Meeting Abstract
Supplemental feeding of birds by humans can affect host-parasite interactions. For example, increased food availability can have both a positive and negative effect on parasite resistance in the host. These interactions could be mediated by the host’s gut microbiota because studies have found that host diet can affect their gut microbiota and gut microbiota can affect the immune system. In this study, I determined the effects of supplemental feeding on interactions between Eastern Bluebirds (Sialia sialis) and their parasitic nest flies (Protocalliphora sialia) in northern Minnesota. Specifically, I tested whether experimental manipulations of mealworm availability and parasite abundance affect gut microbiota and the antibody-mediated immune response in Bluebirds. I found that supplemental feeding of Bluebirds dramatically reduced parasite abundance compared to unsupplemented birds, which was mediated by the nestling antibody response. Gut bacterial diversity increased in supplemented nestlings and this diversity was negatively related to parasite abundance and positively related to the antibody response. These results suggest that supplemental feeding of bluebirds can improve the health of the birds by increasing their resistance to parasites, which could be mediated by the gut microbiota of nestlings.
