Tarictic hornbill
...that the casque of the Tarictic hornbill is hollow and made of keratin?
...that the casque of the <b id="mwFA"><a class="mw-redirect" href="./Tarictic_hornbill" id="mwFQ" rel="mw:WikiLink" title="Tarictic hornbill">Tarictic hornbill</a></b> is hollow and made of <a href="./Keratin" id="mwFg" rel="mw:WikiLink" title="Keratin">keratin</a>?