Peeing Is Socially Contagious in Chimps
Welcome back to the Abstract! What a week. It kicked off with Blue Monday, a date considered the most depressing of the year in the Northern Hemisphere for dubious reasons (in short: it was invented, like most of our reality, by an ad campaign).
This column will channel the latent crappy vibes with a parade of grotesqueries from the grand world of excrement research. Then, scientists are bringing back the ‘80s with new bioluminescent hues worthy of a Lite-Brite pegboard. Last, if you actually are feeling blue, I recommend Norwegian wood. Not the song. Not the novel. I’m talking about real pine trees in Norway. They see all. They will understand.
Monkey See (Pee), Monkey Do (Pee)
Onishi, Ena et al. “Socially contagious urination in chimpanzees.” Current Biology.
It’s time to put the “pee” in chimpanzee by watching pee come out of chimpanzees. That’s what researchers in Japan did for more than 600 hours to find out if urination is a form of social contagion in chimps. In other words, they observed 20 adult captive chimpanzees (16 males and 4 females) at the Kumamoto Sanctuary of Kyoto University to assess whether they were more likely to pee if they saw other chimps pee.
“The decision to urinate involves a complex combination of both physiological and social considerations,” said researchers led by Ena Onishi of Kyoto University. “However, the social dimensions of urination remain largely unexplored.”
First of all, let’s all congratulate ourselves for performing this complex physiological and social decision multiple times a day. I didn’t even realize we were such pros.
But back to the study: the team meticulously recorded the number and timing of “urination events” along with the relative distances between “the urinator and potential followers.” The results revealed that urination is, in fact, socially contagious for chimps and that low-dominant individuals were especially likely to pee after watching others pee. Call it: pee-r pressure.
The study gets extra points for including depictions of contagious urination in art history as part of its supplemental information, like those disconcerting fountain statues that pee out water. But the “number one” standout is a 1784 sketch by Thomas Rowlandson entitled “Sympathy, or A Family On A Journey Laying The Dust.”
Cups runneth over in this contagious urination event that even encompasses dogs and horses. I’m frankly surprised the buggy isn’t also engaged in gushing urination.
In addition to documenting a unique phenomenon, this artwork is nature’s call to revive the euphemism “laying the dust” for (I assume?) urination. You’re no longer going to the restroom; you are laying the dust. It just goes to show you never know what you’ll learn from a study about contagious chimp urination.
San Francisco’s Best Eats (for Coyotes)
You’ve seen the pee study, now here’s the number two follow-through. A study out this week reconstructed the diets of coyotes in San Francisco by collecting more than 1,000 scats from 2019 to 2022. Of that initial poopy haul, 707 bonafide coyote dumps were analyzed with metabarcoding and genotyping to reveal what these streetwise canines were eating.
“We collected scats from urban green spaces, including parks, golf courses, and gardens across San Francisco,” said researchers led by Tal Caspi of the University of California, Davis. “We only collected scats that we estimated to be less than 1 week old given their appearance and time since last visit.”
By analyzing this dookie-base, the team found that coyotes in densely populated neighborhoods were more reliant on human food scraps than coyotes in greener neighborhoods that had access to prey in parks. That finding seems intuitive, given that coyotes are opportunistic omnivores that will eat whatever’s available, but it’s still fascinating how much coyote diets varied, even with packs living just a few blocks away from each other.
“The greatest dietary differences were between Presidio and Coit Tower, even though a coyote can easily traverse the 3-km distance between them,” the team said. “The Presidio is the largest green space in San Francisco (6 km2) and has many native plant communities, sprawling grasslands, and a low percent cover of impervious surfaces. Conversely, Coit Tower is a tourist attraction in the densely populated Telegraph Hill neighborhood and, in part as a result of historical redlining, has less plant cover and lower species richness than formerly greenlined neighborhoods such as the Presidio.”
It's the age-old story of the city coyote and the just-a-bit-less city coyote. But while there were interesting variations in diet, all of these Bay Area coyotes were dining on a daily dim sum of chicken, pork, beef, and fish from human sources. As a cat lover, it pains me to report that domestic cats were commonly detected in the poops, though at low levels. That said, my general feeling is that a predator is skilled enough to catch a cat—animals that I have seen, with my own eyes, defy physics—it kind of deserves to eat it.
Lite-Brites in a Petri Dish
Congratulations: You’ve waded through some sewage, and it’s time to wipe those eyeballs out. Fortunately, scientists published a spectacular new rainbow of bioluminescent hues this week. Call it a palette cleanser.
Just look at these laboratory lite-brites! This study has clearly earned its keep based on aesthetic value alone, but the authors helpfully put some science in there too. Bioluminescence is the biological ability to generate light through chemical reactions, which is why some creatures can glow in the dark. This mesmerizing superpower is also a helpful tool in labs, as certain cells or research targets can be labelled with bioluminescent hues to aid observation.
“Bioluminescence, an optical marker that does not require excitation by light, allows researchers to simultaneously observe multiple targets, each exhibiting a different color,” said researchers led by Mitsuru Hattori of Osaka University. “Notably, the colors of the bioluminescent proteins must sufficiently vary to enable simultaneous detection.”
The team’s innovation in this study was to debut a method that expanded the color variation, allowing “simple and simultaneous observation of multiple biological targets and phenomena.” To prove their point, they made the Tron mouse pictured above.
Has science gone too far? Yes. But boy, does it look cool doing it.
Cruel Summer (Scots Pine Version)
It’s well-known that trees are nature’s librarians, meticulously keeping records of climate and environmental changes dating back centuries. But over the past decade, scientists have discovered a special type of blue ring in conifers that specifically memorializes cold summers. Low temperatures prevent lignification of the cell walls in the wood, creating the color pattern.
“Blue Rings (BRs) are a relatively newly described anatomical feature in conifers,” said researchers led by Agata Buchwald of Adam Mickiewicz University. “In the current literature, the formation of BRs is associated with cold growing season conditions” in various pine species, though “the potential of BRs in shrubs for paleoclimate studies still has to be explored.”
With that in mind, there was only one thing to do: Hike up Mount Iškoras in Norway and see what the Scots pines and Juniper shrubs had to say. The team took cores from dozens of plants high in the treeline, and discovered blue rings from the year 1902 and, to a lesser degree, in 1877, indicating that summers in those years were colder than average.
The testimony of the trees not only lines up with historical temperature records, it also coincides with major volcanic events. In the spring of 1902, for instance, Mount Pelée erupted on the Caribbean island of Martinique, killing 30,000 people in one of the worst volcanic disasters on record. The reverberations of this tragedy were etched in blue in the hearts of trees 8,000 miles away on Nordic mountaintops. Reality is so wild and enchanting; it’s a shame it can’t compete with ad campaigns.
Regardless of whether you are as blue as a non-lignified tree ring, thanks for reading. See you next week!