Table 2 

Between species comparisons (II). 

Raw data: GLZ (Binomial distribution and logit link function). Dependent variable: with vs without specialized cuckoo egg morphs 



Population Density 
CV population density 
Body mass 
Duration of nestling period 



Model 1 
χ^{2 }= 5.17, P = 0.023 
χ^{2 }= 0.74, P = 0.39 
χ^{2 }= 0.66, P = 0.42 

Model 2 
χ^{2 }= 7.72, P = 0.005 
χ^{2 }= 0.86, P = 0.35 
χ^{2 }= 0.65, P = 0.42 



Phylogenetically independent contrasts: Multiple regression throughout the origin 



Beta(SE) 
Beta(SE) 
Beta(SE) 
Beta(SE) 

Model 1 
0.24(0.11), P < 0.04 
0.16(0.11), P > 0.1 
0.09(0.11), P > 0.4 

Model 2 
0.28(0.11), P = 0.01 
0.19(0.11), P > 0.1 
0.12(0.11), P > 0.2 



Comparisons between species for which the European cuckoo has and has not evolved specialized egg morphs. Raw data were compared by means of Generalized Linear Models and Chisquare statistic (df = 1 for all performed analyses). Phylogentically independent contrasts were compared by means of regression analyses through the origin (corrected df = 64 for all performed analyses). Model 1 and model 2 respectively include population density and coefficient of variation (CV) in population density as independent variables. 

Soler et al. BMC Evolutionary Biology 2009 9:88 doi:10.1186/14712148988 