JOURNAL OF BAT RESEARCH & CONSERVATION 13

Abstract: Bats are major consumers of arthropods, including many agricultural pest species, and can thus reduce and prevent crop damage. However, few, if any, data is available on the potential role of bats in pest control in central Europe. Evidence that bats prey upon locally important pest species would be an important first step to demonstrate their value to local farmers and facilitate conservation measures. In this pilot study, we used a DNA metabarcoding approach to investigate the diet composition of common pipistrelles and brown long-eared bats captured in orchards in Belgium. We show that the spotted wing drosophila (Drosophila suzukii), one of the most harmful pest species in this region, was part of the diet of common pipistrelles. This pest species was recorded in one of the five samples from common pipistrelles. Our results indicate that bats can be valuable assets for biological pest suppression in West-European orchards, thus setting a path for future studies.

Abstract: Ultrasound detectors are becoming an increasingly used tool in bat research. Still, the lack of standardization of measurement criteria in the analysis of recordings is problematic when attempting identifications. For instance, the analytical procedures depend on the technique for obtaining the spectral content of an echolocation pulse (eg. zero-crossing, Fourier analysis) –which is directly related to the detection device and software-, and they should be as consistent as possible among studies’ and observers’ to allow comparisons. Using full-spectrum recordings of a Myotis species, we measured the minimum frequency and maximum frequency on the spectrogram, as well as considering four thresholds on the power spectrum: at -55 and -50 decibels from 0 decibels, and at 18 and 6 decibels below peak frequency. Focusing on the minimum frequency, we found statistically significant differences of measurements obtained on the spectrogram vs. power spectrum, with higher mean values in the latter as product of pulse truncation, as well as statistically significant differences between two trained observers. The measurements relative to the peak frequency were less variable. Without proper considerations, these issues may represent confounding factors and derive data unsuitable for cross-studies comparisons and potential misidentifications. We make recommendations about measurement criteria and emphasize the importance of replication and more rigorous reports.

Resumen: En las últimas décadas se han publicado varios casos de murciélagos que exceden los 20 años de longevidad máxima. La mayoría de éstos se corresponden con especies holárticas que hibernan; sin embargo, datos de longevidad de especies tropicales son aún escasos. En esta nota damos a conocer el primer registro de longevidad para una especie de la familia Natalidae. En este estudio reportamos la recaptura de un macho de Nyctiellus lepidus que había sido marcado 16,9 años antes en la misma cueva en la región central de Cuba. Esta especie es endémica de Cuba (incluyendo la Isla de la Juventud) y las Bahamas, y se refugia exclusivamente en cuevas. Nyctiellus lepidus tiene una masa corporal de aproximadamente 2 g, lo que lo ubica entre los murciélagos más pequeños del mundo. Basado en el coeficiente de longevidad, la proporción entre la longevidad observada y la esperada, se estimó que puede vivir 3,9 veces de lo esperado para su masa corporal. Este registro de longevidad constituye uno de los más largos para murciélagos insectívoros no hibernantes.

Abstract: Over the last two decades, there have been several longevity records of bats that have exceeded 20 years, mostly corresponding to Holarctic hibernating species. Whereas such data of tropical bats is still scarce. Here we report the first longevity record for the Gervais´s funnel-eared bat, Nyctiellus lepidus (Gervais, 1837) (family Natalidae). We recaptured a male individual that had been banded 16.9 years previously in the same cave in Central Cuba. This species is endemic to Cuba (including Isla de la Juventud) and the Bahamas and is an obligate cave-dwelling bat. Weighing nearly 2 grams, N. Lepidus is one of the world’s smallest bats. Based on longevity quotient (the ratio of observed to predicted longevity), we estimate that its lifespan is 3.9 times longer than expected for its body mass. This longevity record constitutes one of the longest in a non-hibernating insectivorous bat.

Abstract: An unexpected record of Tadarida teniotis (Rafinesque, 1814) (adult male) was made in Kharkiv city, NE Ukraine. The bat was found in a private flat on the thirteenth floor of a multi-storey building (1970s construction). This new record is much further North than documented from in-hand and acoustic records of this species in the Russian Caucasus – 850 km, Bulgaria – 1200 km, and Crimea – 600 km. Two main interpretations of this record are presented: (i) it represents a species range expansion due to urbanization and climate warming, or (ii) an accidental transportation by a vehicle. In either of these circumstances, this species should to be included in the bat species list of the Ukraine.

