Fig. 3
From: Factors underlying migratory timing of a seasonally migrating bird
The relationship between migration date and spring onset (A and B) and latitude-corrected migration distance (C and D), with and without population as a factor. Trendlines represent linear regression predicted using full models of timing with 95% confidence intervals. Without considering population, spring onset and latitude-corrected migration distance were strong predictors of timing with negative relationships (p < < 0.001 in both cases; A and C), with earlier migrants traveling to locations with later spring onset and a much greater distance east/west of the capture site. When the data was broken up by population however, the relationship between spring onset and timing changed to a positive one in both the Midwest and Atlantic populations (B). Similarly, at the population scale, latitude-corrected migration distance flipped its relationship in the Atlantic population.
