Notes on the geographic range and distribution of two free-tailed bat species (Chiroptera, Molossidae) in Costa Rica

Nyctinomops laticaudatus (É. Geoffroy St.-Hilaire, 1805) and Eumops nanus (Miller, 1900) are 2 species with distributions that are expected for Costa Rica. However, voucher specimens that confirm the presence of these species in the country are absent or missing in museum collections. Here we document voucher specimens and present data that confirm the presence of N. laticaudatus and E. nanus in Costa Rica

Canines as a measuring tool for leaf tent construction in Dermanura watsoni

Many animals are capable of constructing structures to modify the environment for their own benefit. The design of these structures requires animals to perceive dimensions. However, how animals take measurements to achieve the final design of the structures they construct is known for only very few species. In the Neotropics, a few bat species build roosts or leaf tents that serve different purposes. Thomas’s fruit-eating bat (Dermanura watsoni) constructs tents that have complex designs, when compared to other tent building bats. The bifid tent is a design built by producing a long, J-shaped cut on each side of understory plant leaves. We expect that to accomplish this complex design bats would require precise measurements during tent construction. We measured several bat morphological traits to infer which of them, if any, was used by the bats as a measuring device. Dermanura watsoni uses the distance between their lower canines to increase the perpendicular distance of the J-cut to the central vein of the leaf along the J-cut. The bat adds the distance between the canines to each subsequent secondary vein cut. This is the first study to infer which body part D. watsoni most likely uses as a measuring tool. Our results provide new insight into the evolution of body parts as measuring devices during tent construction in related and unrelated tent-building bat species.UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

Área de acción y comportamiento de forrajeo de Ectophylla alba (Chiroptera: Phyllostomidae) en dos sitios de Sarapiquí, Costa Rica

Villalobos Chaves, D. (2014). Área de acción y comportamiento de forrajeo de Ectophylla alba (Chiroptera: Phyllostomidae) en dos sitios de Sarapiquí, Costa Rica. [Tesis de Licenciatura]. Universidad Nacional, Heredia, C.R.La disponibilidad y distribución de los recursos son factores que influyen fuertemente en el comportamiento de los animales, especialmente para aquellas especies especialistas o con requerimientos específicos. A nivel biológico, la especialización implica una fuerte dependencia entre las actividades de las especies y sus recursos más importantes, sin embargo, su evolución está limitada por muchas y particulares características. En este trabajo, se investigó la influencia de la especialización sobre el comportamiento de forrajeo y los movimientos espaciales de una especie de murciélago neotropical que presenta robustas especializaciones en diversos aspectos de su biología (i.e., refugios y dieta). Para esto, se le dio seguimiento, con técnicas de radiotelemetría, a 9 individuos de Ectophylla alba en Sarapiquí, Costa Rica. Además, también se determinaron las localizaciones espaciales y la disponibilidad de árboles de Ficus colubrinae y de refugios. Se encontró una alta variabilidad individual en el tamaño de las áreas de acción, áreas de forrajeo y distancias de forrajeo. Además, la mayoría de las áreas núcleo se caracterizaron por ser de un tamaño pequeño y por la constante presencia de recurso alimentario. Por último, los resultados obtenidos sugieren que características como distancia y la disponibilidad de frutos son las variables que mejor predicen el uso de los árboles por parte de los murciélagos. El costo energético requerido en las actividades nocturnas de la especie y la alta dependencia a recursos específicos en el paisaje (especialmente recurso alimentario) probablemente causen que los movimientos espaciales de E. alba sean altamente variables a nivel individual y de sexo. Por otro lado, el aumento de la probabilidad de uso de los arboles según variables específicas y la constante presencia de recurso alimentario en las áreas núcleo sugieren que los movimientos espaciales realizadas por la especie podrían reducir el costo energético de un forrajeo específico (hacia Ficus colubrinae únicamente) y de los vuelos exploratorios para cada individuo. Dichos comportamientos podrían reflejar estrategias para maximizar la obtención de energía.The availability and distribution of resources are factors that strongly influence the behavior of animals, especially for those species that are specialists or have specific requirements. At the biological level, specialization implies a strong dependence between the activities of the species and its most important resources, however, its evolution is limited by many particular characteristics. In this work, the influence of specialization on the foraging behavior and spatial movements of a Neotropical bat species that presents robust specializations in various aspects of its biology (i.e., shelters and diet) was investigated. For this, 9 individuals of Ectophylla alba were followed up with radiotelemetry techniques in Sarapiquí, Costa Rica. In addition, the spatial locations and availability of Ficus colubrinae trees and refuges were also determined. High individual variability was found in the size of home ranges, foraging areas, and foraging distances. In addition, most of the core areas were characterized by being small in size and by the constant presence of food resources. Finally, the results obtained suggest that characteristics such as distance and fruit availability are the variables that best predict the use of trees by bats. The energy cost required in the nocturnal activities of the species and the high dependence on specific resources in the landscape (especially food resources) probably cause the spatial movements of E. alba to be highly variable at the individual and sex levels. On the other hand, the increase in the probability of tree use according to specific variables and the constant presence of a food resource in the core areas suggest that the spatial movements carried out by the species could reduce the energy cost of a specific forage (towards Ficus colubrinae only) and exploratory flights for each individual. Such behaviors could reflect strategies to maximize energy harvest.Universidad Nacional, Costa RicaEscuela de Ciencias Biológica

