[3][4] Birks was educated at Montreal High School and Lower Canada College, and was studying architecture at McGill University when the war broke out.
[5][6] Birks enlisted in the Canadian Expeditionary Force on 31 August 1915, serving as a lieutenant in the 73rd Battalion (Royal Highlanders of Canada),[6][7] and was wounded in November 1916 during the Battle of the Somme.
[8] He flew solo after only 21⁄2 hours of flight training,[2] and was commissioned as a second lieutenant in the RFC on 13 August 1917,[9] but did not travel out to England until November.
[10] He was assigned to "C" Flight, flying a Sopwith Camel single seat fighter, and became the preferred wingman of fellow Canadian ace Billy Barker.
[2] Birks' first aerial victory came on 18 March, when he destroyed a Rumpler reconnaissance aircraft over Pravisdomini, killing an Austro-Hungarian pilot named Shneeberger.
66 Squadron on 1 July 1918, returning to the Home Establishment to serve as an instructor at the School of Aerial Fighting and Gunnery from September.