Figure 1.

Overview of vector, resident and migrant population dynamics throughout the annual cycle (a), and associated timing for each period (b). (a) Schematic of the population and infection dynamics of a partially migratory host population, where resident and migratory populations share their breeding grounds with a disease-causing vector. Each large rectangle represents the breeding, migratory and wintering range of the migrant. Squares represent the populations of susceptible (S) and infected (I) migrant and resident (subscripts M, R respectively) hosts, and circles represent susceptible and infected vectors (subscript V). Solid arrows represent transitions between states resulting from births, deaths and infection; dashed arrows indicate variables influencing transmission rates. (b) Seasonal presence of residents, migrants and vectors throughout the migratory range. Grey shaded regions represent the timing of habitat use by the migrant, black lines indicate seasonal presence of migrants, residents and adult vectors during their breeding (thick lines) or nonbreeding (thin lines) period. Solid grey vertical lines represent the timing of migratory departure and arrival, and the grey dashed line denotes the onset of breeding in resident hosts and vectors.