An integrative approach to understanding diversity patterns and assemblage rules in Neotropical bats.

Understanding the mechanisms shaping species composition of assemblages is critical for incorporating ecological and evolutionary perspectives into biodiversity conservation. Thus, we quantified the relative support of community assembly mechanisms by assessing how species richness relates to the functional and phylogenetic biodiversity of Neotropical bat assemblages. We assessed the association of functional diversity for functional categories and phylogenetic diversity with species richness for 20 assemblages of Neotropical bats. In addition, we contrasted functional and phylogenetic diversity against null models to determine the mechanisms that structure the assemblages. We hypothesize functional/phylogenetic overdispersion for high species sites and a positive relationship between those dimensions of diversity and richness. Functional divergence increased with species richness, indicating that the variability in ecological attributes among abundant bats increases as the assemblages contain more species. Taxa were more distantly related as richness increases, but distances among closely related species remained constant. We found a consistent tendency of clustering of functional traits in site assemblages, particularly in abundant species. We proposed competition between clades as a possible mechanism modulating the community structure in Neotropical bat assemblages. Our results suggest that decreasing overlap in functional traits between abundant species could promote coexistence with rare species that can buffer ecosystem function due to species loss.

Systematics and diversification of the Ichthyomyini (Cricetidae, Sigmodontinae) revisited: evidence from molecular, morphological, and combined approaches.

Ichthyomyini, a morphologically distinctive group of Neotropical cricetid rodents, lacks an integrative study of its systematics and biogeography. Since this tribe is a crucial element of the Sigmodontinae, the most speciose subfamily of the Cricetidae, we conducted a study that includes most of its recognized diversity (five genera and 19 species distributed from southern Mexico to northern Bolivia). For this report we analyzed a combined matrix composed of four molecular markers (RBP3, GHR, RAG1, Cytb) and 56 morphological traits, the latter including 15 external, 14 cranial, 19 dental, five soft-anatomical and three postcranial features. A variety of results were obtained, some of which are inconsistent with the currently accepted classification and understanding of the tribe. Ichthyomyini is retrieved as monophyletic, and it is divided into two main clades that are here recognized as subtribes: one to contain the genus Anotomys and the other composed by the remaining genera. Neusticomys (as currently recognized) was found to consist of two well supported clades, one of which corresponds to the original concept of Daptomys. Accordingly, we propose the resurrection of the latter as a valid genus to include several species from low to middle elevations and restrict Neusticomys to several highland forms. Numerous other revisions are necessary to reconcile the alpha taxonomy of ichthyomyines with our phylogenetic results, including placement of the Cajas Plateau water rat (formerly Chibchanomys orcesi) in the genus Neusticomys (sensu stricto), and the recognition of at least two new species (one in Neusticomys, one in Daptomys). Additional work is necessary to confirm other unanticipated results, such as the non-monophyletic nature of Rheomys and the presence of a possible new genus and species from Peru. Our results also suggest that ichthyomyines are one of the main Andean radiations of sigmodontine cricetids, with an evolutionary history dating to the Late Miocene and subsequent cladogenesis during the Pleistocene.

Time partitioning among neotropical frugivorous bats: effects of phylogeny, body size, and abundance / Distribución del tiempo entre murciélagos frugívoros neotropicales: efectos de la filogenia, el tamaño corporal y la abundancia

Abstract Introduction: Resource partitioning by promoting coexistence is essential to determine species richness and composition in natural communities. However, the partitioning of time has been questioned as a mechanism that promotes the coexistence of ecologically similar species. Objective: To determine the importance of the partitioning of time as a mechanism that promotes coexistence, we compared the activity patterns of tropical frugivorous bats. Methods: We captured bats with mist nets from sunset to sunrise in three study sites (tropical dry forest, wet forest, and rainforest) to calculate activity patterns of the species using Kernel density estimation. We used the superposition coefficient (Δ1) to compare activity patterns between (1) bat assemblages of study sites, (2) frugivorous species in the same site, and (3) populations of the same species among different sites. To determine whether the overlap in the activity patterns was related to the ecological similarity of species, we evaluated the association between Δ1 and similarity in abundances and body mass and phylogenetic closeness. Results: We found geographical variations in the overall activity patterns of the assemblages of the three localities. Likewise, we found variations in activity patterns between species at each study site and between populations in different study sites. Overlap in activity patterns tended to decrease as species were phylogenetically more closely related and similar in abundance and body size. Conclusions: Our results provide empirical support for the role of temporal segregation in activity patterns as a mechanism that promotes the coexistence of ecologically similar species in nature.

