Unraveling the diversity of Trypanosoma species from Central Mexico: Molecular confirmation on the presence of Trypanosoma dionisii and novel Neobat linages.

Bats are one of the groups of mammals with the highest number of associated Trypanosoma taxa. There are 50 Trypanosoma species and genotypes infecting more than 75 species of bats across five continents. However, in Mexico, the inventory of species of the genus Trypanosoma associated with bats is limited to only two species (Trypanosoma vespertilionis and Trypanosoma cruzi) even though 140 species of bats inhabit this country. Specifically, 91 bat species have been recorded in the state of Veracruz, but records of trypanosomatids associated with this mammalian group are absent. Due to the complex Trypanosoma-bat relationship, the high diversity of bat species in Veracruz, as well as the lack of records of trypanosomatids associated with bats for this state, the aim of this work was to analyze the diversity of species of the genus Trypanosoma and their presence from a bat community in the central area of the state of Veracruz, Mexico. During the period of January to August 2022 in the Tequecholapa Environmental Management Unit where bats were collected using mist nets and blood samples were obtained from their thumbs. We extracted genetic material and amplified a fragment of 800 bp of the 18S ribosomal gene of the genus Trypanosoma by conventional PCR. The positive amplicons were sequenced, and phylogenetic reconstruction was performed to identify the parasite species. A total of 285 bats (149♀, 136♂) belonging to 13 species from 10 genera and a single family (Phyllostomidae) were collected. Twenty-three specimens from six species tested positive for the presence of Trypanosoma dionisii, Trypanosoma sp. Neobat 4, and a potential novelty species provisionally named as Trypanosoma sp. Neobat 6. The results of the present work increase the number of species of the genus Trypanosoma infecting bats in Mexico and in the Neotropical region.

Thermal niche breadth and their relationship with sturnira bat species diversification.

The interaction between climatic conditions and the ability of organisms to maintain homeostasis regulates the distribution of species on the planet. However, its influence on macroevolutionary dynamics is not well understood. It has been suggested that diversification rates will be different in lineages with narrow thermal niches (specialists) to diversification rates in generalist lineages, but the evidence for this is elusive. Here, we tested this hypothesis by using the most diverse (in species richness and geographic range variation) tropical bat genus within the Phyllostomidae family. We estimated the realized thermal niche breadth of Sturnira species from their geographic range and categorized them as generalists, cold specialists, or warm specialists. We compared dynamic evolutionary models that differ in 1) niche breadth evolution, 2) parental niche breadth inheritance, and 3) whether niche breadth evolution is associated with shifts in diversification rates. Our best-performing model indicates that most Sturnira species arose as specialists in warm climates and that over time, their niche breadth broadens, and just a subset of those species becomes specialists in cold environments. We found that the evolution of realized thermal niche breadth causes fluctuations in per-lineage rates of diversification, where warm specialists boast the highest speciation rates. However, we found no evidence of these changes in niche neither triggering nor being a result of speciation events themselves; this suggests that diversification events in Sturnira could instead depend on allopatric speciation processes such as the development of geographic barriers.

Neuronal scaling in the olfactory system of bats.

Comparative studies are a common way to address large-scale questions in sensory biology. For studies that investigate olfactory abilities, the most commonly used metric is olfactory bulb size. However, recent work has called into question the broad-scale use of olfactory bulb size. In this paper, we use three neuroanatomical measures with a more mechanistic link to olfactory function (number of olfactory sensory neurons (OSNs), number of mitral cells (MCs), and number of glomeruli) to ask how species with different diets may differ with respect to olfactory ability. We use phyllostomid bats as our study system because behavioral and physiological work has shown that fruit- and nectar-feeding phyllostomids rely on odors for detecting, localizing, and assessing potential foods, while insect-eating species do not. Therefore, we predicted that fruit- and nectar-feeding bats would have larger numbers of these three neuroanatomical measures than insect-eating species. In general, our results supported the predictions. We found that fruit-eaters had greater numbers of OSNs and glomeruli than insect-eaters, but we found no difference between groups in number of MCs. We also examined the allometric relationship between the three neuroanatomical variables and olfactory bulb volume, and we found isometry in all cases. These findings lend support to the notion that neuroanatomical measures can offer valuable insights into comparative olfactory abilities, and suggest that the size of the olfactory bulb may be an informative parameter to use at the whole-organism level.

