Figure 2
From: Barn swallows long-distance migration occurs between significantly temperature-correlated areas
Frequency distributions of the distances of the correlation peak between temperatures relevant to migration from Africa to Europe and (red or blue bars) the actual wintering locations of barn swallows, or (grey bars) the randomly generated positions in Africa (local scale randomization, see Methods) in either cluster N (A, red) or cluster S (B, blue).
