Effects of experimental brood size of focal males and females (in separate analyses) on their association patterns with stimulus birds.

Models in R script were almer(response variable∼brood size+(1|hatching nest)+(1|foster brood)+(1|tutoring group)+(1|year)); blmer(response variable∼brood size+(1|hatching nest)+(1|foster brood)+(1|tutoring group/matched pair)+(1|year)).cModel including song preferences in the operant test as a covariate (see text for details).Transformations were darcsine or Box-Cox by a factor λ = 0.45e, 0.606f and -0.238g.