High blood parasite infection rate and low fitness suggest ecological traps for pied flycatchers breeding near forest water-bodies

Blood parasites are considered to have strong negative effects on host fitness. There is some evidence that suggests that negative fitness consequences may be associated with the proximity to the areas where blood parasite vectors reproduce. This study tested for relationships between haemosporidian infection prevalence and parasitemia of breeding pied flycatchers (Ficedula hypoleuca) and their fitness parameters at different distances from forest water bodies. Prevalence and parasitemias (the intensity of infection) of haemosporidians generally decreased with increasing distance from forest lakes, streams, and bogs. Fledgling numbers were lower, and their condition was worse in the vicinity of water bodies, compared to one kilometer away from lakes and streams. This study suggests that forest areas around water bodies represent ecological traps. Installing nest boxes in the vicinity of forest water-bodies creates unintended ecological traps that may have conservation implications.