Echolocating bats use echo delay for target ranging and Doppler shift information for relative ve... more Echolocating bats use echo delay for target ranging and Doppler shift information for relative velocity recognition. However, how they perceive moving objects remains unclear. To investigate this question, we played back echolocation pulses in real-time as virtual echoes to Japanese horseshoe bats ( Rhinolophus ferrumequinum nippon ) on a perch in a flight room. Since echoes coming back from an approaching object are theoretically characterized by both changes in echo delay and the presence of Doppler shift, we reproduced an artificial approaching object by encoding these two acoustic parameters in the virtual echoes. As a result, only Doppler shift evoked bats flight reaction, showing that they use only Doppler shift and not change in echo delay to perceive approaching objects. Also, we played back only constant frequency (CF) component and confirmed that they use the CF component to detect Doppler shift. Furthermore, as a response to the Doppler shift in the perceived echo, bats i...
A repository of data and codes used in Visualization of bat echo space by using acoustic simulati... more A repository of data and codes used in Visualization of bat echo space by using acoustic simulation.Bat species are listed in the readme.
This row dataset was used for original article entitled "Modulation of acoustic navigation b... more This row dataset was used for original article entitled "Modulation of acoustic navigation behaviour by spatial learning in the echolocating bat Rhinolophus ferrumequinum nippon (https://doi.org/10.1038/s41598-020-67470-z)".
Background Echolocating bats use echo information to perceive space, control their behavior, and ... more Background Echolocating bats use echo information to perceive space, control their behavior, and adjust flight navigation strategies in various environments. However, the echolocation behavior of bats, including echo information, has not been thoroughly investigated as it is technically difficult to measure all the echoes that reach the bats during flight, even with the conventional telemetry microphones currently in use. Therefore, we attempted to reproduce the echoes received at the location of bats during flight by combining acoustic simulation and behavioral experiments with acoustic measurements. By using acoustic simulation, echoes can be reproduced as temporal waveforms (including diffracted waves and multiple reflections), and detailed echo analysis is possible even in complex obstacle environments. Results We visualized the spatiotemporal changes in the echo incidence points detected by bats during flight, which enabled us to investigate the “echo space” revealed through ec...
Landscape heterogeneity is regarded as a key factor for maintaining biodiversity and eco-system f... more Landscape heterogeneity is regarded as a key factor for maintaining biodiversity and eco-system function in production landscapes. We investigated whether grassland sites at close vicinity to forested areas are more frequently used by bats. Considering that bats are important consumers of herbivorous insects, including agricultural pest, this is important for sustainable land management. Bat activity and species richness were assessed using repeated monitoring from May to September in 2010 with acoustic monitoring surveys on 50 grassland sites in the Biosphere Reserve Schorfheide-Chorin (North-East Germany). Using spatial analysis (GIS), we measured the closest distance of each grassland site to potentially connecting landscape elements (e.g., trees, linear vegetation, groves, running and standing water). In addition, we assessed the distance to and the percent land cover of forest remnants and urban areas in a 200 m buffer around the recording sites to address dif-ferences in the l...
Bats emit a series of echolocation calls with an increasing repetition rate (the terminal buzz), ... more Bats emit a series of echolocation calls with an increasing repetition rate (the terminal buzz), when attempting to capture prey. This is often used as an acoustic indicator of prey-capture attempts. However, because it is directly linked to foraging efficiency, predation success is a more useful measure than predation attempts in ecological research. The characteristics of echolocation calls that consistently signify predation success across different situations have not been identified. Due to additional influencing factors, identification of these characteristics is particularly challenging for wild bats foraging in their natural environment compared to those in flight chambers. This study documented the natural foraging behavior of wild Japanese large-footed bat Myotis macrodactylus using synchronized acoustic and video recordings. From the video recordings, we could assign 137 attacks to three outcome categories: prey captured (51.8%), prey dropped (29.2%), and failed attempt (...
Im Rahmen einer internetbasierten Umfrage wurde die Einschätzung von Expert*innen aus der Genehmi... more Im Rahmen einer internetbasierten Umfrage wurde die Einschätzung von Expert*innen aus der Genehmigungspraxis von Windenergieanlagen (Vertreter*innen der Naturschutzbehörden und dem Windenergiesektor, Mitglieder und Mitarbeiter*innen von Umweltschutzorganisationen, Wissenschaftler*innen und Fachgutachter*innen) zur Vereinbarkeit von Artenschutz, speziell Fledermausschutz, und dem Ausbau erneuerbarer Energien, speziell Windenergieproduktion, abgefragt. Mehrheitlich bewerteten die Fachexpert*innen das derzeitige Artenschutzrecht als nicht zu streng und zudem als nicht hinderlich für den weiteren Ausbau der Windenergieproduktion in Deutschland. Des Weiteren bewertete die Mehrheit der Umfrageteilnehmer*innen die Windenergieproduktion an Waldstandorten als nicht im Sinne einer umweltverträglichen Energiewende und als zu sehr konfliktbelastet. Windenergievorhaben und Fledermausschutz: Was fordern Expert*innen zur Lösung des GrünGrün-Dilemmas?
