. Functional differences in echolocation call design in an adaptive radiation of bats. Ecol Evol 2021; 11:16153-16164. [PMID: 34824818 PMCID: PMC8601877 DOI: 10.1002/ece3.8296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 10/18/2021] [Indexed: 11/15/2022] Open
Abstract
All organisms have specialized systems to sense their environment. Most bat species use echolocation for navigation and foraging, but which and how ecological factors shaped echolocation call diversity remains unclear for the most diverse clades, including the adaptive radiation of neotropical leaf-nosed bats (Phyllostomidae). This is because phyllostomids emit low-intensity echolocation calls and many inhabit dense forests, leading to low representation in acoustic surveys. We present a field-collected, echolocation call dataset spanning 35 species and all phyllostomid dietary guilds. We analyze these data under a phylogenetic framework to test the hypothesis that echolocation call design and parameters are specialized for the acoustic demands of different diets, and investigate the contributions of phylogeny and body size to echolocation call diversity. We further link call parameters to dietary ecology by contrasting minimum detectable prey size estimates (MDPSE) across species. We find phylogeny and body size explain a substantial proportion of echolocation call parameter diversity, but most species can be correctly assigned to taxonomic (61%) or functional (77%) dietary guilds based on call parameters. This suggests a degree of acoustic ecological specialization, albeit with interspecific similarities in call structure. Theoretical MDPSE are greatest for omnivores and smallest for insectivores. Omnivores significantly differ from other dietary guilds in MDPSE when phylogeny is not considered, but there are no differences among taxonomic dietary guilds within a phylogenetic context. Similarly, predators of non-mobile/non-evasive prey and predators of mobile/evasive prey differ in estimated MDPSE when phylogeny is not considered. Phyllostomid echolocation call structure may be primarily specialized for overcoming acoustic challenges of foraging in dense habitats, and then secondarily specialized for the detection of food items according to functional dietary guilds. Our results give insight into the possible ecological mechanisms shaping the diversity of sensory systems, and their reciprocal influence on resource use.
Collapse
Affiliation(s)
| | - Sharlene E. Santana
- Department of BiologyUniversity of WashingtonSeattleWashingtonUSA
- Burke Museum of Natural History and CultureUniversity of WashingtonSeattleWashingtonUSA
| |
Collapse
|
21
|
Hearing sensitivity: An underlying mechanism for niche differentiation in gleaning bats. Proc Natl Acad Sci U S A 2021; 118:2024943118. [PMID: 34426521 DOI: 10.1073/pnas.2024943118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Tropical ecosystems are known for high species diversity. Adaptations permitting niche differentiation enable species to coexist. Historically, research focused primarily on morphological and behavioral adaptations for foraging, roosting, and other basic ecological factors. Another important factor, however, is differences in sensory capabilities. So far, studies mainly have focused on the output of behavioral strategies of predators and their prey preference. Understanding the coexistence of different foraging strategies, however, requires understanding underlying cognitive and neural mechanisms. In this study, we investigate hearing in bats and how it shapes bat species coexistence. We present the hearing thresholds and echolocation calls of 12 different gleaning bats from the ecologically diverse Phyllostomid family. We measured their auditory brainstem responses to assess their hearing sensitivity. The audiograms of these species had similar overall shapes but differed substantially for frequencies below 9 kHz and in the frequency range of their echolocation calls. Our results suggest that differences among bats in hearing abilities contribute to the diversity in foraging strategies of gleaning bats. We argue that differences in auditory sensitivity could be important mechanisms shaping diversity in sensory niches and coexistence of species.
Collapse
|
22
|
Chhaya V, Lahiri S, Jagan MA, Mohan R, Pathaw NA, Krishnan A. Community Bioacoustics: Studying Acoustic Community Structure for Ecological and Conservation Insights. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.706445] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The diversity of animal acoustic signals has evolved due to multiple ecological processes, both biotic and abiotic. At the level of communities of signaling animals, these processes may lead to diverse outcomes, including partitioning of acoustic signals along multiple axes (divergent signal parameters, signaling locations, and timing). Acoustic data provides information on the organization, diversity and dynamics of an acoustic community, and thus enables study of ecological change and turnover in a non-intrusive way. In this review, we lay out how community bioacoustics (the study of acoustic community structure and dynamics), has value in ecological monitoring and conservation of diverse landscapes and taxa. First, we review the concepts of signal space, signal partitioning and their effects on the structure of acoustic communities. Next, we highlight how spatiotemporal ecological change is reflected in acoustic community structure, and the potential this presents in monitoring and conservation. As passive acoustic monitoring gains popularity worldwide, we propose that the analytical framework of community bioacoustics has promise in studying the response of entire suites of species (from insects to large whales) to rapid anthropogenic change.
Collapse
|
23
|
López-Bosch D, Huang JCC, Wang Y, Palmeirim AF, Gibson L, López-Baucells A. Bat echolocation in continental China: a systematic review and first acoustic identification key for the country. MAMMAL RES 2021. [DOI: 10.1007/s13364-021-00570-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
24
|
Gessinger G, Page R, Wilfert L, Surlykke A, Brinkløv S, Tschapka M. Phylogenetic Patterns in Mouth Posture and Echolocation Emission Behavior of Phyllostomid Bats. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.630481] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
While phyllostomid bats show an impressive range of feeding habits, most of them emit highly similar echolocation calls. Due to the presence of an often prominent noseleaf, it has long been assumed that all phyllostomids emit echolocation calls exclusively through the nostrils rather than through the mouth. However, photo evidence documents also phyllostomid bats flying with an opened mouth. We hypothesized that all phyllostomid species emit echolocation calls only through the nostrils and therefore fly consistently with a closed mouth, and that observations of an open mouth should be a rare and random behavior among individuals and species. Using a high-speed camera and standardized conditions in a flight cage, we screened 40 phyllostomid species. Behavior varied distinctly among the species and mouth posture shows a significant phylogenetic signal. Bats of the frugivorous subfamilies Rhinophyllinae and Carolliinae, the nectarivorous subfamilies Glossophaginae and Lonchophyllinae, and the sanguivorous subfamily Desmodontinae all flew consistently with open mouths. So did the animalivorous subfamilies Glyphonycterinae, Micronycterinae and Phyllostominae, with the notable exception of species in the omnivorous genus Phyllostomus, which consistently flew with mouths closed. Bats from the frugivorous subfamily Stenodermatinae also flew exclusively with closed mouths with the single exception of the genus Sturnira, which is the sister clade to all other stenodermatine species. Further, head position angles differed significantly between bats echolocating with their mouth closed and those echolocating with their mouths opened, with closed-mouth phyllostomids pointing only the nostrils in the direction of flight and open-mouth phyllostomids pointing both the nostrils and mouth gape in the direction of flight. Ancestral trait reconstruction showed that the open mouth mode is the ancestral state within the Phyllostomidae. Based on the observed behavioral differences, we suggest that phyllostomid bats are not all nasal emitters as previously thought and discuss possible reasons. Further experiments, such as selectively obstructing sound emission through nostrils or mouth, respectively, will be necessary to clarify the actual source, plasticity and ecological relevance of sound emission of phyllostomid bats flying with their mouths open.
