Bilateral size dimorphism in House Sparrow gynandromorphs.
The bilateral gynandromorph was first observed in Rock Island, IL (41[degrees]27'54"N, 90[degrees]33'50"W) on 16 December 2008 in a yard adjacent to the 84-ha Black Hawk Forest Nature Preserve along the Rock River in northwestern Illinois.
Although gynandromorphs have been reported previously, they have not been analyzed at this level of detail," Blanche Capel told Science News.
Chickens aren't the only animals that can become gynandromorphs.
This configuration is "reversed" in regards to the orientation of the gonads, which is a rare condition for avian gynandromorphs (Kumerloeve 1954).
A White-ruffed Manakin (Corapipo altera) bilateral gynandromorph was collected on 3 March 2004 near Santa Fe, Panama during a scientific expedition co-sponsored by the Barrick Museum of Natural History (MBM) and the Smithsonian Tropical Research Institute.