Table 3.

Principal component analysis results with loadings that contribute most to each factor in bold.

Variables Entered (Medians)	Factor 1	Factor 2	Factor 3	Factor 4	Factor 5	Factor 6	Factor 7	Factor 8	Factor 9
Song rate	0.78	−0.56	0.05	0.00	0.25	0.06	−0.08	0.05	−0.04
Time singing	0.78	−0.56	0.01	−0.04	0.22	0.05	−0.11	−0.04	0.04
Displacements	0.76	0.41	0.03	0.19	−0.08	0.44	0.13	−0.07	−0.01
Wing waving	0.76	0.45	−0.03	−0.14	−0.12	−0.41	−0.13	−0.07	−0.01
Gathering nest material	0.82	0.54	0.02	0.07	−0.14	−0.04	0.03	0.12	0.02
Look in nest box	−0.13	0.51	0.44	−0.18	0.70	−0.05	0.07	0.00	0.00
Feeding	−0.20	0.11	0.89	−0.13	−0.24	0.18	−0.23	0.01	0.00
Drinking	0.18	−0.37	0.65	0.55	−0.12	−0.25	0.20	−0.01	0.00
Gonad volume	−0.24	0.27	−0.19	0.87	0.20	0.01	−0.21	0.00	0.00