Collapse
|
25
|
Abstract
Animals must encode fundamental physical relationships in their brains. A heron plunging its head underwater to skewer a fish must correct for light refraction, an archerfish shooting down an insect must "consider" gravity, and an echolocating bat that is attacking prey must account for the speed of sound in order to assess its distance. Do animals learn these relations or are they encoded innately and can they adjust them as adults are all open questions. We addressed this question by shifting the speed of sound and assessing the sensory behavior of a bat species that naturally experiences different speeds of sound. We found that both newborn pups and adults are unable to adjust to this shift, suggesting that the speed of sound is innately encoded in the bat brain. Moreover, our results suggest that bats encode the world in terms of time and do not translate time into distance. Our results shed light on the evolution of innate and flexible sensory perception.
Collapse
|
26
|
Bat echolocation plasticity in allopatry: a call for caution in acoustic identification of Pipistrellus sp. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-03002-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Abstract
Animals modify their behaviours and interactions in response to changing environments. In bats, environmental adaptations are reflected in echolocation signalling that is used for navigation, foraging and communication. However, the extent and drivers of echolocation plasticity are not fully understood, hindering our identification of bat species with ultrasonic detectors, particularly for cryptic species with similar echolocation calls. We used a combination of DNA barcoding, intensive trapping, roost and emergence surveys and acoustic recording to study a widespread European cryptic species complex (Pipistrellus pipistrellus and Pipistrellus pygmaeus) to investigate whether sibling bat species could exhibit extreme echolocation plasticity in response to certain environmental conditions or behaviours. We found that P. pygmaeus occupied the acoustic niche of their absent congeneric species, producing calls with P. pipistrellus’ characteristic structure and peak frequencies and resulting in false positive acoustic records of that species. Echolocation frequency was significantly affected by the density of bats and by maternity rearing stage, with lower frequency calls emitted when there was a high density of flying bats, and by mothers while juveniles were non-volant. During roost emergence, 29% of calls had peak frequencies typical of P. pipistrellus, with calls as low as 44 kHz, lower than ever documented. We show that automatic and manual call classifiers fail to account for echolocation plasticity, misidentifying P. pygmaeus as P. pipistrellus. Our study raises a vital limitation of using only acoustic sampling in areas with high densities of a single species of a cryptic species pair, with important implications for bat monitoring.
Significance statement
Ultrasonic acoustic detectors are widely used in bat research to establish species inventories and monitor species activity through identification of echolocation calls, enabling new methods to study and understand this elusive understudied group of nocturnal mammals. However, echolocation call signalling in bats is intrinsically different to that of other taxa, serving a main function of navigation and foraging. This study demonstrates an extreme level of plasticity, showing large variation in call frequency and structure in different situations. We showcase the difficulty and limitation in using acoustic sampling alone for bat monitoring and the complications of setting parameters for species identification for manual and automatic call classifiers. Our observations of call frequency variation correlated with density and absence of congenerics provide novel insights of behavioural echolocation plasticity in bats.
Collapse
|
27
|
Smeraldo S, Bosso L, Salinas‐Ramos VB, Ancillotto L, Sánchez‐Cordero V, Gazaryan S, Russo D. Generalists yet different: distributional responses to climate change may vary in opportunistic bat species sharing similar ecological traits. Mamm Rev 2021. [DOI: 10.1111/mam.12247] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Sonia Smeraldo
- Wildlife Research Unit Dipartimento di Agraria Università degli Studi di Napoli Federico II Via Università n. 100 80055 Portici Napoli Italy
| | - Luciano Bosso
- Wildlife Research Unit Dipartimento di Agraria Università degli Studi di Napoli Federico II Via Università n. 100 80055 Portici Napoli Italy
| | - Valeria B. Salinas‐Ramos
- Wildlife Research Unit Dipartimento di Agraria Università degli Studi di Napoli Federico II Via Università n. 100 80055 Portici Napoli Italy
| | - Leonardo Ancillotto
- Wildlife Research Unit Dipartimento di Agraria Università degli Studi di Napoli Federico II Via Università n. 100 80055 Portici Napoli Italy
| | - Víctor Sánchez‐Cordero
- Laboratorio de Sistemas de Información Geográfica Departamento de Zoología Instituto de Biología Universidad Nacional Autónoma de México Av. Universidad 04510 Ciudad de México Mexico
| | - Suren Gazaryan
- Institute of Ecology of Mountain Territories RAS Armand 37A360000 Nalchik Russia
| | - Danilo Russo
- Wildlife Research Unit Dipartimento di Agraria Università degli Studi di Napoli Federico II Via Università n. 100 80055 Portici Napoli Italy
- School of Biological Sciences University of Bristol 24 Tyndall Avenue BristolBS8 1TQUK
| |
Collapse
|
28
|
Oedin M, Brescia F, Millon A, Murphy BP, Palmas P, Woinarski JC, Vidal E. Cats
Felis catus
as a threat to bats worldwide: a review of the evidence. Mamm Rev 2021. [DOI: 10.1111/mam.12240] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Malik Oedin
- Institut Agronomique Néo‐Calédonien (IAC) Equipe ARBOREAL (AgricultuRe BiOdiveRsité Et vALorisation) BP 73, Portlaguerre Païta Province Sud98890New Caledonia
- Aix Marseille Université Institut Méditerranéen de Biodiversité et d’Ecologie marine et continentale (IMBE) CNRS, IRD Avignon Université Technopôle Arbois‐Méditerranée, Bât. Villemin, BP 80 Aix‐en‐Provence Aix en Provence13090France
- Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE) CNRS, IRD, Avignon Université, Centre IRD Nouméa ‐ BPA5 Aix Marseille Université Nouméa Cedex98848Nouvelle‐Calédonie
| | - Fabrice Brescia
