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Abstract Interactions among humans, livestock, and wildlife within disturbed ecosystems, such as those impacted by climate change, can facilitate pathogen spillover transmission and increase disease emergence risks. The study of future climate change impacts on the distribution of free-ranging bats is therefore relevant for forecasting potential disease burden. This study used current and future climate data and historic occurrence locations of the vampire bat speciesDesmodus rotundus, a reservoir of the rabies virus to assess the potential impacts of climate change on disease reservoir distribution. Analyses included a comprehensive comparison of different climate change periods, carbon emission scenarios, and global circulation models (GCMs) on final model outputs. Models revealed that, although climatic scenarios and GCMs used have a significant influence on model outputs, there was a consistent signal of range expansion across the future climates analyzed. Areas suitable forD. rotundusrange expansion include the southern United States and south-central portions of Argentina and Chile. Certain areas in the Amazon Rainforest, which currently rests at the geographic center ofD. rotundus’ range, may become climatically unsuitable for this species within the context of niche conservatism. While the impacts of rabies virus transmitted byD. rotunduson livestock are well known, an expansion ofD. rotundusinto novel areas may impact new mammalian species and livestock with unexpected consequences. Some areas in the Americas may benefit from an assessment of their preparedness to deal with an expectedD. rotundusrange expansion. 

Abstract BackgroundTrypanosomaare protozoa parasites that infect animals and can cause economic losses in cattle production.Trypanosomalive in the blood and are transmitted by hematophagous insects, such as flies in the genusTabanus.Using ecological niche models, we explored the current geography of six commonTabanusspecies in Brazil, which are considered vectors ofTrypanosoma vivaxandTr. evansiin the Neotropics. MethodsWe used georeferenced data and biotic and abiotic variables integrated using a fundamental ecological niche modeling approach. Modeling results from sixTabanusspecies were used to identify risk areas ofTrypanosomatransmission in Latin America accounting for area predicted, landscape conditions, and density of livestock. We performed Jaccard, Schoener, and Hellinger metrics to indicate the ecological niche similarities of pairs ofTabanusspecies to identify known and likely vectors overlapping in distribution across geographies. ResultsOur results revealed significant ecological niche similarities for twoTabanusspecies (T. pungensandT. sorbillans), whereasT. triangulumandT. importunushave low ecological similarity. Ecological niche models predicted risk ofTrypanosomatransmission across Neotropical countries, with the highest risk in southern South America, Venezuela, and central Mexico. ConclusionsMore than 1.6 billion cattle and 38 million horses are under a threat category for infection risk. Furthermore, we identified specific areas and livestock populations at high risk of trypanosomiasis in Latin America. This study reveals the areas, landscapes, and populations at risk ofTrypanosomainfections in livestock in the Americas. Graphical Abstract 

Cockroaches are vectors of pathogens and parasites that pose public health risks, especially in developing countries with poor hygiene and inadequate infrastructure. This study aimed to identify the household factors associated with the occurrence of cockroaches and the helminth parasites they carry in a rural community. Data on household infrastructure, presence of domestic animals, and insect control methods were collected from 70 households in rural Guatemala. Cockroaches were captured using traps and manually. A Generalized Linear Mixed Model revealed that households with concrete roofs had 94% lower abundance of cockroaches than those with metal sheet roofs, while the presence of cats increased cockroach abundance by 2.6 times (p < 0.05). Six genera of helminths, including the acanthocephalan zoonotic parasiteMoniliformis moniliformis, were identified, marking the first report of such parasites in household cockroaches in Guatemala. These results highlight the need for improved housing infrastructure and integrated pest management strategies to mitigate the risks associated with cockroach-borne parasites in vulnerable communities. 

