ALS, one page, 7.5 x 10, September 4, 1923. Letter to a gentleman. In part: “I have finally made something for your guest-book! and, of course, it is a bird. To me it is the most interesting in my aviary and to watch it develop from a plain, sparrow-like-creature into this be-plumed beauty is a revelation.” To the right of the text, Plath has added a gorgeous ink and watercolor depiction of the bird perched on a tree branch, labeled “Paradise Whydah Bird.” Affixed to a slightly larger sheet. In fine condition. Born in Chicago, Karl Plath made his mark on the art world with his extraordinary work on birds. After studying at the Academy of Fine Arts, he frequently exhibited around the country during the 1920s–1940s. He also served as the Curator of Birds at the Brookfield Zoo, traveled the world in search of rare specimens, and amassed his own aviary of hundreds of species. A stunning painting from the highly regarded ornithologist and artist. RR Auction COA.