- Institut Agronomique Néo‐Calédonien (IAC) Equipe ARBOREAL (AgricultuRe BiOdiveRsité Et vALorisation) BP 73, Portlaguerre Païta Province Sud98890New Caledonia
| | - Alexandre Millon
- Aix Marseille Université Institut Méditerranéen de Biodiversité et d’Ecologie marine et continentale (IMBE) CNRS, IRD Avignon Université Technopôle Arbois‐Méditerranée, Bât. Villemin, BP 80 Aix‐en‐Provence Aix en Provence13090France
| | - Brett P. Murphy
- NESP Threatened Species Recovery Hub Research Institute for the Environment and Livelihoods Charles Darwin University Casuarina NT0909Australia
| | - Pauline Palmas
- Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE) CNRS, IRD, Avignon Université, Centre IRD Nouméa ‐ BPA5 Aix Marseille Université Nouméa Cedex98848Nouvelle‐Calédonie
- Université de la Polynésie Française Ifremer, ILM, IRD, EIO UMR 241, BP 52998713 Papeete Faaa98702Polynésie Française
| | - John C.Z. Woinarski
- NESP Threatened Species Recovery Hub Research Institute for the Environment and Livelihoods Charles Darwin University Casuarina NT0909Australia
| | - Eric Vidal
- UMR ENTROPIE (IRD, Université de La Réunion, CNRS, Université de la Nouvelle‐Calédonie, Ifremer) Centre IRD Nouméa ‐ BP A5 Cedex98848New Caledonia
| |
Collapse
|
29
|
Lattenkamp EZ, Nagy M, Drexl M, Vernes SC, Wiegrebe L, Knörnschild M. Hearing sensitivity and amplitude coding in bats are differentially shaped by echolocation calls and social calls. Proc Biol Sci 2021; 288:20202600. [PMID: 33402076 PMCID: PMC7892409 DOI: 10.1098/rspb.2020.2600] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Differences in auditory perception between species are influenced by phylogenetic origin and the perceptual challenges imposed by the natural environment, such as detecting prey- or predator-generated sounds and communication signals. Bats are well suited for comparative studies on auditory perception since they predominantly rely on echolocation to perceive the world, while their social calls and most environmental sounds have low frequencies. We tested if hearing sensitivity and stimulus level coding in bats differ between high and low-frequency ranges by measuring auditory brainstem responses (ABRs) of 86 bats belonging to 11 species. In most species, auditory sensitivity was equally good at both high- and low-frequency ranges, while amplitude was more finely coded for higher frequency ranges. Additionally, we conducted a phylogenetic comparative analysis by combining our ABR data with published data on 27 species. Species-specific peaks in hearing sensitivity correlated with peak frequencies of echolocation calls and pup isolation calls, suggesting that changes in hearing sensitivity evolved in response to frequency changes of echolocation and social calls. Overall, our study provides the most comprehensive comparative assessment of bat hearing capacities to date and highlights the evolutionary pressures acting on their sensory perception.
Collapse
Affiliation(s)
- Ella Z Lattenkamp
- Department Biology II, Ludwig Maximilians University Munich, Martinsried, Germany.,Neurogenetics of Vocal Communication Group, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
| | - Martina Nagy
- Museum für Naturkunde, Leibniz-Institute for Evolution and Biodiversity Science, Berlin, Germany
| | - Markus Drexl
- German Center for Vertigo and Balance Disorders (IFB), Ludwig Maximilians University, Munich, Germany
| | - Sonja C Vernes
- Neurogenetics of Vocal Communication Group, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Lutz Wiegrebe
- Department Biology II, Ludwig Maximilians University Munich, Martinsried, Germany
| | - Mirjam Knörnschild
- Museum für Naturkunde, Leibniz-Institute for Evolution and Biodiversity Science, Berlin, Germany.,Animal Behavior Lab, Freie Universität, Berlin, Germany.,Smithsonian Tropical Research Institute, Balboa, Ancón, Panama
| |
Collapse
|
30
|
Hyzy BA, Russell RE, Silvis A, Ford WM, Riddle J, Russell K. Occupancy and Detectability of Northern Long‐eared Bats in the Lake States Region. WILDLIFE SOC B 2020. [DOI: 10.1002/wsb.1138] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Brenna A. Hyzy
- College of Natural Resources University of Wisconsin Stevens Point Stevens Point WI 54481 USA
| | - Robin E. Russell
- U.S. Geological Survey, National Wildlife Health Center Madison WI 53705 USA
| | - Alex Silvis
- West Virginia Division of Natural Resources Elkins WV 26241 USA
| | - W. Mark Ford
- U.S. Geological Survey, Virginia Cooperative Fish and Wildlife Research Unit Blacksburg VA 24061 USA
| | - Jason Riddle
- College of Natural Resources University of Wisconsin Stevens Point Stevens Point WI 54481 USA
| | - Kevin Russell
- College of Natural Resources University of Wisconsin Stevens Point Stevens Point WI 54481 USA
| |
Collapse
|
31
|
Murphy KJ, Ciuti S, Kane A. An introduction to agent-based models as an accessible surrogate to field-based research and teaching. Ecol Evol 2020; 10:12482-12498. [PMID: 33250988 PMCID: PMC7679541 DOI: 10.1002/ece3.6848] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/17/2020] [Accepted: 08/31/2020] [Indexed: 01/09/2023] Open
Abstract
There are many barriers to fieldwork including cost, time, and physical ability. Unfortunately, these barriers disproportionately affect minority communities and create a disparity in access to fieldwork in the natural sciences. Travel restrictions, concerns about our carbon footprint, and the global lockdown have extended this barrier to fieldwork across the community and led to increased anxiety about gaps in productivity, especially among graduate students and early-career researchers. In this paper, we discuss agent-based modeling as an open-source, accessible, and inclusive resource to substitute for lost fieldwork during COVID-19 and for future scenarios of travel restrictions such as climate change and economic downturn. We describe the benefits of Agent-Based models as a teaching and training resource for students across education levels. We discuss how and why educators and research scientists can implement them with examples from the literature on how agent-based models can be applied broadly across life science research. We aim to amplify awareness and adoption of this technique to broaden the diversity and size of the agent-based modeling community in ecology and evolutionary research. Finally, we discuss the challenges facing agent-based modeling and discuss how quantitative ecology can work in tandem with traditional field ecology to improve both methods.
