Bats, Echolocation
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Recent papers in Bats, Echolocation
Se estudió el orden Chiroptera en la Reserva Nacional Pampa del Tamarugal (RNPT) con la finalidad de corroborar la presencia de ciertas especies y realizar un estudio comparativo acústico y morfológico. Se realizaron capturas con redes de... more
Se estudió el orden Chiroptera en la Reserva Nacional Pampa del Tamarugal (RNPT) con la finalidad de corroborar la presencia de ciertas especies y realizar un estudio comparativo acústico y morfológico. Se realizaron capturas con redes de neblina, los individuos fueron medidos y registrados acústicamente para posterior análisis. Se capturó cuatro especies (Myotis atacamensis, Histiotus Montanus, H. macrotus e H. laephotis), correspondientes a dos géneros. Se observaron diferencias de coloración entre las especies del género Histiotus, sin embargo sus medidas corporales resultaron homogéneas. H. laephotis mostró medidas alares mayores y un largo total menor que las restantes dos especies y se observó que H. monanus posee orejas menores que las otras dos especies (< 30 mm). Se identificaron caracteres acústicos para las cuatro especies, M. atacamensis presentó llamadas (FM) con frecuencia peak a 56,5 ± 6,9 kHz y duración promedio de 2.7 ± 0,7 ms, en cambio las especies del género Histiotus presentaron llamadas FM-QCF. H. laephotis e H. montanus mostraron diferencias significativas, excepto para frecuencia final. Entre H. laephotis e H macrotus se observaron diferencias significativas únicamente en la duración de los pulsos, frecuencia inicial y frecuencia peak. H. montanus e H. macrotus presentaron diferencias significativas para todas las variables, salvo frecuencia inicial. Se caracterizó la morfología de los murciélagos de la RNPT y se presentó el primer análisis acústico de las vocalizaciones de M. atacamensis e H. macrotus. La existencia de diferencias significativas a nivel acústico entre especies del género Histiotus, indica que las metodologías bioacústicas son útiles tanto para identificar especies, como para estimar su actividad
Brazil is a megadiverse country with more than 180 bat species. However, most inventories have been mostly made using mist-net sampling and roost search and due to the lack of bioacoustics studies, the bat fauna is certainly... more
Brazil is a megadiverse country with more than 180 bat species. However, most inventories have been mostly made using mist-net sampling and roost search and due to the lack of bioacoustics studies, the bat fauna is certainly subrepresented and biased. The knowledge on distribution and ecology of Brazilian bats is mainly within the Phyllostomidae. Reliable data on bat echolocation calls is the key to improve the knowledge on the distribution patterns and foraging ecology of the remaining eight bat families present in the country. Our work aims to (i) integrate information on echolocation calls of non-phyllostomids occurring in Brazil; (ii) detect regional changes in the acoustic profile of those species; (iii) identify gaps in knowledge both in terms of species and regions sampled; and (iv) to point out which species are acoustically recognizable in a reliable way. Finally, we present a key to supporting the acoustic identification of non-phyllostomids in Brazil. We compiled publications on echolocation calls of Neotropical bat species occurring in Brazil and summarized qualitative and quantitative information of acoustic parameters used in call descriptions. We considered 93 non-phyllostomid bat species to occur in Brazil of which 65 have been acoustically described but for 28 we found no published information. Information on echolocation calls was retrieved from 47 publications and acquired in 17 countries. The use of bioacoustics can be a fundamental tool to expand the knowledge on Brazilian bats and improve their conservation.
- by Frederico Hintze and +3
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- Brazil, Chiroptera, Echolocation, Neotropical Bats
PREFACE This book is designed as a guide aimed at satisfying the needs of those conducting field work on bats in the Amazon. It is largely based on Lim et al. (2001), with modifications derived from both personal observations and three... more
PREFACE
This book is designed as a guide aimed at satisfying the needs of those conducting field work on bats in the Amazon. It is largely based on Lim et al. (2001), with modifications derived from both personal observations and three years of field experience in the Brazilian Amazon at the Biological Dynamics of Forest Fragments Project (BDFFP), as well as a thorough revision of available bat keys and scientific papers describing new species.
Our aim was to write a straightforward, easy-to-use guide that would be both practical and very visual, and would facilitate bat species identification in the field. We tried to avoid as much as possible confusing features such as fur colour, as well as certain skull and teeth characteristics that cannot be easily measured under field conditions.
