| wangiella dermatitidis isolated from bats in manaus brazil. | wangiella dermatitidis was isolated for the first time from the macroscopically asymptomatic internal organs of 2 phyllostomus discolor, 1 molossus molossus, 1 sturnira lilium and 1 myotis albescens among bats captured in the region of manaus, brazil. the dermatiaceous fungi isolated exhibited polymorphism at 25 and 37 degrees c, showing toruloid hyphae, integrated and terminal phialides without collarettes and yeast-like cells. the fungi did not hydrolyze gelatin, casein or starch. some ecologi ... | 1979 | 531715 |
| venezuelan encephalitis virus infection in neotropical bats. ii. experimental infections. | eighty-nine neotropical bats of five species were inoculated subcutaneously with epizootic or enzootic strains of venezuelan encephalitis (ve) virus. viremia was detected in 92.5% of all bats, but no illness attributable to virus infection was observed. detectable viremias averaged slightly over 4 days in artibeus jamaicensis and a. lituratus, and 2.8 days in phyllostomus discolor, and maximal viremia titers in these three species averaged 6.9, 6.6, and 4.6 log10 smicld50 per ml of blood, respec ... | 1978 | 646022 |
| spinturnicid mites (gamasida: spinturnicidae) associated with bats in central brazil. | the results of a survey of spinturnicid mites (gamasida: spinturnicidae) infesting bats near brasília, d.f., brazil, are presented. one hundred twenty-five bats were collected, representing three families and 15 species. seven species of spinturnicid mites (genus periglischrus) were collected from nine species of bats (family phyllostomidae). each of the following six species of periglischrus was associated with a single species of bat: periglischrus acutisternus machado-allison and p. torrealba ... | 1989 | 2795621 |
| audio-vocal learning in a non-human mammal: the lesser spear-nosed bat phyllostomus discolor. | in the course of development, pups of the neotropical bat phyllostomus discolor seem to adapt their isolation calls to the vocal signature of their mother's directive calls. under controlled experimental conditions however, audio-vocal learning so far has not been demonstrated in any terrestrial mammal except man. in the present study one group of bat pups was hand-reared in the absence of conspecific vocalizations, whereas an unvarying, digitally stored maternal directive call was repeatedly pr ... | 1994 | 7827315 |
| phylogenetic diversity of bat trypanosomes of subgenus schizotrypanum based on multilocus enzyme electrophoresis, random amplified polymorphic dna, and cytochrome b nucleotide sequence analyses. | trypanosome stocks isolated from bats (chiroptera) and belonging to the subgenus schizotrypanum were analyzed by multilocus enzyme electrophoresis (mlee) at 22 loci, random amplified polymorphic dna (rapd) with 14 primers and/or cytochrome b nucleotide sequence. bat trypanosomes belonged to the species trypanosoma cruzi marinkellei (10 stocks), trypanosoma dionisii (four stocks) and trypanosoma vespertilionis (three stocks). one t. rangeli stock and seven stocks of t. cruzi sensu stricto, the ag ... | 2003 | 12797982 |
| absent or low rate of adult neurogenesis in the hippocampus of bats (chiroptera). | bats are the only flying mammals and have well developed navigation abilities for 3d-space. even bats with comparatively small home ranges cover much larger territories than rodents, and long-distance migration by some species is unique among small mammals. adult proliferation of neurons, i.e., adult neurogenesis, in the dentate gyrus of rodents is thought to play an important role in spatial memory and learning, as indicated by lesion studies and recordings of neurons active during spatial beha ... | 2007 | 17520014 |
| mites (mesostigmata: spinturnicidae and spelaeorhynchidae) associated with bats in northeast brazil. | in this article, we present the results of a study about mites associated with bats collected in the state of pernambuco, northeast brazil. of the 331 bats collected, 23 were found naturally infested by mites, corresponding to an overall prevalence of 6.9% (95% confidence interval: 4.5-10.2). four mite species were collected from seven bat species. the following mite-bat associations were recorded: periglischrus acutisternus machado-allison on phyllostomus discolor wagner; periglischrus ojastii ... | 2009 | 19496446 |
| new insights into telomeric dna sequence (ttaggg)n location in bat chromosomes. | molossidae species, cynomops abrasus (2n = 34, fundamental number, fn = 64), eumops auripendulus (2n = 42, fn = 62), molossus rufus (2n = 48, fn = 64), molossops temminckii (2n = 48, fn = 64), and nyctinomops laticaudatus (2n = 48, fn = 64), and phyllostomidae species, phyllostomus discolor (2n = 32, fn = 60), have karyotypes with different chromosome and fundamental numbers, different localization of constitutive heterochromatin, and different numbers and location of nucleolar organizer regions ... | 2009 | 19731218 |
| [ectoparasitic flies (diptera: streblidae) of bats (mammalia: chiroptera) from são luís, maranhão, brazil: infestation rates and the host-parasite association]. | this study reports the first records of the parasitism rates of the association among ectoparasitic flies of the family streblidae found in phyllostomid bats in the state of maranhão. specimens were collected in patches of secondary forest and borders of mangrove in the village of quebra pote, located in the south portion of the island of são luís. a total of 201 flies of 15 species and eight genera [aspidoptera falcata wenzel, a. phyllostomatis (perty), mastoptera minuta costa lima, megistopoda ... | 2009 | 19943006 |
| bats (mammalia: chiroptera) in native and reforested areas in rancho alegre, paraná, brazil. | abstract: generally, natural environments have been transformed into small forest remnants, with the consequent habitat loss and species extinction. the north paraná state is not an exception, since only 2 to 4% of the original ecosystem occurs in small fragments of stational semidecidual forest. we studied the species richness and abundance of bats in two forest fragments from the fazenda congonhas, in rancho alegre city, parana state, brazil. four samplings were undertaken in a legally protect ... | 2010 | 21246993 |
