Baker-Gabb studied agriculture and then biology at Massey University in Palmerston North, New Zealand, graduating in 1978 with a master's degree in science for his work on the swamp harrier.
Between 1988 and 1989 he studied the habits of the red goshawk in the Northern Territory until 1990 when he joined the Department of Conservation and Environment in Victoria as a manager of threatened fauna, a role he carried out until 1992.
[2][3] From 1993, Baker-Gabb served as Director of the Royal Australasian Ornithologists Union, and during his term of office he established the Gluepot Reserve in South Australia.
After 1997, Baker-Gabb founded an environmental consulting company that specialised in threatened species recovery, wildlife surveys, the production of management plans and the assessment of properties for acquisition as reserves.
[2][3] Baker-Gabb married conservationist and ornithologist Julie Catherine (Kate) Fitzherbert in 1981, managing editor for the Handbook of Australian, New Zealand and Antarctic Birds from 1986 to 1987 and then supporter services co-ordinator for the Royal Australasian Ornithologists Union until 2000.