Table 1 Summary of linear mixed models of egg volume of blue tits in relation to year, site and clutch size. Two separate models are shown: (i) with year as a categorical factor and (ii) with year as a continuous variable. Clutch ID included as a random effect

1.207 ± 0.022

1;883.5

3927.5

<  0.0001

11;760.2

1.3

0.239

−0.056 ± 0.006

1;762.7

71.7

<  0.0001

−0.0042 ± 0.0017

1;884.6

6.2

0.013

1;753.9

1.3

0.330

11;739.9

1.3

0.212

11;804.0

1.6

0.098

5.306 ± 1.998

1;776.5

7.0

0.008

−0.002 ± 0.0009

1;776.5

4.2

0.040

−0.059 ± 0.006

1;777.8

87.1

<  0.0001

1;793.3

1.8

0.180

1;782.9

1.2

0.259

1;776.9

1.9

0.164

1;790.4

2.7

0.101