Collapse
Affiliation(s)
- Kilian J. Murphy
- School of Biology and Environmental Science and the Earth InstituteUniversity College DublinDublinIreland
| | - Simone Ciuti
- School of Biology and Environmental Science and the Earth InstituteUniversity College DublinDublinIreland
| | - Adam Kane
- School of Biology and Environmental Science and the Earth InstituteUniversity College DublinDublinIreland
| |
Collapse
|
32
|
Loureiro LO, Engstrom MD, Lim BK. Does evolution of echolocation calls and morphology in Molossus result from convergence or stasis? PLoS One 2020; 15:e0238261. [PMID: 32970683 PMCID: PMC7514107 DOI: 10.1371/journal.pone.0238261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 08/12/2020] [Indexed: 11/20/2022] Open
Abstract
Although many processes of diversification have been described to explain variation of morphological traits within clades that have obvious differentiation among taxa, not much is known about these patterns in complexes of cryptic species. Molossus is a genus of bats that is mainly Neotropical, occurring from the southeastern United States to southern Argentina, including the Caribbean islands. Molossus comprises some groups of species that are morphologically similar but phylogenetically divergent, and other groups of species that are genetically similar but morphologically distinct. This contrast allows investigation of unequal trait diversification and the evolution of morphological and behavioural characters. In this study, we assessed the role of phylogenetic history in a genus of bat with three cryptic species complexes, and evaluated if morphology and behavior are evolving concertedly. The Genotype by Sequence genomic approach was used to build a species-level phylogenetic tree for Molossus and to estimate the ancestral states of morphological and echolocation call characters. We measured the correlation of phylogenetic distances to morphological and echolocation distances, and tested the relationship between morphology and behavior when the effect of phylogeny is removed. Morphology evolved via a mosaic of convergence and stasis, whereas call design was influenced exclusively through local adaptation and convergent evolution. Furthermore, the frequency of echolocation calls is negatively correlated with the size of the bat, but other characters do not seem to be evolving in concert. We hypothesize that slight variation in both morphology and behaviour among species of the genus might result from niche specialization, and that traits evolve to avoid competition for resources in similar environments.
Collapse
Affiliation(s)
- Livia O. Loureiro
- Hospital for Sick Children SickKids Learning Institute, The Centre for Applied Genomics, Toronto, Ontario, Canada
- Department of Natural History, Royal Ontario Museum, Toronto, Ontario, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
| | - Mark D. Engstrom
- Department of Natural History, Royal Ontario Museum, Toronto, Ontario, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
| | - Burton K. Lim
- Department of Natural History, Royal Ontario Museum, Toronto, Ontario, Canada
| |
Collapse
|
33
|
López‐Cuamatzi IL, Vega‐Gutiérrez VH, Cabrera‐Campos I, Ruiz‐Sanchez E, Ayala‐Berdon J, Saldaña‐Vázquez RA. Does body mass restrict call peak frequency in echolocating bats? Mamm Rev 2020. [DOI: 10.1111/mam.12196] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Issachar L. López‐Cuamatzi
- Facultad de Ciencias Biológicas Benemérita Universidad Autónoma de Puebla Blvd, Valsequillo y Av, San Claudio, Edificio BIO 1, Ciudad Universitaria, Col. Jardines de San ManuelC.P. 72570 Puebla México
| | - Víctor H. Vega‐Gutiérrez
- Maestría en Ciencias Biológicas, Centro Tlaxcala de Biología de la Conducta Universidad Autónoma de Tlaxcala Carretera Tlaxcala‐Puebla Km. 1.5C.P. 90062Tlaxcala de Xicohténcatl Tlaxcala México
| | - Iván Cabrera‐Campos
- Maestría en Ciencias Biológicas, Centro Tlaxcala de Biología de la Conducta Universidad Autónoma de Tlaxcala Carretera Tlaxcala‐Puebla Km. 1.5C.P. 90062Tlaxcala de Xicohténcatl Tlaxcala México
| | - Eduardo Ruiz‐Sanchez
- Departamento de Botánica y Zoología Centro Universitario de Ciencias Biológicas y Agropecuarias Universidad de Guadalajara Camino Ing. Ramón Padilla Sánchez 2100, Nextipac45200Zapopán Jalisco México
| | - Jorge Ayala‐Berdon
- CONACyT Universidad Autónoma de Tlaxcala Carretera Tlaxcala‐Puebla Km. 1.5 C.P. 90062 Tlaxcala de Xicohténcatl Tlaxcala México
| | - Romeo A. Saldaña‐Vázquez
- Instituto de Investigaciones en Medio Ambiente Xavier Gorostiaga S.J. Universidad Iberoamericana Puebla Blvd. del Niño Poblano No. 2901, Col. Reserva Territorial Atlixcáyotl C. P. 72820 San Andrés Cholula Puebla México
| |
Collapse
|
34
|
Zamora‐Gutierrez V, Ortega J, Avila‐Flores R, Aguilar‐Rodríguez PA, Alarcón‐Montano M, Avila‐Torresagatón LG, Ayala‐Berdón J, Bolívar‐Cimé B, Briones‐Salas M, Chan‐Noh M, Chávez‐Cauich M, Chávez C, Cortés‐Calva P, Cruzado J, Cuevas JC, Del Real‐Monroy M, Elizalde‐Arellano C, García‐Luis M, García‐Morales R, Guerrero JA, Guevara‐Carrizales AA, Gutiérrez EG, Hernández‐Mijangos LA, Ibarra‐López MP, Iñiguez‐Dávalos LI, León‐Madrazo R, López‐González C, López‐Téllez MC, López‐Vidal JC, Martínez‐Balvanera S, Montiel‐Reyes F, Murrieta‐Galindo R, Orozco‐Lugo CL, Pech‐Canché JM, Pérez‐Pérez L, Ramírez‐Martínez MM, Rizo‐Aguilar A, Robredo‐Esquivelzeta E, Rodas‐Martínez AZ, Rojo‐Cruz MA, Selem‐Salas CI, Uribe‐Bencomo E, Vargas‐Contreras JA, MacSwiney G. MC. The Sonozotz project: Assembling an echolocation call library for bats in a megadiverse country. Ecol Evol 2020; 10:4928-4943. [PMID: 32551071 PMCID: PMC7297765 DOI: 10.1002/ece3.6245] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 03/06/2020] [Accepted: 03/09/2020] [Indexed: 11/23/2022] Open
Abstract
Bat acoustic libraries are important tools that assemble echolocation calls to allow the comparison and discrimination to confirm species identifications. The Sonozotz project represents the first nation-wide library of bat echolocation calls for a megadiverse country. It was assembled following a standardized recording protocol that aimed to cover different recording habitats, recording techniques, and call variation inherent to individuals. The Sonozotz project included 69 species of echolocating bats, a high species richness that represents 50% of bat species found in the country. We include recommendations on how the database can be used and how the sampling methods can be potentially replicated in countries with similar environmental and geographic conditions. To our knowledge, this represents the most exhaustive effort to date to document and compile the diversity of bat echolocation calls for a megadiverse country. This database will be useful to address a range of ecological questions including the effects of anthropogenic activities on bat communities through the analysis of bat sound.
