Myotis sodalis (Indiana bat) and Myotis grisescens (gray bat) are federally endangered species in the United States that use a limited number of hibernacula, placing them at risk of extirpation and/or extinction from various threats. Understanding their genetic structure and diversity can help inform the management and preservation of their adaptive genetic variation, but prior genetic studies of these species were based on small numbers of microsatellites and mitochondrial DNA. Here, we used genotyping-by-sequencing (GBS) to assess the genetic population structure and effective sizes of M. sodalis and M. grisescens. We genotyped 146,548 single-nucleotide polymorphisms (SNPs) from 45 M. sodalis and 57,902 SNPs from 47 M. grisescens individuals spread across their ranges. Population structure for each species was assessed using ADMIXTURE and Principal Component Analyses (PCA) of GBS data. Myotis sodalis showed no geographic structure in genetic diversity, suggesting a panmictic population structure. Although there was also no evidence of subpopulations of M. grisescens, a PCA for M. grisescens indicated some east–west population variation and gene flow across the Mississippi River Valley. Coalescent modeling suggested an effective population size of 360,977 (95% Confidence Interval, CI 349,488–368,414) for M. sodalis and 41,888 (CI 41,400–243,122) for M. grisescens, with increasing population sizes for both across evolutionary timescales. From a genetic conservation standpoint, M. sodalis may best be managed as a single population, whereas M. grisescens should be managed with consideration of maintaining the genetic variation of both eastern and western groups.

A Rhinolophus ferrumequinum maternity roost in Pembrokeshire, West Wales, U.K. was monitored from 1994 to 2023, as part of the U.K. national survey between days 92–112 (1 April = day 1). The onset of births, determined from pup forearm lengths, occurred earlier than anticipated in five years from days 63–77, in 1997, 2005, 2007, 2011 and 2014. In those five years between 0.5–20.6% of the exit count would have been pups 28–35 days old, which were nearly adult size and able to fly outside the roost (9.5 ± 8.5%, 0 ± SD). Since 2014 the population exceeded 650 adult bats and there was insufficient time to measure pup forearm lengths whilst adults were out of the roost so alternative methods of estimating birth timing were devised. Nightly external activity periods at the maternity roost identified the date when births commenced and presumed foraging activity changed from pre-partum, when bats were absent from dusk to dawn, to post-partum when mothers returned to feed their pups. Changes in the onset of early births were statistically related to changes in the integrated air temperature, defined as the accumulated temperature above a threshold in April of 7°C (degree days). A significant (P < 0.01) polynomial equation explained a moderate proportion (R² = 33.6%) of the non-linear increase in the integrated air temperature over time. The probability of an early birth onset (P) was predicted by a significant (P = 0.014) binary logistic model. The odds of an early birth onset, relative to a later birth onset, was elevated by 1.04 (95% CI = 1.01, 1.08) for every one degree day increase in integrated air temperature. The probability of an early birth onset increased from P = 0.107 when the integrated air temperature was 38.7 degree days up to P = 0.942 when the integrated air temperature was 152.0 degree days. At the principal U.K. maternity roosts integrated air temperatures in April were in the same ranges annually from 2011 to 2023. Therefore, monitoring of the integrated air temperature in April provides a simple noninvasive method to predict the extent and pace of the shift in birth timing of R. ferrumequinum in future associated with climate change.

Understanding the effects of habitat loss on communities is essential for biodiversity conservation and maintenance of ecosystem services. Considering that bats are efficient consumers of arthropods, including insects of economic interest, knowledge on how local and landscape factors influence bat assemblages may provide the basis for enhancement of key ecosystem functions, such as natural control for arthropods. Based on the species richness (total and insectivorous) and on the defaunation index (DI), defined as the loss or depletion of an animal species attribute, we investigated how the landscape can influence patterns of leaf-nosed bats and their potential of arthropod consumption in the Brazilian Atlantic Forest. We calculated species richness and DI using a compilation of bat records in the Atlantic Forest over 20 years (focal assemblages) and IUCN's potential occurrence polygons (reference assemblages used in DI). We quantified the vegetation cover, the dominant type and the heterogeneity of the matrix within circular landscapes around each sampling site of focal assemblages. One hundred and four assemblages were included in the analyses, most of them in the southeast of the Atlantic Forest, with agriculture as the dominant non-natural matrix. We found a negative effect of matrix heterogeneity on DI, and a positive effect of forest cover on the richness of insectivorous bats. The results highlight the importance of forest remnants in fragmented landscapes in the Brazilian Atlantic Forest for the maintenance of leaf-nosed bats and their potential for arthropod consumption.

