Roger was the Director of Uganda National Parks prior to his appointment as CEO to RZSS in 1972 a post that he held for 26 years until his retirement. During this period and during his retirement he has chaired a wide range of organisations including the World Zoo Organisation, the European Association of Zoo's and Aquaria and the British and Irish Association of Zoos and Aquaria. He was also a Board Member and Deputy Chairman of Scottish Natural Heritage, Chairman of the National Trust for Scotland and President of the Scottish Wildlife Trust and the Association of British Wild Animal Keepers.