Are Dolphins "Pissing in the Wind" or Trying to Communicate?

Numerous diverse animals use scent to communicate with individuals of their own or other species. They may intentionally deposit scent containing various pheromones by urinating, defecating, or by depositing glandular secretions—called scent-marking—to communicate with others or scent might merely be left unintentionally as animals move here and there. Many different odors can be transmitted in the air but while scent communication doesn’t appear to be all that common in fully aquatic animals, there are a number of different examples. For example, a recent study has shown that bottlenose dolphins use scent—the taste of urine—to identify friends and differentiate them from unrelated dolphins ,and now it seems highly likely that Amazon river dolphins (Inia geoffrensis) called botos can intentionally use "aerial urination" to communicate with other dolphins in addition to simply having to pee.

Because I'm always looking for research that shows somewhat surprising results, I was intrigued to read a paper published in the journal Behavioural Processes by Claryana Araújo-Wang, Mauricio Cantor, and John Y. Wang titled "Aerial urination suggests undescribed sensory modality and social function in river dolphins." An excellent review of this field study can be found in an essay by Melissa Hobson titled "These adult male dolphins pee in the air. Scientists have questions." She describes "aerial urination" as follows: "The dolphin rolls lazily onto his back, pokes his penis out of the water, and shoots an enthusiastic jet of urine into the air. The stream arcs through the sky like a yellow rainbow."

In the study of wild botos, 36 instances of aerial urination were noted during 218.9 hours of observing botos, and 67% of the urinations occurred when there were other dolphins around to receive them, Only males were urinators and recipients of the tastes carried in the urine. The researchers hypothesized that the bristles on a botos rostrums are able to detect urine streams and that "aerial urination, often occurring in the presence of other males, serves social or communicative functions beyond the physiological need for waste elimination." It's also known that captive dolphins pay more attention to the urine of friends suggesting they knew who had been peeing into the wind by tasting their urine.

In addition to the significance of this research for learning more about these and perhaps other dolphins, there also are some practical, in-the-water conservation aspects of this research. The results of this study strongly suggest that polluted waters may block, mask, or otherwise affect chemicals in the water that the dolphins need for socially interacting with one another.

The importance of studying rare and weird behaviors and how other animals sense their worlds

While aerial urinating is rare and somewhat weird, it likely has social functions in botos, other dolphins, and perhaps other animals. It's also important to keep in mind that in many species, mating only occurs once a year, but this rare event is crucial for the maintenance of local groups, populations, and species so rarity isn’t synonymous with being unimportant.

Concerning peeing into the air, one of the researchers, Araújo-Wang, thinks river dolphins may be "advertising male quality in terms of social position or physical condition.” They, and perhaps individuals of other species, may also use pheromones to inform others about who they are, their social status, and their health.

In addition to the significance of what this study discovered about these river dolphins, it also highlights how little we know about the nitty-gritty aspects of the behavior of countless species. This not only applies to animals with whom we’re less familiar and who inhabit homes with which we’re less familiar, but also to animals with whom we regularly interact and live in places we often visit.

It's essential to keep an open mind about what's happening in the heads and hearts of other animals because they can inform us not only about how they sense their worlds in ways that are alien to us, but also about how seemingly harmless activities by humans can have large effects on their well-being without our being aware of the damage we're doing.

Rare and weird behaviors are important to many other animals and they also should be important to us. On the lighter side of things, I often ponder if other animals wonder why we do many of the weird (to them) things we do and how can we not appreciate the different and alien ways in which they negotiate their own worlds including firing urine into the air, tasting the urine of other animals, and doing what comes naturally because it works for them, as weird as it might seem to us, in various social and nonsocial situations.