Behavioral experiments with acoustic measurements have revealed the intriguing strategies of flig... more Behavioral experiments with acoustic measurements have revealed the intriguing strategies of flight navigation and the use of ultrasound by echolocating bats in various environments. However, the echolocation behavior of bats has not been thoroughly investigated in regard to the environment they perceive via echolocation because it is technically difficult to measure all the echoes that reach the bats during flight, even with the conventional telemetry microphones currently in use. Therefore, we attempted to reproduce the echoes of bats during flight by combining acoustic simulation and behavioral experiments with acoustic measurements. As a result, we visualized the spatiotemporal changes in the echo incidence points detected by bats during flight, which enabled us to investigate the “echo space” revealed through echolocation. In addition, we could observe how the distribution of visualized echoes concentrated at the obstacle edges after the bats became more familiar with their env...
Using echolocation, bats receive acoustic information on their surroundings, which is assumed to ... more Using echolocation, bats receive acoustic information on their surroundings, which is assumed to help them sophisticatedly navigate complex environments. In this study, to understand spatial learning and acoustic sensing in bats, we investigated how flight and echolocation control changed in Rhinolophus ferrumequinum nippon as they learnt about their surroundings in an obstacle course that they flew through repeatedly. In these experiments, two testing environments (acoustically permeable and acoustically reflective) were prepared using chains and acrylic boards as obstacles to evaluate the interactive effects of spatial learning and flight environments. We found that bats reduced the meandering width of their flights and pulse emissions, and also seemed to reduce their shifts in pulse direction as they learnt more about their environments in both conditions. Throughout all our experiments, the bats with slower flight speeds tended to emit more pulses, which suggests that the number...
Echolocating bats use echo delay for target ranging and Doppler shift information for relative ve... more Echolocating bats use echo delay for target ranging and Doppler shift information for relative velocity recognition. However, how they perceive moving objects remains unclear. To investigate this question, we played back echolocation pulses in real-time as virtual echoes to Japanese horseshoe bats ( Rhinolophus ferrumequinum nippon ) on a perch in a flight room. Since echoes coming back from an approaching object are theoretically characterized by both changes in echo delay and the presence of Doppler shift, we reproduced an artificial approaching object by encoding these two acoustic parameters in the virtual echoes. As a result, only Doppler shift evoked bats flight reaction, showing that they use only Doppler shift and not change in echo delay to perceive approaching objects. Also, we played back only constant frequency (CF) component and confirmed that they use the CF component to detect Doppler shift. Furthermore, as a response to the Doppler shift in the perceived echo, bats i...
A repository of data and codes used in Visualization of bat echo space by using acoustic simulati... more A repository of data and codes used in Visualization of bat echo space by using acoustic simulation.Bat species are listed in the readme.
This row dataset was used for original article entitled "Modulation of acoustic navigation b... more This row dataset was used for original article entitled "Modulation of acoustic navigation behaviour by spatial learning in the echolocating bat Rhinolophus ferrumequinum nippon (https://doi.org/10.1038/s41598-020-67470-z)".
Background Echolocating bats use echo information to perceive space, control their behavior, and ... more Background Echolocating bats use echo information to perceive space, control their behavior, and adjust flight navigation strategies in various environments. However, the echolocation behavior of bats, including echo information, has not been thoroughly investigated as it is technically difficult to measure all the echoes that reach the bats during flight, even with the conventional telemetry microphones currently in use. Therefore, we attempted to reproduce the echoes received at the location of bats during flight by combining acoustic simulation and behavioral experiments with acoustic measurements. By using acoustic simulation, echoes can be reproduced as temporal waveforms (including diffracted waves and multiple reflections), and detailed echo analysis is possible even in complex obstacle environments. Results We visualized the spatiotemporal changes in the echo incidence points detected by bats during flight, which enabled us to investigate the “echo space” revealed through ec...
