Clutch size and haemoparasite species richness in adult and nestling blue tits

Publisher Website
Google Scholar
Abstract
Diseases have been recently suggested as a potential cost that parents and offspring pay for an elevated reproductive effort in wild organisms. We investigated the relationship between clutch size and the number of blood parasite species (species richness) infecting adult and nestling blue tits (Parus caeruleus). Four protozoan (Haemoproteus majoris, Leucocytozoon majoris, Hepatozoon parus, and Trypanosoma avium) and one helminth (Microfilariae) species were found infecting adults and two protozoan species (T. avium and L. majoris) were found in nestlings. Females laying larger clutches showed a higher haemoparasite species richness, but infection in male parents was not associated with clutch size. The species richness of haemoparasites per nestling was also positively correlated with clutch size. Both relationships in female and nestling blue tits may be explained in terms of the trade-off between reproduction and number and quality of the progeny. This is the first report of a connection between clutch size and blood parasitemias of their offspring, and it suggests new tools for exploring potential trade-offs among fitness components in wild organisms.