Sexual dimorphism in bats is understudied, with conflicting evidence across species and geographic regions. ForDesmodus rotundus, the common vampire bat, previous reports on morphological sex differences have been inconsistent. This study aimed to assess sexual dimorphism inD. rotundususing a combination of contemporary field measurements and historical museum specimens. We analyzed six morphometric traits, including body mass, head length, body length, tibia length, ear length, and forearm length. Data were collected from 46 wild-captured individuals from five locations across Colombia in South America. Additionally, forearm length was examined in an expanded dataset of 490 specimens, including additional 444 individuals from museum vouchers collected over the past century. Principal components analysis and hierarchical clustering of the six-trait dataset showed patterns of differentiation between sexes, with partial overlap. Forearm length, analyzed independently in the full 490-specimen dataset, showed strong evidence of sexual dimorphism. Females had significantly longer forearms (mean = 61.8 mm) than males (mean = 58.5 mm), with non-overlapping 95% confidence intervals and a highly significant t-test result (t = −12.68, p < 2 × 10 ⁻ ¹⁶). Sex explained 25.7% of the variation in forearm length (R² = 0.26). Tibia length also differed significantly between sexes of the wild-catch individuals (p = 0.004), with females exhibiting greater values. Comparisons between museum specimens (historical) and wild-caught specimens (contemporary) showed no significant differences across time in either sex. Among females, the difference was not significant (t = −0.93, df = 208, p = 0.355), and the same was true for males (t = −0.01, df = 278, p = 0.992). A follow-up MANOVA on the six morphometric traits indicated a significant effect of sex (Pillai’s trace = 0.389, approx. F(6,39)=4.14, p < 2.2 × 10 ⁻ ¹⁶). After correcting for multiple comparisons, significant sexual dimorphism remained for forearm and tibia lengths, with forearm showing the strongest signal. These findings provide robust support for modest but consistent female-biased dimorphism inD. rotundus. The use of both multivariate and univariate analysis, combined with long-term historical data, enhanced the reliability of signals detected regarding morphological differences.Desmodus rotundusplay a role as a primary reservoir for zoonotic viruses, has potential relevance in biomedical research, and provides ecosystem services. Understanding sex-based morphological variation is critical to inform public health, ecology, and biological conservation strategies. Females were consistently larger than males, but segregation was not absolute, with some individuals falling outside the expected data range for their sex. This study contributes to a clearer understanding of morphological variation and lays the groundwork for future research into the ecological and evolutionary drivers of dimorphism in bats. 

Abstract Mosquito-borne diseases pose a dire threat to humanity, claiming over 700,000 lives annually. At the local scale, the interplay between several environmental factors influences mosquito biology: temperature, precipitation, and temporal variations profoundly shape mosquito populations, impacting disease transmission dynamics. However, how environmental conditions modulate sugar feeding has been critically understudied. To bridge this knowledge gap, we conducted field captures across distinct ecological settings: urban and forested areas at high and low elevations. We used established mosquito trapping techniques and satellite-derived data to examine environmental parameters and mosquito abundance dynamics. Moreover, we investigated the relationship between mosquito size, sugar consumption, and environmental variables by analyzing wing length, nectar presence, and carbohydrate concentrations. Results showed a higher proportion of sugar-fed mosquitoes in urban habitats, correlated to the presence of ornamental plants on which mosquitoes can feed and associated with Aedes albopictus dominating the mosquito population (81.3% of trapped individuals). In contrast, Culex mosquitoes accounted for 87.2% of the mosquito populations at both high- and low-elevation forested sites. Altogether, our results identify an interplay between environmental and physiological factors with implications for population prediction and, by extension, mosquito control strategies. 

Bats serve as reservoir hosts for numerous zoonotic pathogens of public health significance, including coronaviruses, lyssaviruses, and henipaviruses, while simultaneously playing critical roles in ecosystem function through pollination, seed dispersal, and pest control. The increasing frequency of bat-associated disease outbreaks has intensified research interest; yet standardized protocols for safe and effective bat sampling remain fragmented. We conducted a systematic review of bat sampling practices and synthesized comprehensive guidelines for capturing, handling, and sampling free-ranging bats for epidemiological surveillance and outbreak investigations. Our framework emphasizes three key elements, including (i) biosecurity measures to prevent pathogen spillover transmission from bats to humans, (ii) biosafety protocols to avoid spillback transmission, and (iii) welfare considerations to minimize the impact on bat populations. Through analysis of published literature and field protocols, we identified significant gaps between recommended and common practices in bat research. We present evidence-based recommendations for capture techniques, specimen collection, sample processing, and storage methods, with particular attention to maintaining sample quality while ensuring safety. Additionally, we provide detailed guidance for field laboratory setup, personnel training requirements, and emergency response procedures. The implementation of these standardized protocols will enhance the quality and compatibility of bat research data while protecting both human and bat health. This guide serves as a foundation for safe, ethical, and effective investigation of bat-borne pathogen epidemiology and ecology, particularly in resource-limited settings where disease emergence risks are often highest. 

BackgroundRabies is an acute and progressive viral zoonotic disease of the nervous system, which widely affects domestic animals in Latin America. Vampire bat-borne rabies virus (RABV) has significant negative impacts on the livestock industry via animal mortality. Nevertheless, the landscape level factors that facilitate or limit RABV transmission from vampire bats to livestock remain elusive. MethodsTo determine how abiotic and biotic factors modulate RABV spillover from vampire bats to livestock, we assessed the role of different landscape variables on the occurrence of RABV spillover fromDesmodus rotundusto livestock in Colombia. Using ecological niche modeling as the theoretical and analytical framework, we analyzed ecological and epidemiological RABV data to reconstruct spillover transmission events. ResultsAnthropogenic variables including livestock and human density were consistently selected as predictors of RABV spillover from vampire bats to livestock. Cattle density had the highest average relative contribution to final ecological niche models (64.7%). We also found improvement of RABV spillover risk estimates when sampling bias in the form of cattle density was used in the modeling process. High risk for RABV spillover (0.75-0.98) was consistently predicted in the Caribbean region of Colombia. Nevertheless, more widespread moderate RABV spillover risk was predicted more broadly across the country when sampling bias was accounted for. ConclusionOur modelling effort revealed that variable selection and use of bias surface have tractable impacts on final projections of spillover risk. Our results also indicate that human activity drives RABV spillover risk to a greater extent than ecological or climatological factors. Results from this study provide important information about landscape conditions linked to RABV transmission risk, where livestock vaccination should be prioritized. 

