Biology subjects

Chavez, W.

Publications and source records attributed to Chavez, W..

3 recordsLinked to original sources

bioRxiv2025

Spillover of H5 influenza viruses to vampire bats at the marine-terrestrial interface

The highly pathogenic H5N1 avian influenza A virus (IAV) clade 2.3.4.4b has spread globally and spilled over into multiple mammalian species, raising concerns about its pandemic potential. In late 2022, clade 2.3.4.4b viruses devastated seabird and marine mammal populations along the Pacific coast of South America. Here, we report the first evidence of H5 IAV infections in wild bats globally, focusing on common vampire bats (Desmodus rotundus) in coastal areas of Peru. Longitudinal serological screening, stable isotope analysis and metabarcoding revealed repeated exposures to H5 IAVs in vampire bats which feed on coastal wildlife species heavily impacted by the 2.3.4.4b epizootic, but no evidence of infection in populations without access to marine prey. We further report bat gene flow between IAV-exposed and IAV-naive populations, and IAV infections in a vampire bat colony that fed on both marine and terrestrial livestock prey, providing insights into how future IAV epizootics might spread spatially within bats and between marine and terrestrial ecosystems if a bat reservoir were established. Immunohistochemistry demonstrated that the H5 haemagglutinin protein binds to the upper respiratory tract of vampire bats, suggesting bat tissue susceptibility to H5 IAVs. Finally, vampire bat-derived kidney, liver, and lung cells supported entry, replication, and egress of avian and mammalian 2.3.4.4b viruses, confirming cellular infectivity. These results illustrate how combining ecological inference and experimental virology can pinpoint the species origins and biological significance of viral spillover at species interfaces. Recurrent exposures from marine wildlife, tissue and cellular susceptibility to H5N1 IAVs, and connections to other IAV-susceptible terrestrial mammals establish the prerequisite conditions for vampire bats to spread IAVs between marine and terrestrial environments or to form a novel reservoir of highly pathogenic IAVs.

ecology↗

bioRxiv2025

Diverse behavioural responses of vampire bats to human disturbance revealed by state-space modelling of sparse GPS data.

In Latin America, management of vampire bats has had inconsistent effects on the spread of lethal rabies infections from bats to humans and livestock. Positive and negative effects on rabies are hypothesised to reflect changes in bat roost fidelity and behaviour following human disturbance, but high landscape complexity has precluded monitoring bat movement in the areas where rabies transmission and bat management activity are most intense. We used animal-borne GPS tags to track 93 vampire bats in a rabies hotspot in the Peruvian Andes, where limited satellite visibility led to partial observation of animal locations. Immediately after capture, handling and tag application, 43% of bats, particularly males and bats with longer forearms, disappeared from the study area, suggesting a rapid roost switching response. Among the remaining 55 bats, a Bayesian state-space model revealed high individual heterogeneity on the disturbance night but on average increased flight distances. Over the remaining 8-night study period, bats gradually remained closer to the roost. These disturbance-driven shifts provide mechanisms to explain how bat disturbance can both accelerate and decelerate rabies spatial spread. More broadly, we present a modelling framework to infer key movement metrics in landscapes where GPS data limitations challenge conventional movement models.

ecology↗

bioRxiv2025

Distribution patterns of aquatic birds in a high-Andean wetland in southeastern Peru: an approach based on environmental factors

High-Andean wetlands play a crucial role in the conservation of avian biodiversity, acting as ecological oases amidst the arid Andes. However, these ecosystems face increasing anthropogenic and climatic pressures, jeopardizing both the ecosystem services they provide and the biodiversity they harbor. Moreover, research on these ecosystems remains scarce, limiting the knowledge necessary for their effective conservation. This study, conducted in Lake Piuray in the southeastern Andes of Peru, investigated the spatial and temporal distribution patterns of aquatic birds, assessing the influence of environmental variables such as depth and chlorophyll-a content. From December 2022 to November 2023, monthly surveys were carried out at 13 counting points distributed across four zones of the lake, encompassing natural and altered habitats such as lakeshore beaches and cultivated areas. Distribution maps were generated using weighted interpolation models and additive models to analyze non-linear relationships between bird abundance and environmental variables. Additionally, differences between seasons (wet and dry) and the evaluated zones were analyzed using non-parametric tests. A total of 43 aquatic bird species were recorded, with 19,768 individuals. Areas with low depth (<15 m) and intermediate to high levels of chlorophyll-a (I543 index: 0.20-0.25) concentrated the highest abundance and species richness. Zones with lakeshore beaches showed greater abundance and richness, while deeper zones exhibited the lowest values. At the family level, shorebirds preferred shallow waters, and diving birds tolerated greater depths. Although no significant differences in richness, abundance, and diversity were found between seasons at the community level, differences were identified in six families, with variations in their abundance between the wet and dry seasons. These results highlight the importance of shallow areas with high chlorophyll-a concentrations for the conservation of aquatic birds in high-Andean wetlands. This study is one of the few to analyze the influence of environmental and temporal factors on the distribution of high-Andean aquatic birds, and its representative nature makes it a valuable model for identifying priority areas for the conservation of these species.

ecology↗