Explore the vast range of titles available.

The lowland tapir (Tapirus terrestris) is a megaherbivore integral to ecosystem functioning in South America's tropical landscapes but is increasingly threatened by habitat loss and fragmentation. This study assessed occupancy, detectability, and activity patterns of lowland tapirs across the Orinoquia region of Colombia. We deployed 360 camera traps over 32,000 trap‐days from 2015 to 2023 across nine study areas, evaluating the influence of habitat characteristics and anthropogenic factors on the tapir presence using hierarchical occupancy models. Our results revealed a naïve occupancy of 0.40 and an overall detectability of 0.46. Model‐averaged estimates identified dense forest cover as a critical positive predictor of tapir occupancy (Ψ = 0.58, CI: 0.39–0.64), while proximity to water resources similarly enhanced both occupancy and detectability. Conversely, anthropogenic landscapes such as pastures negatively impacted occupancy probabilities (Ψ = 0.45, CI: 0.40–0.51), whereas crop areas, primarily those used for household consumption, showed a surprising positive association. Taken together, these results indicate higher occupancy in dense forest and near streams, lower occupancy in pastures, no strong positive effect of gallery/riparian belts, and a context‐dependent positive association with smallholder crops. Our findings underscore the importance of dense forests and water bodies for tapir conservation and suggest that effective management strategies must address habitat fragmentation and human–wildlife conflicts. Future conservation efforts should include intensive monitoring, community‐based participatory approaches, and consideration of climate change impacts to ensure the long‐term survival of tapir populations in this rapidly changing landscape. RESUMEN La danta de tierras bajas (Tapirus terrestris) es un megaherbívoro que hace parte integral de la funcionalidad ecológica de los paisajes tropicales de Sur América, el cual se encuentra altamente amenazado como consecuencia de la pérdida y fragmentación de los hábitats. Este estudio buscó determinar la ocupación, detectabilidad y patrones de actividad de la danta de tierras bajas a través de la región de la Orinoquia colombiana. Fueron instaladas 360 cámaras trampa durante 32,000 días efectivos de muestreo entre 2015 y 2023. En total fueron evaluadas nueve áreas de estudio donde se determinó la influencia de las características de hábitat y factores antropogénicos sobre la presencia de las dantas por medio de la implementación de modelos de ocupación jerárquicos. Los resultados revelaron una ocupación naïve de 0.40 y una detectabilidad de 0.46. Las estimaciones promediadas del modelo identificaron el bosque denso como un predictor positivo crítico en la ocupación de la danta (Ψ = 0.58, CI: 0.39–0.64), así como la proximidad a los recursos hídricos mejoró de forma similar tanto la ocupación como la detectabilidad. Por el contrario, los paisajes antropogénicos como los pastos impactaron negativamente en las probabilidades de ocupación (Ψ = 0.45, CI: 0.40–0.51). Las áreas de cultivo, principalmente aquellas utilizadas para el consumo doméstico, mostraron una sorprendente asociación positiva. En conjunto, estos resultados indican una mayor ocupación en bosques densos y zonas cercanas a cuerpos de agua, una menor ocupación en pastizales, la ausencia de un efecto positivo marcado de los bosques de galería o ribereños, y una asociación positiva dependiente del contexto con cultivos de pequeña escala. Las carreteras aparecieron como barreras de dispersión significativas, reduciendo la detectabilidad. Nuestros resultados subrayan la importancia de los bosques densos y los cuerpos de agua para la conservación de la danta y sugieren que las estrategias de gestión efectivas deben abordar la fragmentación de los hábitats, la expansión de las carreteras y los conflictos entre el hombre y la fauna. Los futuros esfuerzos de conservación deberían incluir un seguimiento intensivo, enfoques participativos basados en la comunidad y la consideración de los impactos del cambio climático para asegurar la supervivencia a largo plazo de las poblaciones de dantas en este paisaje rápidamente cambiante. Our study reveals that lowland tapir (Tapirus terrestris ) occupancy in Colombia's Orinoquia region is strongly influenced by dense forests and proximity to water bodies, while anthropogenic factors such as pastures and road networks negatively impact their presence. Using an extensive 8 year camera trap dataset and hierarchical occupancy models, we demonstrate that habitat fragmentation and land‐use change shape tapir distribution, with certain crop types unexpectedly supporting their persistence. These findings underscore the urgent need for conservation strategies that prioritize habitat connectivity, community‐based management, and climate‐resilient approaches to ensure the long‐term survival of this keystone megaherbivore.

