Sexual dimorphism of ducks (Cairina moschata, Linnaeus 1758) reared in the southern forest of Côte d'Ivoire

Sexual dimorphism was studied on 213 ducks including 92 males and 121 females of the species Cairina moschata in the southern forest of Côte d'Ivoire. Measurements were made using a tape measure and weighing with an electronic scale. A step-wise discriminant analysis made it possible to examine 21 morphometric descriptors. All linear measures except beak and head with were significantly higher in males than in females. 18 of these 21 parameters are statistically significant with the Mann-Whitney U test. Of these 18 significant descriptors, nine are strongly correlated positively for the first two and the fourth axis while it is negatively for the third factorial axis. The projection of the individuals in the plane of the principal component analysis shows a separation of the batches so that along axis 1 the male individuals gather towards the negative coordinates and the female individuals towards the positive coordinates. The values recorded with the discriminant factor analysis confirm to 92.49% the membership of the specimens to the different defined groups. This analysis proposes a reclassification of two females in the group of males and of 14 males among the females.