Abstract: Chromatic disorders may disrupt adaptive coloration and reduce animals’ capacity to survive and produce young. These disorders have been documented widely for bats across the globe. However, most of these cases are concentrated in regions with well-studied faunal communities, such as Europe or North and South America, with little documentation of chromatic disorders in regions such as Central Africa. We captured a bat in mainland Equatorial Guinea, Central Africa, with distinct white patches on its body and normally pigmented eyes. Here, we report the first recorded case of piebaldism documented in Central Africa for the Nycteridae family, and the first case worldwide for Nycteris arge Thomas, 1903.

Abstract: The brown long-eared bat Plecotus auritus is classified globally as a species of ‘least concern’ by the International Union for Conservation of Nature (IUCN) red list of threatened species, and as ‘data deficient’ in the National classification for Nepal. The present paper reports the first record of its occurrence in Jumla, Karnali and the third for the country, Nepal. One live male adult individual and a few faeces were observed on September 8, 2017 at 12:44PM in Jumla. We include a brief discussion of its morphological features and measurements and the habitat in which it was recorded. The paper provides discussion on the previous two records from the country, emphasizing the need for more intensive research over a prolonged period of time to improve understanding of the species’ distribution, habitat and ecology in the region.

Abstract: By virtue of geology, Nepal harbours hundreds of caves and provides potential habitat for a large variety of bats. However, limited studies have focused on cave-dwelling bat species in Nepal. Our study along the Kaligandaki canyon – the deepest gorge in the world – aimed to explore it’s caves, examine cave inhabiting bat species, and to identify any major prevailing threats to the cave fauna. Roost count surveys, evening emergence counts, harp trap and mist nets were used to assess bats using caves. Out of 20 caves, bat populations were recorded in 13, with guano evident in two additional caves. This included records of a total of 12 species across all studied caves. Cave tourism was observed to be a major threat to bats and the cave environment. Therefore, we recommend the regulation of cave tourism and a halt to tourism-related development in and around these caves.

Abstract: Activity outside day roosts among insectivorous bat species can vary considerably and has been linked to feeding habits. We aimed to assess the time of emergence, duration of the activity, and foraging efficiency in a Brazilian population of Molossus molossus. We also investigated if body mass gain was related to foraging amplitude and night length. We achieved 592 first-time captures and recaptures of 248 adult individuals. The bats were predominantly crepuscular. The average duration of activity outside roosts was 36 min. We found that individuals captured returning to their roosts were significantly heavier (mean = 0.80 g) than those upon emergence, equating to the average consumption of ~22 mg/min insects during the bats’ activity period. Although we only sampled the first of two periods of nightly activity for M. molossus, we show the importance of insectivorous bats for insect suppression, especially when insect abundance peaks during the summer. Further studies should focus on the potential for using bats as a biological control, given that Brazil has a globally significant agricultural economy.

Abstract: Peters’s Trumpet-eared Bat (Phoniscus jagorii) was recently recorded from Sri Lanka (2,100 km west of the nearest known range), which extends its distributional range significantly. We recorded P. jagorii in peninsular India, providing the first confirmed record from India and the second from South Asia. Phylogenetic analysis using cytochrome oxidase I (COI) gene shows similarities between the Indian and Southeast Asian specimens. Comprehensive bat surveys carried out in south India showed that the P. jagorii is more elusive than other bat species in this region and suggests further studies are needed to enable long-term conservation of the species.