Gone with the wind: Do we know the impact that produce wind energy causes on flying vertebrates of Costa Rica?

The clean energy industry has been growing in Costa Rica, especially wind energy, during the last years. However, at least for the best of our knowledge, published scientific information about diversity, and collision rates, upon bats and birds in wind farms of Costa Rica is not-existent. In this manuscript we highlight the importance of establish biological monitoring programs in the wind farms, to determinate changes in the diversity of flying vertebrates, as well to evaluate the impact of wind towers upon the local and regional biodiversity. We suggest to public and private actors involving in wind energy production and conservation in Costa Rica to work together in order to answer the questions formulated in this manuscript as a priority, and eventually mitigate effectively any potential threat on our biodiversity. The development of research and politics related with those issues is critical to make correct decisions in relation with the wind energy future of the country in armony with nature

Lo que el viento se llevó: ¿conocemos el impacto que producir energía eólica causa sobre los vertebrados voladores de Costa Rica?

The clean energy industry has been growing in Costa Rica, especially wind energy, during the last years. However, at least for the best of our knowledge, published scientific information about diversity, and collision rates, upon bats and birds in wind farms of Costa Rica is not-existent. In this manuscript we highlight the importance of establish biological monitoring programs in the wind farms, to determinate changes in the diversity of flying vertebrates, as well to evaluate the impact of wind towers upon the local and regional biodiversity. We suggest to public and private actors involving in wind energy production and conservation in Costa Rica to work together in order to answer the questions formulated in this manuscript as a priority, and eventually mitigate effectively any potential threat on our biodiversity. The development of research and politics related with those issues is critical to make correct decisions in relation with the wind energy future of the country in armony with nature.La industria de energía limpia ha crecido en Costa Rica, especialmente la energía eólica, durante los últimos años. Sin embargo, por lo menos para nuestro mejor conocimiento, la información científica publicada sobre diversidad y tasas de colisión de murciélagos y aves en proyectos eólicos de Costa Rica es inexistente. En este documento resaltamos la importancia de establecer programas de monitoreo biológico periódico en las plantas eólicas, para determinar cambios en la diversidad de vertebrados voladores, así como evaluar el impacto de las torres eólicas sobre la biodiversidad local y regional. Sugerimos a los actores públicos y privados involucrados en la producción de energía eólica y conservación en Costa Rica trabajar juntos, para así contestar las preguntas formuladas en este manuscrito como una prioridad, y eventualmente, mitigar en forma efectiva cualquier amenaza sobre nuestra biodiversidad. El desarrollo de investigación y políticas relacionadas a estos temas es crítico para tomar decisiones correctas en relación con el futuro de la energía eólica del país en armonía con la naturaleza