Resumen Introducción: La partición de recursos es esencial para determinar la riqueza y composición de especies en las comunidades naturales. Sin embargo, la segregacion temporal ha sido cuestionada como un mecanismo que promueve la coexistencia de especies ecológicamente similares. Objetivo: Con el fin de determinar la importancia de la segregación en los patrones de actividad, como mecanismo que promueve la coexistencia; se compararon los patrones de actividad de murciélagos frugívoros neotropicales. Métodos: Se capturaron murciélagos con redes de niebla desde el atardecer hasta el amanecer en tres localidades (bosque seco tropical, bosque muy húmedo y bosque lluvioso submontano) con el fin de calcular los patrones de actividad de las especies empleando la estimación de densidad Kernel. Se utilizó el coeficiente de superposición (Δ) para comparar patrones de actividad entre: (1) ensamblajes de murciélagos de los sitios de estudio, (2) especies frugívoras en el mismo sitio, y (3) poblaciones de la misma especie en diferentes sitios. Resultados: Se encontraron variaciones geográficas en los patrones de actividad de los ensamblajes en las tres localidades. Asimismo, se encontraron variaciones en los patrones de actividad entre especies en cada sitio y entre poblaciones en diferentes sitios. Determinamos que la superposición en los patrones de actividad disminuyó a medida que las especies estaban más relacionadas filogenéticamente, similares en abundancia y tamaño corporal; lo que sugiere una tendencia hacia la segregación temporal de especies ecológicamente similares. Conclusión: Estos resultados proveen apoyo empírico del papel de la segregación temporal en los patrones de actividad como un mecanismo que promueve la coexistencia de especies ecológicamente similares en la naturaleza.

Comparative mitogenome phylogeography of two anteater genera (Tamandua and Myrmecophaga; Myrmecophagidae, Xenarthra): Evidence of discrepant evolutionary traits.

The species within Xenarthra (sloths, anteaters, and armadillos) are quintessential South American mammals. Of the three groups, Vermilingua (anteaters) contains the fewest extant and paleontological species. Here, we sampled and sequenced the entire mitochondrial genomes (mitogenomes) of two Tamandua species (Tamandua tetradactyla and Tamandua mexicana) (n=74) from Central and South America, as well as Myrmecophaga tridactyla (n=41) from South America. Within Tamandua, we detected three different haplogroups. The oldest (THI) contained many specimens with the T. tetradactyla morphotype (but also several with the T. mexicana morphotype) and originated in southeastern South America (currently Uruguay) before moving towards northern South America, where the THII haplogroup originated. THII primarily contained specimens with the T. mexicana morphotype (but also several with the T. tetradactyla morphotype) and was distributed in Central America, Colombia, and Ecuador. THI and THII yielded a genetic distance of 4%. THII originated in either northern South America or "in situ" in Central America with haplogroup THIII, which consisted of ~50% T. mexicana and 50% T. tetradactyla phenotypes. THIII was mostly located in the same areas as THII, i.e., Central America, Ecuador, and Colombia, though mainly in the latter. The three haplogroups overlapped in Colombia and Ecuador. Thus, T. tetradactyla and T. mexicana were not reciprocally monophyletic. For this reason, we considered that a unique species of Tamandua likely exists, i.e., T. tetradactyla. In contrast to Tamandua, M. tridactyla did not show different morphotypes throughout its geographical range in the Neotropics. However, two very divergent genetic haplogroups (MHI and MHII), with a genetic distance of ~10%, were detected. The basal haplogroup, MHI, originated in northwestern South America, whereas the more geographically derived haplogroup, MHII, overlapped with MHI, but also expanded into central and southern South America. Thus, Tamandua migrated from south to north whereas Myrmecophaga migrated from north to south. Our results also showed that temporal mitochondrial diversification for Tamandua began during the Late Pliocene and Upper Pleistocene, but for Myrmecophaga began during the Late Miocene. Furthermore, both taxa showed elevated levels of mitochondrial genetic diversity. Tamandua showed more evidence of female population expansion than Myrmecophaga. Tamandua experienced population expansion ~0.6-0.17 million years ago (Mya), whereas Myrmecophaga showed possible population expansion ~0.3-0.2 Mya. However, both taxa experienced a conspicuous female decline in the last 10 000-20 000 years. Our results also showed little spatial genetic structure for both taxa. However, several analyses revealed higher spatial structure in Tamandua than in Myrmecophaga. Therefore, Tamandua and Myrmecophaga were not subjected to the same biogeographical, geological, or climatological events in shaping their genetic structures.

