Exploring Sexual Dimorphism and Asymmetry in Quail (Coturnix coturnix) Feet Using Geometric Morphometrics

Area of Science:

• * Avian functional morphology and developmental biology.
• * Comparative anatomy and evolutionary biology.

Background:

• * Avian limb morphology offers insights into locomotion, functional anatomy, and developmental stability.
• * Investigating morphological variation and asymmetry is crucial for understanding these aspects in birds.

Purpose of the Study:

• * To analyze shape and size variation in quail (Coturnix coturnix) feet using geometric morphometrics.
• * To assess sexual dimorphism and bilateral asymmetry in quail foot morphology.

Main Methods:

• * Two-dimensional geometric morphometrics applied to 233 quail feet (left and right, male and female).
• * Digitization of 9 homologous landmarks, Generalized Procrustes Analysis, and bilateral symmetry modeling.
• * Statistical analyses including Principal Component Analysis and Procrustes ANOVA.

Main Results:

• * No significant sexual dimorphism in quail foot shape or centroid size was detected.
• * Individual variation, not sex, was the primary driver of shape differences, mainly in toe and claw arrangement.
• * Fluctuating asymmetry was identified as the main source of variation, reflecting developmental instability.

Conclusions:

• * Established a morphological baseline for quail foot structure, emphasizing individual variation over sexual dimorphism.
• * Highlighted fluctuating asymmetry as a key indicator of developmental instability in avian feet.
• * The methodology serves as a reference for future studies on developmental stress, locomotion, and avian anatomy.