[ gdw]
In Leviticus, the ostrich is listed among the unclean birds that should not be eaten. The TLL citations gloss this passage from the Bible. The gloss ostur is probably an error (see ostur1) – not uncommon in medieval times, cf. MED ostrich(e n.1, sense 4. On the difficulties of the taxonomy of medieval bird-names, see David Trotter, ‘Tote manere d’oiseaus: Les noms d’oiseaux en Anglo-Normand’, Cahiers de Lexocologie 103 (2013), 125-43.