Reproductive phenologies of phyllostomid bat populations and ensembles from lowland Amazonia.

Natural selection should favor individuals that synchronize energy-demanding aspects of reproductive activity with periods of high resource abundance and predictability, leading to seasonal patterns of reproduction at the population level. Nonetheless, few studies-especially those on bats in the Neotropics-have used rigorous quantitative criteria to distinguish among phenological patterns for different populations from the same habitat or for the same species in different habitats. To explore such issues, we quantified annual patterns of reproduction in male and in female bats from lowland Amazonia (environs of Iquitos, Peru), and did so at the level of populations and ensembles. Five species exhibited unimodal patterns including Artibeus obscurus, A. planirostris, Carollia benkeithi, Phyllostomus hastatus, and Rhinophylla pumilio. Two species (A. lituratus and Glossophaga soricina) evinced bimodal patterns with reproductive peaks separated by patterns of inactivity, whereas four species (C. brevicauda, C. perspicillata, Sturnira lilium, and S. tildae) evinced a bimodal pattern in which peaks in activity occur in tandem, with the first peak generally markedly higher than the second peak. Frugivore, gleaning animalivore, and nectarivore ensembles exhibited bimodal, unimodal, and bimodal reproductive phenologies, respectively. Nonetheless, interannual variation in phenology (i.e., the monthly timing of peaks within a season rather than the number of peaks per year) characterized four (A. obscurus, C. brevicauda, C. perspicillata, and S. lilium) of the eight species and each of the three ensembles (frugivores, gleaning animalivores, and nectarivores) with adequate sampling. Regardless of interspecific variation in strategies, the phenology of reproduction enhances the likelihood that parturition and recruitment of young into the population occurs during the wet season, the period of likely highest resource abundance. Based on a comparison of our results with those from other well-studied bat populations, four species did not exhibit geographic variation in reproductive phenologies (A. obscurus, G. soricina, C. brevicauda, and R. pumilio), whereas three species evinced such geographic variation (A. lituratus, A. planirostris, and C. perspicillata). Climate change will likely alter the seasons and extents of propitious times for reproductive activities, as well as the reliability of proximate cues for initiating reproduction, compromising current reproductive strategies and leading to altered phenological patterns of reproduction or reproductive success, possibly resulting in local extinction of some species.

La selección natural debería favorecer a individuos que sincronicen aspectos de alta demanda de energía en su actividad reproductiva con períodos de alta abundancia y previsibilidad de recursos, lo que conduciría a patrones estacionales de reproducción a nivel poblacional. No obstante, pocos estudios, especialmente estudios sobre murciélagos en el Neotrópico, han utilizado criterios cuantitativos rigurosos para distinguir entre patrones fenológicos ya sea para diferentes poblaciones dentro del mismo hábitat o para la misma especie en diferentes hábitats. Para explorar este tema, cuantificamos los patrones anuales de reproducción de murciélagos machos (porcentaje de la población con testículos escrotales) y hembras (porcentaje de la población embarazada o lactante) en regiones bajas de la Amazonía (alrededores de Iquitos, Perú) a nivel de poblaciones y de ensamblajes. Cinco especies exhibieron patrones unimodales, incluidos Artibeus obscurus, Artibeus planirostris, Carollia benkeithi, Phyllostomus hastatus, y Rhinophylla pumilio. Dos especies (Artibeus lituratus y Glossophaga soricina) mostraron patrones bimodales, con picos reproductivos separados por patrones de inactividad, mientras que cuatro especies (Carollia brevicauda, Carollia perspicillata, Sturnira lilium, y Sturnira tildae) mostraron un patrón bimodal en el que los picos de actividad ocurren en tándem, con un primer pico considerablemente más alto que el segundo. Los grupos de frugívoros, animalívoros y nectarívoros exhibieron fenologías reproductivas bimodales, unimodales y bimodales respectivamente. No obstante, la variación interanual en la fenología (es decir, el mes dentro de una temporada en que ocurren los picos en lugar del número de picos por año) caracterizó a cuatro (A. obscurus, C. brevicauda, C. perspicillata y S. lilium) de las ocho especies y cada uno de los tres ensamblajes (frugívoros, animalívoros y nectarívoros) con un tamaño de muestra adecuado. Independientemente de la variación en las estrategias, la fenología en la reproducción aumenta la probabilidad de que el parto y el reclutamiento de crías en la población ocurran en la estación húmeda, el período de mayor abundancia de recursos. Cuando comparamos nuestros resultados con los de otras poblaciones de murciélagos mejor estudiadas, cuatro especies no mostraron variación geográfica en sus estrategias reproductivas (A. obscurus, G. soricina, C. brevicauda y R. pumilio), mientras que tres especies si mostraron esta variación geográfica (A. lituratus, A. planirostris y C. perspicillata). Es probable que el cambio climático altere las estaciones y la duración de los periodos propicios para el desarrollo de actividades reproductivas de alta demanda de energía, así como la regularidad de las señales activantes para iniciar la actividad reproductiva, comprometiendo las estrategias reproductivas actuales y conllevando a patrones fenológicos de reproducción alterados, lo que para algunas especies podría resultar en extinciones locales.

