Skip to main content

Table 3 LMMs investigating whether moving up or down the social ladder resulted in more or less within-ejaculate variation in sperm design or total sperm length

From: Social dominance explains within-ejaculate variation in sperm design in a passerine bird

a) Difference (after – before) in the variation in sperm design

Random effects

Estimates ± SE

 

Z

P

 Aviary

0.010 ± 0.010

 

0.91

0.18

 Sampling date

0.007 ± 0.012

 

0.58

0.28

Fixed effects

 

F

df

P

 Intercept

1.115 ± 1.061

   

 Difference in social rank

-0.010 ± 0.025

0.18

1, 50.8

0.68

 Body mass (after)

-0.027 ± 0.026

1.09

1, 47.3

0.30

 Tarsus length

-0.026 ± 0.050

0.27

1, 46

0.60

b) Difference (after – before) in the variation in total sperm length

Random effects

Estimates ± SE

 

Z

P

 Aviary

0.107 ± 0.103

 

1.04

0.15

 Sampling date

0.091 ± 0.141

 

0.64

0.26

Fixed effects

 

F

df

P

 Intercept

10.258 ± 3.224

   

 Difference in social rank

-0.131 ± 0.075

3.04

1, 50.6

0.09

 Body mass

-0.090 ± 0.080

1.26

1, 46.8

0.27

 Tarsus length

-0.427 ± 0.150

8.08

1, 45.7

0.007

  1. Values in bold indicate significance at α = 0.05; tests of random effects are based on Wald-Z