DiastataxicHaving no secondary feather corresponding to the fifth feather of the greater wing coverts. If a secondary is present, the arrangement is called 'eutaxic'. Diastataxy occurs in grebes (family Podicipedidae), geese of the genus Anser, owls (order Strigiformes) and pigeons (family Columbidae).
Search Bird Dictionary
From Peter Weaver's Birdwatcher's Dictionary
Copyright © 1981 by Peter Weaver