Figure 1
From: Commonness and ecology, but not bigger brains, predict urban living in birds
Relationships between rural and urban commonness, and brain mass and urban commonness, of bird species in Oslo. Frequency of occurrence of bird species in urban green spaces in Oslo compared to frequency in the surroundings of Oslo for (a) all species (N = 90), (b) compared to relative brain mass for all species (N = 90) measured as residuals from a regression of brain mass on body mass, (c) compared to frequency in the surroundings of Oslo for forest species (N = 62) , and (d) for farmland species (N = 26). Frequencies were percentage of sites where each species was recorded as present (number of sites in urban area: 93; number of sites outside city: 137 forest sites, 51 farmland sites, 176 sites in total). Unlike all analyses, figures do not control for phylogeny.