Habitat modification may change vertebrate and vector-borne disease distributions. However, natural forest regeneration through secondary succession may mitigate these effects. Here we tested the hypothesis that secondary succession influences the distribution of birds and their haemosporidian parasites (genera Plasmodium and Haemoproteus) in a seasonally dry tropical forest, a globally threatened ecosystem, in Brazil. Moreover, we assessed seasonal fluctuations in parasite prevalence and distribution. We sampled birds in four different successional stages at the peak and end of the rainy season, as well as in the middle and at the end of the dry season. A non-metric multidimensional scaling analysis revealed that bird communities in the pasture (i.e., highly modified) areas were different from those in the early, intermediate, and late successional areas (secondary forests). Among 461 individual birds, haemosporidian prevalence was higher in pasture areas than in the more advanced successional stages, but parasite communities were homogeneous across these areas. Parasite prevalence was higher in pasture-specialists birds (resilient species) than in forest-specialists species, suggesting that pasture-specialists may increase infection risk for co-occurring hosts. We found an increase in prevalence between the middle and end of the dry season, a period associated with the beginning of the breeding season (early spring) in southeastern Brazil. We also found effects of seasonality in the relative prevalence of specific parasite lineages. Our results show that natural forest recovery through secondary succession in SDTFs is associated with compositional differences in avian communities, and that advanced successional stages are associated with lower prevalence of avian haemosporidian parasites.

BackgroundHaemosporidian parasites of the genera Plasmodium and Haemoproteus can have detrimental effects on individual birds and populations. Despite recent investigations into the distribution and richness of these parasites and their vertebrate hosts, little is known about their dipteran vectors. The Neotropics has the highest diversity of mosquitoes in the world, but few studies have tried to identify vectors in this area, hampering the understanding of the ecology of avian malaria in the highly diverse Neotropical environments.MethodsShannon traps and active collection were used to capture 27,110 mosquitoes in a Seasonally Dry Tropical Forest in southeastern Brazil, a highly endangered ecosystem.ResultsWe screened 17,619 mosquito abdomens from 12 different species and several unidentified specimens of Culex, grouped into 1,913 pools, for the presence of haemosporidians. Two pools (out of 459) of the mosquito Mansonia titillans and one pool (out of 29) of Mansonia pseudotitillans were positive for Plasmodium parasites, with the detection of a new parasite lineage in the former species. Detected Plasmodium lineages were distributed in three different clades within the phylogenetic tree revealing that Mansonia mosquitoes are potential vectors of genetically distant parasites. Two pools of Culex spp. (out of 43) were positive for Plasmodium gallinaceum and closely related lineages. We found a higher abundance of these putative vectors in pasture areas, but they were also distributed in areas at intermediate and late successional stages. One pool of the mosquito Psorophora discrucians (out of 173) was positive for Haemoproteus.ConclusionsThe occurrence of different Plasmodium lineages in Mansonia mosquitoes indicates that this genus encompasses potential vectors of avian malaria parasites in Brazil, even though we did not find positive thoraces among the samples tested. Additional evidence is required to assign the role of Mansonia mosquitoes in avian malaria transmission and further studies will add information about evolutionary and ecological aspects of avian haemosporidia and untangle the diversity of their vectors in Brazil.

Host-parasite interactions represent a selective force that may reduce hosts’ lifespan, their reproductive success and survival. Environmental conditions can affect host-parasite communities, leading to distinct patterns of interactions with divergent ecological and evolutionary consequences for their persistence. Here, we tested whether climatic oscillation shapes the temporal dynamics of bird-haemosporidian associations, assessing the main mechanisms involved in the temporal dissimilarity of their interactions’ networks. For two years, we monthly sampled birds in a tropical coastal ecosystem to avian malaria molecular diagnosis. The studied networks exhibited high specialization, medium modularity, with low niche overlap among parasites lineages. Moreover, alpha and β-diversity of hosts, parasites and their interactions, as well as the structure of their networks were temporally consistent, i.e., stable under fluctuations in temperature or precipitation over seasons. The structure and temporal consistency of the studied antagonistic networks suggest a high fidelity between partners, which is likely relevant for their evolutionary persistence.