Bats (Mammalia: Chiroptera) in urban-rural interfaces: community structure associated with pathogen screening in São Paulo-the largest metropolitan region in Brazil.

Little is known about the influence of the urban environments on bat species 'ecology. The urbanization process potentially lead to critical ecological changes in bat communities' intra and interspecific pathogenic transmissions dynamics. To date, the monitoring of pathogens in bats in Brazil has only been done with bats found dead or alive in households, from rabies surveillance systems. The present work aimed to investigate how urbanization influenced bat richness, relative abundance and pathogen occurrence. Most captured bats were Phyllostomidae, especially Sturnira lilium, Artibeus lituratus, A. fimbriatus, Glossophaga soricina, and Platyrrhinus lineatus, among others. From preserved-rural towards urban areas the lesser the bat richness, the higher the relative abundance of the captured bats. Noise level, luminosity and relative humidity correlated with bat abundance. The proportion of genders, sexually active bats and their size (weight, right forearm length, and body condition index) were stable throughout the investigation. Still, the proportion of pregnant females was higher in Spring and the number of juveniles in Summer, evidencing the seasonality of reproduction. Several Enterobacteria were isolated, evidencing a significant role of bats in the circulation of pathogens of medical and veterinary interest. These results are crucial in the pursuit of a harmonious coexistence between humans, bats and domestic animals in areas with different levels of anthropization.

Effects of forest loss and fragmentation on bat-ectoparasite interactions.

Human land use causes habitat loss and fragmentation, influencing host-parasite associations through changes in infestation rates, host mortality and possibly local extinction. Bat-ectoparasite interactions are an important host-parasite model possibly affected by such changes, as this system acts as both reservoirs and vectors of several pathogens that can infect different wild and domestic species. This study aimed to assess how the prevalence and abundance of bat ectoparasites respond to forest loss, fragmentation, and edge length. Bats and ectoparasites were sampled at twenty sites, forming a gradient of forest cover, in southwestern Brazil during two wet (2015 and 2016) and two dry (2016 and 2017) seasons. Effects of landscape metrics on host abundance as well as parasite prevalence and abundance were assessed through structural equation models. Nine host-parasite associations provided sufficient data for analyses, including one tick and eight flies on four bat species. Forest cover positively influenced the prevalence or abundance of three fly species, but negatively influenced one fly and the tick species. Prevalence or abundance responded positively to edge length for three fly species, and negatively for the tick. In turn, number of fragments influenced the prevalence or abundance of four fly species, two positively and two negatively. Our results support species-specific responses of ectoparasites to landscape features, and a tendency of host-generalist ticks to benefit from deforestation while most host-specialist flies are disadvantaged. Differences in host traits and abundance, along with parasite life cycles and environmental conditions, are possible explanations to our findings.

The mitochondrial genomes of big-eared bats, Macrotus waterhousii and Macrotus californicus (Chiroptera: Phyllostomidae: Macrotinae).