Urban areas offer favorable environments for the occupation by colonies of numerous insectivorous bats, indicating a good supply of resources for their support. Studies have shown that reproductive patterns of Neotropical bats can be seasonal in response to the availability of food resources. For an urban population of insectivorous bats, we studied the annual reproductive activity and the diet of Molossus molossus in Bucaramanga city (Colombia) and its relationship with the precipitation regime of the area. We captured bats monthly using mist nets (October 2016 to September 2017), including dry and wet seasons. The reproductive condition of the males was described by testicular histology and, in females, through the observation of external morphological characters and the analysis of vaginal smears. We also studied the stomach contents of 30 of the captured bats and if they change between seasons. Although not all females were in the same reproductive category each month, at the population level there were two pregnancy peaks in the dry seasons, with parturition at the beginning of the rainy seasons. Cytological analysis of vaginal smears optimized the evaluation of the reproductive stage and indicated that all sampled adult females were reproductive throughout the year. Males were reproductive year-round, showing sperm in seminiferous tubules and ducts. Coleoptera (41.3%) and Hymenoptera (37.7%) were the most important prey; the dietary composition and the amount of food consumed did not change between seasons. Females of this population showed a pattern of bimodal polyestry adjusted to the precipitation pattern of the study area, like other urban and wild populations of the species and other Neotropical insectivorous bats.

Las zonas urbanas ofrecen entornos favorables para la ocupación por colonias de numerosos murciélagos insectívoros, indicando un buen suministro de recursos para su sustento. Diversos estudios han demostrado que los patrones reproductivos de los murciélagos neotropicales pueden ser estacionales en respuesta a la disponibilidad de recursos alimenticios. Para una población urbana de murciélagos insectívoros, estudiamos la actividad reproductiva anual y la dieta de Molossus molossus en la ciudad de Bucaramanga (Colombia) y su relación con el régimen de precipitaciones de la zona. Capturamos murciélagos mensualmente utilizando redes de niebla (octubre 2016 a septiembre 2017), incluyendo las estaciones seca y húmeda. La condición reproductiva de los machos se describió mediante histología testicular y, en las hembras, a través de la observación de caracteres morfológicos externos y el análisis de frotis vaginales. También se estudió el contenido estomacal de 30 de los murciélagos capturados y si cambia entre estaciones. Aunque no todas las hembras se encuentran en la misma categoría reproductiva cada mes, a nivel poblacional se observaron dos picos de preñez en las estaciones secas, con partos al inicio de las estaciones lluviosas. El análisis citológico de frotis vaginales optimizó la evaluación de la etapa reproductiva e indicó que todas las hembras adultas muestreadas eran reproductivas a lo largo del año. Los machos eran reproductivos durante todo el año, mostrando espermatozoides en los túbulos y conductos seminíferos. Los coleópteros (41,3%) y los himenópteros (37,7%) fueron las presas más importantes; la composición de la dieta y la cantidad de alimento consumido no variaron entre estaciones. Las hembras de esta población muestran un patrón de poliestría bimodal ajustado al régimen de precipitaciones de la zona de estudio, al igual que otras poblaciones urbanas y silvestres de la especie y otros murciélagos insectívoros neotropicales.

Affiliative relationships between adult males and immature group members have been studied in multimale-multifemale groups of Egyptian fruit bats (Rousettus aegyptiacus) at the Moscow Zoo. At 3–4 weeks of age, when the mothers leave the pups in the colony and fly off to forage, the offspring actively seek contact with other members of the group. Adult males show no sign of avoidance or aggression toward the infants. They sniff, groom and huddle with them. An infant can remain in physical contact with an adult male for more than 50% of the time its mother is away. We found significant differences in the time infants spent with the three adult males of the group. One of them showed a much higher affiliation with infants than the others. At 100–120 days of age, the infants feed on solid food and start to fly. At this point, adult males begin to react aggressively to young males, and adult males exhibit mating behavior with young females.

