Boxplots of diurnal variation of concentrations of glucocorticoid metabolites (GCM; ng/g droppings) of Blue-fronted parrots (<i>Amazona aestiva</i>), kept under natural light variation (sunrise: 06:23 a.m.—sunset: 06:03 p.m).

<p>Respective median values are showed as a line in the boxes. Lower and upper boundaries of the boxes indicate the 25<sup>th</sup> and 75<sup>th</sup> percentiles, respectively. Whiskers above and below the box indicate the 90<sup>th</sup> and 10<sup>th</sup> percentiles. Outliers are show as points. Asterisks beside the box indicate significant differences compared with the 5 to 8 p.m. interval (<i>P</i> ≤ 0.005).</p>