Collapse
Affiliation(s)
- Veronica Zamora‐Gutierrez
- CONACYT—Centro Interdisciplinario de Investigación para el Desarrollo Integral Regional Unidad Durango (CIIDIR)Instituto Politécnico NacionalDurangoMéxico
| | - Jorge Ortega
- Departamento de ZoologíaEscuela Nacional de Ciencias BiológicasInstituto Politécnico NacionalCiudad de MéxicoMéxico
| | - Rafael Avila‐Flores
- División Académica de Ciencias BiológicasUniversidad Juárez Autónoma de TabascoVillahermosaMéxico
| | - Pedro Adrián Aguilar‐Rodríguez
- Centro de Investigaciones TropicalesUniversidad VeracruzanaXalapaMéxico
- Universidad Autónoma de TlaxcalaTlaxcala de XicohténcatlMéxico
| | | | | | | | | | - Miguel Briones‐Salas
- Centro Interdisciplinario de Investigación para el Desarrollo Integral RegionalUnidad Oaxaca (CIIDIR)Instituto Politécnico NacionalOaxacaMéxico
| | - Martha Chan‐Noh
- Campus de Ciencias Biológicas‐AgropecuariasUniversidad Autónoma de YucatánMéridaMéxico
| | - Manuel Chávez‐Cauich
- Campus de Ciencias Biológicas‐AgropecuariasUniversidad Autónoma de YucatánMéridaMéxico
| | - Cuauhtémoc Chávez
- Departamento de Ciencias AmbientalesUniversidad Autónoma Metropolitana‐Unidad LermaLermaMéxico
| | - Patricia Cortés‐Calva
- Programa de Planeación Ambiental y ConservaciónCentro de Investigaciones Biológicas del Noroeste, S.C.La PazMéxico
| | | | - Jesús Carlo Cuevas
- Ingeniería en Recursos Naturales y AgropecuariosUniversidad de GuadalajaraAutlánMéxico
| | | | - Cynthia Elizalde‐Arellano
- Departamento de ZoologíaEscuela Nacional de Ciencias BiológicasInstituto Politécnico NacionalCiudad de MéxicoMéxico
| | - Margarita García‐Luis
- Centro Interdisciplinario de Investigación para el Desarrollo Integral RegionalUnidad Oaxaca (CIIDIR)Instituto Politécnico NacionalOaxacaMéxico
- Instituto Tecnológico del Valle de OaxacaXoxocotlánMéxico
| | | | - José Antonio Guerrero
- Facultad de Ciencias BiológicasUniversidad Autónoma del Estado de MorelosCuernavacaMéxico
| | | | - Edgar G. Gutiérrez
- Departamento de ZoologíaEscuela Nacional de Ciencias BiológicasInstituto Politécnico NacionalCiudad de MéxicoMéxico
| | | | | | | | - Rafael León‐Madrazo
- División Académica de Ciencias BiológicasUniversidad Juárez Autónoma de TabascoVillahermosaMéxico
| | - Celia López‐González
- Centro Interdisciplinario de Investigación para el Desarrollo Integral Regional Unidad Durango (CIIDIR)Instituto Politécnico NacionalDurangoMéxico
| | | | - Juan Carlos López‐Vidal
- Departamento de ZoologíaEscuela Nacional de Ciencias BiológicasInstituto Politécnico NacionalCiudad de MéxicoMéxico
| | | | - Fernando Montiel‐Reyes
- Centro Interdisciplinario de Investigación para el Desarrollo Integral Regional Unidad Durango (CIIDIR)Instituto Politécnico NacionalDurangoMéxico
| | | | - Carmen Lorena Orozco‐Lugo
- Centro de Investigación en Biodiversidad y ConservaciónUniversidad Autónoma del Estado de MorelosCuernavacaMéxico
| | - Juan M. Pech‐Canché
- Facultad de Ciencias Biológicas y AgropecuariasUniversidad VeracruzanaTuxpanMéxico
| | - Lucio Pérez‐Pérez
- División Académica de Ciencias BiológicasUniversidad Juárez Autónoma de TabascoVillahermosaMéxico
| | | | - Areli Rizo‐Aguilar
- Facultad de Ciencias Químicas e IngenieríaUniversidad Autónoma del Estado de MorelosCuernavacaMéxico
| | | | - Alba Z. Rodas‐Martínez
- División Académica de Ciencias BiológicasUniversidad Juárez Autónoma de TabascoVillahermosaMéxico
| | | | | | - Elena Uribe‐Bencomo
- Campus de Ciencias Biológicas‐AgropecuariasUniversidad Autónoma de YucatánMéridaMéxico
| | | | | |
Collapse
|
35
|
D'Angelo G, Janotte E, Schoepe T, O'Keeffe J, Milde MB, Chicca E, Bartolozzi C. Event-Based Eccentric Motion Detection Exploiting Time Difference Encoding. Front Neurosci 2020; 14:451. [PMID: 32457575 PMCID: PMC7227134 DOI: 10.3389/fnins.2020.00451] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Accepted: 04/14/2020] [Indexed: 11/13/2022] Open
Abstract
Attentional selectivity tends to follow events considered as interesting stimuli. Indeed, the motion of visual stimuli present in the environment attract our attention and allow us to react and interact with our surroundings. Extracting relevant motion information from the environment presents a challenge with regards to the high information content of the visual input. In this work we propose a novel integration between an eccentric down-sampling of the visual field, taking inspiration from the varying size of receptive fields (RFs) in the mammalian retina, and the Spiking Elementary Motion Detector (sEMD) model. We characterize the system functionality with simulated data and real world data collected with bio-inspired event driven cameras, successfully implementing motion detection along the four cardinal directions and diagonally.
