Host species, and not environment, predicts variation in blood parasite prevalence, distribution, and diversity along a humidity gradient in northern South America

Abstract

Environmental factors strongly influence the ecology and evolution of vector‐borne infectious diseases. However, our understanding of the influence of climatic variation on host–parasite interactions in tropical systems is rudimentary. We studied five species of birds and their haemosporidian parasites (Plasmodium and Haemoproteus) at 16 sampling sites to understand how environmental heterogeneity influences patterns of parasite prevalence, distribution, and diversity across a marked gradient in water availability in northern South America. We used molecular methods to screen for parasite infections and to identify parasite lineages. To characterize spatial heterogeneity in water availability, we used weather‐station and remotely sensed climate data. We estimated parasite prevalence while accounting for spatial autocorrelation, and used a model selection approach to determine the effect of variables related to water availability and host species on prevalence. The prevalence, distribution, and lineage diversity of haemosporidian parasites varied among localities and host species, but we found no support for the hypothesis that the prevalence and diversity of parasites increase with increasing water availability. Host species and host × climate interactions had stronger effects on infection prevalence, and parasite lineages were strongly associated with particular host species. Because climatic variables had little effect on the overall prevalence and lineage diversity of haemosporidian parasites across study sites, our results suggest that independent host–parasite dynamics may influence patterns in parasitism in environmentally heterogeneous landscapes.

Deeply conserved susceptibility in a multi-host, multi-parasite system

“…2015). Additional interspecific variation may be explained by unique ‘species effects’ (e.g., Pulgarín-R et al . 2018; Ricklefs et al .…”

Interspecific transfer of parasites following a range‐shift in Ficedula flycatchers

“…more important for parasites vectored by Culicoides midges, the primary vectors of Haemoproteus(Kirkeby, Bødker, Stockmarr, & Enøe, 2009). However, a recent study of Amazonian birds did not find such a relationship(Pulgarín-R et al, 2018). Taken together, we therefore theorize that microhabitat differences largely explain the differences in infection rate observed between populations, while different immune responses may dictate interspecific differences in infection rate.Despite the fact that pied flycatchers have a significantly higher rate of blood parasite infections, the pattern of haemosporidian lineage diversity goes in the opposite direction.…”

“…Areas near standing water are often important for determining prevalence of Plasmodium , which is most frequently mosquito‐borne (Wood et al, ), whereas damp and marshy ground is more important for parasites vectored by Culicoides midges, the primary vectors of Haemoproteus (Kirkeby, Bødker, Stockmarr, & Enøe, ). However, a recent study of Amazonian birds did not find such a relationship (Pulgarín‐R et al, ). Taken together, we therefore theorize that microhabitat differences largely explain the differences in infection rate observed between populations, while different immune responses may dictate interspecific differences in infection rate.…”

“…Despite this, only a few studies have previously attempted to investigate interspecific parasite diversity on a larger (i.e., population-wide) spatial scale and these studies have found that host species is a better predictor of parasite community than geography (Dubiec et al, 2016; Pulgarín-R, Gómez, Robinson, Ricklefs, & Cadena, 2018;Scordato & Kardish, 2014). This could mean that host switching is a relatively rare phenomenon that may need a specific set of ecological conditions for the parasite.…”

Host-parasite interaction explains variation in prevalence of avian haemosporidians at the community level

“…The fact that haemosporidian parasites need a vector for completing their cycle life extends the number of elements affecting prevalence of these parasites. Although some studies have shown limited or no relationship between climate and prevalence [34], some have showed that vector populations might increase their number due to climate change and, therefore, vector-borne infectious diseases may increase every year [35]. Vector availability might also change among seasons, thus, during spring the amount of vectors in the wild increase [36] raising the probabilities to become infected [37].…”