anisodactyl

/ (ænˌaɪsəʊˈdæktɪl, ˌænaɪ-) /

adjective Also: anisodactylous

(of the feet of passerine birds) having the first toe directed backwards and the other three toes directed forwards

noun

a bird having this type of feet
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012