Ecological determinants of avian malaria infections: An integrative analysis at landscape, mosquito and vertebrate community levels

Abstract

Vector and host communities, as well as habitat characteristics, may have important but different impacts on the prevalence, richness and evenness of vector-borne parasites. We investigated the relative importance of (1) the mosquito community composition, (2) the vertebrate community composition and (3) landscape characteristics on the prevalence, richness and evenness of avian Plasmodium. We hypothesized that parasite prevalence will be more affected by vector-related parameters, while host parameters should be also important to explain Plasmodium richness and evenness. We sampled 2,588 wild house sparrows (Passer domesticus) and 340,829 mosquitoes, and we performed vertebrate censuses at 45 localities in the Southwest of Spain. These localities included urban, rural and natural landscapes that were characterized by several habitat variables. Twelve Plasmodium lineages were identified in house sparrows corresponding to three major clades. Variation partitioning showed that landscape characteristics explained the highest fraction of variation in all response variables (21.0%-44.8%). Plasmodium prevalence was in addition explained by vector-related variables (5.4%) and its interaction with landscape (10.2%). Parasite richness and evenness were mostly explained by vertebrate community-related variables. The structuring role of landscape characteristics in vector and host communities was a key factor in determining parasite prevalence, richness and evenness, although the role of each factor differed according to the parasite parameters studied. These results show that the biotic and abiotic contexts are important to explain the transmission dynamics of mosquito-borne pathogens in the wild.

Adaptive landscape genetics and malaria across divergent island bird populations

“…Distance to water sources was an important predictor of malaria distributions in both Porto Santo and Tenerife (González‐Quevedo et al, ). Due to the aquatic larval development of mosquitoes, higher vector abundance and malaria are found in proximity to water (Ferraguti et al, ; Ganser et al, ; Illera et al, ). In the present study, distance to urban areas was removed prior to model selection due to a positive collinearity with distance to water sources.…”

“…We modeled the environmental predictors of malaria distributions in Porto Santo to understand fine-scale spatial differences in malaria TA B L E 9 Summary of linear models of the association between genetic variants and malaria risk in Berthelot's pipits on Porto Santo (PS) and Tenerife (TF) higher vector abundance and malaria are found in proximity to water (Ferraguti et al, 2018;Ganser et al, 2016;Illera et al, 2017).…”

Patterns of avian haemosporidian infections vary with time, but not habitat, in a fragmented Neotropical landscape

“…Differences on parasite infections may be due to a variety of other factors, including the phylogeny of birds [ 32 , 70 , 71 ], avian community composition [ 67 , 72 ], bird species [ 14 ], food availability, altitude or woodland edge [ 30 , 73 ], microhabitat [ 74 ] or landscape characteristics [ 75 ]. As observed in other studies, we observed marked differences in infection status depending on bird species, a factor that explained most of the infection variability in our models.…”

Contrasting effects of host species and phylogenetic diversity on the occurrence of HPAI H5N1 in European wild birds

“…Previous studies argue that the dilution effect is actually idiosyncratic, existing only under specific circumstances (Wood et al, 2014;Young et al, 2013). Rigorously assessing the diversity-disease relationship is crucial for better predicting disease dynamics giving the ongoing host range shifts, local extinction events and global biodiversity decline (Ferraguti et al, 2018;Huang et al, 2016;Johnson, De Roode, et al, 2015;Johnson, Ostfeld, et al, 2015).…”