In the species-rich family Phyllostomidae, the genus Macrotus ('big eared' bats) contains only two species; Macrotus waterhousii, distributed in western, central, and southern Mexico, Guatemala and some Caribbean Islands, and Macrotus californicus, distributed in the southwestern USA, and in the Baja California peninsula and the state of Sonora in Mexico. In this study, we sequenced and assembled the mitochondrial genome of Macrotus waterhousii and characterized in detail this genome and that of the congeneric M. californicus. Then, we examined the phylogenetic position of Macrotus in the family Phyllostomidae based on protein coding genes (PCGs). The AT-rich mitochondrial genomes of M. waterhousii and M. californicus are 16,792 and 16,691 bp long, respectively, and each encode 13 PCGs, 22 tRNA genes, 2 rRNA genes, and a putative non-coding control region 1,336 and 1,232 bp long, respectively. Mitochondrial synteny in Macrotus is identical to that reported before for all other cofamilial species. In the two studied species, all tRNAs exhibit a 'typical' cloverleaf secondary structure with the exception of trnS1, which lacks the D arm. A selective pressure analysis demonstrated that all PCGs are under purifying selection. The CR of the two species feature three domains previously reported in other mammals, including bats: extended terminal associated sequences (ETAS), central (CD), and conserved sequence block (CSB). A phylogenetic analysis based on the 13 mitochondrial PCGs demonstrated that Macrotus is monophyletic and the subfamily Macrotinae is a sister group of all remaining phyllostomids in our analysis, except Micronycterinae. The assembly and detailed analysis of these mitochondrial genomes represents a step further to continue improving the understanding of phylogenetic relationships within the species-rich family Phyllostomidae.

Flight performance and wing morphology in the bat Carollia perspicillata: biophysical models and energetics.

Studies on functional performance are important to understand the processes responsible for the evolution of diversity. Morphological trait variation within species influences the energetic cost of locomotion and impacts life history traits, with ecological and evolutionary consequences. This study examined wing morphology correlates of flight performance measured by energetic expenditure in the Seba's short-tailed bat, Carollia perspicillata. In the flight experiments, nature caught bats (59 females, 57 males) were allowed to fly for 3 min in a room. After each flight, thermographic images were taken to measure body temperature, and biophysical models were used to calculate sensible heat loss as a measure of energetic expenditure. Wing morphological traits were measured for each individual and associated with heat loss and power required to fly on performance surfaces. Wing morphological traits explained 7-10% of flight energetic cost, and morphologies with the best performance would save the energy equivalent to 9-30% of total daily requirements. The optimal performance areas within the C. perspicillata morphospace were consistent with predicted selection trends from the literature. A trade-off between demands for flight speed and maneuverability was observed. Wing loading and camber presented sexual dimorphism. These morphological differences are likely associated with more economical but less maneuverable flight in females, leading them to fly more often in open areas along the forest edge. Our findings demonstrate how small scale changes in wing morphology can affect life history strategies and fitness.

Ectoparasitic flies of bats (Mammalia: Chiroptera) in urban green areas of northeastern Brazil.

In urban and degraded areas, ectoparasite abundance can be affected by increasing human population density and habitat fragmentation. This study aimed to characterize the ectoparasitic fly community associated with bats in the urban green areas of Sergipe, Brazil. Campaigns were conducted monthly, for two consecutive nights, between September 2019 and February 2021. To capture the bats, ten mist nets were set up inside and at the edge of the habitat fragments. All ectoparasites found were removed from the bats and stored in 70% alcohol. The specificity index, parasitological rates, and level of parasite aggregation were calculated, and the influence of host sex and seasonality on parasitological rates were verified for the most parasitized bats. The collected ectoparasites corresponded to the families Nycteribiidae (S = 1; n = 26) and Streblidae (S = 13; n = 849), with Trichobius costalimai and Medistopoda aranea being the most abundant species. For some interactions, there was an influence of host sex on the prevalence rates, with the highest number of parasites being found on females, which can be explained by their greater susceptibility to parasitism owing to their long stay in roosts. The seasonality influenced the parasitological rates, and opposing patterns (from what was expected) were observed for some interactions; this influence may be due to the biological differences between parasite species. This study provides relevant data on this interaction, especially for urban areas in northeastern Brazil, expanding the number of studies in the State of Sergipe and promoting future studies.

