 The yellow @-@ tailed black cockatoo is 55 – 65 cm ( 22 – 26 in ) in length and 750 – 900 grams in weight . It has a short mobile crest on the top of its head , and the plumage is mostly brownish @-@ black with paler feather @-@ margins in the neck , nape , and wings , and pale yellow bands in the tail feathers . The tails of birds of subspecies funereus measure around 33 cm ( 13 in ) , with an average tail length 5 cm ( 2 @.@ 0 in ) longer than xanthanotus . Male funereus birds weigh on average around 731 g ( 1 @.@ 612 lb ) and females weigh about 800 g ( 1 @.@ 8 lb ) . Birds of the xanthanotus race on the mainland average heavier than the Tasmanian birds ; the males on the mainland weigh on average around 630 g and females 637 g ( 1 @.@ 404 lb ) , while those on Tasmania average 583 and 585 g ( 1 @.@ 290 lb ) respectively . Both mainland and Tasmanian birds of the xanthanotus race average about 28 cm ( 11 in ) in tail length . The plumage is a more solid brown @-@ black in the eastern subspecies , while the southern race has more pronounced yellow scalloping on the underparts . 
