Jamie Hill, 69, who has been bird-watching for nearly 50 years, spotted the unusual sight of the half red, half white bird, in a tree in Warren County, outside of the city of Erie, last week.
“It was one of the experiences of a lifetime,” Mr Hill told USA Today.
That’s because male northern cardinals have bright red feathers, and females have tan feathers.
This bird was both.
The extremely rare phenomenon is known as “a bilateral gynandromorph”. They differ from hermaphrodites who share both or partial male and female sexual reproductive organs, in that their whole body is divided down the middle biologically and it could, therefore, theoretically mate with either a male or female, and produce young.
For Mr Hill, it all started after a family friend alerted him to a strange looking bird coming to one of her feeders near Grand Valley.
After she texted him a photo taken through a window he raced over and spent an hour lying in wait before it arrived, and then took around 50 photographs.
Writing about his discovery on February 20 in the Erie Bird Observatory blog Mr Hill said: “It was immediately apparent ... it was indeed a cardinal with extremely rare bilateral gynandromorphism. This bird would have a functioning ovary on its left side and a functioning single testis on its right.”
He added: “I have been birding for 48-years and ... I had a once-in-a-lifetime, one-in-a-million bird encounter.”
One of the first scientific recordings of the condition was in 1752, when The Royal Society of England was presented with a unique lobster that was split down the middle in colour, as reported by the BBC.
Since then other animals seen to have the rare condition include chickens, butterflies, snakes, bees, crabs and silk worms as well as birds.
Because of the northern cardinal’s distinct, bright red plumage, it is believed to be noticed more frequently.
A similar northern cardinal was spotted a few years ago near Erie and published in National Geographic in January 2019.
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