From 1966 to 1969, Chalmers lectured in zoology at Makarere University College, Kampala, Uganda, and was scientific director at the National Primate Reserve Centre, Nairobi, Kenya from 1969 until 1970. From 1970 until 1988 he worked for the Open University, first as a lecturer, later as dean of science. He was the Director of the Natural History Museum from 1988 until 2004. He became Warden of Wadham College, Oxford, in 2004. He retired in 2012.
- Oxford Blueprint, 3:10, 15 May 2003.
- University of Oxford Annual Review, 2003/04.
- Natural History Museum Press Release, 9 January 2004.
Dr. Ronald Hedley
| Director of the Natural History Museum
John S. Flemming
| Warden of Wadham College, Oxford