Pteronotus Parnellii Research Articles

A novel tamanavirus (Flaviviridae) of the European common frog (Rana temporaria) from the UK.

Flavivirids are small, enveloped, positive-sense RNA viruses from the family Flaviviridae with genomes of ~9-13 kb. Metatranscriptomic analyses of metazoan organisms have revealed a diversity of flavivirus-like or flavivirid viral sequences in fish and marine invertebrate groups. However, no flavivirus-like virus has been identified in amphibians. To remedy this, we investigated the virome of the European common frog (Rana temporaria) in the UK, utilizing high-throughput sequencing at six catch locations. De novo assembly revealed a coding-complete virus contig of a novel flavivirid ~11.2 kb in length. The virus encodes a single ORF of 3456 aa and 5' and 3' untranslated regions (UTRs) of 227 and 666 nt, respectively. We named this virus Rana tamanavirus (RaTV), as BLASTp analysis of the polyprotein showed the closest relationships to Tamana bat virus (TABV) and Cyclopterus lumpus virus from Pteronotus parnellii and Cyclopterus lumpus, respectively. Phylogenetic analysis of the RaTV polyprotein compared to Flavivirus and Flavivirus-like members indicated that RaTV was sufficiently divergent and basal to the vertebrate Tamanavirus clade. In addition to the Mitcham strain, partial but divergent RaTV, sharing 95.64-97.39 % pairwise nucleotide identity, were also obtained from the Poole and Deal samples, indicating that RaTV is widespread in UK frog samples. Bioinformatic analyses of predicted secondary structures in the 3'UTR of RaTV showed the presence of an exoribonuclease-resistant RNA (xrRNA) structure standard in flaviviruses and TABV. To examine this biochemically, we conducted an in vitro Xrn1 digestion assay showing that RaTV probably forms a functional Xrn1-resistant xrRNA.

Cochlea development shapes bat sensory system evolution.

Sensory organs must develop alongside the skull within which they are largely encased, and this relationship can manifest as the skull constraining the organs, organs constraining the skull, or organs constraining one another in relative size. How this interplay between sensory organs and the developing skull plays out during the evolution of sensory diversity; however, remains unknown. Here, we examine the developmental sequence of the cochlea, the organ responsible for hearing and echolocation, in species with distinct diet and echolocation types within the ecologically diverse bat super-family Noctilionoidea. We found the size and shape of the cochlea largely correlates with skull size, with exceptions of Pteronotus parnellii, whose high duty cycle echolocation (nearly constant emission of sound pulses during their echolocation process allowing for detailed information gathering, also called constant frequency echolocation) corresponds to a larger cochlear and basal turn, and Monophyllus redmani, a small-bodied nectarivorous bat, for which interactions with other sensory organs restrict cochlea size. Our findings support the existence of developmental constraints, suggesting that both developmental and anatomical factors may act synergistically during the development of sensory systems in noctilionoid bats.

Genomic Characterization of Three Novel Bartonella Strains in a Rodent and Two Bat Species from Mexico.

Rodents and bats are the most diverse mammal group that host Bartonella species. In the Americas, they were described as harboring Bartonella species; however, they were mostly characterized to the genotypic level. We describe here Bartonella isolates obtained from blood samples of one rodent (Peromyscus yucatanicus from San José Pibtuch, Yucatan) and two bat species (Desmodus rotundus from Progreso, and Pteronotus parnellii from Chamela-Cuitzmala) from Mexico. We sequenced and described the genomic features of three Bartonella strains and performed phylogenomic and pangenome analyses to decipher their phylogenetic relationships. The mouse-associated genome was closely related to Bartonella vinsonii. The two bat-associated genomes clustered into a single distinct clade in between lineages 3 and 4, suggesting to be an ancestor of the rodent-associated Bartonella clade (lineage 4). These three genomes showed <95% OrthoANI values compared to any other Bartonella genome, and therefore should be considered as novel species. In addition, our analyses suggest that the B. vinsonii complex should be revised, and all B. vinsonii subspecies need to be renamed and considered as full species. The phylogenomic clustering of the bat-associated Bartonella strains and their virulence factor profile (lack of the Vbh/TraG conjugation system remains of the T4SS) suggest that it should be considered as a new lineage clade (L5) within the Bartonella genus.

