On post-ejaculatory wiping

Stop monkeying around and pass me a leaf

Chimpanzees in Budongo Forest in Uganda regularly employ leaves as 'napkins' to wipe their penis after sex, researchers discovered

The authors of a study called High Frequency of Postcoital Penis Cleaning in Budongo Chimpanzees do not beat about the bush. "We report on postcoital penis cleaning in chimpanzees," they write. "In penis cleaning, leaves are employed as 'napkins' to wipe clean the penis after sex. Alternatively, the same cleaning motion can be done without leaves, simply using the fingers. Not all chimpanzee communities studied across Africa clean their penes and, where documented, the behaviour is rare. By contrast, we identify postcoital penis cleaning in Budongo Forest, Uganda, as customary."

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My first thought: What about masturbation?

The Guardian doesn't mention it at all, but the paper does... once. Its little more than a passing acknowledgement, however, all mentions from there on out are specific to coitus, and the data included in their tables follow suit.

Masturbation is a behavior distinct from copulation. The two end in orgasm for the male, but the resemblances end there. The two activities serve entirely different purposes: coitus is for reproduction and social purposes, masturbation (in males) is for monitoring and controlling ejaculate output.

Which is not to say it is impossible that the two activities could have overlapping purposes. That's where this study starts to come into play, or could come into play. But, the paper chooses not to examine masturbation activities in this context. I'm not sure quite why, to be honest.

Take to the baboons: I've seen them almost always finger clean after they pluck the rooster, but I cannot think of a single copulation which involved cleaning. Granted, copulations are much messier affairs, but its the female who dart after sex. The male generally follows leisurely behind for a few paces, or sits down and starts grunting. That'd be an interesting behavior to compare to across species, and in the case of masturbation, it really should not be difficult at all to gather data.

Unless chimps aren't into jerking off as much as most other social primates. I really think I would have heard about it if that was the case.

A final aside: it would be great to see some, you know, significance statistics for the data in this paper. Otherwise, fun read!

Thanks to Pfeng or Retrochef or whatever she prefers to call herself these days for the tip on this paper.

O’Hara, S., & Lee, P. (2006). High Frequency of Postcoital Penis Cleaning in Budongo Chimpanzees Folia Primatologica, 77 (5), 353-358 DOI: 10.1159/000093700