Updated on July 18 at 11:45 p.m. ET*
In April 2015, Kaeli Swift laid a dead crow next to a cherry tree—and waited.
Swift, who studies bird behavior at the University of Washington, had previously shown that crows conduct “funerals” by gathering around the corpses of their peers. Now a film crew had come to capture this behavior.
As if on cue, another crow alighted on a nearby branch and gazed at the cadaver beneath it. Instead of cawing from afar, it flew down and approached the body. Swift wasn’t expecting that, and she certainly wasn’t expecting the crow to then droop its wings, erect its tail, and strut in the way crows only do when they’re about to mate. And sure enough, the living bird mounted the dead one.
Crows, like most birds, have no penises. Instead of penetrative sex, they simply bring vents beneath their tails into contact. To do this, a male needs to swivel his tail beneath a female’s, but since the dead crow was lying belly down, that was impossible. “It was like watching a kid standing on a piece of cardboard and trying to pick it up,” Swift says. “It was thrashing about awkwardly.”
As Swift recounted this week in a blog post called “Putting the ‘crow’ in necrophilia,” someone on the film crew earnestly asked if the living crow was giving the stuffed one CPR. She and her supervisor, John Marzluff, exchanged glances, shook their heads, and left “the word ‘copulation’ to hang awkwardly in the air.” And when the shock subsided, the pair began planning experiments to find out how common crow necrophilia actually is, and why it happens. “What better people to have this happen to than a couple of scientists,” she told me. “We can go forth and science.”