Western Amazon Research Articles

New record of Youngomyia pouteriae Maia, 2001 (Diptera, Cecidomyiidae) in Pouteria caimito (Ruiz & Pav.) Radlk. (Sapotaceae) in the Peruvian Amazon

We report for the first time cylindrical galls of Youngomyia pouteriae Maia, 2001 (Diptera, Cecidomyiidae) on Pouteria caimito (Ruiz & Pav.) Radlk. (Sapotaceae) in Peru. Youngomyia pouteriae were exclusively found in the Atlantic Forest biome, in restinga areas of Rio de Janeiro state, Brazil. In this study, the geographic distribution of this galling species is extended to the western Amazon lowland rainforest in Peru.

The role of climate on the emergence of giant caimanines (Crocodylia, Alligatoroidea) from the Miocene western Amazonian region

The role of climate on the emergence of giant caimanines (Crocodylia, Alligatoroidea) from the Miocene western Amazonian region

Non-destructive and rapid identification of yeasts by nearinfrared spectroscopy and machine learning

This study aimed to apply near-infrared (NIR) spectroscopy combined with machine learning techniques to identify yeast strains rapidly and practically, comparing the results with traditional molecular identification methods. Yeasts were isolated from the digestive tracts of aquatic mining insects collected in the extreme north of the Western Amazon (Roraima), Brazil, and preserved through cryopreservation and mineral oil methods. Molecular identification involved PCR amplification and sequencing of ribosomal DNA regions. NIR spectroscopy, coupled with multivariate analysis and machine learning algorithms such as principal component analysis (PCA), hierarchical cluster analysis (HCA), k-nearest neighbor (KNN), and soft independent modeling by class analogy (SIMCA), was used to analyze and classify the yeast samples, accurately identified yeast strains at the genus and species levels, achieving 100% accuracy in both the calibration and validation sets. The results indicate that this method provides a rapid, non-destructive, and environmentally friendly alternative to traditional molecular techniques, making it suitable for real-time, in situ analysis with minimal sample manipulation.

Continued Breastfeeding in a Birth Cohort in the Western Amazon of Brazil: Risk of Interruption and Associated Factors

Background: Continued breastfeeding reduces infant mortality and provides nutritional, immunological, and developmental benefits for the child. Objectives: A prospective cohort study conducted in 2015 followed 608 children who were breastfed between 6 and 24 months. The study assessed the risk of breastfeeding interruption at 12, 18, and 24 months, as well as the factors associated with this outcome, in a cohort of newborns in Rio Branco, using the life table method. Methods: The factors associated with breastfeeding cessation and their 95% confidence intervals (CI95%) were analyzed using both crude and adjusted Cox proportional hazards regression in a hierarchical model. The risks of breastfeeding cessation at 12, 18, and 24 months were 19%, 65%, and 71%, respectively. Results: Factors positively associated with the risk of breastfeeding cessation include the use of a pacifier before 6 weeks of age (HR = 1.62; CI: 95% 1.24–2.11) and the use of a bottle during the first year of life (HR = 1.41; CI: 95% 1.11–1.78). Maternal return to work after the birth of the baby (HR = 0.78; CI: 95% 0.62–0.97) was found to be negatively associated with the risk of breastfeeding interruption. Conclusions: Early pacifier use before 6 weeks and the introduction of a bottle in the first year affect continued breastfeeding. Maternal employment was associated with reduced risk of breastfeeding cessation, contrary to most studies.

Genetic Variability in the Physicochemical Characteristics of Cultivated Coffea canephora Genotypes.