Two in one: the little bat that pollinates and disperses plants at an urban site in Southeastern Brazil / Dois em um: o pequeno morcego que poliniza e dispersa plantas em local urbano no Sudeste do Brasil

The glossophagine Pallas's long-tongued bat (Glossophaga soricina) fares well in urban environments across its range. In addition to roost sites, there are nectar and fruit sources available in diverse situations across the urban gradient. Phyllostomid bats that thrive in urbanized situations are behaviorally plastic generalists and rely on patches of ornamental or feral plants as food sources. Herein we report on G. soricina and its food sources at an urbanized site in Southeastern Brazil. This small phyllostomid bat consumes nectar from landscaping ornamental plants, besides consuming the soft pulp along with the tiny seeds of pioneer trees and shrubs. In addition to these natural sources, the bat exploits hummingbird feeders to consume the sugared water. Ingested small seeds are defecated in flight, the bat acting as a disperser of pioneer plants that favor cleared areas. Glossophaga soricina role as flower-pollinator and seed-disperser at Neotropical urban areas merits further attention due both to the maintenance of urban biodiversity and delivery of ecosystem services

O morcego beija-flor (Glossophaga soricina) adapta-se a ambientes urbanos na sua área de distribuição. Além de abrigos diurnos, há fontes de néctar e frutos ao longo do gradiente urbano. Morcegos filostomídeos que se adaptam a situações urbanas são generalistas comportamentalmente flexíveis e dependem de trechos com plantas ornamentais ou ferais como fonte alimentar. Relatamos aqui informações sobre o morcego beija-flor e suas fontes alimentares em um local urbanizado no sudeste do Brasil. Este pequeno morcego glossofagíneo busca néctar em plantas usadas em paisagismo, além de consumir a polpa macia, juntamente com as sementes minúsculas, de plantas pioneiras. Além destas fontes naturais, o morcego explora água açucarada dos bebedouros de beija-flores. Sementes pequenas são defecadas em voo e o morcego age como dispersor de plantas poineiras em áreas sem vegetação. A função de G. soricina como polinizador de flores e dispersor de sementes em áreas urbanas nos Neotrópicos merece atenção adicional devido à manutenção da biodiversidade urbana e da prestação de serviços ecossistêmicos.

NeoBat Interactions: A data set of bat-plant interactions in the Neotropics.

Data papers and open databases have revolutionized contemporary science, as they provide the long-needed incentive to collaborate in large international teams and make natural history information widely available. Nevertheless, most data papers have focused on species occurrence or abundance, whereas interactions have received much less attention. To help fill this gap, we have compiled a georeferenced data set of interactions between 93 bat species of the family Phyllostomidae (Chiroptera) and 501 plant species of 68 families. Data came from 169 studies published between 1957 and 2007 covering the entire Neotropical Region, with most records from Brazil (34.5% of all study sites), Costa Rica (16%), and Mexico (14%). Our data set includes 2571 records of frugivory (75.1% of all records) and nectarivory (24.9%). The best represented bat genera are Artibeus (28% of all records), Carollia (24%), Sturnira (10.1%), and Glossophaga (8.8%). Carollia perspicillata (187), Artibeus lituratus (125), Artibeus jamaicensis (94), Glossophaga soricina (86), and Artibeus planirostris (74) were the bat species with the broadest diets recorded based on the number of plant species. Among the plants, the best represented families were Moraceae (17%), Piperaceae (15.4%), Urticaceae (9.2%), and Solanaceae (9%). Plants of the genera Cecropia (46), Ficus (42), Piper (40), Solanum (31), and Vismia (27) exhibited the largest number of interactions. These data are stored as arrays (records, sites, and studies) organized by logical keys and rich metadata, which helped to compile the information on different ecological and geographic scales, according to how they should be used. Our data set on bat-plant interactions is by far the most extensive, both in geographic and taxonomic terms, and includes abiotic information of study sites, as well as ecological information of plants and bats. It has already facilitated several studies and we hope it will stimulate novel analyses and syntheses, in addition to pointing out important gaps in knowledge. Data are provided under the Creative Commons Attribution 4.0 International License. Please cite this paper when the data are used in any kind of publication related to research, outreach, and teaching activities.