Evidence of Viral Communities in Three Species of Bats from Rural Environment in Mexico

Some emerging and reemerging diseases have been associated with certain species of bats. These diseases have emerged in anthropogenic environments where the conditions for spillover of infectious agents between bats, domestic animals, and humans are present. Mexico is the country with the fourth highest bat diversity in the world, and some of these bat species live in anthropogenic environments such as a backyard production system. The objective of this study was to analyze the virome of three species of bats (Artibeus spp., Macrotus waterhousii and Pteronotus parnellii) that inhabit roosts near rural backyard farms and have large geographic distributions. Rectal swabs were taken and analyzed by the next-generation sequencing (NGS). Thus, it was possible to study the virome of these bat species which has not been previously reported. In one of them, P. parnellii, sequences of the family Coronaviridae were found. The detected viral communities of these three bat species included mostly bacteriophages while showing low numbers for known animal viruses. Viral diversities varied among the species studied and differed from previous studies. The findings of this research contribute to our knowledge of the virome of bat species which have large geographical distributions and, as in this case, inhabit anthropogenic habitats differing from intensive farms or urban settelments.

The resting frequency of echolocation signals changes with body temperature in the hipposiderid bat Hipposideros armiger.

ABSTRACTDoppler shift (DS) compensating bats adjust in flight the second harmonic of the constant-frequency component (CF2) of their echolocation signals so that the frequency of the Doppler-shifted echoes returning from ahead is kept constant with high precision (0.1–0.2%) at the so-called reference frequency (fref). This feedback adjustment is mediated by an audio–vocal control system that correlates with a maximal activation of the foveal resonance area in the cochlea. Stationary bats adjust the average CF2 with similar precision at the resting frequency (frest), which is slightly below the fref. Over a range of time periods (from minutes up to years), variations of the coupled fref and frest have been observed, and were attributed to age, social influences and behavioural situations in rhinolophids and hipposiderids, and to body temperature effects and flight activity in Pteronotus parnellii. We assume that, for all DS-compensating bats, a change in body temperature has a strong effect on the activation state of the foveal resonance area in the cochlea, which leads to a concomitant change in emission frequency. We tested our hypothesis in a hipposiderid bat, Hipposideros armiger, and measured how the circadian variation of body temperature at activation phases affected frest. With a miniature temperature logger, we recorded the skin temperature on the back of the bats simultaneously with echolocation signals produced. During warm-up from torpor, strong temperature increases were accompanied by an increase in frest, of up to 1.44 kHz. We discuss the implications of our results for the organization and function of the audio–vocal control systems of all DS-compensating bats.

Hemispheric and Sex Differences in Mustached Bat Primary Auditory Cortex Revealed by Neural Responses to Slow Frequency Modulations.

The mustached bat (Pteronotus parnellii) is a mammalian model of cortical hemispheric asymmetry. In this species, complex social vocalizations are processed preferentially in the left Doppler-shifted constant frequency (DSCF) subregion of primary auditory cortex. Like hemispheric specializations for speech and music, this bat brain asymmetry differs between sexes (i.e., males>females) and is linked to spectrotemporal processing based on selectivities to frequency modulations (FMs) with rapid rates (>0.5 kHz/ms). Analyzing responses to the long-duration (>10 ms), slow-rate (<0.5 kHz/ms) FMs to which most DSCF neurons respond may reveal additional neural substrates underlying this asymmetry. Here, we bilaterally recorded responses from 176 DSCF neurons in male and female bats that were elicited by upward and downward FMs fixed at 0.04 kHz/ms and presented at 0-90 dB SPL. In females, we found inter-hemispheric latency differences consistent with applying different temporal windows to precisely integrate spectrotemporal information. In males, we found a substrate for asymmetry less related to spectrotemporal processing than to acoustic energy (i.e., amplitude). These results suggest that in the DSCF area, (1) hemispheric differences in spectrotemporal processing manifest differently between sexes, and (2) cortical asymmetry for social communication is driven by spectrotemporal processing differences and neural selectivities for amplitude.

