Sexual dimorphism in external morphology and pelvis of the lesser bandicoot rat, Bandicota bengalensis (Gray, 1835) (Mammalia: Rodentia: Muridae)

We used linear morphometric measurements to assess secondary sexual dimorphism in the external traits and pelvis of the lesser bandicoot rat, Bandicota bengalensis (Gray). Multivariate analysis of variance revealed significant difference between the sexes in both external (Wilks' lambda = 0.542, F = 3.378, P < 0.05) and pelvis measurements (Wilks' lambda = 0.238, F = 10.05, P < 0.05). Males were larger than females in most of the external traits. In contrast, females were larger in most variables of the pelvis. Separation between the sexes was also demonstrated in the discriminant analysis. Although allometric slopes did not differ between the sexes, means adjusted for allometry were sexually dimorphic in five out of seven variables of the pelvis. In conclusion, our results revealed differential patterns of secondary sexual dimorphism for the external morphology and pelvis in B. bengalensis. These patterns are explained with respect to the accessible evolutionary theories on mammalian sexual dimorphism.