Global drivers of avian haemosporidian infections vary across zoogeographical regions
Authors: Fecchio Alan , Clark Nicholas J. , Bell Jeffrey A. , Skeen Heather R. , Lutz Holly L. , De La Torre Gabriel M. , Vaughan Jefferson A. , Tkach Vasyl V. , Schunck Fabio , Ferreira Francisco C. , Braga Érika M. , Lugarini Camile , Wamiti Wanyoike , Dispoto Janice H. , Galen Spencer C. , Kirchgatter Karin , Sagario M. Cecilia , Cueto Victor R. , González‐Acuña Daniel , Inumaru Mizue , Sato Yukita , Schumm Yvonne R. , Quillfeldt Petra , Pellegrino Irene , Dharmarajan Guha , Gupta Pooja , Robin V. V. , Ciloglu Arif , Yildirim Alparslan , Huang Xi , Chapa‐Vargas Leonardo , Álvarez‐Mendizábal Paulina , Santiago‐Alarcon Diego , Drovetski Serguei V. , Hellgren Olof , Voelker Gary , Ricklefs Robert E. , Hackett Shannon J. , Collins Michael D. , Weckstein Jason D. , Wells Konstans 
Published: September 2021

Aim

Macroecological analyses provide valuable insights into factors that influence how parasites are distributed across space and among hosts. Amid large uncertainties that arise when generalizing from local and regional findings, hierarchical approaches applied to global datasets are required to determine whether drivers of parasite infection patterns vary across scales. We assessed global patterns of haemosporidian infections across a broad diversity of avian host clades and zoogeographical realms to depict hotspots of prevalence and to identify possible underlying drivers.

Location

Global.

Time period

1994–2019.

Major taxa studied

Avian haemosporidian parasites (genera Plasmodium, Haemoproteus, Leucocytozoon and Parahaemoproteus).

Methods

We amalgamated infection data from 53,669 individual birds representing 2,445 species world‐wide. Spatio‐phylogenetic hierarchical Bayesian models were built to disentangle potential landscape, climatic and biotic drivers of infection probability while accounting for spatial context and avian host phylogenetic relationships.

Results

Idiosyncratic responses of the three most common haemosporidian genera to climate, habitat, host relatedness and host ecological traits indicated marked variation in host infection rates from local to global scales. Notably, host ecological drivers, such as migration distance for Plasmodium and Parahaemoproteus, exhibited predominantly varying or even opposite effects on infection rates across regions, whereas climatic effects on infection rates were more consistent across realms. Moreover, infections in some low‐prevalence realms were disproportionately concentrated in a few local hotspots, suggesting that regional‐scale variation in habitat and microclimate might influence transmission, in addition to global drivers.

Main conclusions

Our hierarchical global analysis supports regional‐scale findings showing the synergistic effects of landscape, climate and host ecological traits on parasite transmission for a cosmopolitan and diverse group of avian parasites. Our results underscore the need to account for such interactions, in addition to possible variation in drivers across regions, to produce the robust inference required to predict changes in infection risk under future scenarios.