Abstract: The use of radio telemetry has been essential for collecting information about bat biology and ecology. The radio-tag is usually glued on the back of the bat and typically falls off after just over a week. In the present study, we present a case where a radiotagged Myotis brandtii was recaptured with its radio-tag still intact and attached, ten months after initial tagging. At the time of recapture, there was no re-growth of hair under the transmitter. Three other radio-tagged Myotis mystacinus were also recaptured after the winter season, but these individuals had shed their radiotags and showed a complete regrowth of hair. Carrying a non-functional transmitter will cause unnecessary costs for the bat. As the onset of moulting is understudied in general, and differs widely between both species, sexes and sexual status, we propose that researchers should put more effort into recapturing radio-tagged bats before the end of the transmitter’s battery life to remove the transmitter. This may be particularly important when the time of tagging does not correspond with the bats’ moulting season. More intra- and interspecific information is needed about the timing of moulting in order to minimize negative effects on bats when using glued on radio-tags.

Abstract: Bangladeshi chiropteran fauna is poorly studied and there is a lack of complete inventories. A total of 39 species of bats have been reported to occur in the country. Great Woolly Horseshoe Bat Rhinolophus luctus, (Temmick 1834) has been expected to occur in northeast Bangladesh based on its presence in north-eastern India and adjoining areas. However, there had been no published report on the occurrence to date. We first report the occurrence of R. luctus in a northeastern forest of Bangladesh. A pair of R. luctus were spotted opportunistically and photographed on September 4, 2019 along the shoreline of a rocky stream in Patharia Hill Reserve Forest while surveying non-human primates. This forest is an important reservoir for several globally threatened species in northeast Bangladesh though the characterization of its biodiversity is yet incomplete. Further study into the regions faunal diversity may reveal additional species, particularly the bats. So, complete assessments of the conservation status of Bangladeshi bat fauna is urgently needed to implement effective conservation measures.

Abstract: Emballonurid bats of the genus Centronycteris are rare and poorly represented in scientific collections and in the literature. We report the second record of Thomas’s Shaggy bat Centronycteris centralis Thomas, 1912 for the Choco biogeographic region of Colombia and the first one for the department of Chocó. This new record fills a large distributional gap of this species in western Colombia and backs the importance of the newly created AICOM Pacurita Chocó-Central where this specimen was collected.

Abstract: Myotis crypticus is a recently described bat species belonging to the Myotis nattereri species complex. Its distribution range is not entirely known and so far has only been found across Italy, southern France, and central and northern Spain. Here we present the first record of M. crypticus for Portugal. In October 2018, one individual of this species was captured at a swarming site within the Natura 2000 Site of Community Importance (SCI) Alvão/Marão in northern Portugal. The morphological identification of the bat in the field was later confirmed molecularly.

Resumen: Un buen conocimiento sobre los posibles lugares de paso migratorio de quirópteros es esencial para entender sus patrones de desplazamiento estacional y adaptar las medidas de conservación que los incumben. En la presente nota actualizamos la información acerca de la presencia de murciélagos detectados en la isla de Alborán, un remoto enclave del Mediterráneo occidental entre África y Europa. Aunque existen varias observaciones aisladas de quirópteros en la isla, hasta la fecha tan solo se había publicado la identificación de un registro puntual de Tadarida teniotis. En esta aportación se amplía la información de la presencia de este grupo en primavera y otoño, incluyendo otro registro de la misma especie y la primera cita conocida de Hypsugo savii en el lugar. Estos hallazgos se relacionan con ejemplares esporádicos de murciélagos observados en la isla que volaban, probablemente, entre África y Europa. Los datos sugieren la posibilidad de desplazamientos intercontinentales de quirópteros sobre el mar entre sus orillas africanas y europeas.