| nucleolar behavior during meiosis in four species of phyllostomid bats (chiroptera, mammalia). | we analyzed the behavior of the nucleolus, nucleolar structures and nucleolus organizer regions (nors) during meiotic division in four species of phyllostomid bats that have different numbers and locations of nors. nucleoli began disassembly at leptotene, and the subcomponents released from the nucleolus were dispersed in the nucleoplasm, associated with perichromosomal regions, or they remained associated with nors throughout division. in phyllostomus discolor, a delay in nucleolus disassembly ... | 2011 | 21491366 |
| hematological survey of common neotropical bat species from costa rica. | although bats are one of the largest groups within the class mammalia and may carry several zoonotic diseases, basic information about their hematology is limited. in this study, hematocrit (hct), total white blood cell counts (twbc; leukocytes), and differential white blood cell counts (dwbc) of free-ranging neotropical bats were quantified. blood samples from 255 bats representing 26 species from the families of emballonuridae (3 species; 33 individuals), molossidae (2 species; 26 individuals) ... | 2011 | 22950309 |
| detection of leishmania spp. in bats from an area of brazil endemic for visceral leishmaniasis. | the multihost parasites leishmania spp. infect a broad range of wild mammalian species including bats. several species of bats have adapted to a variety of food resources and shelters in urban areas. this study aimed to detect leishmania spp. dna in bats present in forest fragments located in metropolitan areas endemic for leishmaniasis in campo grande, mato grosso do sul (ms), brazil. blood samples were obtained from 80 individuals, including eight species of phyllostomidae and one species of v ... | 2017 | 28233434 |
| different direct effects of light intensity on the entrained activity rhythm in neotropical bats (chiroptera, phyllostomidae). | in the two neotropical chiroptera species, artibeus lituratus and phyllostomus discolor, the influence of illumination intensity during the d-time of an ld 12:12 h on the locomotory activity rhythm was investigated by offering specific rectangular illumination schedules. in ld 12:12 (10(1):10(-4)lux), a. lituratus and p. discolor exhibit a stable unimodal basic activity pattern. by increasing the light intensity during d-time to 10(-1) lux the activity pattern, especially in a. lituratus, can be ... | 1978 | 24924818 |
| morphophysiology and ultrastructure of the male reproductive accessory glands of the bats carollia perspicillata, glossophaga soricina and phyllostomus discolor (chiroptera: phyllostomidae). | the male reproductive accessory glands (rags) are important organs that contribute to the secretion of different substances that composed the ejaculate. despite this important function, their composition, anatomy and function vary widely between species. thus, the rags of three species of phyllostomid bats were morphologically and ultrastructurally characterized and compared in this study. the rags of the three analyzed species are composed of a prostate and a pair of bulbourethral glands (bg). ... | 2016 | 27425652 |
| comparative analysis of the male reproductive accessory glands of bat species from the five brazilian subfamilies of the family phyllostomidae (chiroptera). | this study aimed to morphologically characterize and compare the male reproductive accessory glands (rags) of bats belonging to the five brazilian subfamilies of the family phyllostomidae (carollia perspicillata-carollinae; desmodus rotundus-desmodontinae; glossophaga soricina-glossophaginae; phyllostomus discolor-phyllostominae and platyrrhinus lineatus-stenodermatinae). the study demonstrated that the rags of phyllostomid bats were comprised of a pair of extra-abdominal bulbourethral glands an ... | 2015 | 25471705 |
| the aerodynamic cost of head morphology in bats: maybe not as bad as it seems. | at first sight, echolocating bats face a difficult trade-off. as flying animals, they would benefit from a streamlined geometric shape to reduce aerodynamic drag and increase flight efficiency. however, as echolocating animals, their pinnae generate the acoustic cues necessary for navigation and foraging. moreover, species emitting sound through their nostrils often feature elaborate noseleaves that help in focussing the emitted echolocation pulses. both pinnae and noseleaves reduce the streamli ... | 2015 | 25739038 |
| karyotypic variation in rhinophylla pumilio peters, 1865 and comparative analysis with representatives of two subfamilies of phyllostomidae (chiroptera). | the family phyllostomidae belongs to the most abundant and diverse group of bats in the neotropics with more morphological traits variation at the family level than any other group within mammals. in this work, we present data of chromosome banding (g, c and ag-nor) and fluorescence in situ hybridization (fish) for representatives of rhinophylla pumilio peters, 1865 collected in four states of brazil (amazonas, bahia, mato grosso and pará). two karyomorphs were found in this species: 2n=34, fn=6 ... | 2012 | 24260663 |
| phylogenetic reconstruction by cross-species chromosome painting and g-banding in four species of phyllostomini tribe (chiroptera, phyllostomidae) in the brazilian amazon: an independent evidence for monophyly. | the subfamily phyllostominae comprises taxa with a variety of feeding strategies. from the cytogenetic point of view, phyllostominae shows different rates of chromosomal evolution between genera, with phyllostomus hastatus probably retaining the ancestral karyotype for the subfamily. since chromosomal rearrangements occur rarely in the genome and have great value as phylogenetic markers and in taxonomic characterization, we analyzed three species: lophostoma silvicola (lsi), phyllostomus discolo ... | 2015 | 25806812 |
| the absence of spatial echo suppression in the echolocating bats megaderma lyra and phyllostomus discolor. | acoustic orientation most often takes place in echoic environments. the mammalian auditory system shows a variety of specializations to suppress misleading spatial information mediated by echoes. psychophysically these specializations are summarized as the precedence effect. this study investigates how echolocating bats deal with multiple reflections of their sonar emissions from different spatial positions. in a two-alternative, forced choice paradigm, a study was made of the extent to which th ... | 2006 | 16354786 |