The objective of this study was to characterize the genetic divergence and selection gains of the physicochemical grains traits of 68 genotypes of C. canephora most cultivated in the Western Amazon. For this purpose, the following characteristics were evaluated over two harvests: aqueous extract, ash, acidity, pH, protein, ether extract, soluble solids, phenolic compounds, soluble sugars, reducing sugars, and non-reducing sugars. The genotype × measurement interaction effect was significant for all characteristics, with a predominant simple interaction, resulting in smaller changes in the ranking of genotypes. Out of a total of 45 genotypic correlation estimates, 8 were significant, of which 5 were related to acidity. The dispersion of the first two components associated with reference points shows that the genotypes BRS3193, AS1, AS2, AS3, N16, CA1, and AS7 were closest to the ideal type of higher performance. Selection for the main characteristic of soluble sugars resulted in estimates of genetic progress lower than those observed using selection indices. The genetic materials present high genetic diversity, allowing the selection of reference plants with high levels of sugars (BRS3193, AS3, GJ25, and LB30), proteins (BRS2357), lipids (GJ30), and phenolic compounds in their green beans (BRS3193) and high water solubility (AS2).

Activity, foraging mode, and abundance of the aquatic coral snake Micrurus surinamensis (Cuvier, 1816) (Serpentes: Elapidae) in the western Brazilian Amazonia

ABSTRACT Elapids of the genus Micrurus actively search for their prey. Here we present new information on the foraging ecology of the aquatic coral snake Micrurus surinamensis based on observations in the western Amazon of Brazil. Eleven individuals of M. surinamensis were observed at night, four of them moving, four hunting in ambush posture, and three actively hunting. Here, we show that M. surinamensis is active mainly at night in aquatic environments and may also be active on the terrestrial environments. Land activity may be related with the search for fish which may eventually be found in this substrate, as well as with the search for water bodies, following the hydrological cycles of flooding and drought. When hunting, the snake uses both foraging modes, being able to actively search for its prey, or ambush it, by keeping the body partially in the water, with the head on the surface. Due to the greater availability of aquatic environments and available prey (fish), M. surinamensis should be more abundant in floodplain forest ecosystems. Additional field observations may help in elucidating the biology on this ecologically differentiated species within the genus Micrurus.

The biogeography of the Amazonian tree flora

We describe the geographical variation in tree species composition across Amazonian forests and show how environmental conditions are associated with species turnover. Our analyses are based on 2023 forest inventory plots (1 ha) that provide abundance data for a total of 5188 tree species. Within-plot species composition reflected both local environmental conditions (especially soil nutrients and hydrology) and geographical regions. A broader-scale view of species turnover was obtained by interpolating the relative tree species abundances over Amazonia into 47,441 0.1-degree grid cells. Two main dimensions of spatial change in tree species composition were identified. The first was a gradient between western Amazonia at the Andean forelands (with young geology and relatively nutrient-rich soils) and central–eastern Amazonia associated with the Guiana and Brazilian Shields (with more ancient geology and poor soils). The second gradient was between the wet forests of the northwest and the drier forests in southern Amazonia. Isolines linking cells of similar composition crossed major Amazonian rivers, suggesting that tree species distributions are not limited by rivers. Even though some areas of relatively sharp species turnover were identified, mostly the tree species composition changed gradually over large extents, which does not support delimiting clear discrete biogeographic regions within Amazonia.

Multiplatform Path-ComDim study of Capixaba, indigenous and non-indigenous Amazonian Canephora coffees

Integrating diverse measurement platforms can yield profound insights. This study examined Brazilian Canephora coffees from Rondônia (Western Amazon) and Espírito Santo (southeast), hypothesizing that geographical and climatic differences along botanical varieties significantly impact coffee characteristics. To test this, capixaba, indigenous, and non-indigenous Amazonian canephora coffees were analyzed using nine distinct platforms, including both spectroscopic techniques and sensory evaluations, to obtain results that are more informative and complementary than conventional single-method analyses. By applying multi-block Path-ComDim analysis to the multiple data sets, we uncovered crucial correlations between instrumental and sensory measurements. This integrated approach not only confirmed the hypothesis but also demonstrated that combining multiple data sets provides a more nuanced understanding of coffee profiles than traditional single-method analyses. The results underscore the value of multiplatform approaches in enhancing coffee quality evaluation, offering a more detailed and comprehensive view of coffee characteristics that can drive future research and improve industry standards.

