Morphological divergence of Creole goats across Peruvian ecosystems

Abstract

Peruvian Creole goats constitute a genetically distinct population shaped by long-term crossbreeding and adaptation. Peru spans ecological gradients that likely drive regional phenotypic differentiation, yet the morphometric basis remains poorly resolved. We assessed the concordance between morphometric structuring of goats, ecosystem distribution, and regional origin. Body weight (BW) and seven linear body measurements (LBM) were recorded in 515 adult female goats sampled across five ecosystems and seven regions. Low-dimensional structure for BW and LBM was explored using uniform manifold approximation and projection with k-means clustering, and cluster separability was assessed using a linear support vector machine. Six body conformation indices supported body-type interpretation. Four morphometric clusters were identified, structured by Andean shrublands (AS), plains seasonally dry forest (PSDF), and inter-Andean seasonally dry forest (IASDF). Clusters C1 and C3 were dominated by AS goats (77% and 79%, respectively), revealing two morphotypes: a convexilinear form with elevated pelvic indices (C1) and a lighter, shorter, longilinear form (C3). Clusters C2 and C4 were mainly formed by PSDF (54%) and IASDF goats (66%), respectively, with C2 characterized by greater stature and thoracic robustness, and C4 by a narrower pelvic conformation. In contrast, goats from the other ecosystems exhibited greater heterogeneity. Each cluster was dominated by >60% of goats from a single region, with C1, C2, C3, and C4 associated with Ica, Piura, Ayacucho, and Amazonas, respectively. These findings establish the first ecosystem-based national morphometric framework for Peruvian Creole goats, linking body conformation to ecological and geographic context and informing conservation and potential geographical indications.