The ecology of Malagasy bat ectoparasites has been little studied and to provide new insights we examine fecal contents of Rousettus madagascariensis and the consumption of invertebrates, specifically Diptera of the families Nycteribiidae and Streblidae. Scat samples from individual Rousettus captured in a cave passage either during the early evening or early morning were collected and analyzed to identify and quantify the arthropods they contained. The presence of fragments in the feces confirm that this species consumes their dipteran ectoparasites. Ingestion rates are higher for bats exiting the cave after dusk than those entering the cave at predawn, indicating that consumption rates are greater when bats are in the day roost site as compared to foraging outside the cave. The quantity of ectoparasite remains is related to the age of individual bats. Given that bat ectoparasites are known to be reservoirs of certain pathogens, the question is raised if transmission between bats of these zoonotic diseases can be via an oral route.

L′écologie des ectoparasites des chauves-souris malgaches a été jusqu′ici peu étudiée. La présente étude évalue la consommation d′ectoparasite de Rousettus madagascariensis, en particulier les diptères de la famille des Nycteribiidae et Streblidae à partir du contenu fécal de la chauve-souris hôte. Des individus de Rousettus ont été capturés en début de soirée en sortant de la grotte ou tôt le matin à l′entrant qui leurs servent de gite diurne. Leurs fèces ont été collectés et analysés pour identifier et quantifier les restes d′arthropode qu′ils contenaient. La présence de fragments de diptères ectoparasites dans les matières fécales confirmait que cette chauve-souris consomme ses ectoparasites. Le taux d′ingestion est plus élevé pour les chauves-souris qui sortent de la grotte après le coucher du soleil par rapport à celles qui entrent dans la grotte avant l′aube. Ce qui indique une forte consommation dans le gite diurne durant le jour que durant les activités de quêtes de nourritures durant la nuit à l′extérieur de la grotte. La quantité d′ectoparasite ingéré varie en fonction de l′âge des chauves-souris. Etant donné que ces ectoparasites sont connus pour être des réservoirs de pathogènes, des questions surviennent sur la possibilité de transmission par voie orale de maladie zoonotique entre les chauves-souris.

Almost nothing is known about the communication calls of the Ussurian tube-nosed bat Murina ussuriensis. To determine social call types, we recorded various calls of M. ussuriensis under experimental conditions and then classified the social calls into different types: simple call, aggressive loud call, aggressive regular call (repeated), squawk call, and courtship call (repeated and complex). Simple calls in both sexes were FM sweep types, and they were used to respond to one another. Aggressive loud calls and aggressive regular calls were emitted by males. Bouts of two to five aggressive calls lasted 1–3 s. The number of aggressive regular calls per night increased when the distance between males was reduced. When dominance was established between males, aggressive loud calls or aggressive regular calls ceased. Squawk calls were emitted by the subordinate male when the dominant male approached. Courtship calls were emitted by both sexes. Courtship calls (repeated and complex) were emitted only by males, and bouts of two to nine courtship calls were 1–3 s long. Each of the calls contained two or three steep frequency-modulated syllables in quick succession, with a variety of calls emitted by each male. The number of courtship calls per bout increased when females were approached. The bats tended to use lower frequency signals for social calls with peak frequencies of approximately 21–34 kHz. This study provides the first report of the social calls of M. ussuriensis and demonstrates that this species uses a complex acoustic communication system.

We update the distributions in Venezuela for the four species of ghost bats of the genus Diclidurus taxonomically recognized and provide additional information on their echolocation calls. Diclidurus albus has the most extensive geographical range, while the majority of the locations recorded for the other species are in the region south of the Orinoco River, with some extensions to the north. The first records of D. scutatus for the west and the northern extreme of Venezuela are reported. Acoustic patterns previously described for D. albus and D. ingens are confirmed; in addition, the first verified vocal signatures of D. isabella and a clarification of D. scutatus search phase calls are provided. We compare the echolocation parameters obtained for all four congeneric species, based on acoustic records whose identities in some cases were verified through simultaneous field observations or the collection of voucher specimens. General characteristics of vocal signatures of Diclidurus include narrow band and quasi-constant frequency (QCF) search phase pulses in ranges correlated with body size, with long inter-pulse intervals. The characteristic frequency of the dominant harmonic represents the most important acoustic parameter for species separation and identification, showing an inversely proportional relationship with body size. The majority of sampling sites for species of Diclidurus in Venezuela correspond to open spaces associated with water bodies and forests with different levels of disturbance. Diclidurus albus and D. ingens were the species found with the highest frequencies in areas whose environmental conditions have been influenced by anthropogenic activities, while D. isabella showed a greater relationship with pristine areas where primary and extensive forests represented the dominant vegetation.