Effect of seasonality and microclimate on the variation in bat-fly load (Diptera: Streblidae) in a cave bat assemblage in a dry forest

Abstract Seasonality causes fluctuations in the availability of resources, affecting the presence and abundance of animal species. These fluctuations can have an impact on parasite-host relationships, which in turn can be exacerbated by microclimatic changes to which bat-flies are exposed. We characterized the bat-fly load and evaluated the effect of seasonality on five bat species in a dry forest. We evaluated variations in microclimatic conditions inside the cave Cerro Huatulco between seasons and the response of the bat-fly load. We collected 1165 bat-fly specimens belonging to 16 species from 688 bats. The obtained results indicate that the mean abundance and infestation intensity exhibited changes between seasons in Artibeus jamaicensis, Desmodus rotundus, Glossophaga soricina, and Pteronotus parnellii. In the case of the effect of microclimate conditions, we observed that prevalence is negatively correlated with temperature in G. soricina, while mean abundance and mean infestation intensity were negatively related to temperature in A. jamaicensis and G. soricina. The present study provides significant information about host-parasite relationships in a dry forest and discusses the relevance of abiotic and biotic factors that could affect host-parasite interactions, as well as the importance of each parasite load parameter for the understanding of this interaction.

Estimation of bat colony size even with low recapture rates: an example based on the Cormack-Jolly-Seber model in Oaxaca, México

Introduction: Reproduction is a critical phase for most living organisms and in bats the reproductive strategies exhibit considerable complexity and variability. Objective: In this paper, we describe the reproductive patterns and population dynamics of seven bat species (Artibeus toltecus, Carollia perspicillata, Glossophaga soricina, Mormoops megalophylla, Pteronotus davyi, Pteronotus parnellii and Natalus stramineus) that roost in a mine (La Mina) and two caves (El Apanguito and Cerro Huatulco) found in the municipalities of Pluma Hidalgo and Santa Maria Huatulco, in the State of Oaxaca, in southeastern México. Methods: Sampling was conducted once a month from July 2016 to June 2017. Results: A total of 5 836 bats were captured, tagged and, released, including 14 species, 10 genera, and five families. The most abundant species were Pteronotus davyi and P. parnellii, representing 41.01 % and 32.34 % of the captures, respectively. Artibeus toltecus, Carollia perspicillata, and Glossophaga soricina showed seasonal bimodal polyoestry without a postpartum oestrus pattern, whereas Mormoops megalophylla, Natalus stramineus, Pteronotus davyi, and Pteronotus parnellii showed a restricted seasonal monoestrous pattern. Conclusions: The reproductive activity of each species seems to be synchronized with the beginning of the rainy season. Future studies should consider aspects of vaginal cytology and include environmental factors to better understand the relationship of certain factors with the onset of reproductive activity of neotropical bat species.

Correlating Cochlear Morphometrics from Parnell's Mustached Bat (Pteronotus parnellii) with Hearing.

Morphometric analysis of the inner ear of mammals can provide information for cochlear frequency mapping, a species-specific designation of locations in the cochlea at which different sound frequencies are encoded. Morphometric variation occurs in the hair cells of the organ of Corti along the cochlea, with the base encoding the highest frequency sounds and the apex encoding the lowest frequencies. Changes in cell shape and spacing can yield additional information about the biophysical basis of cochlear tuning mechanisms. Here, we investigate how morphometric analysis of hair cells in mammals can be used to predict the relationship between frequency and cochlear location. We used linear and geometric morphometrics to analyze scanning electron micrographs of the hair cells of the cochleae in Parnell's mustached bat (Pteronotus parnellii) and Wistar rat (Rattus norvegicus) and determined a relationship between cochlear morphometrics and their frequency map. Sixteen of twenty-two of the morphometric parameters analyzed showed a significant change along the cochlea, including the distance between the rows of hair cells, outer hair cell width, and gap width between hair cells. A multiple linear regression model revealed that nine of these parameters are responsible for 86.9% of the variation in these morphometric data. Determining the most biologically relevant measurements related to frequency detection can give us a greater understanding of the essential biomechanical characteristics for frequency selectivity during sound transduction in a diversity of animals.

Reinforcement of the larynx and trachea in echolocating and non-echolocating bats.

