With its body turned to one side, you might not notice anything unusual about the cardinal recently spotted in the backyard of two Pennsylvania bird enthusiasts.
But viewed head on, it’s an entirely different story.
The rare bird has the features of both a male and female cardinal, with its bright red coloration abruptly ending in a line that runs right down the middle of its body, where it becomes a much more subdued blondish-brown.
Pennsylvania residents Jeffrey and Shirley Caldwell spotted the incredible half-male half-female cardinal in a dawn redwood just outside of their home a few weeks ago, according to National Geographic.
Its striking appearance is the result of double fertilization, in which a female egg cell that developed with two nuclei is fertilized by two sperm.
The result is what’s known as a bilateral gynandromorph, where the bird appears to be a male and female stitched together.
‘This remarkable bird is a genuine male/female chimera,’ Daniel Hooper, a postdoctoral fellow at the Cornell Lab of Ornithology told National Geographic.
Cardinals are best known for their bright red coloring, but this feature is specific to males.