Authors

Discussion

Trichomonas gallinae is a widespread protozoan parasite infecting a diverse range of avian orders, in particular, free ranging Columbiformes and Falconiformes, and has been found to cause mortality in the rapidly declining European turtle dove. At least 19 strains of T. gallinae have been identified, with certain strains found to be more virulent, resulting in a high rate of mortality in infected individuals, whilst other, less virulent stains often result in asymptomatic infection. As a key aspect of parasite ecology is understanding the dynamics of co-infection, we consider the rate of infection with multiple strains of T. gallinae in the rapidly declining European turtle dove (Streptopelia turtur). This study is one of very few utilising high throughput sequencing to identify the presence of multiple strains of T. gallinae within a single host. Birds were sampled across one wintering (Senegal) and two breeding (France and Hungary) sites. We detected a higher rate of co-infection with multiple strains of T. gallinae than previous studies, with multiple strains being detected in 16% of birds sampled. Four significant interactions were detected among the four dominant strains of T. gallinae identified in this study, all of which were negative. This indicates that, despite a higher rate of co-infection being observed in this study than previously, co-infection occurs less frequently than would be expected if infection were random, suggesting there is a mechanism acting to reduce the presence of multiple strains within the host.