| what noseleaves do for fm bats depends on their degree of sensorial specialization. | many bats vocalizing through their nose carry a prominent noseleaf that is involved in shaping the emission beam of these animals. to our knowledge, the exact role of these appendages has not been thoroughly investigated as for no single species both the hearing and the emission spatial sensitivities have been obtained. in this paper, we set out to evaluate the complete spatial sensitivity of two species of new world leaf-nosed bats: micronycteris microtis and phyllostomus discolor. from an ecol ... | 2010 | 20808438 |
| representation of three-dimensional space in the auditory cortex of the echolocating bat p. discolor. | the auditory cortex is an essential center for sound localization. in echolocating bats, combination sensitive neurons tuned to specific delays between call emission and echo perception represent target distance. in many bats, these neurons are organized as a chronotopically organized map of echo delay. however, it is still unclear to what extend these neurons can process directional information and thereby form a three-dimensional representation of space. we investigated the representation of t ... | 2017 | 28813464 |
| echo-acoustic flow shapes object representation in spatially complex acoustic scenes. | echolocating bats use echoes of their sonar emissions to determine the position and distance of objects or prey. target distance is represented as a map of echo delay in the auditory cortex (ac) of bats. during a bat's flight through a natural complex environment, echo streams are reflected from multiple objects along its flight path. separating such complex streams of echoes or other sounds is a challenge for the auditory system of bats as well as other animals. we investigated the representati ... | 2017 | 28275060 |
| the lombard effect emerges early in young bats: implications for the development of audio-vocal integration. | auditory feedback plays an important role in vocal learning and, more generally, in fine-tuning the acoustic features of communication signals. so far, only a few studies have assessed the developmental onset of auditory feedback. the lombard effect, a well-studied audio-vocal phenomenon, refers to an increase in vocal loudness of a subject in response to an increase in background noise. here, we studied the time course of the lombard effect in developing bats, phyllostomus discolor we show that ... | 2017 | 28011824 |
| congruent representation of visual and acoustic space in the superior colliculus of the echolocating bat phyllostomus discolor. | the midbrain superior colliculus (sc) commonly features a retinotopic representation of visual space in its superficial layers, which is congruent with maps formed by multisensory neurons and motor neurons in its deep layers. information flow between layers is suggested to enable the sc to mediate goal-directed orienting movements. while most mammals strongly rely on vision for orienting, some species such as echolocating bats have developed alternative strategies, which raises the question how ... | 2016 | 27600873 |
| sonar beam dynamics in leaf-nosed bats. | ultrasonic emissions of bats are directional and delimit the echo-acoustic space. directionality is quantified by the aperture of the sonar beam. recent work has shown that bats often widen their sonar beam when approaching movable prey or sharpen their sonar beam when navigating through cluttered habitats. here we report how nose-emitting bats, phyllostomus discolor, adjust their sonar beam to object distance. first, we show that the height and width of the bats sonar beam, as imprinted on a pa ... | 2016 | 27384865 |
| linking the sender to the receiver: vocal adjustments by bats to maintain signal detection in noise. | short-term adjustments of signal characteristics allow animals to maintain reliable communication in noise. noise-dependent vocal plasticity often involves simultaneous changes in multiple parameters. here, we quantified for the first time the relative contributions of signal amplitude, duration, and redundancy for improving signal detectability in noise. to this end, we used a combination of behavioural experiments on pale spear-nosed bats (phyllostomus discolor) and signal detection models. in ... | 2015 | 26692325 |
| sensorimotor model of obstacle avoidance in echolocating bats. | bat echolocation is an ability consisting of many subtasks such as navigation, prey detection and object recognition. understanding the echolocation capabilities of bats comes down to isolating the minimal set of acoustic cues needed to complete each task. for some tasks, the minimal cues have already been identified. however, while a number of possible cues have been suggested, little is known about the minimal cues supporting obstacle avoidance in echolocating bats. in this paper, we propose t ... | 2015 | 26502063 |
| a novel approach identifies the first transcriptome networks in bats: a new genetic model for vocal communication. | bats are able to employ an astonishingly complex vocal repertoire for navigating their environment and conveying social information. a handful of species also show evidence for vocal learning, an extremely rare ability shared only with humans and few other animals. however, despite their potential for the study of vocal communication, bats remain severely understudied at a molecular level. to address this fundamental gap we performed the first transcriptome profiling and genetic interrogation of ... | 2015 | 26490347 |
| biosonar navigation above water i: estimating flight height. | locomotion and foraging on the wing require precise navigation in more than just the horizontal plane. navigation in three dimensions and, specifically, precise adjustment of flight height are essential for flying animals. echolocating bats drink from water surfaces in flight, which requires an exceptionally precise vertical navigation. here, we exploit this behavior in the bat, phyllostomus discolor, to understand the biophysical and neural mechanisms that allow for sonar-guided navigation in t ... | 2015 | 25411456 |
