COMPARATIVE MORPHOLOGY AND MORPHOMETRY OF WING PATAGIA IN Gallus gallus DOMESTICUS AND Numida meleagris: FUNCTIONAL IMPLICATIONS

Abstract

This study aimed to test the hypothesis that Numida meleagris (guinea fowl), as a species retaining greater flight capability than Gallus gallus domesticus (domestic chicken), exhibits structurally reinforced wing patagia reflecting functional adaptations to more demanding biomechanical requirements. A total of 15 guinea fowls (8 males, 7 females) and 14 domestic chickens (7 males, 7 females), aged 6–7 months and maintained under identical husbandry and dietary conditions, were examined through gross anatomical dissection and morphometric analysis. Measurements were recorded using a digital caliper at two standardized wing positions: resting (90° elbow angle) and fully extended (135° elbow angle). These positions were selected to capture the functional range of the propatagium during the downstroke and upstroke phases of the wingbeat cycle. Results indicated that neither species possessed muscular or ligamentous support for the patagium cervicale or patagium alulae. In the metapatagium, both m. serratus superficialis pars metapatagialis and m. latissimus dorsi pars metapatagialis supported this region in chickens, whereas only the former was present in guinea fowls. The propatagium of guinea fowls exhibited significantly denser connective tissue fibers, which obscured the margins of the ligamentum limitans cubiti. Morphometric analysis revealed that the ligamentum propatagiale was significantly shorter in guinea fowls (P < 0.001), yet remained proportionally consistent with long-bone lengths across wing positions in both species. The insertion thickness of the ligamentum propatagiale was significantly greater in guinea fowls (P = 0.05 at 90°; P = 0.001 at 135°). Collectively, these findings suggest that the reinforced propatagial architecture of N. meleagris represents a functional adaptation to sustain higher mechanical loads during active flight, offering new comparative insights into musculoskeletal diversity and evolutionary plasticity within Galliformes.