Integrating natural disasters into protected area designing for global primate conservation under climate change

Disaster risk reduction, an essential function of protected areas (PAs), has been generally overlooked in PA design. Using primates as a model, we designed a disaster risk index (DRI) to measure the disaster sensitivity of primate species. High-conservation-need areas (HCN) were identified by both their richness and number of threatened primate species. We also constructed high-disaster-risk areas (HDR) and climate-sensitive areas (CS) based on a disaster risk assessment and temperature change under climate change. We overlaid HCN and HDR areas to obtain HDR-HCN areas. We defined species conservation targets as the percent of each species’ range that should be effectively conserved using “Zonation”. Landslides had the highest DRI (1.43 ± 0.88), but have been overlooked in previous studies. PA coverage in HDR-HCN (30%) was similar to that in HCN areas (28%), indicating that current PA design fails to account for disaster risk reduction. About 50% of the HDR-HCN areas overlapped with CS areas. Presently, 43% of primate species meet their conservation targets. Fifty-seven of primate species would meet their conservation targets and 67% of primates could benefit from PA expansion if HDR-HCN areas are fully incorporated into PAs. Increasing PA coverage in HDR-HCN areas is essential to achieving both primate conservation and disaster risk reduction. The study calls for integrating disaster risk reduction into PA design guidelines, particularly in regions like the western Amazon, and recommends flexible conservation approaches in other areas.

Endemic and elusive trophic interactions: The first comprehensive description of the diet of short-eared dogs (Atelocynus microtis) in Amazon rainforests

The short-eared dog (Atelocynus microtis) is the only endemic Amazonian canid species, which is also elusive and rarely recorded across its distribution, making it one of the least known canid species in the world. Even though it is considered to be a carnivore species, it has been reported to consume other food items, such as fruits. However, no comprehensive analysis of its diet is currently available in the literature. Here we report the first comprehensive analysis of the diet of wild and re-introduced individuals of A. microtis in the western Amazon (southeastern Peru). Its diet includes at least 34 distinct food items, including arthropods, vertebrates (fish, amphibians, reptiles, birds, and mammals), fruits, and seeds. Our study confirms the potential of A. microtis to be considered omnivorous, as well as expands the known range of food items in its diet. As a mesocarnivore with an omnivorous diet, A. microtis has important potential implications for forest dynamics, such as seed dispersal and regulating prey populations, which should be further investigated.

The small and inconspicuous majority: Revealing the megadiversity and historical biogeography of the Pristimantis unistrigatus species group (Anura, Strabomantidae)

With more than 600 recognized species, the genus Pristimantis is already the most diverse among vertebrates, but described species only represent a fraction of the actual diversity in this clade. This genus is widely distributed throughout the Neotropics and represents an interesting model for biogeographic studies because Pristimantis spp. are direct developing and generally have narrow ecological niches and low dispersal abilities. The P. unistrigatus species group is one of the most important components in the genus (ca. 200 recognized species) and has been supported by morphological but not by molecular evidence. We assessed the species boundaries and distribution in the P. unistrigatus species group and infer spatiotemporal patterns of diversification related to historical landscape changes in the Neotropics. We gathered three mitochondrial, and two nuclear DNA loci from 416 specimens throughout the range of the group, and including 68 nominal species. We redefine the group based on the obtained phylogeny and found 151 candidate species that composes it, with 83 of these remaining undescribed. We recovered 11 major clades within the group that diverged before 13 Ma. The diversification of the group started during the early Miocene most likely in northwestern South America, currently corresponding to western Amazonia and northern Andes. The other neotropical areas subsequently acted as sinks, receiving lineages mostly during the last 10 Ma, after the demise of the Pebas System and the setup of the modern Amazonian hydrographic system.

Human outbreaks of a novel reassortant Oropouche virus in the Brazilian Amazon region.

