Differences in plumage coloration between ventral and dorsal regions on Atlantic Forest birds Gabriel Massaccesi De La Torre, Victor Aguiar de Souza Penha, Lilian Tonelli Manica Ibis, 2025 Plumage coloration is an important trait for communication signalling and camouflage, enabling birds to provide cues of health condition and avoid predators. Such coloration can differ among body regions, with some regions presenting conspicuous coloration, while others are more discreet. Plumage coloration can also be associated with species' life‐history traits, such as diet, habitat and nest type. Despite the relevance to ecology and evolution of bird plumage coloration, little is known regarding the relationship between the coloration of ventral and dorsal regions of bird species, especially in the Atlantic Forest, a global hotspot of biodiversity. Here we assessed plumage brightness and saturation of the dorsal and ventral regions of Atlantic Forest birds, and analysed the differences in coloration and colour variability between the regions. We also tested whether sex dichromatism, nest type, diet, habitat and foraging stratum preference are related to plumage coloration. We found that dorsal regions tend to be darker, more achromatic and less variable across species when compared to ventral regions. Additionally, plumage coloration of bird species incubating in open nests is brighter than in birds from closed nests, while species with sexual dichromatism tend to present darker ventral regions. Our results bring new insights into the role of plumage coloration in Atlantic Forest bird ecology, suggesting that different evolutionary forces may act in different body regions.
Beta diversity, prevalence, and specificity of avian haemosporidian parasites throughout the annual cycle of Chilean Elaenia (Elaenia chilensis), a Neotropical austral migrant Alan Fecchio, Raphael I. Dias, Gabriel M. De La Torre, Jeffrey A. Bell, M. Cecilia Sagario, et al. Parasitology, 2022 Migratory birds are implicated in dispersing haemosporidian parasites over great geographic distances. However, their role in sharing these vector-transmitted blood parasites with resident avian host species along their migration flyway is not well understood. We studied avian haemosporidian parasites in 10 localities where Chilean Elaenia, a long-distance Neotropical austral migrant species, spends part of its annual cycle to determine local parasite transmission among resident sympatric host species in the elaenia's distributional range across South America. We sampled 371 Chilean Elaenias and 1,818 birds representing 243 additional sympatric species from Brazilian wintering grounds to Argentinian breeding grounds. The 23 haemosporidian lineages found in Chilean Elaenias exhibited considerable variation in distribution, specialization, and turnover across the 10 avian communities in South America. Parasite lineage dissimilarity increased with geographic distance, and infection probability byParahaemoproteusdecreased in localities harbouring a more diverse haemosporidian fauna. Furthermore, blood smears from migrating Chilean Elaenias and local resident avian host species did not contain infective stages ofLeucocytozoon, suggesting that transmission did not take place in the Brazilian stopover site. Our analyses confirm that this Neotropical austral migrant connects avian host communities and transports haemosporidian parasites along its distributional range in South America. However, the lack of transmissive stages at stopover site and the infrequent parasite lineage sharing between migratory host populations and residents at breeding and wintering grounds suggest that Chilean Elaenias do not play a significant role in dispersing haemosporidian parasites, nor do they influence local transmission across South America.
Host evolutionary history rather than avian functional traits drives the Plasmodium regional assembly in the Atlantic Forest Gabriel M. De La Torre, Alan Fecchio, Jeffrey A. Bell, Karla M. Campião Functional Ecology, 2022 Disentangling the influence of hosts and environmental factors in parasite community assembly is one of the main challenges in disease ecology. Here we used three approaches to assess the influence of host ecology and evolutionary history, as well as environmental factors on Plasmodium parasite composition within the Atlantic Forest. Using sampling data of 2,241 bird individuals captured within the Brazilian Atlantic Forest, we first calculated the functional and phylogenetic host specificity of Plasmodium lineages. We then tested whether host functional or phylogenetic distance predicts Plasmodium taxonomic and phylogenetic beta diversity among host species. Finally, we tested whether temperature, precipitation, landscape dissimilarity and host turnover (taxonomic, functional and phylogenetic) determine Plasmodium taxonomic and phylogenetic turnover among 13 localities within the Atlantic Forest. We found that 47% of the parasite lineages were more phylogenetic specialists than expected by chance. In addition, both taxonomic and phylogenetic Plasmodium beta diversity were associated with host phylogenetic distance, indicating that closely related avian species are infected by assemblages composed of more closely related Plasmodium lineages. When comparing Plasmodium lineage community among localities, we found host phylogenetic turnover as the most relevant predictor of Plasmodium taxonomic and phylogenetic turnover. On the other hand, environmental variables explained 23% of Plasmodium taxonomic turnover among localities, suggesting that lineage composition is affected by climate and landscape, especially temperature seasonality. Combining all results, our findings suggest host phylogeny is the main driver of the regional Plasmodium assemblages within the Atlantic Forest. Read the free Plain Language Summary for this article on the Journal blog.
