Because my father was the Chicago Tribune columnist Mike Royko, when I started freelancing for the Trib I used (at my own suggestion) a pen name, David Duckman. Duckman was my mother, Carol's (1934-1979), maiden name, and I was very close to her and her side of the family. There's a bit more about my use of the name HERE
I used this nom de byline in the Chicago Tribune and other Chicago-area publications through 1998.
(And the background shot of me in high school with my little billy goat beard circa 1976? No relevance.)