The Brazilian western Amazon is experiencing its largest laboratory-confirmed Oropouche virus (OROV) outbreak, with more than 6,300 reported cases between 2022 and 2024. Here, we sequenced and analyzed 382 OROV genomes from human samples collected in Amazonas, Acre, Rondônia, and Roraima states, between August 2022 and February 2024, to uncover the origin and genetic evolution of OROV in the current outbreak. Genomic analyses revealed that the upsurge of OROV cases in the Brazilian Amazon coincides with spread of a novel reassortant lineage containing the M segment of viruses detected in the eastern Amazon region (2009-2018) and the L and S segments of viruses detected in Peru, Colombia, and Ecuador (2008-2021). The novel reassortant likely emerged in the Amazonas state between 2010 and 2014 and spread through long-range dispersion events during the second half of the 2010s. Phylodynamics reconstructions showed that the current OROV spread was mainly driven by short-range (< 2 km) movements consistent with the flight range of vectors. Nevertheless, a substantial proportion (22%) of long-range (> 10 km) OROV migrations were also detected, consistent with viral dispersion by humans. Our data provides a view of the unprecedented spread and evolution of OROV in Brazilian western Amazon region.

Characteristics of Precipitation and Mesoscale Convective Systems Over the Peruvian Central Andes in Multi 5‐Year Convection‐Permitting Simulations

AbstractUsing the Weather Research and Forecasting model with two planetary boundary layer schemes, ACM2 and MYNN, convection‐permitting model (CPM) regional climate simulations were conducted for a 6‐year period, including a one‐year spin‐up period, at a 15‐km grid spacing covering entire South America and a nested convection‐permitting 3‐km grid spacing covering the Peruvian central Andes region. These two CPM simulations along with a 4‐km simulation covering South America produced by National Center for Atmospheric Research (NCAR), three gridded precipitation products, and rain gauge data in Peru and Brazil, are used to document the characteristics of precipitation and mesoscale convective systems (MCSs) in the Peruvian central Andes region. Results show that all km‐scale simulations generally capture the spatiotemporal patterns of precipitation and MCSs at both seasonal and diurnal scales, although biases exist in aspects such as precipitation intensity and MCS frequency, size, propagation speed, and associated precipitation intensity. The 3‐km simulation using MYNN scheme generally outperforms the other simulations in capturing seasonal and diurnal precipitation over the mountain, while both it and the 4‐km simulation demonstrate superior performance in the western Amazon Basin, based on the comparison to the gridded precipitation products and gauge data. Dynamic factors, primarily low‐level jet and terrain‐induced uplift, are the key drivers for precipitation and MCS genesis along the east slope of the Andes, while thermodynamic factors control the precipitation and MCS activity in the western Amazon Basin and over elevated mountainous regions. The study suggests model improvements and better model configurations for future regional climate projections.

Climate‐Driven Projections of Future Global Wetlands Extent

AbstractWetlands are crucial components of the Earth's system, interacting with various processes such as the hydrological cycle, energy exchanges with the atmosphere, and global nitrogen and carbon cycles. The future trajectory of wetlands is anticipated to be influenced not only by direct human activities, but also by climate change. Here we present our assessment of climate‐driven global changes in wetlands extent, focusing on the main wetland complexes. We used an approach based on the Topographic Hydrological model (TOPMODEL) and soil liquid water content projections from 14 models of the Coupled Model Intercomparison Project Phase 6 (CMIP6). Our analysis reveals a consistent decrease in wetlands extent in the Mediterranean, Central America, and northern South America, with a substantial loss of 28% in the western Amazon Basin for the end of the 21st century (2081–2100) under the SSP370 scenario. Conversely, Central Africa exhibits an increase in wetlands extent, except in the Congo Basin. Nevertheless, most of the areas studied (80%) present uncertain results, due to conflicting projections of changes between the models. Notably, we show that there is significant uncertainty among CMIP6 models regarding liquid soil water content in high latitudes. By narrowing our focus to 10 models, which seem to better represent the thawing of permafrost, we obtain a better inter‐model agreement. We then find a modest declines in the overall global area (&lt;5%), but an average loss of 13% beyond 50°N. Specific areas like the Hudson Bay Lowlands experiencing a 21% decrease and the Western Siberian Lowlands a 15% decrease.

