bare-shanked screech owl
... that the nesting of the bare-shanked screech owl has only been studied once, within the cavity of an oak tree?
... that the nesting of the <b id="mwB24"><a href="./Bare-shanked_screech_owl" id="mwB28" rel="mw:WikiLink" title="Bare-shanked screech owl">bare-shanked screech owl</a></b> has only been studied once, within the cavity of an <a href="./Oak" id="mwB3A" rel="mw:WikiLink" title="Oak">oak</a> tree?