Table 1.

Factors affecting urban commonness of bird species in Oslo

Predictor	df	F	P
Frequency in surrounding sites	1	152.61	<0.0001
Habitat type	3	18.50	<0.0001
Migration	1	1.98	0.16
Nest location	3	6.17	0.0008
Brain mass	1	0.17	0.68
Residual body mass	1	3.91	0.052

Results from ANCOVA (summarized with a sequential sum of squares) showing associations between the frequency of occurrence of bird species (N = 90) in urban sites (N = 93) in Oslo and six predictor variables (frequency of occurrence in surrounding sites, habitat type, migration, nest site and relative brain mass [i.e. ln-transformed brain mass and residual body mass]). Significant values (P < 0.05) are in bold. See Additional file 1: Table S3 for full results from summarization of PGLS model.