User blog comment:Lord Loss/Monster Hunter Theory... Blog/@comment-2194133-20110712201834/@comment-1758220-20110712203943

Some animals are what's called sexually dimorphic. This means that the female and male of a species feature different physical traits than one another. For example, Rathalos and Rathian. However, some species are not sexually dimorphic, such as Great Baggi. This leaves the monster's gender indeterminable at first glance.