Why Are the Tusks of Male Hippos Bigger Than That of Their Female Counterpart?

The size of male hippopotamuses is unusual. Among mammals, the sizes of males are usually far larger than females, but this seems to be different in hippos. The jaws and tusks of males are much bigger. Recent research using data discovered from 60 years ago on close to 3,000 hippos, propose that their semi-aquatic behavior could possibly be crucial in reducing the size dissimilarities between the sexes.