Walter R. Piers, son of Henry W. Piers*, was a civil servant and naturalist. He served in the commissariat department (dealing with the supply of food) of the military in the Cape Colony during 1865 and 1866. In 1869 he qualified as a government land surveyor, but did not practice this profession. In March that year he entered the Cape civil service as a clerk in the Colonial Secretary's Department and subsequently served in the same capacity at Fort Beaufort (from August 1870), Colesberg (September 1872), and Grahamstown (March 1873). From May 1876 he was assistant magistrate of Albany and from February 1878 in addition registrar of the eastern districts court. He was promoted to civil commissioner and resident magistrate at Murraysburg in July 1883, was transferred to the division of Peddie (August 1884), Albert magisterial district (Burgersdorp, January 1893), Paarl (July 1897), East London (September 1901), and Kimberley (1902). During January to June 1897 he was chairman of the rinderpest compensation committee. He left the civil service on pension in 1905 or 1906.
Piers's contributions to natural history appear to have been confined to his first two years at Peddie. During these years he was president of the Peddie Agricultural Society (while the bird collector J.G. Nicholson* was secretary), and chairman of the local government school board. During 1884 he sent notes on injurious insects as well as specimens to Miss Mary Glanville*, Curator of the Albany Museum, Grahamstown, who found the material of much help in working out the life histories of these pests. Piers continued his help in 1885, when he also presented some spiders to the museum. Miss Glanville in turn sent her notes and specimens on insect pests to Miss E.A. Ormerod* in England, who published a book on the subject in 1889.