The synchronization of flight mechanics with respiration and echolocation call emission by bats, while economizing these behaviors, presumably puts compressive loads on the cartilaginous rings that hold open the respiratory tract. Previous work has shown that during postnatal development of Artibeus jamaicensis (Phyllostomidae), the onset of adult echolocation call emission rate coincides with calcification of the larynx, and the development of flight coincides with tracheal ring calcification. In the present study, I assessed the level of reinforcement of the respiratory system in 13 bat species representing six families that use stereotypical modes of echolocation (i.e. duty cycle % and intensity). Using computed tomography, the degree of mineralization or ossification of the tracheal rings, cricoid, thyroid and arytenoid cartilages were determined for non-echolocators, tongue clicking, low-duty cycle low-intensity, low-duty cycle high-intensity, and high-duty cycle high-intensity echolocating bats. While all bats had evidence of cervical tracheal ring mineralization, about half the species had evidence of thoracic tracheal ring calcification. Larger bats (Phyllostomus hastatus and Pterpodidae sp.) exhibited more extensive tracheal ring mineralization, suggesting an underlying cause independent of laryngeal echolocation. Within most of the laryngeally echolocating species, the degree of mineralization or ossification of the larynx was dependent on the mode of echolocation system used. Low-duty cycle low-intensity bats had extensively mineralized cricoids, and zero to very minor mineralization of the thyroids and arytenoids. Low-duty cycle high-intensity bats had extensively mineralized cricoids, and patches of thyroid and arytenoid mineralization. The high-duty cycle high-intensity rhinolophids and hipposiderid had extensively ossified cricoids, large patches of ossification on the thyroids, and heavily ossified arytenoids. The high-duty cycle high-intensity echolocator, Pteronotus parnellii, had mineralization patterns and laryngeal morphology very similar to the other low-duty cycle high-intensity mormoopid species, perhaps suggesting relatively recent evolution of high-duty cycle echolocation in P. parnellii compared with the Old World high-duty cycle echolocators (Rhinolophidae and Hipposideridae). All laryngeal echolocators exhibited mineralized or ossified lateral expansions of the cricoid for articulation with the inferior horn of the thyroid, these were most prominent in the high-duty cycle high-intensity rhinolophids and hipposiderid, and least prominent in the low-duty cycle low-intensity echolocators. The non-laryngeal echolocators had extensively ossified cricoid and thyroid cartilages, and no evidence of mineralization/ossification of the arytenoids or lateral expansions of the cricoid. While the non-echolocators had extensive ossification of the larynx, it was inconsistent with that seen in the laryngeal echolocators.

Leptospira patógenas en murciélagos de Campeche y Yucatán, México

Objetivo. Reportar la infección con Leptospira en riñones de murciélagos de Campeche y Yucatán, México, a través de la amplificación por PCR de dos fragmentos distintos del gen 16S RNA ribosomal. Materiales y métodos. Se realizaron capturas en un sitio de Campeche y dos de Yucatán. A los murciélagos capturados se les aplicó la eutanasia y se les realizó una necropsia para recolectar tejido renal que se usó en la extracción de ADN total. Se realizaron dos PCR convencionales para la amplificación de los fragmentos de 16S RNA ribosomal. Se obtuvieron las secuencias de algunos productos positivos y se analizaron con herramientas bioinformáticas para identificar la especie infectante de Leptospira. Resultados. Se capturaron 69 murciélagos pertenecientes a cuatro familias y a ocho especies distintas. La familia con mayor diversidad fue Phyllostomidae con cinco especies. La especie con mayor frecuencia de captura fue Artibeus jamaicensis (41, 59.4%). Las PCR arrojaron una frecuencia de infección global de 21.7%. Las especies infectadas fueron A. jamaicensis, Pteronotus parnellii y Chiroderma villosum. El análisis bioinformático arrojó un 99.0% de identidad para Leptospira noguchii, Leptospira borgpetersenii y Leptospira santarosai. Conclusiones. Algunas especies de murciélagos de Yucatán y Campeche son portadores renales de leptospiras patógenas, por lo que podrían participar en el ciclo silvestre de transmisión en la región. La frecuencia de infección encontrada en los riñones de los murciélagos utilizados es mayor en comparación con aquellas obtenidas en otros reservorios de Yucatán y Campeche. Nuevas especies de murciélagos son reportadas como portadores de Leptospira para México.

