Henry Lumsden was born in Edinburgh, Scotland and grew up in Aberdeenshire. He joined the RAF in 1941 were he was trained as a pilot and served as a flying instructor.
After the war he joined the Ontario Department of Lands and Forests (later renamed Ministry of Natural Resources) as a biologist. He has intensely studied geese, grouse, goldeneyes and swans.
Beginning in 1982 he started the project to restore Trumpeter Swans to Ontario, which he has continued following his retirement in 1988. The result of this work is a sustained population of Trumpeter Swan in the province. In addition, Harry has an interest in botany which has resulted in several expeditions to eastern Russia to collect plants. He has been awarded the Order of Canada and the Distinguished Ornithologist Award by the Ontario Field Ornithologists.