Today’s blog post is going to cover some provocative subject matter, specifically addressing masturbatory behavior among nonhuman primates. Masturbation is defined as autosexual behavior wherein an individual stimulates their genitalia with or without the aid of a tool (or, in colloquial terms, what is more commonly referred to as a “sex toy”). Various primate species (from human to nonhuman) have been observed masturbating, and these acts occur among both captive and wild nonhuman primate species. Unfortunately, not much is known about these behaviors, which is most likely due to the taboo nature of the subject. Today’s blog post is going to address some specific examples of observed masturbatory behavior among wild nonhuman primate species, as well as address some of the explanations for this behavior.
Masturbatory behaviors have been observed among captive and wild nonhuman primate species for decades. These behaviors among captive nonhuman primate species have not received the same level of attention because they were believed to be artificial behaviors induced by captivity (much to the ire of lay individuals who just so happen to observe these activities). The presence of these behaviors among wild nonhuman primate species has, however, intrigued researchers. Various nonhuman primate species have participated in masturbatory behaviors, including apes and Old and New World monkey species. It is important to note, however, that these behaviors are most common among apes and Old World monkey species, as well as among species that exist in multimale/multifemale groupings. Both male and female nonhuman primates participate in masturbation, but it occurs far more frequently among males.
Masturbatory behaviors among wild nonhuman primate species most often occur without the use of a tool (aka, “sex toy”), meaning the primate uses their hands, feet, or other body parts to stimulate their genitalia. These behaviors occur when the primate is either alone or surrounded by others, be it males or females. It was hypothesized that males who masturbated in front of females did so to encourage sexual intercourse, but this very rarely occurs, suggesting that it is not an efficient means of encouraging sex between the masturbating male and the observant female. There are no explanations for why a male will masturbate in front of other males as no sexual intercourse occurs afterwards. The adjacent males typically pay no attention to the masturbating males. There are very few reports on masturbatory trends among females, so no further comments can be provided.
At the time of composition of this post there was only one published report of a nonhuman primate using a tool when masturbating. The researchers reported that an adolescent male chimpanzee used a discarded bottle to aid in masturbation. The reason for the use of the tool is unclear, although it was noted that the chimpanzees of this troupe have very little fear of humans since they regularly indirectly interact with them. This could be why the chimpanzee’s behavior evolved to use the tool.
As nonhuman primates have been observed masturbating both with and without ejaculating there are several hypotheses for why they participate in this behavior. Because masturbation occurs among lower ranking males who have less access to receptive and reproductive females it is believed that males may masturbate to remove old sperm, thereby increasing their chances of conceiving offspring when they are able to have sexual intercourse with a female. Masturbation could also be a means of relieving sexual tension or stress, particularly among lower ranking males who are unable to participate in frequent or regular sexual activities. For females, acts of masturbation may occur for very different reasons, including reducing the likelihood of acquiring a sexually transmitted disease or increasing the release of pheromones to alert males that she is sexually available.
Ultimately, it is unclear why masturbation occurs among nonhuman primates. It is clearly identified as a pattern of behavior among various species, suggesting that there is probably a biological and evolutionary need for the behavior, despite its negative effects on population growth. This refers to the fact that loss of sperm through ejaculation during masturbation means that the male has less sperm to provide during sexual intercourse, thereby reducing the likelihood of conception during sexual intercourse. This idea, however, has not been widely tested and may not be a legitimate concern. As additional studies continue on these behavior patterns a clearer understanding of these behaviors may be realized.
References
Gamalo, L. E. D., Cabrera, S. M. E., delos Reyes, N. C. L., de Cadiz, A. E., & Chavez Jr, J. B. (2022). Masturbation in a Free-ranging Male Long-tailed Macaque Macaca fascicularis (Raffles, 1821) on Mindanao Island, Philippines. Philippine Journal of Science, 151(6A), 2271-2274.
Hasan, S., Nath, S., Ahmed, M. T., Tasnim, M., Biswas, S., Hossain, M. S., & Ahmed, T. (2021). Masturbation in male capped langurs (Trachypithecus pileatus) at Lawachara National Park, Bangladesh. Bangladesh Journal of Zoology, 49(3), 441-445.
McLennan, M. R., & van Dijk, K. (2021). Use of a novel human object as a masturbatory tool by a wild male chimpanzee at Bulindi, Uganda. Pan Africa News, 28(1), 8-11.
Shalauddin, M., Islam, M. J., & Ahmed, T. (2021). Masturbation in a male Phayre's langur, Trachypithecus phayrei. Primate Biology, 8(2), 43-45.
Thomsen, R., & Soltis, J. (2004). Male masturbation in free-ranging Japanese macaques. International Journal of Primatology, 25(5), 1033-1041.
6 comments:
I find this blog particularly interesting. Before reading this, I did not know that non human primates or any other animal masturbated. Being that human evolved from primates, and are somewhat related I believe this.
I have never considered whether or not nonhuman primates masturbate. I did not know nonhuman primates could obtain sexually transmitted diseases. I was ignorant of the fact that humans lack the ability to process pheromones, which I googled after reading this blog post. Lastly, I wonder if there is any research supporting the idea that nonhuman primates masturbate for pleasure. -Tala Caples
Before reading this article I was aware of masturbation, but I never knew it was known in nonhuman primates or it even went back to the early stages of chimpanzees. It is also interesting that nonhuman primates can get a sexually transmitted disease either, but it interest me to how a nonhuman can catch a STI. Furthermore, I was interested in finding out that for males it is nearly a necessity for males to masturbate so they can relieve their old sperm so when and if they wanted too they can have healthy sperm to produce a baby.
Deona Mckinley
Reading this post was weird yet interesting because I have not given thought to primates and masturbation so reading about it was weird yet informing. To also know they use tools such as their hands and feet was interesting as well. I wish that there were people who could look into why they do so because I am curious to know if it has to do with mating and trying to impress the other sex or if it is simply just for pleasure.
- Keira Robinson
Reading this article I feel kind of ignorant for not thinking that our "primates" technically our ancestors, animals that we evolved from cant possibly masturbate. They literally can do what we can and then some and it was very interesting find these facts out. I'm still mind blown that they can catch STDs like humans can as well. Great Blog!
Jasmine Hill
What I found interesting about this article is that while masturbation is common among male primates, it is less effective in inducing mating behavior and does not elicit a particular response when seen by fellow males. We also noted that the only reports of primates using tools to self-stimulate are indicative of how tool use occurs over the course of evolution.
While the purpose and evolutionary reasons for these behaviors are not yet clear, it is interesting to consider that for the lowly males it may be a means of expelling old sperm or relieving stress. I hope that future studies will shed more light on the biological and evolutionary significance of these behaviors.
Post a Comment