Exploring Sexual Dimorphism in Kadaknath Chickens Through Head Shape Analysis Using Geometric Morphometrics

Sexual dimorphism plays a crucial role in the biology and management of poultry species, influencing breeding, behavior, and productivity. This study aims to investigate sexual dimorphism in Kadaknath chickens using geometric morphometric analysis of head shape variation A total of 16 adult Kadaknath chickens (8 males and 8 females) were analyzed using landmark-based geometric morphometric analysis on lateral head images. Principal Component Analysis (PCA), Canonical Variate Analysis (CVA), and Partial Least Squares (PLS) analysis were performed to assess shape variation and sexual dimorphism. PCA revealed clear shape differences between sexes, with males displaying more pronounced features in the beak, eye, and comb regions. Males also exhibited less within-group shape variation, suggesting greater shape conservation. Females showed narrower ear lobes, shorter combs, and higher shape variation along PC1. CVA confirmed sex-specific differences, particularly in the comb and eye regions. No significant difference in centroid size was observed between sexes, indicating the absence of sexual size dimorphism. PLS analysis demonstrated that between-group variation was greater than within-group variation. The study confirms pronounced sexual dimorphism in Kadaknath chickens, primarily attributed to shape differences independent of overall size. These findings contribute to breed characterization, aid in sex identification, and support conservation strategies. The small sample size may limit the reliability of the CVA results. Future research incorporating 3D morphometrics and larger populations is recommended.