Entry on the Hyacinthine Macaw or Macrocercus hyacinthinus in The Gardens and Menagerie of the Zoological Society Delineated Vol. II (Birds) published in London in 1831 with the sanction of the Council under the superintendence of the Secretary (Ed: N.Vigors) and theVice-Secretary of the Society

THE HYACINTHINE MACCAW

Macrocercus hyacinthinus. Vieill.

This species, first described by Latham, and afterwards figured by Shaw in the Leverian Museum and in his Zoological Miscellany, is one of the rarest of the magnificent group to which it belongs. It would seem that Le Vaillant was unable to procure a specimen, for it is not figured in his splendid work on the family ; nor does any author of the present century appear to have observed it, with the exception of M. Spix. In a former work, the Tower Menagerie, misled, as we now conceive, by the authority of the last named zoologist, and by the unusually fine condition of the bird which we had then before us, we were induced to regard the individual there figured as a distinct species. But subsequent observation has led us to abandon this opinion; and to consider the differences there pointed out as dependent only upon a more advanced age and a finer state of plumage. The brilliancy and depth of the colouring vary considerably in all the individuals that we have seen; the curvature of the bill and claws seems to go on increasing with the growth of the bird; and the tooth of the upper jaw, with its corresponding notch in the lower, may possibly undergo a gradual obliteration from the effects of long continued attrition.

This beautiful species appears to form the passage between the true Maccaws, in which the whole of the cheeks is bare of the common plumage, and the Perruche-Aras of Le Vaillant, the genus Psittacara of Mr. Vigors, in which the cheeks are entirely feathered, with the exception of a circumscribed space encircling the eyes. In the Hyacinthine Maccaw the cheeks are only partially feathered, naked spaces being left round each of the eyes, and also at the junction of the upper and lower mandibles, the latter passing round beneath the chin. The uniform colour of the whole bird is a hyacinthine blue, of greater or less intensity in different individuals, and deeper upon the quill-feathers of the wings and tail. The naked spaces round the orbits and at the base of the bill are of a brilliant yellow; and the bill, legs, and claws are nearly jet black.