David Hunter Gilmore started work as a school teacher, but turned to journalism and advertising, working as a journalist for the New Zealand Herald from 1922. In his spare time he tried his hand at serious writing under the name David Orr. His first book, about Cuthbert the caterpillar, was probably written in 1928, the idea based on an incident on a North Island farm where he stayed as a boy during the influenza epidemic following World War I, however it was not published until more than ten years later when the author was working in advertising in Sydney .
Gilmore served in the Australian army in World War II. After the war, he moved to Tasmania but the post-war flood of imported books undermined his writing income and he returned to New Zealand in 1948. He worked as a sub-editor on the Press in Christchurch for twenty years until his retirement in 1978.
A prolific children's author and illustrator, Gilmore published eleven books and had stories published in NSW School Journal. He was influenced by the style of Walt Disney, and was described in an obituary as 'the Australian Walt Disney'.