Genome-wide ultraconserved elements resolve phylogenetic relationships and biogeographic history among Neotropical leaf-nosed bats in the genus Anoura (Phyllostomidae).

AnouraGray, 1838 are Neotropical nectarivorous bats and the most speciose genus within the phyllostomid subfamily Glossophaginae. However, Anoura species limits remain debated, and phylogenetic relationships remain poorly known, because previous studies used limited Anoura taxon sampling or focused primarily on higher-level relationships. Here, we conduct the first phylogenomic study of Anoura by analyzing 2039 genome-wide ultraconserved elements (UCEs) sequenced for 42 individuals from 8 Anoura species/lineages plus two outgroups. Overall, our results based on UCEs resolved relationships in the genus and supported (1) the monophyly of small-bodied Anoura species (previously genus Lonchoglossa); (2) monotypic status of A. caudifer; and (3) nested positions of "A. carishina", A. caudifer aequatoris, and A. geoffroyi peruana specimens within A. latidens, A. caudifer and A. geoffroyi, respectively (suggesting that these taxa are not distinct species). Additionally, (4) phylogenetic networks allowing reticulate edges did not explain gene tree discordance better than the species tree (without introgression), indicating that a coalescent model accounting for discordance solely through incomplete lineage sorting fit our data well. Sensitivity analyses indicated that our species tree results were not adversely affected by varying taxon sampling across loci. Tree calibration and Bayesian coalescent analyses dated the onset of diversification within Anoura to around âˆ¼ 6-9 million years ago in the Miocene, with extant species diverging mainly within the past âˆ¼ 4 million years. We inferred a historical biogeographical scenario for Anoura of parapatric speciation fragmenting the range of a wide-ranging ancestral lineage centered in the Central to Northern Andes, along with Pliocene-Pleistocene dispersal or founder event speciation in Amazonia and the Brazilian Atlantic forest during the last âˆ¼ 2.5 million years.

A Faithful Gut: Core Features of Gastrointestinal Microbiota of Long-Distance Migratory Bats Remain Stable despite Dietary Shifts Driving Differences in Specific Bacterial Taxa.

Migratory animals live in a world of constant change. Animals undergo many physiological changes preparing themselves for the migration. Although this field has been studied extensively over the last decades, we know relatively little about the seasonal changes that occur in the microbial communities that these animals carry in their guts. Here, we assessed the V4 region of the 16S rRNA high-throughput sequencing data as a proxy to estimate microbiome diversity of tequila bats from fecal pellets and evaluate how the natural process of migration shapes the microbiome composition and diversity. We collected samples from individual bats at two localities in the dry forest biome (Chamela and Coquimatlán) and one site at the endpoint of the migration in the Sonoran Desert (Pinacate). We found that the gut microbiome of the tequila bats is dominated largely by Firmicutes and Proteobacteria. Our data also provide insights on how microbiome diversity shifts at the same site in consecutive years. Our study has demonstrated that both locality and year-to-year variation contribute to shaping the composition, overall diversity, and "uniqueness" of the gut microbiome of migratory nectar-feeding female bats, with localities from the dry forest biome looking more like each other compared to those from the desert biome. In terms of beta diversity, our data show a stratified effect in which the samples' locality was the strongest factor influencing the gut microbiome but with significant variation between consecutive years at the same locality. IMPORTANCE Migratory animals live in a world of constant change. The whole-body ecosystem needs a strong adapting capacity to thrive despite the changes. Our study used next-generation sequencing to determine how gut microbial change along the migratory path of the nectar-feeding tequila bats. The study of the gut microbiome is a great tool that can provide important insights that are relevant not just for management and conservation but also an initial investigation of the extent of the adaptation and preparedness of the individual animals, with respect not just to their current environment but also to all the environments involved in their yearly cycle.

Functional differences in echolocation call design in an adaptive radiation of bats.

