Table 1 LMMs investigating how social status affects within-ejaculate variation in sperm design or total sperm length

Random effects

Estimates ± SE

Z

P

 Aviary

0

0

1

 Sampling date

0.011 ± 0.013

0.87

0.19

Fixed effects

F

df

P

 Intercept

0.75 ± 0.08

 Social status^a

3.38

3, 45

0.027

  Dominant

0.053 ± 0.066

  Subordinate-1

-0.083 ± 0.067

  Subordinate-2

0.139 ± 0.066

 Body mass

0.021 ± 0.036

1.21

1, 45.6

0.28

 Tarsus length

0.039 ± 0.077

2.29

1, 45.2

0.14

 Social status x Body mass^a

1.27

3, 45.1

0.30

  Dominant

-0.020 ± 0.060

  Subordinate-1

0.075 ± 0.058

  Subordinate-2

-0.039 ± 0.057

 Social status x Tarsus length^a

0.91

3, 45.3

0.44

  Dominant

-0.088 ± 0.122

  Subordinate-1

0.131 ± 0.129

  Subordinate-2

0.038 ± 0.100

Random effects

Estimates ± SE

Z

P

 Aviary

1.03

0.15

 Sampling date

0.63

0.26

Fixed effects

F

df

P

 Intercept

2.12 ± 0.24

 Social status^a

0.56

3, 34.4

0.64

  Dominant

-0.024 ± 0.23

  Subordinate-1

-0.009 ± 0.24

  Subordinate-2

-0.26 ± 0.23

Body mass

0.001 ± 0.14

3.45

1, 39.5

0.07

Tarsus length

0.16 ± 0.30

6.90

1, 45

0.012

Social status x Body mass^a

4.34

3, 44.3

0.009

  Dominant

0.45 ± 0.24

  Subordinate-1

0.51 ± 0.22

  Subordinate-2

-0.23 ± 0.22

Social status x Tarsus length^a

0.70

3, 43

0.56

  Dominant

0.11 ± 0.48

  Subordinate-1

0.67 ± .50

  Subordinate-2

0.29 ± 0.39