We decided to group together many of the cryptic species that are still indistinguishable in the field and that can only reliably be identified using molecular methods such as DNA barcoding. Taxonomic
nomenclature throughout this key follows Nogueira et al. (2014). This is an interactive field-guide that we hope will be continuously improved and updated.
We will be delighted to receive readers’ comments and suggestions!
Please send them to: adria.baucells@gmail.com
Thank you!
The Authors
This book is designed as a guide aimed at satisfying the needs of those conducting field work on bats in the Amazon. It is largely based on Lim et al. (2001), with modifications derived from both personal observations and three years of field experience in the Brazilian Amazon at the Biological Dynamics of Forest Fragments Project (BDFFP), as well as a thorough revision of available bat keys and scientific papers describing new species.
Our aim was to write a straightforward, easy-to-use guide that would be both practical and very visual, and would facilitate bat species identification in the field. We tried to avoid as much as possible confusing features such as fur colour, as well as certain skull and teeth characteristics that cannot be easily measured under field conditions.
We decided to group together many of the cryptic species that are still indistinguishable in the field and that can only reliably be identified using molecular methods such as DNA barcoding. Taxonomic
nomenclature throughout this key follows Nogueira et al. (2014). This is an interactive field-guide that we hope will be continuously improved and updated.
We will be delighted to receive readers’ comments and suggestions!
Please send them to: adria.baucells@gmail.com
Thank you!
The Authors
The use of bioacoustics as a tool for bat research is rapidly increasing worldwide. There is substantial evidence that environmental factors such as weather conditions or habitat structure can affect echolocation call structure in bats... more
The use of bioacoustics as a tool for bat research is rapidly increasing worldwide. There is substantial evidence that environmental factors such as weather conditions or habitat structure can affect echolocation call structure in bats and thus compromise proper species identification. However, intraspecific differences in echolocation due to geographical variation are poorly understood, which poses a number of issues in terms of method standardization. We examined acoustic data for Pteronotus cf. rubiginosus from the Central Amazon and the Guiana Shield. We provide the first evidence of intraspecific geographic variation in bat echolocation in the Neotropics, with calls significantly differing in almost all standard acoustic parameters for the two lineages of this clade. We complement our bioacoustic data with molecular and morphological data for both species. Considerable overlap in trait values prevents reliable discrimination between the two sympatric Pteronotus based on morphological characters. On the other hand, significant divergence in the frequency of maximum energy suggests that bioacoustics can be used to readily separate both taxa despite extensive intraspecific variability in their echolocation across the Amazon. Given the relative lack of barriers preventing contact between bat populations from the Central Amazon and French Guiana, the documented acoustic variation needs to be further studied in geographically intermediate locations to understand the potential isolation processes that could be causing the described divergence in echolocation and to determine whether this variation is either discrete or continuous.
- by Adria Lopez-Baucells and +1
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- Acoustics, Bioacoustics, Ecology, Amazonia
Los murciélagos son el orden de mamíferos con más especies en el mundo, distribuyéndose a lo largo y ancho y de todos los continentes, excepto la antártica. Esto ha sido el resultado de un enorme éxito adaptativo, gracias a la capacidad... more
Los murciélagos son el orden de mamíferos con más especies en el mundo, distribuyéndose a lo largo y ancho y de todos los continentes, excepto la antártica. Esto ha sido el resultado de un enorme éxito adaptativo, gracias a la capacidad de volar y al desarrollo de la ecolocación, que les ha permitido colonizar el nicho aéreo y sobreponerse a los depredadores en la oscuridad. Su estudio ha sufrido un enorme salto tecnológico desde las últimas décadas, gracias al desarrollo de equipos detectores de ultrasonidos, los cuales en conjunto con las tradicionales redes de neblina, permiten crear una imagen bastante acertada de la composición de especies y uso de hábitat de ellas. En Chile, se han descrito 11 especies, y de estas, nueve se alimentan exclusivamente de insectos, presentando un servicio ecosistémico de importancia agrícola el podría ser aprovechado en beneficio de la sociedad. Con el objetivo de ampliar el conocimiento existente en Chile sobre este grupo de mamíferos, se realizaron dos estudios utilizando redes de neblina, el detector de ultrasonidos Petersson D240x, el software de análisis de ultrasonidos Avisoft SASLab Pro 4.51 y un análisis discriminante múltiple. Esto nos permitió conocer las características especie-especificas de las llamadas de ecolocación de cada especie registrada. El primer estudio se llevó a cabo en cuatro sitios de la región Metropolitana, (dos en la precordillera de los andes y dos en cerros isla dentro de la depresión intermedia) donde se obtuvieron llamadas de las especies M. chiloensis, T. brasiliensis, L. borealis, L. cinereus e H. montanus y se estudió como se afectaba su actividad al variar ciertos factores ambientales. En un segundo estudio en la región de La Araucanía, se obtuvieron llamadas e individuos