All organisms have specialized systems to sense their environment. Most bat species use echolocation for navigation and foraging, but which and how ecological factors shaped echolocation call diversity remains unclear for the most diverse clades, including the adaptive radiation of neotropical leaf-nosed bats (Phyllostomidae). This is because phyllostomids emit low-intensity echolocation calls and many inhabit dense forests, leading to low representation in acoustic surveys. We present a field-collected, echolocation call dataset spanning 35 species and all phyllostomid dietary guilds. We analyze these data under a phylogenetic framework to test the hypothesis that echolocation call design and parameters are specialized for the acoustic demands of different diets, and investigate the contributions of phylogeny and body size to echolocation call diversity. We further link call parameters to dietary ecology by contrasting minimum detectable prey size estimates (MDPSE) across species. We find phylogeny and body size explain a substantial proportion of echolocation call parameter diversity, but most species can be correctly assigned to taxonomic (61%) or functional (77%) dietary guilds based on call parameters. This suggests a degree of acoustic ecological specialization, albeit with interspecific similarities in call structure. Theoretical MDPSE are greatest for omnivores and smallest for insectivores. Omnivores significantly differ from other dietary guilds in MDPSE when phylogeny is not considered, but there are no differences among taxonomic dietary guilds within a phylogenetic context. Similarly, predators of non-mobile/non-evasive prey and predators of mobile/evasive prey differ in estimated MDPSE when phylogeny is not considered. Phyllostomid echolocation call structure may be primarily specialized for overcoming acoustic challenges of foraging in dense habitats, and then secondarily specialized for the detection of food items according to functional dietary guilds. Our results give insight into the possible ecological mechanisms shaping the diversity of sensory systems, and their reciprocal influence on resource use.

Diversity in olfactory receptor repertoires is associated with dietary specialization in a genus of frugivorous bat.

Mammalian olfactory receptor genes (ORs) are a diverse family of genes encoding proteins that directly interact with environmental chemical cues. ORs evolve via gene duplication in a birth-death fashion, neofunctionalizing and pseudogenizing over time. Olfaction is a primary sense used for food detection in plant-visiting bats, but the relationship between dietary specialization and OR repertoire diversity is unclear. Within neotropical Leaf-nosed bats (Phyllostomidae), many lineages are plant specialists, and some have a distinct OR repertoire compared to insectivorous species. Yet, whether specialization on particular plant genera is associated with the evolution of specialized, less diverse OR repertoires has never been tested. Using targeted sequence capture, we sequenced the OR repertoires of three sympatric species of short-tailed fruit bats (Carollia), which vary in their degree of specialization on the fruits of Piper plants. We characterized orthologous vs duplicated receptors among Carollia species, and explored the diversity and redundancy of the receptor gene repertoire. At the species level, the most dedicated Piper specialist, Carollia castanea, had lower OR diversity compared to the two generalists (C. sowelli and C. perspicillata), but we discovered a few unique sets of ORs within C. castanea with high redundancy of similar gene duplicates. These unique receptors potentially enable C. castanea to detect Piper fruit odorants better than its two congeners. Carollia perspicillata, the species with the most generalist diet, had a higher diversity of intact receptors, suggesting the ability to detect a wider range of odorant molecules. Variation among ORs may be a factor in the coexistence of these sympatric species, facilitating the exploitation of different plant resources. Our study sheds light on how gene duplication and changes in OR diversity may play a role in dietary adaptations and underlie ecological interactions between bats and plants.

Hearing sensitivity: An underlying mechanism for niche differentiation in gleaning bats.

Tropical ecosystems are known for high species diversity. Adaptations permitting niche differentiation enable species to coexist. Historically, research focused primarily on morphological and behavioral adaptations for foraging, roosting, and other basic ecological factors. Another important factor, however, is differences in sensory capabilities. So far, studies mainly have focused on the output of behavioral strategies of predators and their prey preference. Understanding the coexistence of different foraging strategies, however, requires understanding underlying cognitive and neural mechanisms. In this study, we investigate hearing in bats and how it shapes bat species coexistence. We present the hearing thresholds and echolocation calls of 12 different gleaning bats from the ecologically diverse Phyllostomid family. We measured their auditory brainstem responses to assess their hearing sensitivity. The audiograms of these species had similar overall shapes but differed substantially for frequencies below 9 kHz and in the frequency range of their echolocation calls. Our results suggest that differences among bats in hearing abilities contribute to the diversity in foraging strategies of gleaning bats. We argue that differences in auditory sensitivity could be important mechanisms shaping diversity in sensory niches and coexistence of species.

