North Island Kōkako <i>Callaeas wilsoni</i> (front) has blue wattles, and South Island Kōkako <i>Callaeas cinereus</i> (rear) has orange wattles.
By <a href="//commons.wikimedia.org/wiki/J._G._Keulemans" class="mw-redirect" title="J. G. Keulemans">J. G. Keulemans</a>, in W.L. Buller's <i>A History of the Birds of New Zealand</i>. 2nd edition. Published 1888.
published 1888
<a rel="nofollow" class="external free" href="http://www.nzbirds.com/Buller2ndKokakoLg.html">http://www.nzbirds.com/Buller2ndKokakoLg.html</a>, rotated slightly to vertical.