Extract from "Birds at the New Chicago Zoological Park" by Karl Plath, then Curator of Birds, published in August 1937. (Fifth Series, Vol. II, No. 8, Page 288)

I still have my lovely Spix Macaw at home (he summers at the Zoo); unfortunately he is prone to nibbling his plumage and keeps an unsightly rough patch on his "shoulders" and breast - an irritating habit to say the least.

(Karl T. Plath (1886-1970) was a well-known bird artist and keen ornithologist. He was appointed Curator of Birds at the zoo in Chicago in 1935 and retired in 1961)