Elevation does not strongly influence interspecific variation in body size of small Tropical endotherms / La elevación no influencia fuertemente la variación interespecífica en el tamaño corporal de los endotermos tropicales pequeños

Introduction: Body size is an essential trait for endotherms to face the physiological requirements of cold, so there is a tendency to large body size at high altitudes and latitudes, known as Bergmann's rule. However, the validity of this ecomorphological rule to small-bodied endotherms across altitudinal gradients is poorly known. Objective: To understand the effects of environmental variation on body size, we assessed whether interspecific variation in body size of small tropical endotherms follows Bergmann's rule along tropical altitudinal gradients. Methods: We compiled data on elevational ranges and body masses for 133 species of hummingbirds of Colombia. We then assessed the association between body mass and mid-point of the altitudinal distribution using phylogenetic generalized least squares (PGLS) analyses under different evolutionary models. Results: We found a decelerating rate of evolution for body size since the Early Burst model of evolution provided a better fit to body mass data. For elevational range, we found a slow and constant rate since Pagel's lambda model provided a better fit to the mid-point of the altitudinal distribution data. Besides, phylogenetic regression analysis indicated that body mass and the altitudinal range of hummingbirds are associated through the phylogeny, with a positive but slight association (R2= 0.036). Conclusions: We found that body mass and altitude of hummingbirds are positively related, which is in agreement with expectations under Bergmann's rule. However, this association was weaker than expected for small and non-passerine birds like hummingbirds. Thus, our results suggest that environmental changes across altitudinal gradients do not strongly influence body mass in small tropical endotherms as hummingbirds.

Introducción: El tamaño corporal es un rasgo importante para determinar la respuesta de los endotermos a los requerimientos que exigen las zonas frías, por lo cual se espera una tendencia hacia el incremento del tamaño corporal al aumentar la altitud y la latitud. Sin embargo, se conoce poco acerca de la validez de esta regla ecomorfológica, conocida como la regla de Bergmann, para endotermos pequeños en gradientes altitudinales tropicales. Objetivo: Con el fin de entender los efectos de la variación ambiental sobre el tamaño corporal, se evaluó sí la variación interespecífica en la masa corporal de endotermos tropicales pequeños se ajusta a la regla de Bergmann a lo largo de gradientes de elevación. Métodos: Se compilaron datos sobre los rangos de distribución altitudinal y los tamaños corporales de 133 especies de colibríes en Colombia. Posteriormente, se evaluó la asociación entre la masa corporal y el punto medio de distribución altitudinal de los colibríes mediante análisis de mínimos cuadrados generalizados filogenéticos (PGLS) bajo diferentes modelos evolutivos. Resultados: La evolución de la masa corporal se ajustó mejor a un modelo de evolución Early Burst, mientras que el rango de elevación al modelo evolutivo lambda de Pagel; lo que indica que la tasa de evolución es desacelerada para el tamaño del cuerpo, mientras es lenta y constante para el rango de elevación. Además, el análisis de regresión filogenética indica que la masa corporal y el rango de elevación están positiva y ligeramente asociados (R2 = 0.036). Conclusiones: De acuerdo con lo esperado por la regla de Bergmann, los resultados indican que los colibríes tienden a ser más grandes a mayores altitudes. Sin embargo, esta asociación es más débil de lo esperado para aves no paseriformes de tamaño pequeño como los colibríes.Por lo tanto, los resultados sugieren que las variaciones ambientales a lo largo de gradientes de elevación no tienen una influencia fuerte sobre el tamaño corporal de endotermos pequeños como los colibríes.