Collapse
Affiliation(s)
- Giulia D'Angelo
- Event Driven Perception for Robotics, Italian Institute of Technology, iCub Facility, Genoa, Italy
| | - Ella Janotte
- Faculty of Technology and Center of Cognitive Interaction Technology (CITEC), Bielefeld University, Bielefeld, Germany
| | - Thorben Schoepe
- Faculty of Technology and Center of Cognitive Interaction Technology (CITEC), Bielefeld University, Bielefeld, Germany
| | - James O'Keeffe
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Moritz B Milde
- International Centre for Neuromorphic Systems, The MARCS Institute, Western Sydney University, Sydney, NSW, Australia
| | - Elisabetta Chicca
- Faculty of Technology and Center of Cognitive Interaction Technology (CITEC), Bielefeld University, Bielefeld, Germany
| | - Chiara Bartolozzi
- Event Driven Perception for Robotics, Italian Institute of Technology, iCub Facility, Genoa, Italy
| |
Collapse
|
36
|
Izadi MR, Stevenson R, Kloepper LN. Separation of overlapping sources in bioacoustic mixtures. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 147:1688. [PMID: 32237826 DOI: 10.1121/10.0000932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 03/02/2020] [Indexed: 06/11/2023]
Abstract
Source separation is an important step to study signals that are not easy or possible to record individually. Common methods such as deep clustering, however, cannot be applied to signals of an unknown number of sources and/or signals that overlap in time and/or frequency-a common problem in bioacoustic recordings. This work presents an approach, using a supervised learning framework, to parse individual sources from a spectrogram of a mixture that contains a variable number of overlapping sources. This method isolates individual sources in the time-frequency domain using only one function but in two separate steps, one for the detection of the number of sources and corresponding bounding boxes, and a second step for the segmentation in which masks of individual sounds are extracted. This approach handles the full separation of overlapping sources in both time and frequency using deep neural networks in an applicable manner to other tasks such as bird audio detection. This paper presents method and reports on its performance to parse individual bat signals from recordings containing hundreds of overlapping bat echolocation signals. This method can be extended to other bioacoustic recordings with a variable number of sources and signals that overlap in time and/or frequency.
Collapse
Affiliation(s)
- Mohammad Rasool Izadi
- Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Robert Stevenson
- Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Laura N Kloepper
- Department of Biology, Saint Mary's College, Notre Dame, Indiana 46556, USA
| |
Collapse
|
37
|
Massoud D, Abumandour MM. Anatomical features of the tongue of two chiropterans endemic in the Egyptian fauna; the Egyptian fruit bat (Rousettus aegyptiacus) and insectivorous bat (Pipistrellus kuhlii). Acta Histochem 2020; 122:151503. [PMID: 31955907 DOI: 10.1016/j.acthis.2020.151503] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 12/24/2019] [Accepted: 12/27/2019] [Indexed: 12/19/2022]
Abstract
The current study aimed to investigate the tongue (lingual) morphometry, histology, and histochemistry of two chiropterans endemic in the Egyptian fauna, and having different feeding preferences. The tongues of nine adult individuals of each species were utilized in our investigation. The tongue of fruit-eating bat was observed relatively longer than the one of insect-eating bat. Grossly, the insect-eating bat had a lingual prominence on the dorsum of lingual body, while the fruit-eating bat had a concave midline over the lingual body. Histologically, numerous forms of lingual papillae were scattered along the dorsal epithelium of the tongue. The lingual papillae of the fruit-eating bat seem to be well adapted for piercing the skin of a fruit and liquid sap retention. The lingual glands of both species were lodged in the muscular layer. Two main sets were identified; the serous von Ebner's gland usually seen accompanied by the circumvallate papillae and Weber's gland with mixed mucoserous secretions. Von Ebner's gland showed more prominent acidic mucins, while Weber's gland expressed neutral mucins. The lingual epithelium of the fruit-eating bat had an outer covering of cornified non-nucleated epithelium. On the other hand, the insect-eating bat had an outer covering of nucleated epithelium. It is for the first time to record the existence of the entoglossal plates of both species which consisted of a bony core in the fruit-eating bat and a cartilaginous element in the insect-eating bat. The current study represents an attempt to shed more light on the tongue evolution among mammalian vertebrates.
Collapse
|
38
|
Zhang Y, Lin A, Ding J, Yang X, Jiang T, Liu Y, Feng J. Performance of Doppler shift compensation in bats varies with species rather than with environmental clutter. Anim Behav 2019. [DOI: 10.1016/j.anbehav.2019.10.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
39
|
|
40
|
Male responses suggest both evolutionary conservation and rapid change in chemical cues of female widow spiders. Anim Behav 2019. [DOI: 10.1016/j.anbehav.2019.08.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
41
|
Hernández-Jerez A, Adriaanse P, Aldrich A, Berny P, Coja T, Duquesne S, Gimsing AL, Marina M, Millet M, Pelkonen O, Pieper S, Tiktak A, Tzoulaki I, Widenfalk A, Wolterink G, Russo D, Streissl F, Topping C. Scientific statement on the coverage of bats by the current pesticide risk assessment for birds and mammals. EFSA J 2019; 17:e05758. [PMID: 32626374 PMCID: PMC7009170 DOI: 10.2903/j.efsa.2019.5758] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Bats are an important group of mammals, frequently foraging in farmland and potentially exposed to pesticides. This statement considers whether the current risk assessment performed for birds and ground dwelling mammals exposed to pesticides is also protective of bats. Three main issues were addressed. Firstly, whether bats are toxicologically more or less sensitive than the most sensitive birds and mammals. Secondly, whether oral exposure of bats to pesticides is greater or lower than in ground dwelling mammals and birds. Thirdly, whether there are other important exposure routes relevant to bats. A large variation in toxicological sensitivity and no relationship between sensitivity of bats and bird or mammal test-species to pesticides could be found. In addition, bats have unique traits, such as echolocation and torpor which can be adversely affected by exposure to pesticides and which are not covered by the endpoints currently selected for wild mammal risk assessment. The current exposure assessment methodology was used for oral exposure and adapted to bats using bat-specific parameters. For oral exposure, it was concluded that for most standard risk assessment scenarios the current approach did not cover exposure of bats to pesticide residues in food. Calculations of potential dermal exposure for bats foraging during spraying operations suggest that this may be a very important exposure route. Dermal routes of exposure should be combined with inhalation and oral exposure. Based on the evidence compiled, the Panel concludes that bats are not adequately covered by the current risk assessment approach, and that there is a need to develop a bat-specific risk assessment scheme. In general, there was scarcity of data to assess the risks for bat exposed to pesticides. Recommendations for research are made, including identification of alternatives to laboratory testing of bats to assess toxicological effects.