| echo-acoustic flow dynamically modifies the cortical map of target range in bats. | echolocating bats use the delay between their sonar emissions and the reflected echoes to measure target range, a crucial parameter for avoiding collisions or capturing prey. in many bat species, target range is represented as an orderly organized map of echo delay in the auditory cortex. here we show that the map of target range in bats is dynamically modified by the continuously changing flow of acoustic information perceived during flight ('echo-acoustic flow'). combining dynamic acoustic sti ... | 2014 | 25131175 |
| spatiotemporal contrast enhancement and feature extraction in the bat auditory midbrain and cortex. | navigating on the wing in complete darkness is a challenging task for echolocating bats. it requires the detailed analysis of spatial and temporal information gained through echolocation. thus neural encoding of spatiotemporal echo information is a major function in the bat auditory system. in this study we presented echoes in virtual acoustic space and used a reverse-correlation technique to investigate the spatiotemporal response characteristics of units in the inferior colliculus (ic) and the ... | 2013 | 23785132 |
| prevalence, mean intensity of infestation and host specificity of spinturnicidae mites (acari: mesostigmata) on bats (mammalia: chiroptera) in the pantanal, brazil. | acari ectoparasites were collected from bats during 12 months in the rio negro farm (19°34'22″s and 56°14'36″w), aquidauana, mato grosso do sul. a total of 654 bats belonging to the families phyllostomidae, noctilionidae, molossidae, vespertilionidae and emballonuridae were captured. only 136 bats of nine genera and 11 species were parasitised. periglischrus iheringi oudemans was the most abundant mite species, and this prevalence may be related to the low degree of host specificity of this spec ... | 2013 | 23666652 |
| size constancy in bat biosonar? perceptual interaction of object aperture and distance. | perception and encoding of object size is an important feature of sensory systems. in the visual system object size is encoded by the visual angle (visual aperture) on the retina, but the aperture depends on the distance of the object. as object distance is not unambiguously encoded in the visual system, higher computational mechanisms are needed. this phenomenon is termed "size constancy". it is assumed to reflect an automatic re-scaling of visual aperture with perceived object distance. recent ... | 2013 | 23630598 |
| size does not matter: size-invariant echo-acoustic object classification. | echolocating bats can not only extract spatial information from the auditory analysis of their ultrasonic emissions, they can also discriminate, classify and identify the three-dimensional shape of objects reflecting their emissions. effective object recognition requires the segregation of size and shape information. previous studies have shown that, like in visual object recognition, bats can transfer an echo-acoustic object discrimination task to objects of different size and that they spontan ... | 2013 | 23180047 |
| the sonar aperture and its neural representation in bats. | as opposed to visual imaging, biosonar imaging of spatial object properties represents a challenge for the auditory system because its sensory epithelium is not arranged along space axes. for echolocating bats, object width is encoded by the amplitude of its echo (echo intensity) but also by the naturally covarying spread of angles of incidence from which the echoes impinge on the bat's ears (sonar aperture). it is unclear whether bats use the echo intensity and/or the sonar aperture to estimate ... | 2011 | 22031907 |
| sex matters in echoacoustic orientation: gender differences in the use of acoustic landmarks in phyllostomus discolor (lesser spear-nosed bat). | sex-specific differences in orientation strategies are well known for several rodent and primate species with females relying more on landmarks when it comes to visually guided orientation, whereas males preferentially use euclidean cues. we used the echolocating bat phyllostomus discolor for a behavioural study on gender differences in the use of acoustic landmarks. the experimental animals (6 males, 6 females) had to learn and perform a simple orientational task, firstly in the absence of land ... | 2011 | 20803021 |
| neural coding of echo-envelope disparities in echolocating bats. | the effective use of echolocation requires not only measuring the delay between the emitted call and returning echo to estimate the distance of an ensonified object. to locate an object in azimuth and elevation, the bat's auditory system must analyze the returning echoes in terms of their binaural properties, i.e., the echoes' interaural intensity and time differences (iids and itds). the effectiveness of iids for echolocation is undisputed, but when bats ensonify complex objects, the temporal s ... | 2011 | 20740363 |
| pollination biology and floral scent chemistry of the neotropical chiropterophilous parkia pendula. | during the past several decades, the pollination biology of old world plant species pollinated by flying foxes and of new world plants pollinated by highly specialized nectar-feeding glossophagine bats has been studied in detail. however, little is known about neotropical plants that are pollinated by less specialized phyllostomid bats. therefore, we studied the pollination biology of parkia pendula, a tree pollinated by phyllostomus. flowers of p. pendula are arranged in capitula, and a capitul ... | 2010 | 20653900 |
| modelling simultaneous echo waveform reconstruction and localization in bats. | echolocating bats perceive the world through sound signals reflecting from the objects around them. in these signals, information is contained about reflector location and reflector identity. bats are able to extract and separate the cues for location from those that carry identification information. we propose a model based on wiener deconvolution that also performs this separation for a virtual system mimicking the echolocation system of the lesser spearnosed bat, phyllostomus discolor. in par ... | 2010 | 20149838 |
