Fig 9. Lateral shape variation in the upper mandible of the 18.5-week old turkeys.

The right lateral shape variation in the upper mandible explained by (A) PC1 and PC2, and (B) PC1 and PC3 for 1689 male (black) and female (grey) turkeys photographed at 18.5 weeks of age. The light blue beak outlines represent the mean lateral shape of the upper mandible for these 18.5-week old turkeys. The dark blue outlines are visual representations of the lateral upper mandible shape at the minimum and maximum scores for this group along the axis of each principal component.