Fig. 4
From: Factors underlying migratory timing of a seasonally migrating bird
Average migration date within each genetically distinct population versus (A) the latitude-corrected migration distance and (B) the predicted spring onset on the breeding grounds. Dots represent mean values, while bars represent one standard deviation. Both plots show that the Atlantic and West migrate roughly two weeks earlier, on average, than the Midwest population. However, while the Atlantic and Midwest largely overlap in their spring onset distribution (with spring arriving earlier in these breeding ranges than the more northerly West), there is a significant difference in remaining migration distance between the two, as the Atlantic population must migrate nearly double the latitude corrected migration distance of the Midwest.
