Fig. 4

Effects of sparrowhawk age and sex on total prevalence of Haemoproteus, Leucocytozoon and Trypanosoma estimated by logistic model with additive effects of age, sex and year. Age was modeled as a quadratic effect for ages 1–9 years (solid line with shaded area showing the 95% confidence interval), as a quadratic effect for ages 1–7 years (dashed line) or as a linear effect for ages 1–7 years (dotted line). See Additional file 1: Table S1 for parameter estimates. Sample size (numbers along the age axis) and raw prevalence (points) calculated as a simple proportion of positive cases (see Table 1) are shown for each age category