Infección con Toxoplasma gondii (Eucoccidiorida: Sarcocystidae) en murciélagos de Campeche y Yucatán, México

Toxoplasma gondii is a protozoan parasite recognized as the causative agent of toxoplasmosis, a zoonotic disease that affects humans and domestic or wild animals. In Mexico, it represents a public and animal health problem, especially in regions with tropical and subtropical climates. Bats have been reported as accidental hosts in the transmission cycle; however, there is no preceding information in Mexico. Therefore, the aim of the present study is to report the T. gondii infection in bats captured in sites of Campeche and Yucatan states, Mexico. Bats were captured in two sites in Yucatan (X’matkuil and Panaba) and one in Campeche (Hampolol), located in the Yucatan Peninsula. Kidneys, spleen, and liver were collected and used in the total DNA extraction. Toxoplasma gondii infection was detected through the amplification of a B1 gene fragment, using nested PCR. The positive PCR products were purified and sent to sequencing for a posterior sequence identity analysis. Additionally, a phylogenetic tree was made. A total of 69 bats belonging to eight different species were processed: 41 (59.4 %, 41/69) Artibeus jamaicensis; six (8.7 %, 6/69) Pteronotus parnellii; six (8.7 %, 6/69) Noctilio leporinus; six (8.7 %, 6/69) Chiroderma villosum; four (5.8 %, 4/69) Glossophaga soricina; two (2.9 %, 2/69) Carollia sowelli; two (2.89 %, 2/69) Artibeus lituratus; and two (2.9 %, 2/69) Rhogeessa aeneus. The nested PCR identified eight (11.6 %, 8/69) infected bats: six (75 %, 6/8) A. jamaicensis, captured in X'matkuil and Panaba, one (12.5 %, 1/8) G. soricina, and one (12.5 %, 1/8) C. villosum, both captured in Panaba. The alignment analysis yielded 99-100 % for cover and 97-99 % for identity to T. gondii sequences. Our results contribute to the understanding of the T. gondii transmission cycle in the region; however, future research is needed to determine circulating genotypes, as previous studies have demonstrated that these animals might be infected with identified genotypes in other domestic or wild animals and even in humans.

Bat species richness in the region of the Central Valleys of Oaxaca, Mexico

We present a revised checklist of bat species occurring in the semi–urbanized region of the Central Valleys of Oaxaca, Mexico. The checklist is based on surveys using mist nets, recordings of echolocation calls, data from literature, and museum databases. Results show that the Central Valleys of Oaxaca have a species richness of 33 bat species belonging to 22 genera and five families. Species like the Mustached bat Pteronotus parnellii, the Western Red bat Lasiurus blossevillii and the Free–tailed bat Promops centralis were recorded after 32, 30 and 19 years respectively according to the records of the literature. We also recorded four species classified in some risk category according to either the Mexican government’s red list (NOM–059) or the IUCN red list. The recordings of the echolocation calls are the first from the region of Central Valleys of Oaxaca. Bat diversity in the Central Valleys of Oaxaca was underestimated and emphasizes the need for further research

As Blind as a Bat? Opsin Phylogenetics Illuminates the Evolution of Color Vision in Bats.

Through their unique use of sophisticated laryngeal echolocation bats are considered sensory specialists amongst mammals and represent an excellent model in which to explore sensory perception. Although several studies have shown that the evolution of vision is linked to ecological niche adaptation in other mammalian lineages, this has not yet been fully explored in bats. Recent molecular analysis of the opsin genes, which encode the photosensitive pigments underpinning color vision, have implicated high-duty cycle (HDC) echolocation and the adoption of cave roosting habits in the degeneration of color vision in bats. However, insufficient sampling of relevant taxa has hindered definitive testing of these hypotheses. To address this, novel sequence data was generated for the SWS1 and MWS/LWS opsin genes and combined with existing data to comprehensively sample species representing diverse echolocation types and niches (SWS1 n = 115; MWS/LWS n = 45). A combination of phylogenetic analysis, ancestral state reconstruction, and selective pressure analyses were used to reconstruct the evolution of these visual pigments in bats and revealed that although both genes are evolving under purifying selection in bats, MWS/LWS is highly conserved but SWS1 is highly variable. Spectral tuning analyses revealed that MWS/LWS opsin is tuned to a long wavelength, 555–560 nm in the bat ancestor and the majority of extant taxa. The presence of UV vision in bats is supported by our spectral tuning analysis, but phylogenetic analyses demonstrated that the SWS1 opsin gene has undergone pseudogenization in several lineages. We do not find support for a link between the evolution of HDC echolocation and the pseudogenization of the SWS1 gene in bats, instead we show the SWS1 opsin is functional in the HDC echolocator, Pteronotus parnellii. Pseudogenization of the SWS1 is correlated with cave roosting habits in the majority of pteropodid species. Together these results demonstrate that the loss of UV vision in bats is more widespread than was previously considered and further elucidate the role of ecological niche specialization in the evolution of vision in bats.

