Angelo DeSantis/Wikipedia
Biologically speaking, alpaca sex is weird. Scientists have discovered evidence that male alpacas have sex by pushing their penis into the female’s uterus — a first among mammals.
In a recent study, a team of researchers presented evidence that male alpacas impregnate their partners pushing the penis into the uterus of the female — a technique not documented in any other mammal species to date.
The results of the study, led by scientists at Mount Holyoke College in Massachusetts and the North American Camelid Studies Program, were recently published in PLOS One.
Camelids are a group of large, four-legged, even-toed mammals that include camels, llamas and alpacas.
Alpacas are an important livestock animal for farmers in Peru and neighboring countries, as well as some other parts of the world. They are created mainly by your soft fleecebut also for its meat.
Insemination in mammals normally occurs deep in the vagina, as male sperm having to pass through the cervix and then the uterus to reach the female’s egg in the oviducts. In humans, this location is better known as the fallopian tubes.
The penis of some mammals, such as dogs and horses, can come very close to the cervix and, basically, shoot sperm directly into the uterus. However, even in these animals, the penis appears penetrate only the vagina.
But alpaca breeders have noticed that alpaca males penetrate their partners a lot during mating. Males are also known to have very long, thin penises that end with a tip of hard cartilage, almost like a spear.
These two observations have led many people to conclude that insemination in these mammals must occur directly in the uterusbut until now, notes Gizmodo, no clear evidence of this statement has been presented.
The study authors were able to dissect female alpacas, which were being raised for meat, right after they had sex with males — one to 24 hours after the act. These females were compared to those that had not been recently mounted by males.
Even in the space of an hour, the team managed to find sperm inside the female oviducts. Compared to unmounted alpacas, researchers also found clear signs of penile penetration (bleeding) throughout the female reproductive tractreaching the uterus.
“Using female alpacas slaughtered for meat production, we determined that the alpaca penis penetrates to the tips of the uterine horns, wearing down the tract and rupturing fine blood vessels,” the authors wrote. “The entire female reproductive system interacts with the penis, functioning like a vagina“.
While bleeding found in alpacas after sex may suggest a less friendly mating process, there is no evidence of sexual conflict in the species.
Among other things, female alpacas must voluntarily cooperate and adopt a prone position (lying on their stomachs) for penetration and mating to occur, sometimes for an hour.
Instead, researchers believe that the hemorrhage caused by the alpaca’s sex can actually help females get pregnantperhaps triggering a short-term inflammatory response that helps the fertilized egg adhere to the uterine wall.
So, as strange as alpaca sex may seem, it apparently works very well for them, say the study authors.
