Octavius Bourchier Bowker was the eighth child of the 1820 settler Miles Bowker and his wife Anna M. Mitford. Other scientifically minded members of the family were his brothers Thomas Holden Bowker* and James Henry Bowker*, and his sister Mrs Mary Elizabeth Barber*. Octavius probably lived on the family farm Tharfield, near present day Port Alfred, until the death of his father in 1839. He was an extraordinary good marksman and served in the Frontier Wars between 1836 and 1852. In January 1844 he married Mary Anne Bowker* (born Stubbs) in Bathurst. From 1852 he farmed on "Glen Mitford" near Graaff Reinet and also traded in firearms as a partner in the firm Hayton and Bowker. In 1861 he and his wife moved to the Free State where they farmed on the farm "Champagne", near Zastron.
Octavius was interested in birds and in prehistoric artefacts. In 1860 he presented a heron and a crane from the Vaal River to the Albany Museum and in 1864 followed this up with several more birds from the Vaal River. More important though was his donation in 1861 of grooved stones from the Transvaal, used for sharpening and straightening the points of arrows, and a number of bored stones used for weighting digging sticks. These were the first stone artefacts received by the Albany Museum and establish Octavius, like his brother Thomas Holden, as one of the first collectors of prehistoric artefacts in southern Africa. Octavius died on his farm in 1899.