casques
... that the casques of some large hornbill species can take up to six years to reach their full size?
... that the <b id="mwBdU"><a href="./Casque_(anatomy)" id="mwBdY" rel="mw:WikiLink" title="Casque (anatomy)">casques</a></b> of some large hornbill species <i id="mwBdc">(example pictured)</i> can take up to six years to reach their full size?