Seed predation by the wrinkle-faced bat Centurio senex : a new case of this unusual feeding strategy in Chiroptera

Complex animal–plant interactions are present in the Neotropical bat family Phyllostomidae. Many of these interactions are still unknown, mainly due to the paucity of information available on the diet and habits of these species. The wrinkle-faced bat, Centurio senex , has been always considered as an enigmatic species. However, emerging evidence has partially elucidated the feeding ecology of this bat, confirming adaptations to consume hard food items. In addition to this information, here we show evidence of the predation of the seeds of Sideroxylon capiri (Sapotaceae) by C. senex . Bats employed principally deep unilateral bites to process the seeds. Our observations show that endocarp hardness has important implications on the ecological interaction between C. senex and S. capiri , due to the bats inability to puncture seeds with harder endocarps, causing an alternation between predation and dispersal of seeds. Nutritional rewards could be related to the predatory behavior documented. However, additional information is needed to clarify seed predation and seed dispersal patterns that exist between the 2 species. Complejas interacciones planta-animal existen en la familia de murciélagos neotropicales Phyllostomidae. Muchas de estas interacciones continúan desconocidas, principalmente debido a la escasez de información disponible sobre la dieta y hábitos de estas especies. El murciélago de cara arrugada, Centurio senex , ha sido siempre considerada una especie enigmática. No obstante, evidencia emergente ha dilucidado parcialmente la ecología de alimentación de este murciélago, confirmando adaptaciones para el consumo de alimentos duros. Adicionalmente a esta información, aquí presentamos evidencias de la depredación de semillas de Sideroxylon capiri (Sapotaceae) por parte de C. senex . Los murciélagos emplean principalmente mordiscos profundos unilaterales para procesar las semillas. Nuestras observaciones muestran que la dureza del endocarpio tiene importantes implicaciones sobre la interacción ecológica en

Refugios de murciélagos en el sotobosque, disponibilidad y patrones de ocupación en un bosque Neotropical lluvioso de Costa Rica