Proteínas salivales relacionadas con la diversidad de dietas en murciélagos tropicales / Salivary proteins related to the diversity of diets in tropical bats

La familia Phyllostomidae presenta una gran diversidad de dietas que requieren adaptaciones fisiológicas para metabolizar los diferentes alimentos que consumen. En frugívoros de la familia Pteropodidae e insectívoros de las familias Vespertilionidae y Molossidae se han reportado proteínas salivales distintivas de cada dieta. Por ello, se planteó determinar moléculas salivales asociadas con las diferentes dietas de los filostómidos. Los organismos se encontraban en ayuno al tomar la muestra, a la cual se le adicionó un buffer inhibidor de proteasas y se almacenó a -20°C hasta su uso. Las proteínas se identificaron por medio de SDS-PAGE y se evaluó si su presencia en los individuos estaba asociada con la historia evolutiva de las especies. Además, se determinó si las proteínas encontradas estarían relacionadas con la dieta del individuo. Se capturaron 15 especies con dietas nectarívora, insectívora y frugívora. Se encontró una proteína de 60kDa en filostómidos herbívoros y una de 50kDa en vespertilionidos y filostómidos con alto consumo de insectos. Además, se registró una proteína de 30kDa en todos los filostómidos y en 2 de las 3 especies de vespertilionidos. Los análisis indicaron que la presencia de las proteínas no estaría relacionada con la cercanía filogenética y que, para las proteínas de 30 y 50kDa, tampoco sería explicada por la dieta como sí ocurre con la proteína de 60kDa. Los filostómidos habrían retenido de su dieta ancestral insectívora la proteína de 30kDa y adquirido evolutivamente la de 60kDa para procesar plantas y lograr la amplia diversificación ecológica que presentan.

The Phyllostomidae family presents a great diversity of diets that require physiological adaptations to metabolize the different foods that they consume. In frugivores of the family Pteropodidae and insectivores of the families Vespertilionidae and Molossidae, distinctive salivary proteins of each diet have been reported. For this reason, it was proposed to determine salivary molecules associated with the different diets of the phylostomids. The organisms were fasting when taking the sample, to which a protease inhibitor buffer was added and it was stored at -20°C until use. The proteins were identified by means of SDS-PAGE and it was evaluated whether their presence in individuals was associated with the evolutionary history of the species. In addition, it was determined whether the proteins found would be related to the individual's diet. 15 species were caught with nectarivorous, insectivorous and frugivorous diets. A protein of 60kDa was found in herbivorous phyllostomids and a 50kDa protein in vespertilionids and phyllostomids with high insect consumption. In addition, a 30kDa protein was recorded in all phylostomids and in 2 of the 3 species of vespertilionids. The analyzes indicated that the presence of the proteins would not be related to the phylogenetic closeness and that, for the 30 and 50kDa proteins, it would not be explained by the diet as it is the case with the 60kDa protein. The phylostomids would have retained the 30kDa protein from their ancestral insectivorous diet and evolutionarily acquired the 60kDa protein to process plants and achieve the broad ecological diversification they present.

Taxonomic identity of an insular population of sac-winged bat Saccopteryx (Chiroptera: Emballonuridae)

Las poblaciones insulares frecuentemente difieren de las continentales, en morfológica y comportamiento. Consecuentemente, utilizar características externas puede dificultar la identificación taxonómica de especies en las islas. En el Parque Nacional Natural Gorgona, particularmente, ha existido controversia sobre la identidad de varias especies de murciélagos residentes. Nuestro objetivo fue determinar la identidad taxonómica de la población de Saccopteryx de esta isla, que tiene la particularidad de tener actividad diurna. Evaluamos las diferencias entre las poblaciones mediante morfometría (tradicional y geométrica) y llamados de ecolocalización. Además, debido a que las especies difieren en su sistema de apareamiento, evaluamos la conformación de los grupos en los refugios. Pese a la variación en la morfometría craneal y los llamados de ecolocalización entre las poblaciones, la población de Gorgona fue más similar a S. leptura que a S. bilineata. Las conformaciones de los grupos en los refugios sugieren un sistema monógamo como en S. leptura. Por ende, concluimos que la especie de la isla es S. leptura. Adicionalmente, la historia biogeográfica y el aislamiento geográfico de la isla sugieren que esta población puede ser diferente de sus contrapartes continentales debido al efecto fundador, deriva genética y/o adaptaciones a las condiciones ambientales locales.

