Influence of anthropic changes and environmental characteristics on the occurrence of Tegumentary Leishmaniasis in Montes Claros, Minas Gerais, Brazil, between 2012 and 2019.

This is an ecological study that investigated the influence of environmental, socioeconomic characteristics and changes in land use and cover on the occurrence of Tegumentary Leishmaniasis (TL) in the city of Montes Claros. The relationships between the number of cases of TL, which occurred between 2012 and 2019, in each census sector and the standardized covariates (Number of properties, altitude, Brazilian Deprivation Index, Normalized Difference Vegetation Index (NDVI), proportion of sector (PS) deforested, PS that underwent other anthropic alterations and unaltered PS) were evaluated with ecological Bayesian Models. Four multivariate models were constructed, with similar quality of adjustments, but Model 1 was the most parsimonious. Model 1 revealed that for each one-unit increase of standard deviation (SD) in the log of the number of properties, at the altitude and root of the deforested PS, corresponds to an increase of 44%, 34% and 24.5% in the number of cases of TL, respectively. The variable NDVI, included in models 3 and 4, was positively associated with the increase in the number of TL cases, being that for each one-unit increase in the NDVI was verified an increase of 21.3% and 20.2% respectively in the models. This study showed that the spatial distribution of TL cases in the city of Montes Claros occurs in a heterogeneous way and our findings support the hypothesis that socio-environmental characteristics and deforestation influence the occurrence of this disease in the studied area. Thus, these factors must be considered for the development of disease control strategies.

Phyllostomid bat occurrence in successional stages of neotropical dry forests.

Tropical dry forests (TDFs) are highly endangered tropical ecosystems being replaced by a complex mosaic of patches of different successional stages, agricultural fields and pasturelands. In this context, it is urgent to understand how taxa playing critical ecosystem roles respond to habitat modification. Because Phyllostomid bats provide important ecosystem services (e.g. facilitate gene flow among plant populations and promote forest regeneration), in this study we aimed to identify potential patterns on their response to TDF transformation in sites representing four different successional stages (initial, early, intermediate and late) in three Neotropical regions: México, Venezuela and Brazil. We evaluated bat occurrence at the species, ensemble (abundance) and assemblage level (species richness and composition, guild composition). We also evaluated how bat occurrence was modulated by the marked seasonality of TDFs. In general, we found high seasonal and regional specificities in phyllostomid occurrence, driven by specificities at species and guild levels. For example, highest frugivore abundance occurred in the early stage of the moistest TDF, while highest nectarivore abundance occurred in the same stage of the driest TDF. The high regional specificity of phyllostomid responses could arise from: (1) the distinctive environmental conditions of each region, (2) the specific behavior and ecological requirements of the regional bat species, (3) the composition, structure and phenological patterns of plant assemblages in the different stages, and (4) the regional landscape composition and configuration. We conclude that, in tropical seasonal environments, it is imperative to perform long-term studies considering seasonal variations in environmental conditions and plant phenology, as well as the role of landscape attributes. This approach will allow us to identify potential patterns in bat responses to habitat modification, which constitute an invaluable tool for not only bat biodiversity conservation but also for the conservation of the key ecological processes they provide.