Hallux
The hind or 'first' toe of a bird. In a perching bird it is well developed, but in one which runs on open ground it may be much reduced (or even absent) and raised above the level of the other toes, as for example in the plovers (family Charadriidae). In birds with totipalmate feet, the 'hind' toe actually points forward.From Peter Weaver's Birdwatcher's Dictionary
Copyright © 1981 by Peter Weaver