Fig. 1

Arrival events at staging sites relative to the \({\text{TGS}}_{\mathrm{onset}}\) Each arrival event is shown as point coloured according to the (scaled) \(\Delta {\text{arrival}}_{\mathrm{d}}\), with arrival events early relative to the \(TGS_{\mathrm{onset}}\) shown in orange, and arrivals occurring later relative to the \(TGS_{\mathrm{onset}}\) shown in purple. Subsequent arrival events recorded for the same individual and year are connected by lines. Data are shown in interrupted Goode Homolosine projection