Panstrongylus geniculatus is one of the most widely distributed triatomine species in the Americas and an important vector of Trypanosoma cruzi, the causative agent of Chagas disease. This study evaluated changes in the environmental suitability of P. geniculatus under historical, current, and future climate scenarios across the Americas using ecological niche modeling. A total of 347 occurrence records and bioclimatic variables were used to calibrate ecological niche models in kuenm, which were subsequently projected to the Last Glacial Maximum, the current climate, and future conditions (2061–2080) under the RCP4.5 and RCP8.5 scenarios. Model projections indicated broad, relatively stable areas of environmental suitability throughout the Neotropical region, with localized contractions in central Brazil and expansions in northern Mexico, Argentina, and Uruguay. Comparisons among temporal scenarios showed limited changes in environmentally suitable areas, with expansion and contraction areas remaining below 4% of the modeled extent. These results suggest that the climatic niche of P. geniculatus has remained relatively stable across the evaluated historical and future scenarios. The persistence of environmentally suitable areas highlights the importance of maintaining long-term entomological surveillance and vector monitoring under changing climatic conditions.
In the province of Entre Ríos (Argentina), streams are increasingly affected by land-use change, including livestock production, urban expansion, and wastewater discharge, which generate multiple stressors such as pollution, sedimentation, hydromorphological alteration, and habitat degradation. This study assessed benthic macroinvertebrate communities in eight streams exposed to contrasting land uses in a Neotropical lowland region of Entre Ríos. Between 2013 and 2019, streams were sampled using a standardized multi-habitat protocol. Community structure, functional feeding groups (FFGs), and ecosystem attributes were analyzed using univariate and multivariate approaches. A total of 64 taxa were recorded, with lower richness in urban streams. Shredders were absent from urban streams and scarce overall. Urban streams also exhibited reduced abundance, functional diversity, and ecosystem attributes. These results indicate that urbanization negatively affects both community structure and ecosystem functioning. Integrating taxonomic and functional approaches can improve ecological assessments and support conservation and management of freshwater ecosystems under anthropogenic pressure.
The Oilbird (Steatornis caripensis) is an important seed disperser in Neotropical forests whose population dynamics remain poorly understood. We evaluated long-term patterns of abundance and breeding activity in the Dunston Cave colony, Trinidad, and examined their relationships with vegetation productivity and rainfall. Monthly counts of adults and chicks collected between 2004 and 2015 were analyzed in relation to Enhanced Vegetation Index (EVI) data derived from MODIS imagery and local precipitation records. Seed remains collected in October 2015 were also compared with historical dietary data from 1957–1960. Oilbird abundance and vegetation productivity varied significantly over the study period. Diet composition differed from historical records, although palms remained the dominant food resource. Cross-correlation analyses revealed significant associations between colony dynamics, vegetation productivity, and rainfall. Adult and chick abundance peaked during the dry season, when EVI values were comparatively low, whereas rainfall was positively associated with adult abundance after a temporal lag. Breeding activity was concentrated between March and May, with peak chick abundance occurring in April. Our results indicate that seasonal environmental variation is associated with long-term patterns of Oilbird abundance and reproduction. Integrating satellite-derived vegetation indices with ecological monitoring offers a useful approach for assessing environmental influences on tropical frugivorous birds.
Land-use change is a major driver of biodiversity loss in amphibians and reptiles, yet information on species richness and community structure at local spatial scales remains limited. This study assessed the diversity and composition of the herpetofauna in the municipality of Iguala de la Independencia, Guerrero, Mexico. Field surveys were conducted between 2022 and 2023 at four sites representing the municipality’s main habitat types and were complemented by occurrence records from biodiversity databases. Inventory completeness was evaluated using rarefaction curves, and alpha and beta diversity were estimated to characterize community structure. A total of 40 species were recorded, including five amphibians and 35 reptiles. Rarefaction analyses indicated an inventory completeness greater than 98% and predicted a potential richness of approximately 44 species for the municipality. Only one habitat exhibited a Shannon diversity value above 2, corresponding to the highest effective number of species (exp(H’) = 9.24). Species turnover was the main component of beta diversity among habitats. The deciduous low forest showed the highest richness and diversity, although it also exhibited lower evenness among species. These findings provide new information on local-scale patterns of herpetofaunal diversity and highlight the importance of conserving heterogeneous habitats within human-modified landscapes.
La cuenca del río Magdalena ha experimentado una transformación intensa asociada a la concentración histórica de la población y actividades productivas, con implicaciones directas para la persistencia de su biodiversidad. Este estudio caracterizó la composición y distribución de los mamíferos en el Magdalena caldense, mediante la integración de muestreos estandarizados con cámaras trampa y recorridos de observación, literatura científica y registros de colecciones biológicas. Se consolidaron 2894 registros correspondientes a 42 especies (24 familias y 8 órdenes), con mayor riqueza de Carnivora. Cinco especies son endémicas de Colombia y ocho se encuentran en alguna categoría de amenaza a nivel nacional o global, incluyendo Saguinus leucopus, Ateles hybridus y Panthera onca. Los registros históricos se concentraron en elevaciones medias y altas, mientras que los muestreos recientes aportaron información clave para zonas bajas previamente subrepresentadas, lo que redujo vacíos espaciales de información. Estos resultados evidencian la relevancia de la subregión Magdalena caldense para la conservación de mamíferos medianos y grandes en el valle interandino del río Magdalena y proporcionan una línea base robusta para la planificación de estrategias de manejo, conectividad del paisaje y monitoreo a largo plazo.
