“…They can have devastating impacts in naïve populations (Atkinson & Samuel, 2010), and many studies have reported negative associations with infection in endemic areas, including reductions in condition (Marzal, Bensch, Reviriego, Balbontin, & de Lope, 2008;Merino, Moreno, Sanz, & Arriero, 2000), antipredator behavior (Garcia-Longoria, Moller, Balbontin, de Lope, & Marzal, 2015;Mukhin et al, 2016), mating display behavior (Bosholn, Fecchio, Silveira, Braga, & Anciaes, 2016), survival (Asghar et al, 2015;Krams et al, 2013;Sol, Jovani, & Torres, 2003), and reproductive output (Asghar, Hasselquist, & Bensch, 2011;Knowles, Palinauskas, & Sheldon, 2010;Marzal et al, 2013;Merino et al, 2000). Other studies, however, have reported no associations-or even positive associations-with infection (Cornelius, Davis, & Altizer, 2014;Fargallo & Merino, 2004;Piersma & van der Velde, 2012;Podmokla et al, 2014;Zylberberg et al, 2015), or have reported effects that vary among host species (Atkinson & Van Riper, 1991;Ellis, Kunkel, & Ricklefs, 2014;Sorci, 2013), host population (Piersma & van der Velde, 2012), parasite species (Asghar et al, 2011;Lachish, Knowles, Alves, Wood, & Sheldon, 2011;Marzal et al, 2008), and characteristics of individual hosts (Hammers et al, 2016). As such, the extent to which the hemosporidians broadly constitute a selective pressure across different systems and contexts is unclear.…”