| dynamic stimulation evokes spatially focused receptive fields in bat auditory cortex. | bats can orient and hunt for prey in complete darkness using echolocation. due to the pulse-like character of call emission they receive a stroboscopic view of their environment. during target approach, bats adjust their emitted echolocation calls to the specific requirements of the dynamically changing environmental and behavioral context. in addition to changes of the spectro-temporal call features, the spatial focusing of the beam of the sonar emissions onto the target is a conspicuous featur ... | 2010 | 20074213 |
| simulated head related transfer function of the phyllostomid bat phyllostomus discolor. | this paper presents a calculation of the head related transfer function (hrtf) for the frontal hemisphere of the phyllostomid bat phyllostomus discolor using an acoustic field simulation tool based on the boundary element method. from the calculated hrtf results, binaural interaural intensity differences (iids) are derived. | 2008 | 19062853 |
| the auditory cortex of the bat phyllostomus discolor: localization and organization of basic response properties. | the mammalian auditory cortex can be subdivided into various fields characterized by neurophysiological and neuroarchitectural properties and by connections with different nuclei of the thalamus. besides the primary auditory cortex, echolocating bats have cortical fields for the processing of temporal and spectral features of the echolocation pulses. this paper reports on location, neuroarchitecture and basic functional organization of the auditory cortex of the microchiropteran bat phyllostomus ... | 2008 | 18625034 |
| representation of echo roughness and its relationship to amplitude-modulation processing in the bat auditory midbrain. | bats use natural landmarks such as trees for orientation. echoes reflected by a tree are stochastic and complex. the degree of irregular loudness fluctuations of perceived echoes, i.e. the echo roughness, may be used to classify natural objects reliably. bats are able to discriminate and classify echoes of different roughness. a neural correlate of the psychophysical roughness sensitivity has been described in the auditory cortex of the bat phyllostomus discolor. here, the role of the inferior c ... | 2008 | 18547252 |
| comparing passive and active hearing: spectral analysis of transient sounds in bats. | in vision, colour constancy allows the evaluation of the colour of objects independent of the spectral composition of a light source. in the auditory system, comparable mechanisms have been described that allows the evaluation of the spectral shape of sounds independent of the spectral composition of ambient background sounds. for echolocating bats, the evaluation of spectral shape is vitally important both for the analysis of external sounds and the analysis of the echoes of self-generated sona ... | 2008 | 18515714 |
| an autocorrelation model of bat sonar. | their sonar system allows echolocating bats to navigate with high skill through a complex, three- dimensional environment at high speed and low light. the auditory analysis of the echoes of their ultrasonic sounds requires a detailed comparison of the emission and echoes. here an auditory model of bat sonar is introduced and evaluated against a set of psychophysical phantom-target, echo-acoustic experiments. the model consists of a relatively detailed simulation of auditory peripheral processing ... | 2008 | 18491168 |
| phase sensitivity in bat sonar revisited. | an echolocating bat produces echoes consisting of the convolution of echolocation call and the impulse response (ir) of the ensonified object. a crucial question in animal sonar is whether bats are able to extract this ir from the echo. the bat inner ear generates a frequency representation of call and echo and ir extraction in the frequency domain requires accurate analysis of both magnitude and phase information. previous studies investigating the phase sensitivity of bats using a jitter parad ... | 2008 | 18034247 |
| psychophysical and neurophysiological hearing thresholds in the bat phyllostomus discolor. | absolute hearing thresholds in the spear-nosed bat phyllostomus discolor have been determined both with psychophysical and neurophysiological methods. neurophysiological data have been obtained from two different structures of the ascending auditory pathway, the inferior colliculus and the auditory cortex. minimum auditory thresholds of neurons are very similar in both structures. lowest absolute thresholds of 0 db spl are reached at frequencies from about 35 to 55 khz in both cases. overall beh ... | 2008 | 18026733 |
| cortical responses to object size-dependent spectral interference patterns in echolocating bats. | echolocating bats can recognize 3-d objects exclusively through the analysis of the reflections of their ultrasonic emissions. for objects of small size, the spectral interference pattern of the acoustic echoes encodes information about the structure of an object. for some naturally occurring objects such as, e.g., flowers, the interference pattern as well as the echo amplitude can regularly change with the object's size, and bats should be able to compensate for both of these changes for reliab ... | 2007 | 18001272 |
| object-oriented echo perception and cortical representation in echolocating bats. | echolocating bats can identify three-dimensional objects exclusively through the analysis of acoustic echoes of their ultrasonic emissions. however, objects of the same structure can differ in size, and the auditory system must achieve a size-invariant, normalized object representation for reliable object recognition. this study describes both the behavioral classification and the cortical neural representation of echoes of complex virtual objects that vary in object size. in a phantom-target pl ... | 2007 | 17425407 |
