Parasites are thought to adversely affect the physical performance of their hosts  and to be key factors in shaping life history, with effects cascading to communities and ecosystems . Haemosporidian parasites, the causative agents of malaria in the broader sense, commonly occur in temperate and tropical regions and infect a variety of host species including humans, other mammals, reptiles and birds. Depending on lineage and host species, the parasites invade their hosts' inner organs and, particularly, red blood cells . The infection follows a typical pattern with an acute (symptomatic) phase with high levels of parasites in the blood (parasitaemia) followed by a chronic phase with low (or zero) parasitaemia . Malaria in wildlife is often a mild disease, but can have severe consequences, particularly when encountered in new environments by immunologically naive hosts . Acute infections (with high parasitaemia) can result in substantial declines in red blood cell content  owing to haemosporidians targeting haemoglobin as a major nutrient .