Eaglet
The Celtic Tree Alphabet lists the letter for the Yew as "Idho" which is the vowel "I" . The word "Irfind" in Old Irish means "very white"...the white of bleached bone or death. The Yew tree is sacred to the goddess Banba, one of the Celtic Triad, and a death crone goddess. The bird of this tree is the eaglet, whose name in Irish is "Illait", because like death its appetite is endless. The letter and sound also correspond to the Anglo-Saxon rune "Is" or "Ys" which is the rune of "ice" and which is the symbol of death. The bones of the eaglet's nest are white like the snow on its cliff-ledge.
Like the unstrung bow, the eaglet is a symbol of power held in reserve. The bow, when employed, will send an arrow through a knight's armor. The eaglet, when grown, will be the strongest of raptors.