desde una colonia de M. chiloensis, a los cuales se les realizo mediciones morfológicas 6 y se compararon con otros estudios. Se observó que en la región Metropolitana, existe una alta actividad de las especies M. chiloensis y T. brasiliensis en sitios con fuerte presión agrícola, en cambio en sitios naturales, la especie T. brasiliensis presenta una actividad reducida. Los factores ambientales que mayormente afectaron la actividad de vuelo de los murciélagos, fueron velocidad del viento, temperatura ambiente, fase lunar y hábitat. Además se constato que en otoño poseen un peak de actividad aproximadamente 1 a 2 hrs. antes que en primavera. Para la región de La Araucanía, el análisis de las llamadas de M. chiloensis indican que la frecuencia promedio característica para esta especie es 43.4 ± 1.2 kHz, con una duración promedio de 2.1 ± 1.0 ms y un intervalo entre pulsos de 77.5 ± 16.9 ms. Los componentes que se observan en las llamadas de búsqueda para esta especie, son de Frecuencia Modulada (FM) y Frecuencia casi Constante (QCF). El aporte de nuevos datos morfométricos indica diferencias respecto a estudios anteriores. Los registros y análisis acústicos de este murciélago, generan nuevas oportunidades para el estudio de su ecología. Estos estudios son los primeros en generar una base de datos acústicos de las especies de murciélagos insectívoros aéreos de la región Metropolitana y la especie M. chiloensis en la región de La Araucanía. Estos datos serán útiles para detectar especies y realizar análisis de uso de hábitats y forrajeo en el largo plazo, contribuyendo al conocimiento de este orden y su conservación
Texas is home to more wind turbines and more bat species than any other state in the United States. Insectivorous bats provide an important economical ecosystem service in this region through agricultural pest regulation. Unfortunately,... more
Texas is home to more wind turbines and more bat species than any other state in the United States. Insectivorous bats provide an important economical ecosystem service in this region through agricultural pest regulation. Unfortunately, bats can be impacted negatively by wind turbines, and migratory bat species particularly so. To understand how bat activity changes throughout the year in western Texas, activity was monitored through echolocation calls and opportunistic mist-netting efforts over a period of four years (2012–2015). Peaks in activity were observed from March through April, and again in September, which coincides with previously documented migratory
periods for many species native to the High Plains of Texas. Findings presented herein suggest that urban habitats are preferred stopover sites for migratory bat species while traversing arid regions such as those occurring in western Texas. In addition to human-made structures, urban habitats harbor non-native trees that provide suitable roost sites, aggregations of insect prey swarming outdoor light sources, and artificial water sources. It is important to understand bat activity in western Texas, not only for the benefit of agricultural pest suppression, but also to predict how the expansion of wind energy may affect bat populations in this region.
periods for many species native to the High Plains of Texas. Findings presented herein suggest that urban habitats are preferred stopover sites for migratory bat species while traversing arid regions such as those occurring in western Texas. In addition to human-made structures, urban habitats harbor non-native trees that provide suitable roost sites, aggregations of insect prey swarming outdoor light sources, and artificial water sources. It is important to understand bat activity in western Texas, not only for the benefit of agricultural pest suppression, but also to predict how the expansion of wind energy may affect bat populations in this region.
- by Julie Parlos and +2
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- Wind Energy, Agriculture, Bats, Echolocation, West Texas
La gestion des habitats est un des principaux facteurs déterminants pour la conservation d’espèces. Nous avons étudié les habitats utilisées par différentes espèces de chauves-souris en France métropolitaine pendant deux périodes... more
La gestion des habitats est un des principaux facteurs déterminants pour la conservation d’espèces. Nous avons étudié les habitats utilisées par différentes espèces de chauves-souris en France métropolitaine pendant deux périodes reproductives : Lactation (P1) et arrivées des jeunes (P2). Les données utilisées proviennent du programme Vigie Nature du Muséum National d’Histoire Naturelle de Paris et concernent les années 2006 à 2009. Nous avons observé dans un premier temps (sans influence du passage) une correspondance forte entre les habitats utilisées par les différentes espèces, et la littérature. Postérieurement, nous avons observé deux groupes d’espèces selon leur variation d’abondance entre le P1 et le P2. Un premier groupe qui diminuait son abondance au P2, composé des deux espèces de Nyctalus et de E. serotinus, présente une diminution sur ses habitats les plus importants, et une notable augmentation sur des habitats nouveaux ou peu préférés en P1. Et un deuxième groupe composé de P. nathusii/kulhii et P. pipistrellus, dont l’activité augmente au P2 sur les habitats prédominants au P1 aussi bien que sur d’autres habitats, ce qui peut être expliqué par une compétition intra spécifique avec les adultes et pour l’exploration de divers milieux par les jeunes. Ces deux résultats ont été traduits par des coefficients de variation pour chaque passage, lesquels ont montré une valeur plus élevée pour le P1, donc une niche plus étroite, due à une spécialisation sur les habitats les plus « productifs » pour la chasse pendant le période de lactation.