Insular populations can differ from their continental counterparts since they are subject to particular pressures, biotic and abiotic, that can lead to variations in morphology and behavior; thus, the use of external characters may complicate taxonomic identification of insular populations. Even though the bat assemblage of Gorgona Island is a conservation target, there has been controversy about the taxonomic identity of bats from this Colombian National Natural Park. Specifically, our goal was to determine the taxonomic identity of the population of the sac-winged bat (genus Saccopteryx) resident in Gorgona, which have the peculiarity of having diurnal activity. Thus, we assessed differences among populations using morphometrics (traditional and geometric) and echolocation calls. Additionally, since the species of Saccopteryx involved have different mating systems, we assessed roosting association of Gorgona population as a surrogate for mating system. Despite the variation in skull morphometrics and echolocation calls among populations, Gorgona population was more similar to S. leptura than to S. bilineata. Besides, evolutionary allometry was significant, but size explained a small proportion of shape differences among populations. Finally, roosting association of Gorgona population suggests a monogamous mating system such as in S. leptura. We conclude that Saccopteryx from Gorgona corresponds to S. leptura. In addition, biogeographic history and geographic isolation of the island suggest that this population may have differentiated from their mainland counterparts through founder effect, genetic drift and/or adaptation to the local biotic and abiotic environmental conditions.

Composición, estructura trófica y patrón de actividad de murciélagos de sotobosque en la Reserva Forestal Bitaco / Composition, trophic structure and activity patterns of the understory bats of the bitaco forest reserve

ABSTRACT The present study describes composition and trophic structure, and assesses the effect of environmental temperature and rainfall on the pattern of nocturnal activity of understory bats in an Andean forest, in the first half of the night. Seven sampling events were conducted, lasting six nights each one. Ten mist nets were used to capture bats, which were checked every hour between 18:00 and 00:00 hours. Bat species, sex and capture time were registered. In addition, environmental temperature and rainfall were also recorded during sampling. The bat assemblage of the understory of the study area was represented mostly by frugivore species, within this guild there was a lower richness of nomadic than sedentary species. For the first half of the night, bat activity peaked between 18:00 and 19:00 hours and declined to a minimum level between 22:00 and 23:00 hours. The most accurate model to explain variation in bat captures included only the effect of air temperature, which positively affected the number of captures. In conclusion, for the sampled period the activity of the bat assemblage in the study area was not related to rainfall and exhibited a slight but significant relationship with air temperature.

RESUMEN En el presente trabajo se describe la composición y estructura trófica, y se evalúa el efecto de la temperatura ambiental y la precipitación sobre el patrón de actividad nocturna de los murciélagos de sotobosque que habitan que un bosque Andino, para la primera mitad de la noche. Para esto se realizaron siete campañas de muestreo, con una duración de seis noches cada una, en las que se utilizaron diez redes de niebla que operaron entre las 18:00 y 00:00 horas, siendo revisadas cada hora. Además, se registró la temperatura ambiental y la precipitación durante los eventos de muestreo. El ensamblaje de murciélagos de sotobosque del área de estudio estuvo representado principalmente por especies frugívoras, y dentro de este gremio, se registró una menor riqueza de especies nómadas que sedentarias. La actividad de los murciélagos, para la primera mitad de la noche, fue máxima entre las 18:00 y 19:00 horas, disminuyendo hasta alcanzar una actividad mínima entre las 22:00 y 23:00 horas. El modelo más adecuado para explicar la variación en las capturas de murciélagos incluyó sólo el efecto de la temperatura ambiental, la cual afectó positivamente el número de capturas. En conclusión, para el periodo evaluado, la actividad del ensamble de murciélagos de sotobosque en el área de estudio no se relacionó con la precipitación y exhibió relación leve pero significativa con la temperatura ambiental.

An updated perspective on the role of environmental autocorrelation in animal populations.

