where xijk is beak length and eijk is residual error.
Where significant F-values were noted, Tukey’s honestly
significant difference tests were used to determine
where these differences existed. Where the outcome of
transformations was unsatisfactory, Kruskal-Wallis and
Mann-Whitney U-tests in each time were used in place
of parametric approaches. The Minitab V12.1 statistical
package was used for data analysis, and results were
considered significant when P < 0.05 and are expressed,
where appropriate, as the mean ± SEM.