Scientists have taken the first photos of face-to-face copulation by wild gorillas.
The images were captured in Nouabalé-Ndoki National Park in the Republic of Congo.
“Understanding the behavior of our cousins the great apes sheds light on the evolution of behavioral traits in our own species and our ancestors,” said Thomas Breuer, a researcher at the Max Planck Institute for Evolutionary Anthropology and Wildlife Conservation Society (WCS) and lead author of the study, which is published in The Gorilla Gazette. “It is also interesting that this same adult female has been noted for innovative behaviors before.”
The female gorilla in the photograph, named “Leah” by researchers, was observed using tools — another never-before-seen behavior for gorillas in the wild — in 2005. Leah used a stick to test the depth of a pool of water before wading into it.
 Researchers from the Wildlife Conservation Society have taken photos of gorillas in the wild mating ‘face-to-face’ for the first time ever. Not only do these images provide insights into the behavior of gorillas, but the female in the pictures—named ‘Leah’ by the researchers—was also the first wild gorilla observed using tools in 2005. She can be considered a true pioneer among gorillas. Photo credit: © Thomas Breuer — WCS/MPI-EVA |
According to the researchers, face-to-face mating is unusual in primates.
“Researchers say that few primates mate in a face-to-face position, known technically as ventro-ventral copulation; most primate species copulate in what’s known as the dorso-ventral position, with both animals facing in the same direction,” explained a statement from WCS. “Besides humans, only bonobos have been known to frequently employ ventro-ventral mating positions. On a few occasions, mountain gorillas have been observed in ventro-ventral positions, but never photographed. Western gorillas in captivity have been known to mate face-to-face, but not in the wild, which makes this observation a noteworthy first.”
“Our current knowledge of wild western gorillas is very limited, and this report provides information on various aspects of their sexual behavior,” said Breuer. “We can’t say how common this manner of mating is, but it has never been observed with western gorillas in the forest. It is fascinating to see similarities between gorilla and human sexual behavior demonstrated by our observation.”
“Leah” is a western lowland gorilla, an ape listed as Critically Endangered by IUCN as a result of hunting by humans, habitat destruction by loggers and farmers, and outbreaks of Ebola hemorrhagic fever.