Since binge watching Life on Netflix while stoned, I have considered myself well-versed in animal urges. But when it comes to the diversity of flora and fauna on this impossible rock we call Earth, there's always more to witness—like, for example, the homosexual necrophiliac tendencies of birds. In 2014, researchers in Japan caught three sand martin birds in the act of mating with the corpse of another male sand martin. They just recently published this finding in the journal Ornithological Science.
"We observed three sand martin Riparia riparia repeatedly attempting to copulate with a dead bird lying face down on the ground, with its wings spread and lowered. One of the three remained on the ground close to the dead bird and guarded it against copulation from the other two birds. Then, the guarding bird itself attempted to copulate with the dead bird," write the study's authors, Naoki Tomita and Yasuko Iwam. "Based on subsequent dissection the dead sand martin was identified as an adult male."
Here's the video of one of nature's many wonders:
Though necrophilia amongst human animals is explicitly taboo, elsewhere in the animal kingdom various species have been commonly caught in the act of mating with a deceased member of their tribe. (Remember that "mourning" kangaroo who was actually just trying to fuck his dead wife?) Unlike with humans, however, sex between animals and their fallen comrades isn't necessarily motivated by a macabre fetish. "Based on our observations, we propose that the observed homosexual necrophilia may be partly explained by the absence of sexual dimorphism in this species and the posture of the dead martin," the researchers explain. The unfortunate sand martin happened to die in a mating position that is an "important trigger arousing male sex drive."
According to the New Scientist, 30 cases of necrophilia have been recorded across variously deviant birds, some less innocent than others. Dutch researcher Kees Moeliker was the first to document homosexual necrophilia amongst birds in 1995 when he saw a drake mallard die after it crashed into the window of the Natural History Museum of Rotterdam, where he works. He then witnessed as "another drake mallard raped the corpse almost continuously for 75 minutes." Moeliker affectionately named the deceased duck "NMR 9997-00232."
Moeliker didn't see what happened before NMR 9997-00232 died, but he "strongly believes" that it was engaged in a chase with its would-be attacker before it flew into the window. Male drake mallards, Moeliker writes in his paper on the event that was published in 2001, often "chase a single female in the air, trying to force her down and rape her." This behavior is known as "attempted rape flight," and it can also take place between two males of the species, though it is less common.
The fact that the copulation attempt continued after the duck died was a rare discovery. "Necrophilia is known in the mallard, but only among heterosexual 'pairs,'" he writes. "To the best of my knowledge, this case is the first described case of homosexual necrophilia in the mallard."
(Ornithologists that I reached out to declined to comment—citing that the niche topic wasn't their area of expertise—but one did point us to a poetic limerick.)
Other animals, too—like the viral kangaroo—have been caught romancing corpses. Last year in Brazil, Ivan Suzima, a zoologist, stumbled upon lizard necrophilia in the park. According to National Geographic, Sazima saw a male lizard known as the black-and-white tegu mating with the dead body of a female. He returned again the next day and, even though the female's body was thoroughly decomposed, witnessed another male trying to copulate with it. Sazima told the publication that, based on body temperature and lingering pheromones, the males might not have realized that the lizard they were trying to court was a rotting pile of flesh. Similar behavior has been found in other types of lizards and frogs.