 The adult of the " nominate " subspecies of the red @-@ billed chough , P. p. pyrrhocorax , is 39 – 40 centimetres ( 15 – 16 inches ) in length , has a 73 – 90 centimetres ( 29 – 35 inches ) wingspan , and weighs an average 310 grammes ( 10 @.@ 9 oz ) . Its plumage is velvet @-@ black , green @-@ glossed on the body , and it has a long curved red bill and red legs . The sexes are similar ( although adults can be sexed in the hand using a formula involving tarsus length and bill width ) but the juvenile has an orange bill and pink legs until its first autumn , and less glossy plumage . 
