Female Dolphins Appear to Have Sex for Pleasure and Orgasms Thanks to Their Well-developed Clitorises, Scientists Say

Scientists believe female dolphins may have sex for pleasure and achieve orgasm thanks to their large and well-developed clitorises.

To find out more about the sexual behaviour of these creatures, researchers collected clitorises from 11 adult, subadult and calve dolphins who were found on beaches after dying of natural causes. The specimens were then examined using techniques including scans and dissections.

Dr. Dara Orbach, research associate at Mount Holyoke College, told Newsweek: "Dolphins have sex year-round, not only for reproduction but also to solidify social bonds and for social learning.

"Other species that have sex year-round, such as bonobos and humans, are known to experience pleasure. We wondered whether dolphins also experience pleasure. We address this question by looking at how the clitoris is built and how it compares with other animals known to experience orgasm."

There were many similarities between the human and dolphin clitoris, according to the authors of the study. That included evidence of increased sensitivity in the clitoris, and the potential for it to engorge with blood, said Orbach. What's more, the team did not expect the organ to be filled with a relatively large and abundant collections of nerves. These nerve bundles appeared to be much larger than in other mammals known to experience orgasm.

However, the team need to carry out behavioural and physiological tests to confirm whether female dolphins are able to achieve orgasm.

"This type of data is challenging to obtain in dolphins," said Orbach. "For example, dolphins don't have toes, so we can't observe if they curl their toes during copulation."

And she pointed out that testing samples from stranded dolphins does not make for the sort of refined analysis that would give the authors more details on the functions of the clitoris, she said.

"This study is only preliminary, but it is one of the few studies that has examined clitoris morphology is species other than model organisms in a laboratory. We know very little about female reproductive morphology in most wild vertebrate species," said Orbach.

The study, which Orbach co-authored with Dr. Patricia Brennan, was presented at the American Association of Anatomists annual meeting during the 2019 Experimental Biology meeting. It has therefore not yet been published in a peer reviewed journal.

The sexual experiences of animals, if they have them at all, are little understood, although evidence suggests that primates can experience orgasm.

As Marlene Zuk, a professor of ecology, evolution and behavior at the University of Minnesota pointed out in an interview with Popular Science: "We don't know much about orgasms in other species—in fact, scientists are still studying the significance/evolution of female orgasms in humans."