This word has the same etymology as mauviz (see mauviz), and there are also shared forms: as a result, there is some confusion between what are in fact two quite distinct (and easily distinguished) species. See David Trotter, ‘Science avec conscience: réflexions sur le lexique scientifique et le DMF’, in Frédéric Duval (ed.), La ‘logique’ du sens: de la sémantique à la lexicographie. Autour des propositions de Robert Martin (Metz: Université de Metz, 2011), 281-299 (pp. 286-289). For the general problem about bird-names, which is endemic in Anglo-Norman and especially in the gloss materials, see further Trotter, ‘Tote manere d’oiseaus: les noms d’oiseaux en anglo-normand’, Cahiers de lexicologie 103 (2013), 125-143, available online here.