Salim was introduced to the serious study of birds by W. S. Millard, secretary of the Bombay Natural History Society (BNHS) where Amiruddin was a member, who identified an unusually coloured sparrow that young Salim had shot for sport with his toy air gun. Millard identified it as a yellow-throated sparrow, and showed Salim around the Society's collection of stuffed birds. Millard lent Salim a few books including Eha's "Common birds of Bombay", encouraged Salim to make a collection of birds and offered to train him in skinning and preservation. Millard later introduced young Salim to (later Sir) Norman Boyd Kinnear, the first paid curator at the BNHS, who later supported Ali from his position in the British Museum. In his autobiography, "The Fall of a Sparrow", Ali notes the yellow-throated sparrow event as a turning point in his life, one that led him into ornithology, an unusual career choice, especially for an Indian in those days. Even at around 10 years of age, he maintained a diary and among his earliest bird notes were observations on the replacement of males in paired sparrows after he had shot down the male.