Actualizamos las distribuciones en Venezuela de las cuatro especies de murciélagos fantasmas del género Diclidurus taxonómicamente reconocidas y aportamos información adicional sobre sus señales de ecolocación. Diclidurus albus muestra el rango geográfico más extenso, mientras que la mayoría de las localidades registradas para las otras especies se ubica al sur del río Orinoco, con algunas extensiones hacia el norte. Los primeros registros de D. scutatus para el oeste y el extremo norte de Venezuela son reportados. Los patrones acústicos previamente descritos para D. albus y D. ingens son confirmados; adicionalmente, se presentan las primeras firmas vocales de D. isabella y una clarificación de las emisiones de D. scutatus correspondientes a la fase de búsqueda. Comparamos los parámetros de ecolocación obtenidos para las cuatro especies congéneres, basados en registros acústicos cuyas identidades en algunos casos fueron verificadas mediante observaciones simultaneas en campo o la colecta de especímenes comprobantes. Las características generales de las firmas vocales de Diclidurus incluyen pulsos de la fase de búsqueda con banda estrecha y frecuencias casi constantes (QCF) en rangos correlacionados con el tamaño corporal, además de intervalos entre pulsos prolongados. La frecuencia característica de la harmónica dominante representa el parámetro acústico más importante para la separación e identificación de las especies, mostrando una relación inversamente proporcional al tamaño corporal. La mayoría de los sitios de muestreo de las especies de Diclidurus en Venezuela corresponden a espacios abiertos asociados con cuerpos de agua y bosques con diferentes niveles de perturbación. Diclidurus albus and D. ingens fueron las especies halladas con mayores frecuencias en áreas cuyas condiciones ambientales han sido influenciadas por actividades antrópicas, mientras que D. isabella mostró una relación más estrecha con áreas prístinas donde los bosques primarios y extensos representaron la vegetación dominante.

Hibernation patterns of European bat species, especially those that hibernate above ground, remain under-explored. Our study focused on Nyctalus noctula, a common species among above-ground hibernating bats. We conducted the study on 22 individuals, manipulating group size and sex-age ratio in a captive setting, and recorded skin temperature data using temperature loggers. Bats hibernating in groups awoke less frequently and had more prolonged torpor bouts than solitary hibernating bats. The latter cooled faster during periods of arousal, but their time in the warming and euthermic stages was similar to that of individuals hibernating in groups. A general linear model (GLM) analysis revealed that all the factors we examined, including ambient temperature, sex, age, group size, and body mass, significantly affected the likelihood of a bat being in a state of hibernation or arousal. Young females with high body mass and hibernating in a group had a notably higher probability of arousal. Bats in groups maintained skin temperature (Ts) above 0°C, while it dropped around 0°C in some solitary hibernating bats. However, median Ts was similar in all bat groups. Body mass was higher in females compared to males and in adult bats compared to sub-adults. We hypothesized that adult males have greater fat reserves and can afford a longer total arousal time to effectively seek a mate and mating compared to sub-adult males with low body mass. Heavier females used more fat for more frequent arousals to reduce the negative metabolic consequences of hibernation for fast conception and successful pregnancy in spring. At the same time, sub-adult males entered the wintering period with lower body mass and balanced the use of energy resources for survival and mating. It seems that N. noctula, as an above-grounded hibernator, benefits more from group hibernation than solitary hibernation.

Sexual size dimorphism (SSD) is the difference in body size between males and females. One of the most studied patterns in allometric size difference between sexes is Rensch's rule, which describes an increase of SSD with increasing species size when males are the larger sex. However, few studies have tested this rule in bats, and morphological structures other than body size have rarely been included. The objective of this paper was to analyze the patterns of SSD across 28 New World bat species and assess their conformity to Rensch's rule. To do this, I obtained measurements of forearm length, length of the third digit, and length of the fifth digit from 1,151 bat specimens, and through t-tests and reduced major axis regressions, I analyzed patterns of SSD and Rensch's rule. I found high variation in size and wing morphology, with a modest female-biased size in more than half the species, which fails to support Rensch's rule. Larger wing structures in females can improve flight performance to overcome aerodynamic challenges during reproduction when carrying pups and foraging for food. Mechanisms other than body size in females, geographic variation, and the set of species selected may explain the isometric pattern between sexes, which invalidates Rensch's rule for Neotropical bats. Further studies should encompass a broader range of bat species from different lineages, but it is also necessary to analyze SSD based on various traits related to resource use, such as wing and nasal morphology, as well as include the influence of geographic variation and environmental factors.

