Sexual Dimorphism in Red-Splashed White Down Color of Chicks

Abstract IT HAS been shown previously (Byerly and Quinn, 1936, and Quinn and Byerly, 1937) that sexual dimorphism existed in the down color of Rhode Island Red chicks observed at Beltsville and elsewhere, most of the non-spotted, non-striped chicks being males and most of the black spotted and striped chicks being females. In the down color of the Red-Splashed White variety, a mutation from the Rhode Island Red (Quinn, 1934, 1935), no striping is evident but some of the chicks carry red, or red and black, head spotting, the others being pure white. Preliminary observations indicated that most of the chicks with black head spots were females. Observations were then made on the down color and sexes of a larger number of Red-Splashed White chicks to determine whether or not a dimorphism similar to that found in Rhode Island Reds could be noted. These observations of Red-Splashed White chicks were made . . .