Henry Perks Abernethy was a trader in King William's Town and on 1 July 1874 married Elena Mary Anne Jemina Pegler. Later he lived in Kentani, Transkei (now part of the Eastern Cape), for many years. In 1890 he was in charge of the postal agency there. By 1903 he was listed as a storekeeper in the village, and later as a general dealer, until at least 1916. He was the brother-in-law of Miss Alice M Pegler*, who stayed with him as governess and teacher to his daughters.
In 1906 Abernethy sent a collection of insects from the Transkei to the South African Museum. Five species were new to the museum's collection. He and Miss Pegler also donated several collections of other invertebrates from Kentani during the same year. In 1909 the museum received ants from him, also collected at Kentani.