| a neural correlate of stochastic echo imaging. | bats quickly navigate through a highly structured environment relying on echolocation. large natural objects in the environment, like bushes or trees, produce complex stochastic echoes, which can be characterized by the echo roughness. previous work has shown that bats can use echo roughness to classify the stochastic properties of natural objects. this study provides both psychophysical and electrophysiological data to identify a neural correlate of statistical echo analysis in the bat phyllost ... | 2006 | 16421298 |
| echolocation calls and communication calls are controlled differentially in the brainstem of the bat phyllostomus discolor. | echolocating bats emit vocalizations that can be classified either as echolocation calls or communication calls. neural control of both types of calls must govern the same pool of motoneurons responsible for vocalizations. electrical microstimulation in the periaqueductal gray matter (pag) elicits both communication and echolocation calls, whereas stimulation of the paralemniscal area (pla) induces only echolocation calls. in both the pag and the pla, the current thresholds for triggering natura ... | 2005 | 16053533 |
| cochlear sensitivity in the lesser spear-nosed bat, phyllostomus discolor. | behavioral auditory thresholds of phyllostomus discolor are characterized by two threshold minima separated by an insensitive region at about 55 khz (esser and daucher 1996). to investigate whether these characteristics are due to cochlear properties, we recorded distortion product otoacoustic emissions (dpoaes) and calculated relative dpoae threshold curves, which proved to be a good measure of cochlear sensitivity. our results indicate that in p. discolor, cochlear sensitivity, as assessed by ... | 2005 | 15378333 |
| classification of natural textures in echolocation. | through echolocation, a bat can perceive not only the position of an object in the dark; it can also recognize its 3d structure. a tree, however, is a very complex object; it has thousands of reflective surfaces that result in a chaotic acoustic image of the tree. technically, the acoustic image of an object is its impulse response (ir), i.e., the sum of the reflections recorded when the object is ensonified with an acoustic impulse. the extraction of the acoustic ir from the ultrasonic echo and ... | 2004 | 15060282 |
| spectral directionality of the external ear of the lesser spear-nosed bat, phyllostomus discolor. | the directional dependence of sound pressure transformation of head and pinna has been measured in the phyllostomid bat phyllostomus discolor for the frontal hemisphere using a maximum length sequence method. the azimuthal position of the axis of highest pinna gain came closer to the midsagital plane with increasing frequency. the acoustic axis of highest pinna gain was further characterized by an increase of the elevation angle with increasing frequency and a specific decrease at 55 khz. additi ... | 2003 | 14599698 |
| spectral directionality of the external ear of the lesser spear-nosed bat, phyllostomus discolor. | the directional dependence of sound pressure transformation of head and pinna has been measured in the phyllostomid bat phyllostomus discolor for the frontal hemisphere using a maximum length sequence method. the azimuthal position of the axis of highest pinna gain came closer to the midsagital plane with increasing frequency. the acoustic axis of highest pinna gain was further characterized by an increase of the elevation angle with increasing frequency and a specific decrease at 55 khz. additi ... | 2003 | 12855360 |
| periaqueductal gray and the region of the paralemniscal area have different functions in the control of vocalization in the neotropical bat, phyllostomus discolor. | the periaqueductal gray matter and the region of the paralemniscal area were neuroanatomically delineated in the brain of the neotropical bat phyllostomus discolor[wagner (1843) arch. naturgesch., 9, 365-368] and were probed with electrical microstimulation for eliciting vocalizations. in a well-delimited rostral portion of the periaqueductal gray exclusively, communication calls could be triggered at low stimulation currents. communication calls as well as echolocation calls could be elicited a ... | 2002 | 12453061 |
| in vivo blood oxygen binding in hypoxic lesser spear-nosed bats: relationship to control of breathing. | the hypoxic ventilatory threshold of many mammals correlates with their hemoglobin-oxygen affinity (p50). yet, in some small mammals ventilation actually declines, rather than increases, with exposure to decreasing pao2; their air convection requirement (v(e)/v(o2)), however, is elevated in hypoxia. we propose that the threshold of the hypoxic v(e)/v(o2) of small mammals coincides with the inflection ('knee') of their in vivo o2 equilibrium curve (o2ec). in vivo blood gas and ph data were obtain ... | 1999 | 10647863 |
| discrimination of sinusoidally frequency-modulated sound signals mimicking species-specific communication calls in the fm-bat phyllostomus discolor. | in the lesser spear-nosed bat, phyllostomus discolor, maternal directive calls are characterized by an individual type of sinusoidal frequency modulation (= sfm) pattern. beside modulation frequency, modulation depth, carrier frequency, and number of modulation cycles per call contribute to the mother's vocal signature. since juvenile p. discolor learn to adapt their isolation calls to the corresponding call characteristics of the own mother or even to playback of a computer-stored directive cal ... | 1997 | 9163929 |
| the orientation behaviour of the lesser spearnosed bat, phyllostomus discolor (chiroptera) in a model roost. concurrence of visual, echoacoustical and endogenous spatial information. | the orientation behaviour of bats (phyllostomus discolor, phyllostomidae), flying inside an octagonal "roost-like" chamber (phi: 100 cm; h: 150 cm) was examined. it has been shown that the bats begin turning manoeuvres during flight by turning their head towards the direction they intend to proceed to. during early phases of the flights, cumulative navigation errors were evident, indicating that endogenous spatial information plays a major role in the orientation of the bats. during later phases ... | 1996 | 8765560 |