The strong link between bats and their roosts is widely recognized as being particularly significant. Despite this, roosting ecology of bats is poorly understood and much of the basic information is still unknown. In this study, we investigated the availability and occupation patterns of four roost types (trees, caves, termite nests and tents) used by bats at Tirimbina Biological Reserve (TBR), Costa Rica. To accomplish our aim, we systematically surveyed both sides of established trails and transects, looking for understory roosts. Potential roosts were examined for bat presence in order to establish occupation. Roost availability and density were esti-mated using traveled distances (km) and inspected area (10 m for trees/caves and 15 m for tents/termite nests) of each trail or transect sampled. For the tent roosts, data on taxonomic information of plant modified, type of architecture, condition and construction achievement were also recorded. The area surveyed represented 45.4 % of the total area of the TBR (345 ha). Tents were the most common roost (56.6 % of all roosts, N = 223), followed by trees (24.4 %, N = 96), termite nests (18.8 %, N = 74) and caves (0.2 %, N = 1). We detected only 27 roosts occupied by bats (6.8 % of all roosts, 0.17 occupied roosts/ha). Caves showed the highest occupation rate (100 %, N = 1), followed by trees (17.7 %, N = 17), tents (3.6 %, N = 8) and termite nests (1.3 %, N = 1). We found the roosts for 10 species, representing 33.9 % of the bat fauna documented at the reserve (62 species). Density of roosts per bat species varied between 0.017-0.138 roosts/ha. Phyllostomidae was the best-represented family with Micronycteris microtis representing the most common species encountered. Four distinct tent architectures were documented. Bifid architecture was the most common (133 tents), followed by Conical (47 tents), Apical (27 tents) and Inverted Boat (16 tents). Most of the tents found were healthy (76.7 %, N = 171) and totally constructed (88.8 %, N = 198). Our study demonstrated that occupied bat roosts are difficult to find in the forest. When compared to the roost availability, the low occupation rates suggested that, at least in our study area, roosts might not be a limiting resource. Nevertheless, to confirm this hypothesis, information about fidelity and selection process of the species is fundamental for understanding to what extent these roosts meet the requirements to be inhabited or modified. Worldwide conservation efforts on bats should focus on understanding roosting ecology, especially due to anthropogenic pressures that are continuously reducing the availability of roosts, which undoubtedly contributes to the risk of extinction for specialized and sensitive species. Rev. Biol. Trop. 64 (3): 1333-1343. Epub 2016 September 01.La estrecha relación entre los murciélagos y sus refugios es ampliamente reconocida por ser de particular importancia. A pesar de esto, la ecología de los refugios en murciélagos es pobremente comprendida y gran parte de la información básica aún es desconocida. En este estudio, investigamos la disponibilidad y los patrones de ocupación de cuatro tipos de refugios (árboles, cuevas, termiteros y tiendas) utilizados por los murciélagos en la Reserva Biológica Tirimbina (RBT), Costa Rica. Para lograr nuestro objetivo, nosotros inspeccionamos sistemáticamente ambos lados de senderos establecidos y transectos, en busca de refugios a nivel del sotobosque. Los refugios potenciales fueron examinados en busca de murciélagos con el fin de establecer la ocupación de los mismos. La disponibilidad y densidad de los refugios fue estimada utilizando la distancia recorrida (km) y el área inspeccionada (10 m para árboles/cuevas y 15 m para tiendas/termiteros) de cada sendero o transecto muestreado. Para los refugios en tiendas, también se registraron datos sobre información taxonómica de la planta modificada, el tipo de arquitectura, la condición y la consecución de la construcción. El área inspeccionada representa el 45.4 % del área total de la RBT (345 ha). Las tiendas fueron el refugio más común (56.6 % de todos los refugios, N = 223), seguido por los árboles (24.4 %, N = 96), los termiteros (18.8 %, N = 74) y las cuevas (0.2 %, N = 1). Detectamos únicamente 27 refugios ocupados por murciélagos (6.8 % de todos los refugios, 0.17 refugios ocupados/ha). Las cuevas mostraron la tasa más alta de ocupación (100 %, N = 1), seguido por los árboles (17.7 %, N = 17), las tiendas (3.6 %, N = 8) y los termiteros (1.3 %, N = 1). Encontramos los refugios de 10 especies, lo que representa un 33.9 % de la fauna de murciélagos documentada en la reserva (62 especies). La densidad de refugios por especie de murciélago varió entre 0.017-0.138 refugios/ha. Phyllostomidae fue la familia mejor representada, con Micronycteris microtis como la especie más común encontrada en los refugios. Cuatro tipos de arquitectura fueron documentadas en las tiendas. La arquitectura Bífida fue la más común (133 tiendas), seguida por la Cónica (47 tiendas), la Apical (27 tiendas) y la Bote Invertido (16 tiendas). La mayoría de las tiendas encontradas se encontraban en buen estado (76.7 %, N = 171) y totalmente construidas (88.8 %, N = 198). Nuestro estudio demostró que encontrar refugios ocupados por murciélagos en el bosque es difícil. Cuando es comparada con la disponibilidad de refugios, la baja tasa de ocupación sugiere que, al menos en nuestra área de estudio, los refugios podrían no ser un recurso limitante. No obstante, para confirmar esta hipótesis, información acerca de la fidelidad y el proceso de selección de las especies es fundamental para comprender en que medida estos refugios cumplen con los requerimientos para ser habitados o modificados. A nivel mundial, los esfuerzos de conservación de los murciélagos deberían priorizar en comprender la ecología de los refugios, especialmente debido a que las presiones antropogénicas están continuamente reduciendo la disponibilidad de este recurso, lo cual sin duda alguna contribuye al riesgo de extinción para las especies más sensibles y especializadas.Universidad Nacional, Costa RicaEscuela de Ciencias Biológica