Background Host associated gut microbiota are important in understanding the coevolution of host-microbe, and how they may help wildlife populations to adapt to rapid environmental changes. Mammalian gut microbiota composition and diversity may be affected by a variety of factors including geographic variation, seasonal variation in diet, habitat disturbance, environmental conditions, age, and sex. However, there have been few studies that examined how ecological and environmental factors influence gut microbiota composition in animals' natural environments. In this study, we explore how host habitat, geographical location and environmental factors affect the fecal microbiota of Cynomys ludovicianus at a small spatial scale. We collected fecal samples from five geographically distinct locations in the Texas Panhandle classified as urban and rural areas and analyzed them using high throughput 16S rRNA gene amplicon sequencing. Results The results showed that microbiota of these fecal samples was largely dominated by the phylum Bacteroidetes . Fecal microbiome diversity and composition differed significantly across sampling sites and habitats. Prairie dogs inhabiting urban areas showed reduced fecal diversity due to more homogenous environment and, likely, anthropogenic disturbance. Urban prairie dog colonies displayed greater phylogenetic variation among replicates than those in rural habitats. Differentially abundant analysis revealed that bacterial species pathogenic to humans and animals were highly abundant in urban areas which indicates that host health and fitness might be negatively affected. Random forest models identified Alistipes shahii as the important species driving the changes in fecal microbiome composition. Despite the effects of habitat and geographic location of host, we found a strong correlation with environmental factors and that- average maximum temperature was the best predictor of prairie dog fecal microbial diversity. Conclusions Our findings suggest that reduction in alpha diversity in conjunction with greater dispersion in beta diversity could be indicative of declining host health in urban areas; this information may, in turn, help determine future conservation efforts. Moreover, several bacterial species pathogenic to humans and other animals were enriched in prairie dog colonies near urban areas, which may in turn adversely affect host phenotype and fitness.

Recently, Maestri, Luza, et al. (2016) assessed the effect of ecology and phylogeny on body size variation in communities of South American Sigmodontinae rodents. Regrettably, a cursory analysis of the data and the phylogeny used to address this question indicates that both are plagued with inaccuracies. We urge \"big data\" users to give due diligence at compiling data in order to avoid developing hypotheses based on insufficient or misleading basic information.

The Neotropics harbors a high diversity of species and several hypotheses have been proposed to account for this pattern. However, while species of forested domains are frequently studied, less is known of species from open vegetation formations occupying, altogether, a larger area than the Amazon Forest. Here we evaluate the role of historical barriers and the riverine hypothesis in the speciation patterns of small mammals by analyzing an ancient rodent lineage (Thrichomys, Hystricomorpha). Phylogenetic and biogeographic analyses were carried out with mitochondrial and nuclear DNA markers to analyze the evolutionary relationships between Thrichomys lineages occurring in dry domains along both banks of the Rio São Francisco. This river is one of the longest of South America whose course and water flow have been modified by inland tectonic activities and climate changes. Molecular data showed a higher number of lineages than previously described. The T. inermis species complex with 2n = 26, FN = 48 was observed in both banks of the river showing a paraphyletic arrangement, suggesting that river crossing had occurred, from east to west. A similar pattern was also observed for the T. apereoides complex. Thrichomys speciation occurred in Late Miocene when the river followed a different course. The current geographic distribution of Thrichomys species and their phylogenetic relationships suggested the existence of frequent past connections between both banks in the middle section of the Rio São Francisco. The extensive palaeodune region found in this area has been identified as a centre of endemism of several vertebrate species and is likely to be a center of Thrichomys diversification.

