Figure 2.

Prevalence curves from the multi-host model against effective R₀(t) values [47]. (a) R₀^e(t) values for species in Delaware Bay both with and without environmental transmission; (b) the migratory duck (mig) prevalence alongside the effective R₀(t) for migratory ducks individually; (c) the resident duck (res) prevalence and the effective R₀(t) for resident ducks individually; and (d) the ruddy turnstone (RUTU) prevalence with the effective R₀(t) for ruddy turnstones individually. In (b)–(d), the times of low transmission for the species shown are shaded and the R₀^e values are shown with environmental transmission. We assume the population size for each host to be 10 000 [33,39,52]. Initial conditions in the duck hosts are S(0) = 225, I(0) = 1, R(0) = 9774 (robustness to initial conditions is shown in the electronic supplementary material); for the ruddy turnstones they are S(0) = 9999, I(0) = 1, R(0) = 0. We assume that some virus is present initially at Delaware Bay and the duck breeding grounds, with V(0) = 100. We assume no virus is initially present at the ruddy turnstone wintering and breeding grounds [26,50].