SummaryAn examination of twenty‐four male babirusa skulls indicates that the long tusks have an important function in intraspecific fighting. The upper tusks have developed a shielding, protective function whilst the lower tusks are offensive and daggerlike. As the upper tusks do not hone the lower canines as in other suids, the babirusa male actively sharpens his lower tusks on trees. Wear patterns on the tusks suggest that mainland babirusa use the upper tusks to interlock and hold their opponents' lower tusks during combat. In the Buru race this hooking function appears to have been lost and the upper tusks have a butting function instea