| detection of frequency modulation in the fm-bat phyllostomus discolor. | in a two-alternative forced-choice procedure lesser spear-nosed bats, phyllostomus discolor, had to discriminate between a pure tone stimulus and a sinusoidally frequency-modulated signal generated at the same carrier frequency as the tone. modulation depths of the sfm stimuli were reduced until the animals' performance dropped below the 75%-correct level which was used to determine difference limens for detection of frequency modulation (fmdl). the dependence of fmdls on modulation and carrier ... | 1996 | 8667292 |
| hearing in the fm-bat phyllostomus discolor: a behavioral audiogram. | absolute auditory thresholds of six adult lesser spear-nosed bats phyllostomus discolor (chiroptera, phyllostomidae) were determined in a two-alternative forced-choice procedure. behavioral response to pure tone stimuli could be elicited throughout the tested frequency range of 5-142 khz. the shape of the average audiogram is characterized by two sensitivity peaks and a pronounced increase of thresholds around 55 khz, and towards the limits of the tested frequency range. the spectral extent of b ... | 1996 | 8667291 |
| ventilatory and metabolic responses of a bat, phyllostomus discolor, to hypoxia and co2: implications for the allometry of respiratory control. | the ventilatory and metabolic responses of lesser spear-nosed bats to hypoxia and hypercapnia were measured to determine whether these corresponded to preliminary allometries and a positive relationship between hypoxic ventilatory threshold and p50. ventilatory responses of lesser spear-nosed bats to 3, 5 and 7% co2 differed significantly from ventilation on air and each other. the magnitude of their ventilatory response to co2 is consistent with the prediction of a smaller ventilatory response ... | 1996 | 8923744 |
| behavioral auditory thresholds in neonate lesser spear-nosed bats, phyllostomus discolor. | | 1990 | 2388703 |
| mapping the distribution of language related genes foxp1, foxp2 and cntnap2 in the brains of vocal learning bat species. | genes including foxp2, foxp1 and cntnap2, have been implicated in human speech and language phenotypes, pointing to a role in the development of normal language-related circuitry in the brain. although speech and language are unique human phenotypes, a comparative approach is possible by addressing language-relevant traits in animal model systems. one such trait, vocal learning, represents an essential component of human spoken language, and is shared by cetaceans, pinnipeds, elephants, some bir ... | 2018 | 29297931 |
| six reference-quality genomes reveal evolution of bat adaptations. | bats possess extraordinary adaptations, including flight, echolocation, extreme longevity and unique immunity. high-quality genomes are crucial for understanding the molecular basis and evolution of these traits. here we incorporated long-read sequencing and state-of-the-art scaffolding protocols1 to generate, to our knowledge, the first reference-quality genomes of six bat species (rhinolophus ferrumequinum, rousettus aegyptiacus, phyllostomus discolor, myotis myotis, pipistrellus kuhlii and mo ... | 2020 | 32699395 |
| morphometric variation in periglischrus torrealbai (acari: spinturnicidae) on three species of host bats (chiroptera: phyllostomidae) with a new record of host species. | we evaluated morphometric variation of the mite periglischrus torrealbai (spinturnicidae) on three species of host bats: phyllostomus discolor, p. hastatus, and tonatia bidens (phyllostomidae). a total of 67 females and 74 males of p. torrealbai were collected from 41 host individuals of these three bat species that were sampled in brazil, paraguay, and peru. twenty-one measurements from the dorsal side and 28 from the ventral side were recorded from female mites and 21 dorsal and 34 ventral mea ... | 2018 | 29222666 |
| vocal production learning in the pale spear-nosed bat, phyllostomus discolor. | vocal production learning (vpl), or the ability to modify vocalizations through the imitation of sounds, is a rare trait in the animal kingdom. while humans are exceptional vocal learners, few other mammalian species share this trait. owing to their singular ecology and lifestyle, bats are highly specialized for the precise emission and reception of acoustic signals. this specialization makes them ideal candidates for the study of vocal learning, and several bat species have previously shown evi ... | 2020 | 32289244 |
| eco-epidemiology of the venezuelan equine encephalitis virus in bats of córdoba and sucre, colombia. | alphavirus infection associated encephalitis is an emerging infectious disease with a high impact on public health in latin america. | 2019 | 30578748 |
| dengue virus in bats from córdoba and sucre, colombia. | natural infection of dengue virus (denv) in bats is an unexplored field in colombia. to detect the presence of denv in bats, a descriptive prospective study using a nonprobabilistic sampling was carried out; 286 bats in 12 sites were caught. sample tissues of different animals were obtained; the rna was obtained from tissues and a nested-rt-pcr was carried out and detected amplicons of 143 fragment of the ns5 gene were sequenced by the sanger method. in nonhematophagous bats carollia perspicilla ... | 2019 | 31211661 |
| cyto- and myeloarchitectural brain atlas of the pale spear-nosed bat (phyllostomus discolor) in ct aided stereotaxic coordinates. | the pale spear-nosed bat phyllostomus discolor, a microchiropteran bat, is well established as an animal model for research on the auditory system, echolocation and social communication of species-specific vocalizations. we have created a brain atlas of phyllostomus discolor that provides high-quality histological material for identification of brain structures in reliable stereotaxic coordinates to strengthen neurobiological studies of this key species. the new atlas combines high-resolution im ... | 2020 | 32936343 |
| biosonar spatial resolution along the distance axis: revisiting the clutter interference zone. | many echolocating bats forage close to vegetation - a chaotic arrangement of prey and foliage where multiple targets are positioned behind one another. bats excel at determining distance: they measure the delay between the outgoing call and the returning echo. in their auditory cortex, delay-sensitive neurons form a topographic map, suggesting that bats can resolve echoes of multiple targets along the distance axis - a skill crucial for the forage-amongst-foliage scenario. we tested this hypothe ... | 2020 | 32843361 |