Bats frequently feed over water bodies, but the net value of the water bodies depends on characteristics such as the amount of physical clutter the water body has. More physical clutter may reduce the detection of prey by bats and may... more
Bats frequently feed over water bodies, but the net value of the water bodies depends on characteristics such as the amount of physical clutter the water body has. More physical clutter may reduce the detection of prey by bats and may also increase energetic costs by increasing in the number of obstacles to avoid. Consequently, we hypothesized that increasing physical clutter affected the use of an artificial pond where the Lesser Bulldog Bat Noctilio albiventris, a Neotropical fishing bat, forages regularly over water. We experimentally tested this idea recording the number of passes and feeding buzzes emitted by the bats on different nights when we added two levels of obstacles over the water and on control nights with no obstacles. We only found differences between the treatment with the highest obstacle density and the control; there were fewer passes and less feeding buzzes with more obstacles. Therefore, the addition of obstacles did affect the foraging behavior of N. albiventris. Furthermore, we suggest that increasing physical clutter, as in our experiments, may be a cost-effective way to reduce conflicts between local fisher farmers and fishing bats in Neotropical rural areas.
In " What is it like to be boring and myopic? " Kathleen Akins offers an interesting, empirically driven, argument for thinking that there is nothing that it is like to be a bat. She suggests that bats are " boring " in the sense that... more
In " What is it like to be boring and myopic? " Kathleen Akins offers an interesting, empirically driven, argument for thinking that there is nothing that it is like to be a bat. She suggests that bats are " boring " in the sense that they are governed by behavioral scripts and simple, non-representational, control loops, and are best characterized as biological automatons. Her approach has been well received by philosophers sympathetic to empirically informed philosophy of mind. But, despite its influence, her work has not met with any critical appraisal. It is argued that a reconsideration of the empirical results shows that bats are not boring automatons, driven by short input-output loops, instincts, and reflexes. Grounds are provided for thinking that bats satisfy a range of philosophically and scientifically interesting elaborations of the general idea that consciousness is best understood in terms of representational functions. A more complete examination of bat sensory capabilities suggests there is something that it is like after all. The discussion of bats is also used to develop an objection to strongly neurophilosophical approaches to animal consciousness.
Echolocation is characteristic of bats of the suborder Microchiroptera. Though recent studies of echolocation calls in Latin America have generated significant advances in knowledge about distribution, habitat use and ecology of bats, the... more
Echolocation is characteristic of bats of the suborder Microchiroptera. Though recent studies of echolocation calls in Latin America have generated significant advances in knowledge about distribution, habitat use and ecology of bats, the recording and analysis of bat calls is barely known in Chile. As a first step in studies on the ecology of the endemic Chilean myotis bat (Myotis chiloensis), we carried out morphometric measures and analyzed echolocation calls in a rural site near Pucón (39°15'S 17°W) in the Araucanía Region of southern Chile. During January 2009, we obtained 22 records from captured and 75 records from flying individuals. The analysis of calls in searching phase showed that the terminal frequency for this species is 43.4 ± 1.2 kHz, with a mean duration of 2.1 ± 1.0 ms and an interval between pulses of 77.5 ± 16.9 ms. The calls are FM – QCF, as is characteristic for the family Vespertilionidae. The contribution of new morphometric data from captured and released individuals indicates differences from previous studies. The records and acoustic analysis establishes a baseline for more detailed future ecological investigation of this and other bat species in Chile.