In Brazil, most studies of the Culicidae family are concentrated in rainforest regions. As such, there is a lack of knowledge regarding the diversity of Culicidae in regions with different climatic and vegetational characteristics. The aim of this study was to compile an inventory of Culicidae in protected areas of the semi-arid region of the state of Minas Gerais, Brazil, in order to better understand the diversity of the family within this region. The study was conducted across four protected areas in the northern region of the state, in tropical dry forest (TDF) fragments. Sampling methods included Shannon trap and CDC light trap, as well as active collection. A total of 11,219 mosquito specimens were collected between August 2008 and July 2012, belonging to 11 genera and 45 species; 15 new records for the state of Minas Gerais were registered, as well as 26 new records for semi-arid regions within the state. The high number of new Culicidae records in this region demonstrates the importance of inventory studies for increasing the knowledge of culicid biodiversity in Minas Gerais, and in particular within semi-arid regions of the state.

The use of a sensitive and accurate parasite detection methodology is crucial in studies exploring prevalence of parasites in host populations or communities, and uncertainty in identifying parasite genera and/or lineages may limit the understanding of host-parasite interactions. Here, we used a multistate occupancy approach that accounts for imperfect detection to assess whether sex and breeding season influenced the prevalence of a specific Haemoproteus lineage (TARUF02) in a whitelined tanager population. Likewise, we explored whether the probability of detecting the target parasite in an infected bird using PCR and sequencing analyses may be influenced by season and host sex. We found little evidence that sex influenced the probability of an individual host being infected by a haemosporidian parasite. Conversely, we found that the probability of infection by Haemoproteus TARUF02 was ~30% higher during the breeding season, reflecting a higher prevalence of this parasite in this season. the probability that pcR detects DnA of haemosporidian parasite was higher for female birds, suggesting that they are more prone to be parasitized with parasitemia levels that are more successfully detected by molecular analysis. Sequencing successfully determined the Haemoproteus TARUF02 lineage in 60% of samples collected during the breeding season and 84% of samples collected during the non-breeding season. Understanding the ecology of hosts and aspects of their physiology that may influence the parasite infection is essential to better understanding of hemoparasite infections and how parasites influence their native hosts, through decreasing reproductive success, lifespan, and/ or survival. One of the most common parasites of wild birds are haemosporidians, vector-borne protozoans that infect several host species worldwide. Haemosporidians of the genera Haemoproteus are divided into two subgenera that differ in their vectors and vertebrate hosts. The subgenus H. (Haemoproteus) is transmitted by louse flies (Diptera: Hippoboscidae) and infects birds of the Order Columbiformes 1 as well as seabirds of the orders Suliformes 2-4 and Charadriiformes 4. The subgenus H. (Parahaemoproteus) is transmitted primarily by Culicoides biting midges (Diptera: Ceratopogonidae) 1 and infects birds of various orders and families 1. These parasites are closely connected to their hosts with impacts ranging from sublethal effects on the fitness of the host to the decline and extinction of populations 5-8. They can exert important selective pressure on the hosts through effects

Avian haemosporidians are parasites with great capacity to spread to new environments and new hosts, being considered a good model to host-parasite interactions studies. Here, we examine avian haemosporidian parasites in a protected area covered by Restinga vegetation in northeastern Brazil, to test the hypothesis that haemosporidian prevalence is related to individual-level traits (age and breeding season), species-specific traits (diet, foraging strata, period of activity, species body weight, migratory status, and nest shape), and climate factors (temperature and rainfall). We screened DNA from 1,466 birds of 70 species captured monthly from April 2013 to March 2015. We detected an overall prevalence (Plasmodium/Haemoproteus infection) of 22% (44 host species) and parasite’s lineages were identified by mitochondrial cyt b gene. Our results showed that migration can be an important factor predicting the prevalence of Haemoproteus (Parahaemoproteus), but not Plasmodium, in hosts. Besides, the temperature, but not rainfall, seems to predict the prevalence of Plasmodium in this bird community. Neither individual-level traits analyzed nor the other species-specific traits tested were related to the probability of a bird becoming infected by haemosporidians. Our results point the importance of conducting local studies in particular environments to understand the degree of generality of factors impacting parasite prevalence in bird communities. Despite our attempts to find patterns of infection in this bird community, we should be aware that an avian haemosporidian community organization is highly complex and this complexity can be attributed to an intricate net of factors, some of which were not observed in this study and should be evaluated in future studies. We evidence the importance of looking to host-parasite relationships in a more close scale, to assure that some effects may not be obfuscated by differences in host life-history.