While at Leavenworth in 1920, Stroud found a nest with three injured sparrows in the prison yard, and raised them to adulthood. Prisoners were sometimes allowed to buy canaries, and Stroud had started to add to his collection to occupy his time raising and caring for his birds, which he could sell for supplies and to help support his mother. According to Stroud, he used a "razor blade and nail for tools" and made his first bird cage out of wooden crates.