Meeting Abstract
Avian malaria is a widespread phenomenon, found in all avian orders and on almost every continent. While avian malaria has been linked to the decline of some insular birds, in most species its effects are sub-lethal. Several studies in captive and wild populations have shown that chronic, low intensity infections reduce survival and reproductive success of infected birds. However, it is unclear how infections in mothers affect offspring. We manipulated infection in wild red-winged blackbird mothers (Agelaius phoeniceus) and measured effects of experimentally reduced parasite load on reproduction of treated adult females as well as growth, physiology, and immune function of their offspring. In the wild, red-winged blackbirds are able to tolerate infection fairly well, breeding successfully and surviving across years. However, past work with individuals from this population in captivity has revealed significant costs associated with avian malarial infections. Birds at our field site experience an unusually high incidence of Haemosporidian infection (>90 % of individuals infected with 1 or more genus of Haemosporidian). To reduce infections, we caught adult females before onset of egg-laying, and treated them with anti-malarial medications or a control solution. Our results provide experimental evidence that decreased avian malarial infections lead to higher reproductive success in adult females and affect offspring quality and viability.
