Figure 1.

Central map shows area of interest within the United Kingdom and location of study areas; (A) Southport urban (number of transects t = 2), (B) Southport rural (t = 1), (C) Ainsdale North (t = 4), (D) Ainsdale South (t = 4), (E) Formby North (t = 4), (F) Formby South (t = 3), (G) Hightown (t = 2), and (H) Ince Blundell (t = 5). The surrounding plots show the squirrel densities (mean, weighted by transect length) calculated from transect surveys within that area (upper chart in plot area). The dashed lines indicate actual estimated squirrel densities, while the solid lines show those data with two-point smoothing. Red squirrel pox incidence based on submission of squirrelpox virus (SQPV)-positive carcases is shown in the lower chart in plot areas at 0 m (within study area) and up to 1500 m from the study area (the distance that SQPx cases shown to have the strongest association to red squirrel PGR in subsequent analysis). SQPV-positive cases were assumed to be capable of affecting multiple study areas (no physical barriers were present); therefore, all SQPV-positive cases within 1500 m are plotted for each area irrespective of whether they feature in plots for other areas The vertical gray dashed lines indicate 6 months prior to and after the first and last cases of red squirrel SQPx in that area. Transects are grouped depending on geographic location and whether either or both species were observed.