Coexistence of two sympatric cryptic bat species in French Guiana: insights from genetic, acoustic and ecological data

BackgroundThe distinction between lineages of neotropical bats from the Pteronotus parnellii species complex has been previously made according to mitochondrial DNA, and especially morphology and acoustics, in order to separate them into two species. In these studies, either sample sizes were too low when genetic and acoustic or morphological data were gathered on the same individuals, or genetic and other data were collected on different individuals. In this study, we intensively sampled bats in 4 caves and combined all approaches in order to analyse genetic, morphologic, and acoustic divergence between these lineages that live in the same caves in French Guiana.ResultsA multiplex of 20 polymorphic microsatellite markers was developed using the 454-pyrosequencing technique to investigate for the first time the extent of reproductive isolation between the two lineages and the population genetic structure within lineages. We genotyped 748 individuals sampled between 2010 and 2015 at the 20 nuclear microsatellite loci and sequenced a portion of the cytochrome c oxydase I gene in a subset of these. Two distinct, non-overlapping haplogroups corresponding to cryptic species P. alitonus and P. rubiginosus were revealed, in accordance with previous findings. No spatial genetic structure between caves was detected for both species. Hybridization appeared to be quite limited (0.1–4%) using microsatellite markers whereas introgression was more common (7.5%) and asymmetric for mitochondrial DNA (mtDNA).ConclusionsThe extremely low rate of hybridization could be explained by differences in life cycle phenology between species as well as morphological and acoustical distinction between sexes in one or the other species. Taken together, these results add to our growing understanding of the nature of species boundaries in Pteronotus parnelli, but deserve more in-depth studies to understand the evolutionary processes underlying asymmetric mtDNA introgression in this group of cryptic species.

Genotoxicological analyses of insectivorous bats (Mammalia: Chiroptera) in central Brazil: The oral epithelium as an indicator of environmental quality

The micronucleus (MN) test of the human buccal mucosa was developed more than 30 years ago, although this technique has only recently been applied to wild mammals. This paper presents a pioneering study in the genotoxicological evaluation of the exfoliated cells of the buccal mucosa of bats. The assay was applied to two insectivorous bat species (Noctilio albiventris and Pteronotus parnellii) sampled in riparian corridors located in the city of Palmas (capital of the Brazilian state of Tocantins), with the results being compared with those obtained for a third insectivorous species (Nyctinomops laticaudatus), which has established a colony under a road bridge in the same region. This colony represents one of the largest molossidae populations ever recorded in Brazil. A significantly higher frequency of micronuclei was recorded in this colony, as well as a number of other nuclear abnormalities, including binucleated cells, cells with condensed chromatin and karyolysis, in comparison with the bats from the riparian corridors, indicating that the bats from the bridge colony are more susceptible to genotoxic damage. Thus, it is demonstrated the importance of the biomarker (MN) for use in wild animals and allows to conclude that colony bats are more susceptible to genotoxic damages.

