Evidence for strain-specific virulence of Trichomonas gallinae in African columbiformes

Infection by parasites or pathogens can have marked physiological impacts on individuals. In birds, infection may affect moult and feather growth, which is an energetically demanding time in the annual cycle. Previous work has suggested a potential link between clinically visible Trichomonas gallinae infection and wing length in Turtle doves Streptopelia turtur arriving on breeding grounds. First, T. gallinae infection was characterised in 149 columbids from five species, sampled on Turtle dove wintering grounds in Senegal during the moulting period, testing whether infection by T. gallinae is linked to moult. T. gallinae prevalence was 100%, so rather than testing for differences between infected and uninfected birds, we tested for differences in moult progression between birds infected by different T. gallinae strains. Twelve strains of T. gallinae were characterised at the ITS1/5.8S/ITS2 region, of which six were newly identified within this study. In Turtle doves only, evidence for differences in wing length by strain was found, with birds infected by strain Tcl-1 having wings nearly 6 mm longer than those infected with strain GEO. No evidence was found for an effect of strain identity within species on moult progression, but comparisons between infected and uninfected birds should be further investigated in species where prevalence is lower.