Neogale africana (Desmarest, 1818), Amazon Weasel, is a poorly known South American carnivore, with records from north-central Brazil to Ecuador and south to central Peru and central Brazil. Based on two videographic records, we report the presence of this species in Bolivia and document a new elevational record. Furthermore, our new record extends the species' distribution by 900 km from the nearest locality in Peru, and by 1500 km from the nearest Brazilian locality. Current gaps in its distribution are attributable to the low detectability and rarity of this mustelid.

Protozoan parasites are known for their remarkable capacity to persist within the bodies of vertebrate hosts, which frequently results in prolonged infections and the recurrence of diseases. Understanding the molecular mechanisms that underlie the event of persistence is of paramount significance to develop innovative therapeutic approaches, given that these pathways still need to be thoroughly elucidated. The present article provides a comprehensive overview of the latest developments in the investigation of protozoan persistence in vertebrate hosts. The focus is primarily on the function of persisters, their formation within the host, and the specific molecular interactions between host and parasite while they persist. Additionally, we examine the metabolomic, transcriptional, and translational changes that protozoan parasites undergo during persistence within vertebrate hosts, focusing on major parasites such as Plasmodium spp., Trypanosoma spp., Leishmania spp., and Toxoplasma spp. Key findings of our study suggest that protozoan parasites deploy several molecular and physiological strategies to evade the host immune surveillance and sustain their persistence. Furthermore, some parasites undergo stage differentiation, enabling them to acclimate to varying host environments and immune challenges. More often, stressors such as drug exposure were demonstrated to impact the formation of protozoan persisters significantly. Understanding the molecular mechanisms regulating the persistence of protozoan parasites in vertebrate hosts can reinvigorate our current insights into host–parasite interactions and facilitate the development of more efficacious disease therapeutics.

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.

Abstract The Andean cloud forests of Ecuador are home to numerous unique mammals. Rodents of the tribe Thomasomyini are particularly abundant in many Andean localities, with Thomasomys – the largest genus in the subfamily Sigmodontinae (51 species) – especially species-rich and diverse. Despite recent advances on the systematics of the genus, where seven species have been described in the last five years, there is tantalizing evidence that its true diversity remains completely understood. Over the course of approximately ten years of fieldwork in Ecuador, a significant number of Thomasomys specimens were collected from various localities in both, the eastern and western Andean ranges. Through an extensive genetic study of these specimens, augmented with what is available in public databases, we argue that there exist at least 20 undescribed species in the genus, with no less that twelve potential new species in Ecuador alone. In this paper, we describe two of these species belonging to the group cinereus , one recently collected and the other previously referred to as Thomasomys sp. 1; further, we present an updated cyt b gene tree of the genus. The gene tree includes at least 56 valid and putative species and supports the monophyly of the genus, while at the same time suggest a paraphyletic “ aureus ” group. Our findings suggest that the genus likely exhibits additional hidden diversity in significant portions of Colombia, Peru, and Bolivia which calls for the need for a comprehensive reassessment of the entire genus. The recognition of these two new species brings the total number of known Thomasomys to 53 species, 19 of which occur in Ecuador, including 17 that are endemic to this country.

Insectivorous bats of the family Vespertilionidae have been grouped into eight tribes, with Lasiurini showing an extensive distribution in South America. In Bolivia, three species of lasiurine bats have been reported: Lasiurus blossevillii (Lesson & Garnot, 1826), L. ega (Gervais, 1856), and L. villosissimus (É. Geoffroy St.-Hilaire, 1806). The morphological analyses of specimens of this genus deposited in Bolivian scientific collections and comparisons with specimens from other countries (including holotypes) prompt us to report the first records of three species: Lasiurus atratus Handley 1996, L. castaneus Handley 1960, and L. egregius (Peters, 1870) in Bolivia, expanding their known geographic ranges to the southwestern part of the Amazon.

We review the taxonomic identities of museum specimens of three bat species previously reported from Bolivia. We comment on some erroneously reported taxa, or taxa either not represented by voucher materials or based on insufficient data (including acoustic detections) to verify their taxonomic affinities. As result of this review, the list of bat species known to occur in Bolivia is updated to eight families and 133 species, unlike the nine families and 146 species of previous lists. Some recommendations for future research and a brief historical revision of bat inventories in the country are included.