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

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.

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 (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 pueden 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.

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

New records on the use of man-made constructions as diurnal roosts by bats from the southern Amazon in central Brazil

ABSTRACT Roosts are a key part of bat species' life stories. Information on roost use enables us to understand the biological processes underlying bat ecology and is crucial with regard to the natural-roost loss and environmental pressures related to habitat destruction that has been considered as a threat affecting bat conservation. The aim of this study was to collect new data on the diurnal artificial-roost use by bats in a landscape from the southern Amazon. We observed bat species roosting at an abandoned house in a highly fragmented ecotone between the Amazon and Cerrado biomes. We observed one Trachops cirrhosus individual roosting in physical contact with one Phyllostomus hastatus. One year later, we noticed a compositional change at this roost, in which we found a large colony of Pteronotus parnellii. These findings may shed light on the potential flexibility of the roosting requirements of these species in such landscapes. Moreover, this is one of the first records of the use of human constructions by P. parnelli in such fragmented landscapes, a bat species that until recently was thought of as being associated only with well-preserved natural roosts.

MURCIÉLAGOS (MAMMALIA: CHIROPTERA) ASOCIADOS CON UNA CUEVA EN EL PARQUE NACIONAL YURUBÍ, SIERRA DE AROA, ESTADO YARACUY, VENEZUELA

<p>Las cuevas constituyen un recurso importante para murciélagos en los bosques ya que ofrecen protección y condiciones climáticas que favorecen a la reproducción, especialmente para aquellas especies con hábitos cavernícolas. Durante 12 meses (2013-2014), se llevó a cabo un estudio sobre uso de una cueva por parte de murciélagos en el Parque Nacional Yurubí-Sierra de Aroa, Estado Yaracuy, Venezuela. Se colocó una trampa de arpa una vez por mes y estuvo activa antes de que los murciélagos emergieran del refugio. Después de tomar datos sobre abundancia, los individuos fueron marcados y liberados en el sitio. Se registraron seis especies pertenecientes a las familias Mormoopidae y Phyllostomidae. Pteronotus parnellii, Anoura geoffroyi y Carollia perspicillata fueron capturados todos los meses y en los tres se observó indicios reproductivos. P. parnellii y A. geoffroyi fueron los más abundantes con una mayor presencia para el primero. Por otro lado, Phyllostomus hastatus, Lonchorhina aurita y Desmodus rotundus usaron el refugio temporalmente, sin evidenciar alguna condición reproductiva. Se observaron cambios en el tamaño de las colonias y composición de especies, evidencia de que el refugio es usado permanentemente por algunas especies durante la reproducción y de forma temporal por otras, que aparentemente se estarían favoreciendo sólo del resguardo que ofrece.</p>