El dimorfismo sexual del tamaño (DST) es la diferencia en el tamaño corporal entre machos y hembras. Uno de los patrones mas estudiados en la diferencia de tamaño alométrico entre sexos es la regla de Rensch que describe un aumento del DST con el aumento del tamaño de la especie cuando los machos son el sexo más grande. Sin embargo, existen pocos estudios realizados en murciélagos y en contadas ocasiones se han incluido estructuras morfológicas distintas del tamaño corporal para probar esta regla. El objetivo de este artículo fue analizar los patrones de DST en 28 especies de murciélagos neotropicales y evaluar la validez de la regla de Rensch. Para ello, obtuve medidas de la longitud del antebrazo, longitud del tercer y quinto dígito de 1,151 especímenes de murciélagos, y a través de pruebas t y de regresiones de eje mayor reducido, analicé patrones de DST y la regla de Rensch. Encontré una gran variación en el tamaño y la morfología alar con un ligero aumento de las hembras en más de la mitad de las especies, lo cual no respalda la regla de Rensch. Estructuras alares más grandes en las hembras pueden mejorar el rendimiento de vuelo para superar los desafíos aerodinámicos durante la reproducción cuando cargan a las crías y buscan alimento. Mecanismos distintos del tamaño corporal en las hembras, así como la variación geográfica, y el conjunto de especies seleccionadas pueden explicar el patrón de isometría entre sexos que invalida la regla de Rensch para murciélagos neotropicales. Futuros estudios deberían abarcar una mayor variedad de especies de murciélagos de diferentes linajes, pero también es necesario analizar el DST en función en diversos rasgos relacionados con el uso de recursos, como la morfología alar y nasal, además de incluir la influencia de la variación geográfica y los factores ambientales.

Comparative neurobiology allows us to investigate relationships between phylogeny and the brain and understand the evolution of traits. Bats constitute an attractive group of mammalian species for comparative studies, given their large diversity in behavioural phenotypes, brain morphology, and array of specialised traits. Currently, the order Chiroptera contains over 1,450 species within 21 families and spans ca. 65 million years of evolution. To date, 194 Neotropical bat species (ca. 13% of the total number of species around the world) have been recorded in Central America. This study includes qualitative and quantitative macromorphological descriptions of the brains of 12 species from six families of Neotropical bats. These analyses, which include histological neuronal staining of two species from different families (Phyllostomus hastatus and Saccopteryx bilineata), show substantial diversity in brain macromorphology including brain shape and size, exposure of mesencephalic regions, and cortical and cerebellar fissure depth. Brain macromorphology can in part be explained by phylogeny as species within the same family are more similar to each other. However, macromorphology cannot be explained by evolutionary time alone as brain differences between some phyllostomid bats are larger than between species from the family Emballonuridae despite being of comparable diverging distances in the phylogenetic tree. This suggests that faster evolutionary changes in brain morphology occurred in phyllostomids — although a larger number of species needs to be studied to confirm this. Our results show the rich diversity in brain morphology that bats provide for comparative and evolutionary studies.