Collapse
|
42
|
|
43
|
Corcoran AJ, Weller TJ. Inconspicuous echolocation in hoary bats ( Lasiurus cinereus). Proc Biol Sci 2019; 285:rspb.2018.0441. [PMID: 29720417 DOI: 10.1098/rspb.2018.0441] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/10/2018] [Indexed: 01/05/2023] Open
Abstract
Echolocation allows bats to occupy diverse nocturnal niches. Bats almost always use echolocation, even when other sensory stimuli are available to guide navigation. Here, using arrays of calibrated infrared cameras and ultrasonic microphones, we demonstrate that hoary bats (Lasiurus cinereus) use previously unknown echolocation behaviours that challenge our current understanding of echolocation. We describe a novel call type ('micro' calls) that has three orders of magnitude less sound energy than other bat calls used in open habitats. We also document bats flying close to microphones (less than 3 m) without producing detectable echolocation calls. Acoustic modelling indicates that bats are not producing calls that exceed 70-75 dB at 0.1 m, a level that would have little or no known use for a bat flying in the open at speeds exceeding 7 m s-1 This indicates that hoary bats sometimes fly without echolocation. We speculate that bats reduce echolocation output to avoid eavesdropping by conspecifics during the mating season. These findings might partly explain why tens of thousands of hoary bats are killed by wind turbines each year. They also challenge the long-standing assumption that bats-model organisms for sensory specialization-are reliant on sonar for nocturnal navigation.
Collapse
Affiliation(s)
- Aaron J Corcoran
- Department of Biology, Wake Forest University, PO Box 7325, Reynolda Station, Winston-Salem, NC 27109, USA
| | - Theodore J Weller
- USDA Forest Service, Pacific Southwest Research Station, Arcata, CA 95521, USA
| |
Collapse
|
44
|
Deploying Acoustic Detection Algorithms on Low-Cost, Open-Source Acoustic Sensors for Environmental Monitoring. SENSORS 2019; 19:s19030553. [PMID: 30699950 PMCID: PMC6387379 DOI: 10.3390/s19030553] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/16/2019] [Accepted: 01/24/2019] [Indexed: 12/02/2022]
Abstract
Conservation researchers require low-cost access to acoustic monitoring technology. However, affordable tools are often constrained to short-term studies due to high energy consumption and limited storage. To enable long-term monitoring, energy and space efficiency must be improved on such tools. This paper describes the development and deployment of three acoustic detection algorithms that reduce the power and storage requirements of acoustic monitoring on affordable, open-source hardware. The algorithms aim to detect bat echolocation, to search for evidence of an endangered cicada species, and also to collect evidence of poaching in a protected nature reserve. The algorithms are designed to run on AudioMoth: a low-cost, open-source acoustic monitoring device, developed by the authors and widely adopted by the conservation community. Each algorithm addresses a detection task of increasing complexity, implementing extra analytical steps to account for environmental conditions such as wind, analysing samples multiple times to prevent missed events, and incorporating a hidden Markov model for sample classification in both the time and frequency domain. For each algorithm, we report on real-world deployments carried out with partner organisations and also benchmark the hidden Markov model against a convolutional neural network, a deep-learning technique commonly used for acoustics. The deployments demonstrate how acoustic detection algorithms extend the use of low-cost, open-source hardware and facilitate a new avenue for conservation researchers to perform large-scale monitoring.
Collapse
|
45
|
Young S, Carr A, Jones G. CCTV Enables the Discovery of New Barbastelle (Barbastella barbastellus) Vocalisations and Activity Patterns Near a Roost. ACTA CHIROPTEROLOGICA 2018. [DOI: 10.3161/15081109acc2018.20.1.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Susan Young
- Bramley Lodge, Beech Trees Lane, Ipplepen, Newton Abbot, TQ12 5TW, United Kingdom
| | - Andrew Carr
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ, United Kingdom
| | - Gareth Jones
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ, United Kingdom
| |
Collapse
|
46
|
Kraker-Castañeda C, Santos-Moreno A, Lorenzo C, MacSwiney G. MC. Effect of intrinsic and extrinsic factors on the variability of echolocation pulses of Myotis nigricans (Schinz, 1821) (Chiroptera: Vespertilionidae). BIOACOUSTICS 2018. [DOI: 10.1080/09524622.2018.1461685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Cristian Kraker-Castañeda
- Departamento de Conservación de la Biodiversidad, El Colegio de la Frontera Sur (ECOSUR), San Cristóbal de Las Casas, Mexico
- Unidad para el Conocimiento, Uso y Valoración de la Biodiversidad, Centro de Estudios Conservacionistas (CECON), Universidad de San Carlos de Guatemala, Guatemala City, Guatemala
| | - Antonio Santos-Moreno
- Laboratorio de Ecología Animal, Centro Interdisciplinario de Investigación para el Desarrollo Integral Regional (CIIDIR), Unidad Oaxaca, Instituto Politécnico Nacional, Oaxaca, Mexico
| | - Consuelo Lorenzo
- Departamento de Conservación de la Biodiversidad, El Colegio de la Frontera Sur (ECOSUR), San Cristóbal de Las Casas, Mexico
| | | |
Collapse
|
47
|
Kuc R. Comparing phase-sensitive and phase-insensitive echolocation target images using a monaural audible sonar. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2018; 143:2379. [PMID: 29716281 DOI: 10.1121/1.5033903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This paper describes phase-sensitive and phase-insensitive processing of monaural echolocation waveforms to generate target maps. Composite waveforms containing both the emission and echoes are processed to estimate the target impulse response using an audible sonar. Phase-sensitive processing yields the composite signal envelope, while phase-insensitive processing that starts with the composite waveform power spectrum yields the envelope of the autocorrelation function. Analysis and experimental verification show that multiple echoes form an autocorrelation function that produces near-range phantom-reflector artifacts. These artifacts interfere with true target echoes when the first true echo occurs at a time that is less than the total duration of the target echoes. Initial comparison of phase-sensitive and phase-insensitive maps indicates that both display important target features, indicating that phase is not vital. A closer comparison illustrates the improved resolution of phase-sensitive processing, the near-range phantom-reflectors produced by phase-insensitive processing, and echo interference and multiple reflection artifacts that were independent of the processing.