Despite the large body of literature on avian migratory behavior, there is little information about stopover sites during bird movement, including the population-level drivers of breeding grounds and wintering grounds. Stopovers play an essential role in bird migratory site chains for energy supply and rest. There is an urgent need to detect and protect stopover sites to secure the long-term sustainability of migratory network connectivity and robustness. To address this challenge, we reconstructed a migration network and identified geographic hotspots denoted as stopover sites by analyzing the high-density population movements of 52 focal migratory bird species with observation data from eBird through PageRank algorithm. Furthermore, potential alternative stopover sites were explored using a word embedding technique based on geo-functional similarity. Our study was conducted in North and Central America during a three-year period and revealed three key areas, including Florida peninsula and its inland, the region of Central America, and the region near Puget Sound. Results from this study can be used for conservation prioritization guidance. 

Rodentia is the most widely distributed, diverse, and numerous order of the class Mammalia. Nevertheless, rodents are poorly studied in terms of their conservation compared to other mammalian orders. Chile has one of the highest rates of extinction risk in the world for mammals (20%), where rodents have the highest risk (32%). The data of threatened rodent species is not comprehensive, as many species are still classified as data deficient. This lack of information could mean that the actual number of threatened species is higher than currently recognized. Using different databases, the biogeography, conservation status, ecological roles of rodent species in Chile are updated and described, and their potential zoonotic implication discussed. Results revealed that rodent species richness is highest in the northern and central-southern regions of Chile, where fewer protected areas exist, suggesting an inefficient role of public protected areas for the conservation of rodents and potentially other taxa. The conservation classification by the Chilean government did not match the conservation status from international classifications, revealing poor information for several species at national level. Functional traits of the species studied suggest that rodents are good predictors of ecosystem health due to their rapid life cycles and wide distribution, although distribution was predictive for only some species. Our results indicated that better information on the distribution and rodent species richness provide opportunities to understand complex rodent-borne diseases such as hantavirus. This study validates the use of rodents as indicators to assess ecosystem health and design effective biodiversity conservation plans. 

Rabies is a zoonotic infectious disease of global distribution that impacts human and animal health. In rural Latin America, rabies negatively impacts food security and the economy due to losses in livestock production. The common vampire bat,Desmodus rotundus, is the main reservoir and transmitter of rabies virus (RABV) to domestic animals in Latin America.Desmodus rotundusRABV is known to impact the cattle industry, from small farmers to large corporations. We assessed the main patterns of rabies in cattle attributed toD.rotundusRABV across Latin America. Epidemiological data on rabies from Latin America were collected from the Pan American Health Organization spanning the 1970–2023 period. Analyses revealed an average of 450 outbreaks annually for the countries whereD.rotundusis distributed, with at least 6 animals dying in each outbreak. Brazil, Colombia, Peru, and Mexico were the Latin American countries with the highest number of rabies outbreaks during the study period and are the most affected countries in recent years. Findings suggest a re-emergence of bat-borne rabies in the region with more outbreaks reported in recent years, especially during the 2003–2020 period. Rabies outbreaks in cattle in the 2000–2020 period were significantly more frequent than in previous decades, with an increase in cross-species transmission after 2002. The size of outbreaks, however, was smaller in recent years, involving lower cattle mortality. Peru, El Salvador, and Brazil showed a strong association (R = 0.73,p= 0.01) between rabies incidence inD.rotundus(rates per million humans: 1.61, 0.94, and 1.09, respectively) and rabies outbreaks in cattle (rates per million cattle: 465.85, 351.01, and 48.22, respectively). A sustained, standardized, and widespread monitoring ofD.rotundusdemography and health could serve to inform an early warning system for the early detection of RABV and other bat-borne pathogens in Latin America. Current data can be used to forecast when, where, and in which intensity RABV outbreaks are more likely to occur in subtropical and tropical Latin America. A decrease in the size of outbreaks could suggest that strategies for epidemic management (e.g., education, early diagnosis, vaccination) have been effective. The increase in the number of outbreaks could suggest that the factors facilitating cross-species transmission could be on the rise.