La neurobiología comparativa nos permite investigar las relaciones entre filogenia y el cerebro, y comprender la evolución de rasgos. Los murciélagos constituyen un grupo atractivo de especies de mamíferos para estudios comparativos, dada su gran diversidad en fenotipos de comportamiento, morfología cerebral y variedad de rasgos especializados. Actualmente, el orden de murciélagos Chiroptera contiene más de 1,450 especies a lo largo de 21 familias y abarcando ca. 65 millones de años de evolución. 194 especies de murciélagos Neotropicales han sido registrados en América Central en la actualidad. Este estudio incluye descripciones macromorfológicas cualitativas y cuantitativas de cerebros de doce especies de seis familias de murciélagos Neotropicales. Estos análisis, que incluyen tinción neuronal usando una técnica histológica en dos especies de diferentes familias (Phyllostomus hastatus y Saccopteryx bilineata), muestran una diversidad sustancial en la macromorfología cerebral, incluida la forma y el tamaño del cerebro, la exposición de las regiones mesencefálicas y la profundidad de las fisuras corticales y cerebelosas. La macromorfología del cerebro puede explicarse en parte por la filogenia, ya que las especies dentro de la misma familia son más similares entre sí. Sin embargo, la macromorfología no puede explicarse solo por el tiempo evolutivo, ya que entre algunas especies de murciélagos filostómidos hay mayores diferencias que entre especies de la familia Emballonuridae, a pesar de tener distancias divergentes comparables en el árbol filogenético. Esto sugiere que se produjeron cambios evolutivos más rápidos en la morfología del cerebro en filostómidos, aunque para confirmar esto es necesario estudiar un mayor número de especies. Nuestros resultados muestran la gran diversidad en la morfología del cerebro que proporcionan los murciélagos para estudios comparativos y evolutivos.

Echolocating bats emit echolocation calls from the mouth or nose. Bats that emit calls from the nose have oddly developed dome-shaped nasal bones, but variations in the morphology of these bones are poorly understood. This study compared trends in the morphological variations of the cranium focusing on smooth structure such as the nasal swellings and the braincase, and investigated the morphological variability correlated with ultrasound vocalizations. We newly constructed three-dimensional (3-D) skull mesh models of the two Japanese rhinolophid species Rhinolophus nippon and Rhinolophus cornutus from the Korean Peninsula, the Japanese Archipelago, and Jeju Island, and compared the variations in cranium size and shape using 3-D geometric morphometrics. Additionally, we also tested trends in two representative body size indices, forearm length and centroid size. The results indicate that forearm length and log-transformed centroid size represented different trends among local populations. The results of 3-D geometric morphometrics show a significant difference in cranium shape between the two species, and between the Jeju Island population and the Japanese mainland population of R. nippon, indicating variability in the pair of nasal swellings related to nasophonation of the echolocation call. The anterior median swelling varied within the R. nippon populations, and the posterior median swelling varied between R. nippon and R. cornutus. These findings suggest that the variability between the anterior median swelling creates different echolocation peak frequencies in local populations, and that the posterior median swellings are quite similar among local populations because of the strong functional constraint of diet and echolocation.

Especially in the temperate zone, female bats are exposed to increased energy demands during gestation. In addition, abiotic factors, such as ambient temperature and pathogen load, can significantly affect reproduction success. Bats are considered natural reservoirs for a wide variety of pathogenic agents, and have developed strong immune systems to cope. Nevertheless, very little is known about the influence of these pathogenic microorganisms on bat health as most infections are asymptomatic. In this study, we monitored presence of non-tuberculous mycobacteria (NTM) in female common noctule bats Nyctalus noctula during gestation. Eight NTM species, subspecies or complexes (Risk Group 1: Mycobacterium hiberniae and M. terrae complex; Risk Group 2: M. arupense, M. avium ssp. hominissuis, M. fortuitum, M. interjectum, M. peregrinum, M. septicum) were confirmed as part of the female gut microbiome during gestation, with representation changing during foetal development. Following hibernation, most females were infected, though infection load and severity were relatively low. Just prior to parturition, however, a high proportion of females were infected with a high, often pathogenic, NTM load. Females who gave birth to twins had a higher (though non-significant) proportion of positive samples after hibernation and before parturition. Negative correlations between two consecutive measurements suggest that female N. noctula can cope with NTM loading, even during energy-demanding pregnancies. Bat faeces appear to be a source of numerous NTM species and, as such, bats can be considered as vectors for NTM spread in the environment.