Ecological theory predicts that the presence of temporal autocorrelation in environments can considerably affect population extinction risk. However, empirical estimates of autocorrelation values in animal populations have not decoupled intrinsic growth and density feedback processes from environmental autocorrelation. In this study we first discuss how the autocorrelation present in environmental covariates can be reduced through nonlinear interactions or by interactions with multiple limiting resources. We then estimated the degree of environmental autocorrelation present in the Global Population Dynamics Database using a robust, model-based approach. Our empirical results indicate that time series of animal populations are affected by low levels of environmental autocorrelation, a result consistent with predictions from our theoretical models. Claims supporting the importance of autocorrelated environments have been largely based on indirect empirical measures and theoretical models seldom anchored in realistic assumptions. It is likely that a more nuanced understanding of the effects of autocorrelated environments is necessary to reconcile our conclusions with previous theory. We anticipate that our findings and other recent results will lead to improvements in understanding how to incorporate fluctuating environments into population risk assessments.

Demography of population recovery: survival and fidelity of peregrine falcons at various stages of population recovery.

Factors influencing vital demographic rates and population dynamics can vary across phases of population growth. We studied factors influencing survival and fidelity of peregrine falcons in south Scotland-north England at two stages of population growth: when the population was recovering from pesticide-related declines and density was low, and when it had largely recovered from pesticide effects and density was high. Fidelity was higher for: adults and subadults than for juveniles, females than for males, and juveniles and adults during the low-density than during the high-density study period. Survival was age specific, with lower survival for juveniles than for older birds (juveniles, 0.600 ± SE 0.063; subadults, 0.811 ± 0.058; adults, 0.810 ± 0.034). Furthermore, there was some evidence that survival was generally lower for all age classes during the low-density period than during the high-density period, possibly due to a chronic, persistent effect of organochlorine pesticides as the population recovered. Evidence for a density-dependent effect on survival was weak, but a negative effect of density on fidelity of juveniles (dispersing age class) during the recovery phase suggests density-dependent dispersal when the population was increasing. Our results show how population density can influence demographic parameters differently and how such influences can vary across phases of population growth.

Murciélagos de cola corta (Carollia: Phyllostomidae) del Parque Nacional Natural Gorgona (Colombia) y sus implicaciones biogeográficas / Short-tailed bats (Carollia: Phyllostomidae) from Gorgona National Natural Park (Colombia) and its biogeographical implications

Taxonomy of short-tailed bats (Phyllostomidae: Carollia) has been unclear due to the extreme morphological similarity among species and the significant morphological variation within species. The identity of the Carollia species in Gorgona National Natural Park (Colombian Pacific) has been controversial due to the high morphological similarity between Carollia perspicillata and C. brevicauda. C. perspicillata is common in lowlands, and more likely to be the Gorgona species than C. brevicauda, while geological evidence suggests that common between 1 500 and 3 000m. We recorded eight measurements from jaws and skulls of confirmed C. perspicillata (24 individuals) and C. brevicauda (23) and 35 individuals captured in Gorgona. Discriminant analyses showed that, contrary to expectations based on current altitudinal distributions, the Gorgona population is morphologically closer to C. brevicauda. Biological evidence suggests that Gorgona was connected in the past to mainland South America. Gorgona may be the highest part of a now submerged mountain range (“Cordillera de la Costa”) that was part of the continent during the Pleistocene glaciations. Consequently, I hypothesize that C. brevicauda colonized Gorgona overland during last Pleistocene glaciations. Rev. Biol. Trop. 62 (Suppl. 1): 435-445. Epub 2014 February 01.

