'Half-male, half-female' cardinal photographed in Pennsylvania

A Northern Cardinal that appears to be half-female and half-male has been photographed in Pennsylvania.

Retired ornithologist Jamie Hill, 69, documented the bird and told the BBC it was a "once-in-a-lifetime, one-in-a-million encounter". Though not unheard of, mixed sex birds are rare.

The Northern Cardinal with bilateral gynandromorphism in Pennsylvania (Jamie Hill).

A friend of Mr Hill told him that she had seen an "unusual bird" coming to her bird feeders in Warren County in the state of Pennsylvania. At first he wondered if the bird was leucistic. However, after seeing mobile phone pictures, he suspected it had bilateral gynandromorphism – when a bird has both a functioning ovary and a functioning single testis.

"After I captured the images, my heart was pounding for the next five hours until I could get home and process the digital images to see what I actually had," Mr Hill explained.

"I have been searching for the long-thought-extinct Ivory-billed Woodpecker for almost two decades, and photographing this rare version of one of our most common backyard birds, this gynandromorph Northern Cardinal, was almost as exciting as I think I would get if I actually found the woodpecker," he said.