| post-natal development of the envelope following response to amplitude modulated sounds in the bat phyllostomus discolor. | bats use a large repertoire of calls for social communication, which are often characterized by temporal amplitude and frequency modulations. as bats are considered to be among the few mammalian species capable of vocal learning, the perception of temporal sound modulations should be crucial for juvenile bats to develop social communication abilities. however, the post-natal development of auditory processing of temporal modulations has not been investigated in bats, so far. here we use the mini ... | 2020 | 32028065 |
| the neural basis of dim-light vision in echolocating bats. | echolocating bats evolved a sophisticated biosonar imaging system that allows for a life in dim-light habitats. however, especially for far-range operations such as homing, bats can support biosonar by vision. large eyes and a retina that mainly consists of rods are assumed to be the optical adjustments that enable bats to use visual information at low light levels. in addition to optical mechanisms, many nocturnal animals evolved neural adaptations such as elongated integration times or enlarge ... | 2019 | 31747669 |
| processing of fast amplitude modulations in bat auditory cortex matches communication call-specific sound features. | bats use a large repertoire of calls for social communication. in the bat phyllostomus discolor, social communication calls are often characterized by sinusoidal amplitude and frequency modulations with modulation frequencies in the range of 100-130 hz. however, peaks in mammalian auditory cortical modulation transfer functions are typically limited to modulation frequencies below 100 hz. we investigated the coding of sinusoidally amplitude modulated sounds in auditory cortical neurons in p. dis ... | 2019 | 30785811 |
| optic and echo-acoustic flow interact in bats. | echolocating bats are known to fly and forage in complete darkness, using the echoes of their actively emitted calls to navigate and to detect prey. however, under dim light conditions many bats can also rely on vision. many flying animals have been shown to navigate by optic flow information and, recently, bats were shown to exploit echo-acoustic flow to navigate through dark habitats. here, we show for the bat phyllostomus discolor that, in lighted habitats where self-motion-induced optic flow ... | 2019 | 30728158 |
| ontogeny of auditory brainstem responses in the bat, phyllostomus discolor. | hearing is the primary sensory modality in bats, but its development is poorly studied. for newborns, hearing appears essential in maintaining contact with their mothers and to develop echolocation abilities. here we measured auditory brainstem responses (abrs) to clicks and narrowband tone pips covering a large frequency range (5-90 khz) in juveniles (p7 to p200) and adults of the bat, phyllostomus discolor. tone-pip audiograms show that juveniles at p7 are already quite responsive, not only be ... | 2019 | 30612027 |
| flutter sensitivity in fm bats. part i: delay modulation. | echolocating bats measure target distance by the time delay between call and echo. target movement such as the flutter of insect wings induces delay modulations. perception of delay modulations has been studied extensively in bats, but only concerning how well bats discriminate flutter frequencies, never with regard to flutter magnitude. we used an auditory virtual reality approach to generate changes in echo delay that were independent of call repetition rate, mimicking fluttering insect wings. ... | 2018 | 30244365 |
| flutter sensitivity in fm bats. part ii: amplitude modulation. | bats use echolocation to detect targets such as insect prey. the echolocation call of frequency-modulating bats (fm bats) typically sweeps through a broad range of frequencies within a few milliseconds. the large bandwidth grants the bat high spatial acuity in depicting the target. however, the extremely short call duration and the overall low duty cycle of call emission impair the bat's capability to detect e.g. target movement. nonetheless, fm bats constitute more than 80% of all echolocating ... | 2018 | 30242470 |
| volitional control of social vocalisations and vocal usage learning in bats. | bats are gregarious, highly vocal animals that possess a broad repertoire of social vocalisations. for in-depth studies of their vocal behaviours, including vocal flexibility and vocal learning, it is necessary to gather repeatable evidence from controlled laboratory experiments on isolated individuals. however, such studies are rare for one simple reason: eliciting social calls in isolation and under operant control is challenging and has rarely been achieved. to overcome this limitation, we de ... | 2018 | 29880634 |
| biomechanical control of vocal plasticity in an echolocating bat. | many animal species adjust the spectral composition of their acoustic signals to variable environments. however, the physiological foundation of such spectral plasticity is often unclear. the source-filter theory of sound production, initially established for human speech, applies to vocalizations in birds and mammals. according to this theory, adjusting the spectral structure of vocalizations could be achieved by modifying either the laryngeal/syringeal source signal or the vocal tract, which f ... | 2016 | 26823102 |
| comparative analysis of sars-cov-2 and its receptor ace2 with evolutionarily related coronaviruses. | the pandemic covid-19 is caused by the severe acute respiratory syndrome coronavirus 2 (sars-cov-2) and it is spreading very rapidly worldwide. to date, the origin and intermediate hosts of sars-cov-2 remain unclear. in this study, we conducted comparative analysis among sars-cov-2 and non-sars-cov-2 coronavirus strains to elucidate their phylogenetic relationships. we found: 1, the sars-cov-2 strains analyzed could be divided into 3 clades with regional aggregation; 2, the non-sars-cov-2 common ... | 2020 | 33186121 |