Pelvic Shape Variation in Domestic Rabbits: Influence of Sex, Breed and Reproductive Status

Abstract

The present study investigates the influence of biological and functional factors-namely, sex, reproductive status, age and breed-on pelvic morphology in domestic rabbits (Oryctolagus cuniculus) using two-dimensional geometric morphometric methods. A total of 38 skeletally mature individuals (19 males and 19 females, of which 13 were nulliparous and 6 had a history of parturition) were examined through pelvic radiographs. Landmark-based shape analysis was conducted on digitized radiographic images to quantify morphological variation. Procrustes ANOVA results indicated no statistically significant shape differences between males and females, nor between parous and nulliparous females. Additionally, no significant pelvic shape variation was detected among different breeds. A multivariate model incorporating both age and sex also failed to reveal a meaningful association with shape variability. Principal component analysis (PCA) revealed that the first two principal components accounted for a substantial proportion of overall shape variation, yet this variation did not correspond with any of the investigated biological categories. These findings suggest that pelvic morphology in domestic rabbits remains relatively stable regardless of sex, reproductive status, or breed, with shape variation largely reflecting individual-level differences rather than group-level functional or developmental constraints. This study contributes to the anatomical understanding of lagomorphs and provides a baseline for future research exploring the functional morphology and clinical assessment of the pelvic region in rabbits.