Cave ecosystems are known for their unique relationships among various species. In this study, we report an unusual interaction between a bat and a cockroach in the Grutas de Martínez de la Torre cave system in Oaxaca, Mexico. While cave cockroaches are known to feed on bat pups falling down to the ground, and some species of insectivorous bats prey on cockroaches, this interaction was different. A small lesser naked-backed bat (Pteronotus fulvus) was captured with a lesion on its back, which was caused by a cockroach (Nyctantonina azteca) who created a large cavity between the patagium and epidermal epithelium tissue where it was found. The cockroach showed injuries on its left side, including its tegmina, legs II and III, and antenna. The wounds on both organisms were not recent, indicating that this interaction had been going on for some time. If we had not detected this event, it is likely that this relationship would have persisted until one of them died. The observed interaction is difficult to categorize, however we evaluated two hypotheses; one being predation and the other parasitism. From our analysis of data presented in this paper we found support for an opportunistic case of parasitism, in which N. azteca persisted underneath the wing membrane of P. fulvus. Biotic relationships between bats and cockroaches in cave ecosystems are complex and have the potential for unexpected species interactions.

Los ecosistemas de cuevas son reconocidos por sus singulares relaciones entre diversas especies. En este estudio, presentamos una interacción poco común entre un murciélago y una cucaracha registrada en el sistema de cuevas Grutas de Martínez de la Torre, en Oaxaca, México. Aunque se tiene conocimiento de que las cucarachas de cuevas se alimentan de crías de murciélagos que caen al suelo, y algunas especies de murciélagos insectívoros cazan cucarachas, esta interacción fue excepcional. Un murciélago de espalda desnuda menor (Pteronotus fulvus) fue capturado con una lesión en su espalda. Esta lesión fue causada por una cucaracha (Nyctantonina azteka) que creó una gran cavidad entre el patagio y el tejido del epitelio epidérmico donde se encontraba. La cucaracha mostraba lesiones en su lado izquierdo, incluyendo sus tegminas, patas II y III, y antena. Las heridas en ambos organismos no eran recientes, lo que indica que esta interacción llevaba algún tiempo ocurriendo. Si no hubiéramos detectado este evento, es probable que esta relación hubiera persistido hasta que uno de ellos muriera. La interacción observada es difícil de categorizar, sin embargo, evaluamos dos hipótesis; una siendo la depredación y la otra el parasitismo. A partir de nuestro análisis de los datos presentados en este documento, encontramos respaldo para un caso oportunista de parasitismo, en el cual N. azteca persistía debajo de la membrana alar de P. fulvus. Las relaciones bióticas entre murciélagos y cucarachas en ecosistemas de cuevas son complejas y tienen el potencial de generar interacciones entre especies inesperadas.

This study shows the abundance of contamination by microplastics (MPs) and the first record of contamination by MPs in bats. Additionally, we tried to understand the mechanism of the environmental contamination of bats. Therefore, the digestive and respiratory tracts from 81 adult bats belonging to 25 species were extracted for analysis. Bats were captured in different locations in the Brazilian Amazon (Altamira, Bragança, Brasil Novo, Medicilândia, Nova Timboteua, Placas, São Félix do Xingu, Uruará and Vitória do Xingu, all in the state of Pará). The results showed that all species were contaminated with MPs in at least one of the analyzed systems. For the digestive system, the form of contamination occurs through bioaccumulation and biomagnification by the ingestion of contaminated food or water. In the case of the respiratory system, contamination occurs through the inhalation of MPs suspended in the atmospheric air. The different foraging characteristics of bats, the type of capture strategy for this food, and the type of habitat reinforce the idea that plastic contaminants are present in all environments.

Este estudio muestra la abundancia de contaminación por microplásticos (MP) y el primer registro de contaminación por PM en murciélagos. Además, intentamos comprender el mecanismo de contaminación ambiental de los murciélagos. Por lo tanto, se extrajeron para su análisis los tractos digestivo y respiratorio de 81 murciélagos adultos de 25 especies. Los murciélagos fueron capturados en diferentes localidades de la Amazonía brasileña (Altamira, Bragança, Brasil Novo, Medicilândia, Nova Timboteua, Placas, São Félix do Xingu, Uruará y Vitória do Xingu, todos en el estado de Pará). Los resultados mostraron que todas las especies estaban contaminadas con PM en al menos uno de los sistemas analizados. Para el sistema digestivo, la forma de contaminación se produce por bioacumulación y biomagnificación por la ingestión de alimentos o agua contaminados. Mientras que para el sistema respiratorio, la contaminación se produce por la inhalación de PM suspendidas en el aire atmosférico. Las diferentes características de alimentación de los murciélagos, el tipo de estrategia de captura de este alimento y el tipo de hábitat refuerzan la idea de que los contaminantes plásticos están presentes en todos los entornos.