Inter- and intraspecific variation in the Artibeus species complex demonstrates size and shape partitioning among species.

Neotropical leaf-nosed bats (family Phyllostomidae) are one of the most diverse mammalian families and Artibeus spp. is one of the most speciose phyllostomid genera. In spite of their species diversity, previous work on Artibeus crania using linear morphometrics has uncovered limited interspecific variation. This dearth of shape variation suggests that differences in cranial morphology are not contributing to niche partitioning across species, many of which are often found in sympatry. Using two-dimensional geometric morphometric methods on crania from eleven species from the Artibeus species complex, the current study demonstrates substantial cranial interspecific variation, sexual size and shape dimorphism, and intraspecific geographic variation. The majority of species were shown to have a unique size and shape, which suggests that each species may be taking advantage of slightly different ecological resources. Further, both sexual size and shape dimorphism were significant in the Artibeus species complex. Male and female Artibeus are known to have sex specific foraging strategies, with males eating near their roosts and females feeding further from their roosts. The presence of cranial sexual dimorphism in the Artibeus species complex, combined with previous work showing that different fruit size and hardness is correlated with different cranial shapes in phyllostomids, indicates that the males and females may be utilizing different food resources, leading to divergent cranial morphotypes. Additional field studies will be required to confirm this emergent hypothesis. Finally, significant geographical shape variation was found in a large intraspecific sample of Artibeus lituratus crania. However, this variation was not correlated with latitude and instead may be linked to local environmental factors. Additional work on ecology and behavior in the Artibeus species complex underlying the morphological variation uncovered in this study will allow for a better understanding of how the group has reached its present diversity.

Movement syndromes of a Neotropical frugivorous bat inhabiting heterogeneous landscapes in Brazil.

BACKGROUND: There is growing evidence that individuals within populations can vary in both habitat use and movement behavior, but it is still not clear how these two relate to each other. The aim of this study was to test if and how individual bats in a Stunira lilium population differ in their movement activity and preferences for landscape features in a correlated manner. METHODS: We collected data on movements of 27 individuals using radio telemetry. We fitted a heterogeneous-space diffusion model to the movement data in order to evaluate signals of movement variation among individuals. RESULTS: S. lilium individuals generally preferred open habitat with Solanum fruits, regularly switched between forest and open areas, and showed high site fidelity. Movement variation among individuals could be summarized in four movement syndromes: (1) average individuals, (2) forest specialists, (3) explorers which prefer Piper, and (4) open area specialists which prefer Solanum and Cecropia. CONCLUSIONS: Individual preferences for landscape features plus food resource and movement activity were correlated, resulting in different movement syndromes. Individual variation in preferences for landscape elements and food resources highlight the importance of incorporating explicitly the interaction between landscape structure and individual heterogeneity in descriptions of animal movement.

Chromosome Painting in Lonchorhina aurita Sheds Light onto the Controversial Phylogenetic Position of Sword-Nosed Bats (Chiroptera, Phyllostomidae).

The subfamily Lonchorhininae encompasses 6 species of sword-nosed bats (Lonchorhina) and is one of the most problematic lineages in the Neotropical leaf-nosed bats (Phyllostomidae) phylogeny. There are at least 5 different hypotheses to explain when the subfamily diverged from the remaining phyllostomids, but none with robust statistical support. Here, we generated a chromosome painting homology map of Lonchorhina aurita karyotype (2n = 32 and FN = 60) using whole-chromosome probes of Macrotus californicus (MCA; 2n = 40 and FN = 60). We placed the karyotype changes of L. aurita in a phylogenetic context to discuss the most likely branching position of Lonchorhininae based on karyotypic evolution. We show that L. aurita has a derived karyotype with 24 segments homologous to the 20 MCA chromosomes used as probes. Comparative analyses between 7 published painted bats species across 4 phyllostomid subfamilies (Macrotinae, Phyllostominae, Glossophaginae, and Lonchophyllinae) revealed that one inversion (MCA 4inv) and one fusion (MCA 17 + 18) are shared derived features between the karyotypes of L. aurita and species of Phyllostominae not yet observed in other bats. Our data show that chromosomal homology maps may contribute with new insights into a long-standing phylogenetic debate that has endured for decades.