Table 1.
Statistical values were derived from models that investigated the evolutionary associations between nest wall construction and the absolute egg mass, absolute body mass and relative egg mass. Each of these models also included two interactive effects (i.e. mass and birds being as a passerine, mass and nest site). We applied the natural log-transformation to the mass data before building the models. Phylogenetic correlation was assessed using alpha values, which provided an estimate of the degree of conservation observed in the examined traits across species. A lower alpha value indicates a higher level of trait conservation. Bold p-values indicate statistical significance.
|
model |
fixed factors |
N |
estimate |
p-value |
alpha |
|---|---|---|---|---|---|
|
wall ~ egg + passerine + site + egg*passerine + egg*site |
egg |
4030 |
−2.255 |
<0.001 |
0.005 |
|
passerine |
1.485 |
0.080 |
|||
|
site (non-ground) |
−0.165 |
0.601 |
|||
|
egg*passerine |
1.682 |
<0.001 |
|||
|
egg*site (non-ground) |
0.292 |
0.325 |
|||
|
wall ~ body + passerine + site + body*passerine + body*site |
body |
4030 |
−1.646 |
<0.001 |
0.007 |
|
passerine |
1.569 |
0.066 |
|||
|
site (non-ground) |
0.384 |
0.111 |
|||
|
body*passerine |
1.563 |
<0.001 |
|||
|
body*site (non-ground) |
−0.196 |
0.362 |
|||
|
wall ~ rel.egg + passerine + site + rel.egg*passerine + rel.egg*site |
egg |
4030 |
0.154 |
0.224 |
0.005 |
|
passerine |
1.975 |
0.081 |
|||
|
site (non-ground) |
1.408 |
<0.001 |
|||
|
egg*passerine |
0.256 |
0.355 |
|||
|
egg*site (non-ground) |
−0.406 |
0.030 |