Researchers at the Powdermill Nature Reserve at the Carnegie Museum of Natural History in Rector, Pennsylvania, have discovered a rare songbird that is half-female, half-male.
They haven’t made such a discovery in 15 years, and the center has recorded fewer than 10 bilateral gynandromorphs total in the approximately six decades it has kept records of 800,000 captured birds.
Bilateral gynandromorphy is a condition in which an animal possesses male and female traits divided down the middle of its body. It is believed to stem from an error during egg formation in birds. Bilateral gynandromorphs are rare, but normal. The condition occurs in a number of species, including earthworms, spiders, crustaceans and snails.
The bird is a rose-breasted grosbeak. Males and females of this type of bird have different plumage coloration. This unique bird displays male characteristics on the right, and female characteristics on the left.
“Everyone here, I mean the whole crew, was just so excited,” Annie Lindsay, the organization’s bird banding program manager, told CNN. “There was this scientific interest, of course. But also happiness for seeing something that was so rare.”
The center posted some incredible photos of the unique bird on Facebook:
The post explained that the bird hatched last year at the earliest, meaning it has successfully reached adulthood.
The researchers are unsure as to whether this bird can breed.
“In female songbirds, the left ovary is the functional ovary, and because this bird’s left side is the female side, it may be able to produce viable eggs,” Lindsay told Live Science. “However, the bird would also need to behave as a female to attract a male mate, and that isn’t something we are able to observe during normal banding operations.
The bird’s age, sex and body measurements were recorded, and its feathers were collected for genetic analysis before it was released.