Landscape heterogeneity is regarded as a key factor for maintaining biodiversity and eco-system f... more Landscape heterogeneity is regarded as a key factor for maintaining biodiversity and eco-system function in production landscapes. We investigated whether grassland sites at close vicinity to forested areas are more frequently used by bats. Considering that bats are important consumers of herbivorous insects, including agricultural pest, this is important for sustainable land management. Bat activity and species richness were assessed using repeated monitoring from May to September in 2010 with acoustic monitoring surveys on 50 grassland sites in the Biosphere Reserve Schorfheide-Chorin (North-East Germany). Using spatial analysis (GIS), we measured the closest distance of each grassland site to potentially connecting landscape elements (e.g., trees, linear vegetation, groves, running and standing water). In addition, we assessed the distance to and the percent land cover of forest remnants and urban areas in a 200 m buffer around the recording sites to address dif-ferences in the l...
Bats emit a series of echolocation calls with an increasing repetition rate (the terminal buzz), ... more Bats emit a series of echolocation calls with an increasing repetition rate (the terminal buzz), when attempting to capture prey. This is often used as an acoustic indicator of prey-capture attempts. However, because it is directly linked to foraging efficiency, predation success is a more useful measure than predation attempts in ecological research. The characteristics of echolocation calls that consistently signify predation success across different situations have not been identified. Due to additional influencing factors, identification of these characteristics is particularly challenging for wild bats foraging in their natural environment compared to those in flight chambers. This study documented the natural foraging behavior of wild Japanese large-footed bat Myotis macrodactylus using synchronized acoustic and video recordings. From the video recordings, we could assign 137 attacks to three outcome categories: prey captured (51.8%), prey dropped (29.2%), and failed attempt (...
Im Rahmen einer internetbasierten Umfrage wurde die Einschätzung von Expert*innen aus der Genehmi... more Im Rahmen einer internetbasierten Umfrage wurde die Einschätzung von Expert*innen aus der Genehmigungspraxis von Windenergieanlagen (Vertreter*innen der Naturschutzbehörden und dem Windenergiesektor, Mitglieder und Mitarbeiter*innen von Umweltschutzorganisationen, Wissenschaftler*innen und Fachgutachter*innen) zur Vereinbarkeit von Artenschutz, speziell Fledermausschutz, und dem Ausbau erneuerbarer Energien, speziell Windenergieproduktion, abgefragt. Mehrheitlich bewerteten die Fachexpert*innen das derzeitige Artenschutzrecht als nicht zu streng und zudem als nicht hinderlich für den weiteren Ausbau der Windenergieproduktion in Deutschland. Des Weiteren bewertete die Mehrheit der Umfrageteilnehmer*innen die Windenergieproduktion an Waldstandorten als nicht im Sinne einer umweltverträglichen Energiewende und als zu sehr konfliktbelastet. Windenergievorhaben und Fledermausschutz: Was fordern Expert*innen zur Lösung des GrünGrün-Dilemmas?
Behavioral experiments with acoustic measurements have revealed the intriguing strategies of flig... more Behavioral experiments with acoustic measurements have revealed the intriguing strategies of flight navigation and the use of ultrasound by echolocating bats in various environments. However, the echolocation behavior of bats has not been thoroughly investigated in regard to the environment they perceive via echolocation because it is technically difficult to measure all the echoes that reach the bats during flight, even with the conventional telemetry microphones currently in use. Therefore, we attempted to reproduce the echoes of bats during flight by combining acoustic simulation and behavioral experiments with acoustic measurements. As a result, we visualized the spatiotemporal changes in the echo incidence points detected by bats during flight, which enabled us to investigate the “echo space” revealed through echolocation. In addition, we could observe how the distribution of visualized echoes concentrated at the obstacle edges after the bats became more familiar with their env...
Using echolocation, bats receive acoustic information on their surroundings, which is assumed to ... more Using echolocation, bats receive acoustic information on their surroundings, which is assumed to help them sophisticatedly navigate complex environments. In this study, to understand spatial learning and acoustic sensing in bats, we investigated how flight and echolocation control changed in Rhinolophus ferrumequinum nippon as they learnt about their surroundings in an obstacle course that they flew through repeatedly. In these experiments, two testing environments (acoustically permeable and acoustically reflective) were prepared using chains and acrylic boards as obstacles to evaluate the interactive effects of spatial learning and flight environments. We found that bats reduced the meandering width of their flights and pulse emissions, and also seemed to reduce their shifts in pulse direction as they learnt more about their environments in both conditions. Throughout all our experiments, the bats with slower flight speeds tended to emit more pulses, which suggests that the number...
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