Hans Julius Duncker

He completed a PhD in zoology from the University of Göttingen in 1905. On 5 October 1907 he married Elsa Zwerusmann (born June 4, 1884) in Dessau. He joined Bremer secondary school as a teacher of natural sciences and mathematics in 1909. In 1912 he became a member of the German Ornithological Society. He became a father on 24 April 1913 when a son was born but the child died next year. His second child, a daughter was born on 28 August 1915. In 1921, he began to work with Karl Reich, the first person to make recordings of bird song and who was well known for creating a strain of canaries that sang Nightingale Luscinia megarhynchos songs.

In the early 1920s, he began conducting several breeding experiments on birds to study the heritability of plumage colors and structures, such as the hood. From 1925 Duncker collaborated with Carl Hubert Cremer and extended his experiments to include budgerigars. He contributed regularly to the Journal of Ornithology and other ornithological journals.