The roles of anurans in antagonistic networks are explained by life-habit and body-size Amanda Caroline DUDCZAK, Gabriel Massaccesi DE LA TORRE, Lorena EUCLYDES, Karla Magalhães CAMPIÃO Integrative Zoology, 2022 Interactions among living beings are the structuring basis of ecosystems, and studies of networks allow us to identify the patterns and consistency of such interactions. Antagonistic networks reflect the energy flow of communities, and identifying network structure and the biological aspects that influence its stability is crucial to understanding ecosystem functioning. We used antagonistic anuran interactions—predator–prey and host–parasite—to assess structural patterns and to identify the key anuran species structuring these networks. We tested whether anuran body‐size and life‐habit are related to their roles in these networks. We collected individuals of 9 species of anurans from an area of the Atlantic Forest in Brazil and identified their prey and helminth parasites. We used network (modularity, specialization, and nestedness) and centrality metrics (degree, closeness, and betweenness) to identify the role of anuran species in both networks. We then evaluated whether anuran body‐size or life‐habit were related to anuran centrality using generalized linear mixed models. The networks formed specialized interactions in compartments composed by key species from different habits. In our networks, anurans with rheophilic and cryptozoic habit are central in predator‐prey networks, and those with larger body size and arboreal and cryptozoic habit in the host‐parasite network. This study represents a step towards a better understanding of the influential factors that affect the structure of anuran antagonist networks, as well as to recognize the functioning roles of anuran species.
Ecological specificity explains infection parameters of anuran parasites at different scales Lorena Euclydes, Gabriel M. De La Torre, Amanda Caroline Dudczak, Francisco Tiago de Vasconcelos Melo, Karla Magalhães Campião Parasitology, 2022 Understanding the determinants of parasite infection in different hosts is one of the main goals of disease ecology. Evaluating the relationship between parasite–host specificity and infection parameters within host communities and populations may contribute to this understanding. Here we propose two measures of specificity that encompasses phylogenetic and ecological relatedness among hosts and investigated how such metrics explain parasite infection prevalence and mean infection intensity (MII). We analysed the parasites associated with an anuran community in an area of Atlantic Forest and used the number of infected hosts and the net relatedness index to calculate the phylogenetic and ecological specificities of the parasites. These specificity measures were related to infection metrics (prevalence and MII) with generalized linear mixed models at community (all hosts) and population (infected host species) scales. Parasite prevalence was correlated with the number of infected hosts and, when considering only multi-host parasites, was positively related to parasite ecological specificity at community and population scales. Thus, parasite species have similar prevalences in ecologically closer hosts. No relationship was found for parasite MII. Incorporating ecological characteristics of hosts in parasite specificity analyses improves the detection of patterns of specificity across scales.
Migration and season explain tick prevalence in Brazilian birds A. Fecchio, C. Lugarini, A. Ferreira, J. D. Weckstein, K. M. D. Kuabara, et al. Medical and Veterinary Entomology, 2021 Neotropical birds are mostly parasitized by immature ticks and act as reservoir hosts of tick‐borne pathogens of medical and veterinary interest. Hence, determining the factors that enable ticks to encounter these highly mobile hosts and increase the potential for tick dispersal throughout migratory flyways are important for understanding tick‐borne disease transmission. We used 9682 individual birds from 572 species surveyed across Brazil and Bayesian models to disentangle possible avian host traits and climatic drivers of infestation probabilities, accounting for avian host phylogenetic relationships and spatiotemporal factors that may influence tick prevalence. Our models revealed that the probability of an individual bird being infested with tick larvae and nymphs was lower in partial migrant hosts and during the wet season. Notably, infestation probability increased in areas with a higher proportion of partial migrant birds. Other avian ecological traits known to influence tick prevalence (foraging habitat and body mass) and environmental condition that might constrain tick abundance (annual precipitation and minimum temperature) did not explain infestation probability. Our findings suggest that migratory flyways harbouring a greater abundance of migrant bird hosts also harbour a higher prevalence of immature ticks with potential to enhance the local transmission of tick‐borne pathogens and spread across regions.