Resumen: El nóctulo mediano (Nyctalus noctula) es un murciélago forestal migrador, clasificado como “preocupación menor” por la IUCN, y como “vulnerable” en el Catálogo Español de Especies Amenazadas debido a su escasez regional. En la península Ibérica únicamente se tiene constancia de seis agrupaciones de nóctulos medianos, en Castilla y León, Navarra, Zaragoza, Lleida y Madrid. Entre los veranos de 2018 y 2019 se identificaron al menos 18 ejemplares y un mínimo de diez refugios utilizados por esta especie en una alameda del término municipal de Almaraz de Duero (Zamora, España) ubicada a orillas del río Duero. Los refugios se localizaron mediante la detección de llamadas sociales emitidas por los machos, todos ellos en nidos abandonados de pícidos (Picidae) y construidos sobre álamos blancos (Populus alba). La altura de los nidos ocupados varió entre los 8 y los 14 metros. Además, en septiembre de 2019 se capturó un macho, confirmando las observaciones acústicas. El tamaño de los grupos que utilizaban los refugios varió entre individuos solitarios y un máximo de 17 ejemplares observados en septiembre de 2019. Los datos obtenidos no permiten conocer la composición de los grupos, aunque las llamadas sociales son las típicas de cortejo, dato que confirmaría la existencia de al menos una colonia de apareamiento. La nueva localidad se encuentra a unos 300 kilómetros de las más cercanas conocidas (Almazán y Aranjuez), y amplía hacia el oeste el área de distribución de las agrupaciones de nóctulos medianos tanto en la península Ibérica como a nivel europeo y mundial. La alameda estudiada se encuentra protegida al estar incluida en el espacio Natura 2000, ZEC Cañones del Duero (ES4190102) y ZEPA Cañones del Duero (ES0000206), considerándose un bosque muy relevante para la especie, cuya conservación es prioritaria.

Resumen: Los quirópteros forestales han sido, en general, poco estudiados hasta la aparición de los detectores de ultrasonidos y los programas de reconocimiento e identificación de vocalizaciones, lo que ha facilitado su detectabilidad y estudio. Además, a nivel peninsular los datos y registros de estos murciélagos son relativamente escasos. Con esta nota ampliamos el rango de distribución de los nóctulos en la península ibérica y la información sobre incidencias en parques eólicos. La presencia en la provincia de Soria de nóctulo pequeño (Nyctalus leisleri) y nóctulo mediano (Nyctalus noctula) es por el momento anecdótica, mientras que para el nóctulo grande (Nyctalus lasiopterus) es algo más frecuente. Recientemente se ha descrito la presencia de una agrupación de nóctulo mediano en Almazán (Soria) con avistamientos desde 2016, así como de nóctulo pequeño y grande en la zona conocida como Pinar Grande al noroeste de Soria. En este trabajo aportamos nuevas citas procedentes de estudios de siniestralidad en instalaciones eólicas de la provincia obtenidas de la base de datos de la Junta de Castilla y León, donde se constata la presencia de estas especies entre 2005 y 2019, así como otras citas recopiladas en los últimos años a través de muestreo mediante redes y detectores de ultrasonidos. Los ejemplares de nóctulo mediano encontrados durante los estudios en parques eólicos en el sur de la provincia que pudieron ser sexados (26% del total de los siniestros) eran todos machos probablemente machos en fase de apareamiento provenientes del parque de La Arboleda de Almazán. En el caso del nóctulo grande, las citas resultaron dispersas por la provincia, pero recurrentes a lo largo de los últimos años. En cambio, las citas de nóctulo pequeño fueron especialmente escasas en parques eólicos.

Abstract: Frosted myotis (Myotis pruinosus) is a rare and little-known bat, listed as Endangered by the IUCN. Although it inhabits forests and has been suspected to roost in tree cavities, all roosting individuals found to date were in caves. Hereby, I report a discovery of an individual roosting in a tree cavity made by Japanese pygmy woodpecker (Picoides kizuki), in a large pine tree in an old-growth mixed forest in Nikko National Park, Japan. This observation confirms that frosted myotis roosts in tree cavities but does not support the hypothesis that dependence on larger cavities explains the species’ affinity with old-growth forests.

Abstract: There has been an increase in commercial bat detectors and noise filtering software for monitoring bat activity. In this study, we compare the recording efficiency of three bat detectors from the popular brand Wildlife Acoustics (Echo Meter 3, Echo Meter Touch Pro 1 and Song Meter 2 BAT) and the effectiveness of two noise filtering software (Kaleidoscope and SonoBat Batch Scrubber). To do so, we recorded 7513 files from 13 urban parks in Madrid in 2017, that were manually identified to species level. The results show that the Echo Meter 3 records significantly less activity than the Echo Meter Touch Pro 1 and Song Meter 2 BAT. Our results also identify SonoBat Batch Scrubber as more reliable than Kaleidoscope for preventing false negatives. Therefore, our study demonstrates that different bat detectors, and different noise filtering software, can provide different results.