Browsing by Author "Pascoli, Graziela Virginia Tolesano"

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    Higher infection probability of haemosporidian parasites in Blue-black Grassquits (Volatinia jacarina) inhabiting native vegetation across Brazil.
    (2021) Fecchio, Alan; Ribeiro, Rayane de Tasso Moreira; Ferreira, Francisco C.; Dutra, Daniela de Angeli; Pascoli, Graziela Virginia Tolesano; Oliveira, Renata Duarte Alquezar de; Khan, Asmat Ullah; Pichorim, Mauro; Moreira, Patrícia de Abreu; Nascimento, Maria de Jesus Costa; Monteiro, Eliana Ferreira; Mathias, Bruno S.; Guimarães, Lilian de Oliveira; Simões, Roseli F.; Braga, Érika Martins; Kirchgatterk, Karin; Dias, Raphael I.
    Human induced changes on landscape can alter the biotic and abiotic factors that influence the transmission of vector-borne parasites. To examine how infection rates of vector-transmitted parasites respond to changes on natural landscapes, we captured 330 Blue-black Grassquits (Volatinia jacarina) in Brazilian biomes and assessed the prevalence and diversity of avian haemosporidian parasites (Plasmodium and Haemoproteus) across avian host populations inhabiting environment under different disturbance and climatic conditions. Overall prevalence in Blue-black Grassquits was low (11%) and infection rates exhibited considerable spatial variation, ranging from zero to 39%. Based on genetic divergence of cytochrome b gene, we found two lineages of Haemoproteus (Parahaemoproteus) and 10 of Plasmodium. We showed that Blue-black Grassquit populations inhabiting sites with higher proportion of native vegetation cover were more infected across Brazil. Other landscape metrics (number of water bodies and distance to urban areas) and climatic condition (temperature and precipitation) known to influence vector activity and promote avian malaria transmission did not explain infection probability in Blue-black Grassquit populations. Moreover, breeding season did not explain prevalence across avian host populations. Our findings suggest that avian haemosporidian prevalence and diversity in Blue-black Grassquit populations are determined by recent anthropogenic changes in vegetation cover that may alter microclimate, thus influencing vector activity and parasite transmission.
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    Host life-history traits predict haemosporidian parasite prevalence in tanagers (Aves: Thraupidae).
    (2022) Penha, Victor Aguiar de Souza; Domingos, Fabricius Maia Chaves Bicalho; Fecchio, Alan; Bell, Jeffrey A.; Weckstein, Jason D.; Ricklefs, Robert E.; Braga, Erika Martins; Moreira, Patrícia de Abreu; Soares, Letícia; Latta, Steven; Pascoli, Graziela Virginia Tolesano; Oliveira, Renata Duarte Alquezar de; Claro, Kleber Del; Manica, Lilian Tonelli
    Vector-borne parasites are important ecological drivers influencing life-history evolution in birds by increasing host mortality or susceptibility to new diseases. Therefore, understanding why vulnerability to infection varies within a host clade is a crucial task for conservation biology and for understanding macroecological life-history patterns. Here, we studied the relationship of avian life-history traits and climate on the prevalence of Plasmodium and Parahaemoproteus parasites. We sampled 3569 individual birds belonging to 53 species of the family Thraupidae. Individuals were captured from 2007 to 2018 at 92 locations. We created 2 phylogenetic generalized least-squares models with Plasmodium and Parahaemoproteus prevalence as our response variables, and with the following predictor variables: climate PC1, climate PC2, body size, mixed-species flock participation, incubation period, migration, nest height, foraging height, forest cover, and diet. We found that Parahaemoproteus and Plasmodium prevalence was higher in species inhabiting open habitats. Tanager species with longer incubation periods had higher Parahaemoproteus prevalence as well, and we hypothesize that these longer incubation periods overlap with maximum vector abundances, resulting in a higher probability of infection among adult hosts during their incubation period and among chicks. Lastly, we found that Plasmodium prevalence was higher in species without migratory behaviour, with mixed-species flock participation, and with an omnivorous or animal-derived diet. We discuss the consequences of higher infection prevalence in relation to life-history traits in tanagers.