Invasive Bubalus bubalis may reduce by half the flooded area in a western Amazonian Ramsar site

Invasive Bubalus bubalis may reduce by half the flooded area in a western Amazonian Ramsar site

Severe Acute Respiratory Syndrome and COVID-19 Under the Urban Hierarchy of Municipalities in the State of Rondônia (Western Amazon)

Analyzing the SARS data can provide insights into the severe form of COVID-19, contributing to short, medium, and long-term pandemic response planning. The virus entered Brazilian through air travel, spreading via airport connections. The spatial diffusion of COVID-19 transmission is linked to the territorial division of labor (referring to characteristic daily activities), as reflected in the urban hierarchical network, which serves as a framework for analyzing COVID-19 transmission. This analysis covers mobility aspects such as density, connectivity and the movement of people at different scales. The objective is to evaluate the transmission of SARS and COVID-19 in the state of Rondônia, Western Amazon, between 2020 and 2021, using geoprocessing techniques for spatiotemporal analysis. Maps depicting the urban hierarchy (understood as cities organized by size, from smallest to largest) of the municipalities of Rondônia, along with SARS incidence rates and their standard deviation, were created using QGIS program, version 2.18.20. Spatiotemporal analysis was conducted using Kulldorff statistics to identify clusters of SARS cases in each municipality. A higher concentration of SARS rates ​​was observed in municipalities in the northwestern part of the state. Six spatiotemporal clusters were identified, but no clear pattern of spatial distribution was observed. The spatial diffusion of COVID-19 transmission is linked to the territorial division of labor (i.e., the spatial classification based on the predominant economic activity in each area), as evidenced by the urban hierarchical network, which serves as a reference for analyzing COVID-19 transmission.

A new Late Miocene stem Octodontoid (Rodentia: Caviomorpha: Octochinchilloi) from the Solimões Formation (Brazil): paleobiogeographic implications

ABSTRACT Caviomorphs are the neotropical hystricognathous rodents (Ctenohystrica: Hystricognathi: Caviomorpha). Octodontoidea are today the richest and most speciose clade of caviomorphs. Their fossil record also reveals a wide array of extinct species, including Acarechimys, a taxon with a widespread South American distribution and extensive temporal range. This genus comprises at least five species documented in deposits ranging from the late Oligocene to the Middle Miocene. Here, we report the discovery of a new species of Acarechimys from Upper Miocene deposits of the Envira River (PRE06 outcrop), situated in the Acre State, western Brazilian Amazonia. The new species differs from the other species of the genus in having lower molars with a strong posterior arm of the metaconid, the presence of a mesostylid (usually prominent) and a neomesolophid forwardly directed and connected to the metalophulid I on m1 but not on m2–3, and the absence of posterior arm of the protoconid. This taxon represents the youngest known species of the Acarechimys lineage to date. Its occurrence in Western Amazonia strengthens support for the hypothesis that South American rodent lineages survived longer during the Neogene at low latitudes than in the southern regions of the continent.

Factors associated with quality of life in adults with diabetes registered in Primary Care in the Western Amazon

Factors associated with quality of life in adults with diabetes registered in Primary Care in the Western Amazon

Quality of life and associated factors among adults with high blood pressure registered in Primary Care in the Western Amazon

Quality of life and associated factors among adults with high blood pressure registered in Primary Care in the Western Amazon

Tropical Andean climate variations since the last deglaciation

Global warming during the Last Glacial Termination was interrupted by millennial-scale cool intervals such as the Younger Dryas and the Antarctic Cold Reversal (ACR). Although these events are well characterized at high latitudes, their impacts at low latitudes are less well known. We present high-resolution temperature and hydroclimate records from the tropical Andes spanning the past ~16,800 y using organic geochemical proxies applied to a sediment core from Laguna Llaviucu, Ecuador. Our hydroclimate record aligns with records from the western Amazon and eastern and central Andes and indicates a dominant long-term influence of changing austral summer insolation on the intensity of the South American Summer Monsoon. Our temperature record indicates a ~4 °C warming during the glacial termination, stable temperatures in the early to mid-Holocene, and slight, gradual warming since ~6,000 y ago. Importantly, we observe a ~1.5 °C cold reversal coincident with the ACR. These data document a temperature change pattern during the deglaciation in the tropical Andes that resembles temperatures at high southern latitudes, which are thought to be controlled by radiative forcing from atmospheric greenhouse gases and changes in ocean heat transport by the Atlantic meridional overturning circulation.