- by Gonzalo Ossa and +2
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- Myotis, Bats, Echolocation
Eumops maurus and Eumops hansae are rarely captured Neotropical molossid bats for which information on taxonomy, natural history, and spatial distribution are scarce. This translates into a poor understanding of their ecology and limits... more
Eumops maurus and Eumops hansae are rarely captured Neotropical molossid bats for which information on taxonomy, natural history, and spatial distribution are scarce. This translates into a poor understanding of their ecology and limits the delimitation of useful characters for their identification. Here, we describe records of these two molossids from the Central Brazilian Amazon, providing data on their external and craniodental morphology, DNA barcode (COI) sequences complemented by acoustic data for the species. Morphological characters, DNA sequence data and phylogenetic relationships within the genus Eumops were consistent with those previously described for both species. Echolocation call characteristics did not differ significantly so as to be useful for separating E. maurus and E. hansae from other congeners. Our records are, respectively the first and the second for Central Amazonia as one individual previously attributed to Eumops amazonicus from Manaus may be considered a junior synonym for E. hansae. These new records increase the extent of the species’ known ranges, partially filling in previous existing gaps in their distribution in central South America. Our data further suggest that these molossid bats forage in a wider range of habitats than previously thought.
The production of echolocation calls in bats along with forces produced by contraction of thoracic musculature used in flight presumably puts relatively high mechanical loads on the lower respiratory tract (LRT). Thus, there are likely... more
The production of echolocation calls in bats along with forces produced by contraction of thoracic musculature used in flight presumably puts relatively high mechanical loads on the lower respiratory tract (LRT). Thus, there are likely adaptations to prevent collapse or distortion of the bronchial tree and trachea during flight in echolocating bats. By clearing and staining (Alcian blue and Alizarin red) LRTs removed from nonvolant neonates, semivolant juveniles, volant subadults, and adult Jamaican fruit bats (Artibeus jamaicensis), I found that calcification of the tracheal, primary bronchial, and secondary bronchial (lobar) cartilage rings occurs over the span of about 3 days and coincides with later developmental stages of flight and the increased production of echolocation calls. Tracheal rings that are immediately adjacent to the larynx calcified first, followed by more caudal tracheal rings and then the rings of the primary and secondary bronchi. I suggest that calcification of LRT cartilage rings in echolocating bats provides increased rigidity to counter the thoracic compressions incurred during flight. Calcification of the LRT rings is an adaptation to support the emission of laryngeally produced echolocation calls during flight in bats.
Many philosophers have held that we cannot say what it is like to be a bat as they present a fundamentally alien form of life. Another view held by some philosophers, bat scientists, and even many laypersons is that echolocation is,... more
Many philosophers have held that we cannot say what it is like to be a bat as they present a fundamentally alien form of life. Another view held by some philosophers, bat scientists, and even many laypersons is that echolocation is, somehow, at least in part, a kind of visual experience. Either way, bat echolocation is taken to be something very mysterious and exotic. I utilize empirical and intuitive considerations to support an alternative view making a much more mundane contention about bat phenomenology: echolocatory experience probably just has an auditory character. These points also call for further reflection on our intuitions about animal consciousness and standard arguments for the explanatory gap.
Few studies have been conducted on the bat fauna of the Arica and Parinacota region, northern Chile. The genus Promops (Gervais, 1855) is a poorly known group of molossid bats, with three species widely distributed in Central and South... more
Few studies have been conducted on the bat fauna of the Arica and Parinacota region, northern Chile. The genus Promops (Gervais, 1855) is a poorly known group of molossid bats, with three species widely distributed in Central and South America. We report for the first time the species Promops davisoni in Chile. Identification was based on echolocation calls obtained at the Azapa and Lluta valleys and compared to reference calls from Tacna, Peru. We report the species as far as 127 km south of the previous published southernmost record in Pampa Alta, Peru. In addition we obtained an individual found at the Anzota caves, near the city of Arica. The species is found on the coast and in the fluvial valleys of Northern Chile, with altitudes ranging from sea level to 822 m a.s.l. We propose that the distribution of P. davisoni may extend further south, to the locality of Tana in the Tarapacá region, based on the capacity of the species to cross distances of over 100 km over large desert areas. With this species, we increase the known bat fauna of Chile to 14 species, and the bat fauna of the Arica and Parinacota region to nine species.
Platalina genovensium is a poorly known bat species from the west coast of Peru and Chile, considered as near threatened because of its narrow range of distribution. There are few records in Peru, and only one record in the Azapa valley,... more
Platalina genovensium is a poorly known bat species from the west coast of Peru and Chile, considered as near threatened because of its narrow range of distribution. There are few records in Peru, and only one record in the Azapa valley, northern Chile from the year 1996. Here we report a new record for P. genovensium for the Azapa valley 19 years afterwards, confirming the presence of the species in the Arica y Parinacota region, Chile.
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