Collapse
Affiliation(s)
- Roman Kuc
- Department of Electrical Engineering, Yale University, New Haven, Connecticut 06511, USA
| |
Collapse
|
48
|
Russo D, Ancillotto L, Jones G. Bats are still not birds in the digital era: echolocation call variation and why it matters for bat species identification. CAN J ZOOL 2018. [DOI: 10.1139/cjz-2017-0089] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The recording and analysis of echolocation calls are fundamental methods used to study bat distribution, ecology, and behavior. However, the goal of identifying bats in flight from their echolocation calls is not always possible. Unlike bird songs, bat calls show large variation that often makes identification challenging. The problem has not been fully overcome by modern digital-based hardware and software for bat call recording and analysis. Besides providing fundamental insights into bat physiology, ecology, and behavior, a better understanding of call variation is therefore crucial to best recognize limits and perspectives of call classification. We provide a comprehensive overview of sources of interspecific and intraspecific echolocation call variations, illustrating its adaptive significance and highlighting gaps in knowledge. We remark that further research is needed to better comprehend call variation and control for it more effectively in sound analysis. Despite the state-of-art technology in this field, combining acoustic surveys with capture and roost search, as well as limiting identification to species with distinctive calls, still represent the safest way of conducting bat surveys.
Collapse
Affiliation(s)
- Danilo Russo
- Wildlife Research Unit, Dipartimento di Agraria, Università degli Studi di Napoli Federico II, 80055 Portici, Italy
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, United Kingdom
| | - Leonardo Ancillotto
- Wildlife Research Unit, Dipartimento di Agraria, Università degli Studi di Napoli Federico II, 80055 Portici, Italy
| | - Gareth Jones
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, United Kingdom
| |
Collapse
|
49
|
Todd BD, Müller R. A comparison of the role of beamwidth in biological and engineered sonar. BIOINSPIRATION & BIOMIMETICS 2017; 13:016014. [PMID: 29130894 DOI: 10.1088/1748-3190/aa9a0f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Sonar is an important sensory modality for engineers as well as in nature. In engineering, sonar is the dominating modality for underwater sensing. In nature, biosonar is likely to have been a central factor behind the unprecedented evolutionary success of bats, a highly diverse group that accounts for over 20% of all mammal species. However, it remains unclear to what extent engineered and biosonar follow similar design and operational principles. In the current work, the key sonar design characteristic of beamwidth is examined in technical and biosonar. To this end, beamwidth data has been obtained for 23 engineered sonar systems and from numerical beampattern predictions for 151 emission and reception elements (noseleaves and ears) representing bat biosonar. Beamwidth data from these sources is compared to the beamwidth of a planar ellipsoidal transducer as a reference. The results show that engineered and biological both obey the basic physical limit on beamwidth as a function of the ratio of aperture size and wavelength. However, beyond that, the beamwidth data revealed very different behaviors between the engineered and the biological sonar systems. Whereas the beamwidths of the technical sonar systems were very close to the planar transducer limit, the biological samples showed a very wide scatter away from this limit. This scatter was as large, if not wider, than what was seen in a small reference data set obtained with random aluminum cones. A possible interpretation of these differences in the variability could be that whereas sonar engineers try to minimize beamwidth subject to constraints on device size, the evolutionary optimization of bat biosonar beampatterns has been directed at other factors that have left beamwidth as a byproduct. Alternatively, the biosonar systems may require beamwidth values that are larger than the physical limit and differ between species and their sensory ecological niches.
Collapse
Affiliation(s)
- Bryan D Todd
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, United States of America
| | | |
Collapse
|
50
|
Bankoff RJ, Jerjos M, Hohman B, Lauterbur ME, Kistler L, Perry GH. Testing Convergent Evolution in Auditory Processing Genes between Echolocating Mammals and the Aye-Aye, a Percussive-Foraging Primate. Genome Biol Evol 2017; 9:1978-1989. [PMID: 28810710 PMCID: PMC5553384 DOI: 10.1093/gbe/evx140] [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] [Accepted: 07/25/2017] [Indexed: 01/04/2023] Open
Abstract
Several taxonomically distinct mammalian groups-certain microbats and cetaceans (e.g., dolphins)-share both morphological adaptations related to echolocation behavior and strong signatures of convergent evolution at the amino acid level across seven genes related to auditory processing. Aye-ayes (Daubentonia madagascariensis) are nocturnal lemurs with a specialized auditory processing system. Aye-ayes tap rapidly along the surfaces of trees, listening to reverberations to identify the mines of wood-boring insect larvae; this behavior has been hypothesized to functionally mimic echolocation. Here we investigated whether there are signals of convergence in auditory processing genes between aye-ayes and known mammalian echolocators. We developed a computational pipeline (Basic Exon Assembly Tool) that produces consensus sequences for regions of interest from shotgun genomic sequencing data for nonmodel organisms without requiring de novo genome assembly. We reconstructed complete coding region sequences for the seven convergent echolocating bat-dolphin genes for aye-ayes and another lemur. We compared sequences from these two lemurs in a phylogenetic framework with those of bat and dolphin echolocators and appropriate nonecholocating outgroups. Our analysis reaffirms the existence of amino acid convergence at these loci among echolocating bats and dolphins; some methods also detected signals of convergence between echolocating bats and both mice and elephants. However, we observed no significant signal of amino acid convergence between aye-ayes and echolocating bats and dolphins, suggesting that aye-aye tap-foraging auditory adaptations represent distinct evolutionary innovations. These results are also consistent with a developing consensus that convergent behavioral ecology does not reliably predict convergent molecular evolution.
Collapse
Affiliation(s)
- Richard J Bankoff
- Department of Anthropology, Pennsylvania State University, University Park, PA.,Intercollege Program in Bioethics, Pennsylvania State University, University Park, PA
| | - Michael Jerjos
- Department of Anthropology, Pennsylvania State University, University Park, PA
| | - Baily Hohman
- Department of Anthropology, Pennsylvania State University, University Park, PA
| | - M Elise Lauterbur
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY
| | - Logan Kistler
- Department of Anthropology, Pennsylvania State University, University Park, PA.,Department of Anthropology, National Museum of Natural History, Smithsonian Institution, Washington DC
| | - George H Perry
- Department of Anthropology, Pennsylvania State University, University Park, PA.,Department of Biology, Pennsylvania State University, University Park, PA
| |
Collapse
|