Fig. 1From: Days to visit an offshore island: effect of weather conditions on arrival fuel load and potential flight range for common blackbirds Turdus merula migrating over the North SeaThe study area is Helgoland (red triangle). Based on ringing recoveries, four possible coastal destinations for autumn (yellow diamonds) and spring (blue diamonds) were chosen as example flight paths (autumn = solid lines; spring = dashed lines) with different flight distances (km). The area covered from 50° to 60°N and 0° to 10°E is subdivided by a spatial resolution of 25 NCEP reanalysis grid cell intercepts (2.5° × 2.5°); exemplified by Helgoland (solid box). Black dots represent the centre of each grid from which the weather parameters are obtained (see methods)Back to article page