2.4. Statistical analyzes
The bacterial load of the nest box entrance hole and the nest box interior variables were normalized by ln transformation prior to analyses. A two-way ANOVA was used to test whether the study area and the occupancy of the nest box affected the nest box entrance hole bacterial load in the study year; the interaction term was also calculated. This approach was repeated for nest box interior bacterial load. Interactions, both significant and non-significant were included in the models. Analyses were performed using Statistica ver. 12 software (StatSoft Inc., 2014).