A coalescent-based estimator of genetic drift, and acoustic divergence in the Pteronotus parnellii species complex

Determining the processes responsible for phenotypic variation is one of the central tasks of evolutionary biology. While the importance of acoustic traits for foraging and communication in echolocating mammals suggests adaptation, the seldom-tested null hypothesis to explain trait divergence is genetic drift. Here we derive FST values from multi-locus coalescent isolation-with-migration models, and couple them with estimates of quantitative trait divergence, or PST, to test drift as the evolutionary process responsible for phenotypic divergence in island populations of the Pteronotus parnellii species complex. Compared to traditional comparisons of PST to FST, the migration-based estimates of FST are unidirectional instead of bidirectional, simultaneously integrate variation among loci and individuals, and posterior densities of PST and FST can be compared directly. We found the evolution of higher call frequencies is inconsistent with genetic drift for the Hispaniolan population, despite many generations of isolation from its Puerto Rican counterpart. While the Hispaniolan population displays dimorphism in call frequencies, the higher frequency of the females is incompatible with sexual selection. Instead, cultural drift toward higher frequencies among Hispaniolan females might explain the divergence. By integrating Bayesian coalescent and trait analyses, this study demonstrates a powerful approach to testing genetic drift as the default evolutionary mechanism of trait differentiation between populations.

A three-dimensional digital neurological atlas of the mustached bat (Pteronotus parnellii)

Substantial knowledge of auditory processing within mammalian nervous systems emerged from neurophysiological studies of the mustached bat (Pteronotus parnellii). This highly social and vocal species retrieves precise information about the velocity and range of its targets through echolocation. Such high acoustic processing demands were likely the evolutionary pressures driving the over-development at peripheral (cochlea), metencephalic (cochlear nucleus), mesencephalic (inferior colliculus), diencephalic (medial geniculate body of the thalamus), and telencephalic (auditory cortex) auditory processing levels in this species. Auditory researchers stand to benefit from a three dimensional brain atlas of this species, due to its considerable contribution to auditory neuroscience. Our MRI-based atlas was generated from 2 sets of image data of an ex-vivo male mustached bat's brain: a detailed 3D-T2-weighted-RARE scan [(59 × 63 x 85) μm3] and track density images based on super resolution diffusion tensor images [(78) μm3] reconstructed from a set of low resolution diffusion weighted images using Super-Resolution-Reconstruction (SRR). By surface-rendering these delineations and extrapolating from cortical landmarks and data from previous studies, we generated overlays that estimate the locations of classic functional subregions within mustached bat auditory cortex. This atlas is freely available from our website and can simplify future electrophysiological, microinjection, and neuroimaging studies in this and related species.

Precise Doppler shift compensation in the hipposiderid bat, Hipposideros armiger

Bats of the Rhinolophidae and Hipposideridae families, and Pteronotus parnellii, compensate for Doppler shifts generated by their own flight movement. They adjust their call frequency such that the frequency of echoes coming from ahead fall in a specialized frequency range of the hearing system, the auditory fovea, to evaluate amplitude and frequency modulations in echoes from fluttering prey. Some studies in hipposiderids have suggested a less sophisticated or incomplete Doppler shift compensation. To investigate the precision of Doppler shift compensation in Hipposideros armiger, we recorded the echolocation and flight behaviour of bats flying to a grid, reconstructed the flight path, measured the flight speed, calculated the echo frequency, and compared it with the resting frequency prior to each flight. Within each flight, the average echo frequency was kept constant with a standard deviation of 110 Hz, independent of the flight speed. The resting and reference frequency were coupled with an offset of 80 Hz; however, they varied slightly from flight to flight. The precision of Doppler shift compensation and the offset were similar to that seen in Rhinolophidae and P. parnellii. The described frequency variations may explain why it has been assumed that Doppler shift compensation in hipposiderids is incomplete.

Seasonal variation of gastro-intestinal helminths of three bat species in the dry forest of western Mexico

Studies on helminths of chiropterans are relatively uncommon compared to those of other animals, and seasonal changes in helminth load have been rarely examined. We characterized the gastro-intestinal helminth load of 3 bats species to test for the existence of seasonal changes in response to known seasonal environmental and bat prey fluctuations. We did not find seasonal variation in most of the cases. However, the prevalence of 4 endoparasite species was significantly higher during one of the seasons. The highest richness was registered in Pteronotus parnellii during the wet season. The effective number of species was higher during the dry season in the 3 species of Pteronotus. Diet seems to be an important driver of helminth infracommunity structure, but we found heterogeneous patterns in the relationship between diversity and load of helminths and seasonal patterns of bat's diets and abundance of potential intermediate hosts.