A. Duncan published "Notes on the genus Pyromelana (Bishop Birds), with reference in particular to the seasonal changes of plumage and nidification [nesting] in captivity of P. oryx (Red Bishop Bird)", in the Journal of the South African Ornithologists' Union (Vol. 1(2), pp. 57-60) in December 1905. He served as a member of the Union's council from 1907 to 1909, but later that year was no longer listed as a member. However, in May 1916 the Union amalgamated with the Transvaal Biological Society to form the South African Biological Society, and A. Duncan, then living in Johannesburg, is listed as a foundation member of the latter. In 1911, already residing in Johannesburg, he had joined the South African Association for the Advancement of Science.