Experimental hyperthyroidism was induced in normal and castrated male and female sparrows by injection of crystalline thyroxin into the breast muscle. Definite color modifications occur in the regenerating feathers of various regions, particularly in the chestnut brown contour feathers and the black breast feathers of the male. The color of the modified male plumage resembles the female type more than that of the normal male, although the plumage of the female also shows pigment changes. It is possible that the thyroid may be involved in the control of sexual dimorphism in feather pattern.
Proceedings of the Iowa Academy of Science
©1935 Iowa Academy of Science, Inc.
Miller, Dorothea Starbuck
"Modifications Induced in the Plumage of Passer Domesticus (linnaeus) by Experimental Hyperthyroidism,"
Proceedings of the Iowa Academy of Science, 42(1), 208-209.
Available at: https://scholarworks.uni.edu/pias/vol42/iss1/99