Morphometric characterization of four Indonesian duck populations (Anas platyrhynchos): Alabio, Debung, Mojosari, and PMp Agrinak

Four Indonesian duck populations, Alabio, Debung, Mojosari, and PMp Agrinak, lack comparison under a consistent morphometric framework. We evaluated eight traits, within-population correlations, and multivariate variation in 408 adult female ducks aged 10–12 months. Alabio, Mojosari, and PMp Agrinak were measured at one breeding facility, whereas Debung was sampled from smallholder flocks, confounding population with production environment. Measurements included body weight (BW), breast girth (BrG), breast length (BrL), body length (BdL), wing length (WL), neck length (NL), bill length (BL), and shank length (SL). Population differences were assessed using Welch’s ANOVA and Games–Howell tests, correlations using Pearson coefficients with false discovery rate control, and patterns using standardized principal component analysis (PCA). All traits differed among populations (p < 0.001). PMp Agrinak showed the highest BW, BrG, and BL, whereas Debung had the greatest WL, NL, and SL. Alabio had the smallest linear dimensions, and Mojosari was intermediate. BrG correlated positively with BW (r = 0.37–0.56) and WL across populations. PC1 (43.12%) reflected body size; PC2 (18.10%) contrasted BW and BrG against WL, NL, and SL. Together, these axes explained 61.22% of variance, with PC2 largely reflecting between-population mean differences. Overlapping 95% ellipses and environmental confounding preclude conclusions about genetic differentiation.