Skip to main content
Fig. 1 | Climate Change Responses

Fig. 1

From: Did British breeding birds move north in the late 20th century?

Fig. 1

Distributional shifts among British breeding bird species between 1968–72 vs. 1988–91. Changes in species range sizes were calculated as log10 transformation of the ratio of the number of occupied cells in T2 to the number of occupied cells in T1. a Plots the overall change in distributional margins (defined as the mean distance of all marginal cells recorded in the second period of the comparison minus all marginal cells in the first period). Positive values on the x-axis indicate range expansions (outward shifts), while negative values indicate range contractions (inward shifts). Regression statistics were obtained after regressing changes in range size against changes in mean position of marginal cells. X = 0 regression intercepts in a indicate mean distributional shifts (km) for species with no overall change in the number of grid cells occupied. b plots changes in occupancy (contractions and expansions) among marginal cells for contracting species (−), species with stable ranges (0), and expanding species (+). The size of the bars is proportional to the mean proportion of the marginal cells over all species in the group (see Additional file 2: Figure S1 for details)

Back to article page