La identidad de la especie de Carollia (Chiroptera: Phyllostomidae) en el Parque Nacional Natural Gorgona ha sido controvertida debido a la alta similitud entre C. perspicillata y C. brevicauda. C. perspicillata es la especie con mayor probabilidad de habitar en la isla debido a que actualmente se distribuye en las tierras bajas de la costa pacífica colombiana, mientras C. brevicauda es una especie predominantemente de tierras altas. Con el objetivo de resolver la controversia acerca de la especie del género Carollia que habita la isla, se realizaron análisis morfométricos con base en característica de cráneos y mandíbulas de especímenes de las dos especies y del PNN Gorgona. Los resultados evidenciaron que, contrario a lo esperado, esta población insular es morfológicamente más similar a C. brevicauda. Evidencia biológica para diferentes grupos de organismos sugiere que Gorgona puede haber estado conectada a los andes y las zonas bajas del pacífico del sur de Colombia-norte de Ecuador en el pasado. Por otra parte, existe evidencia geológica que muestra que Gorgona es la parte más alta de una cordillera (Cordillera de la Costa) que se encuentra sumergida actualmente, pero que probablemente fue parte del continente durante el Pleistoceno. Por lo tanto, con base en esta evidencia biológica y geológica se plantea la hipótesis de una ruta de colonización de C. brevicauda a Gorgona desde los Andes a través de la Cordillera de la Costa. Este proceso pudo facilitarse por el descenso marino durante las glaciaciones del Pleistoceno.

Distribución y abundancia de murciélagos en bosques con diferente grado de intervención en el Parque Nacional Natural Gorgona (Colombia) / Distribution and abundance of bat assemblages among different forest covers in Gorgona National Natural Park, Colombia

Bats are important for maintenance of ecological processes in tropical forests since they are among the most abundant mammals and play a crucial role in tropical succession. Due to the importance of bats to forest dynamics and to the lack of ecological information, a study was conducted to quantify the variation in species richness, abundance and occurrence of bats in forest with different levels of perturbation in Gorgona National Natural Park; accounting for imperfect detectability. Bats were captured with mist-nets in three areas that differed in their perturbation levels (2 sites per area). A total of 670 bats representing 10 species and three families (Emballonuridae, Phyllostomidae y Vespertilionidae) were captured. The frugivorous species Dermanura rosenbergi (44.1%), Carollia brevicauda (20.9%) and Artibeus lituratus (30.1%) were the most captured species, and 6 out of 10 were insectivorous. Detection probability (p) increased with the increase in perturbation level (p perturbed>p secondary>p primary), and was highest for frugivorous bats. The best model for occurrence (Ψ) revealed that probabilities of occurrence increased with perturbation levels (Ψperturbed>Ψsecondary>Ψprimary) and differed among species. Substantial differences in abundance were due to an additive effect of perturbation level, body size, and guild. Abundance increased with perturbation level (Nperturbed>Nsecondary>Nprimary), decreased with body size, and was highest for frugivorous bats. Bats had higher occurrence and abundance values in most disturbed areas, but they also occurred in less disturbed areas. Consequently, bats can potentially eat fruits from different stages of succession, promoting seed movement among zones that are suitable for colonization. Bats should be considered a conservation target for Gorgona. Rev. Biol. Trop. 62 (Suppl. 1): 419-434. Epub 2014 February 01.

Se cuantificó la variación de la comunidad de murciélagos en bosques con diferente grado de intervención en el Parque Nacional Natural Gorgona. Para esto se realizaron capturas en tres zonas (dos sitios en cada zona) durante tres eventos de muestreo. El análisis de datos consideró la detección imperfecta, permitiendo realizar una inferencia confiable acerca de los cambios en presencia, abundancia y riqueza entre tipos de coberturas. Los resultados evidenciaron una considerable variación en detectabilidad relacionada con variaciones entre gremios tróficos y tipos de cobertura. Las tasas de presencia aumentaron al disminuir la cobertura boscosa (Ψb.intervenido>Ψb. secundario>Ψb. primario) y fueron diferentes entre especies. La abundancia incrementó al aumentar el nivel de intervención (Nb.intervenido>Nb.secundario>Nb primario), disminuyó con el tamaño corporal y fue mayor para frugívoros y nectarívoros que para insectívoros. Los resultados sugieren que las comunidades de murciélagos despliegan fuertes respuestas al grado de intervención. Aunque se presentó mayor presencia y abundancia en el área más intervenida, los murciélagos también utilizaron las menos intervenidas. Esto puede incrementar el movimiento de las semillas entre diferentes estadíos sucesionales. Por lo tanto, el estudio de la comunidad de murciélagos puede ser importante para monitorear el estado de recuperación de los bosques del PNN Gorgona y para entender los procesos ecológicos que generan la recuperación de estos.