Blood parasites of the order haemosporidia include malaria and are known to have played a prominent role in shaping human history. Birds are known to be infected with blood parasites in the genera Haemoproteus, Leucocytozoon, and Plasmodium, but the effects of the majority of these parasites on fitness are poorly characterized in most wild host populations. Furthermore, it has been shown that anthropogenic disturbances such as climate change and urbanization have increased the prevalence of these parasites in wild host populations.
Many studies have focused on host resistance to blood parasitism, but we still lack experimental evidence supporting the possibility of host tolerance to blood parasites in avian systems. I am working to fill this knowledge gap through a two-fold project. First, I will present data on a 3 year-long survey of blood parasites in two closely related passerine species, the black-capped and mountain chickadee, with potentially differing strategies to defend themselves against blood parasites. Second, I will discuss preliminary results from experimental work that I am carrying out this upcoming Summer.
Results/Conclusions
Mountain chickadees experience higher parasite infection prevalence (percent of individuals sampled that are infected) and diversity of parasites than black-capped chickadees. However, infections with blood parasites don’t appear to have a negative effect on body condition for mountain chickadees. To further explore these findings, I am carrying out experimental work to determine the effect of infections with blood parasites on chickadee fitness. This work involves the use of a network of 150 nest boxes established at Sugarloaf Mountain, in Boulder Colorado. I am experimentally treating chickadees with either an antiprotozoal medication to remove infection, or a control. Chickadee fitness is quantified based off of body condition and breeding success.